JP6161561B2 - Sheet-like deodorant foam molded product, process for producing the same, and foamed food container - Google Patents

Description

  The present invention relates to a foam sheet that is debrominated and deodorized by blending a specific deodorant, a method for producing the same, and a foam-molded and deodorized foam using the sheet-like deodorant foam molded article. Relates to a foamed food container.

  Foamed sheets made by blending a thermoplastic resin such as polystyrene with a low-boiling solvent such as butane have excellent thermoformability and produce food containers and the like with high efficiency by embossing under heating. Because it can be used widely.

  Especially in recent years, food is often frozen and stored, and there is a style of eating habits in which such frozen food is eaten by high-frequency heating directly using a microwave oven without providing a thawing process. It is being established. In this case, the food container is used as a container for storing food when stored frozen, used as a heat-resistant container for high-frequency heating when heated at high frequency, and used as tableware when eating heated food. It is used.

  Such foamed food containers are used as storage containers for frozen foods as described above, are used as heat-resistant containers for high-frequency heating, and are used as tableware. Different. For example, when it is used as a container for storing frozen food, it is often stored in a freezer at −20 ° C. or lower, and the container needs to be flexible even in such a low temperature environment. That is, it is necessary to have a low temperature impact resistance that the container is not easily damaged even if the container is dropped in a state where the food is stored under the low temperature condition as described above. In addition, when performing high-frequency heating, the temperature of the food contained therein is 100 ° C. or higher, and thus heat resistance that can withstand such a temperature is required. Furthermore, since the food prepared in this way is used as a container, it is necessary to prevent odors from the container from being transferred to the food. In addition, it is a problem if the working environment is deteriorated due to odor and the manufacturing operation cannot be performed at the time of the foaming molding for manufacturing the container.

  In order to improve the low temperature resistance of the resin container as described above, a method of blending elastic high impact polystyrene (HIPS), (meth) acrylic acid modified polystyrene, polyphenylene ether or the like is employed. In particular, blending polyphenylene ether with polystyrene increases the heat resistance of the obtained molded article, so that a resin composition that is very preferable in terms of physical properties can be formed.

  However, polyphenylene ether itself has a peculiar odor, and when producing a molded body foamed into a sheet used for producing a foamed food container, the working environment deteriorates due to this odor, and it takes a long time. It is difficult to continue the molding process. Moreover, if this odor moves to food, the commercial value as food will be impaired.

  Under such circumstances, in Patent Document 1 (Patent No. 4699327), when a hydrophobic zeolite is blended with a resin composition comprising polystyrene and a modified polyphenylene ether, the hydrophobic zeolite is blended uniformly in advance with polystyrene. It is disclosed that hydrophobic zeolite can be uniformly dispersed in the modified polyphenylene ether / polystyrene composition by blending this master batch when kneading polystyrene and modified polyphenylene ether. ing. Thus, the composition in which the hydrophobic zeolite is uniformly dispersed has an effect that the odor during the production is remarkably reduced.

  In order to uniformly disperse the hydrophobic zeolite in the resin foam as described above, a master batch in which the hydrophobic zeolite is dispersed in a high concentration in a thermoplastic resin in advance is manufactured, and polystyrene and modified polyphenylene ether are kneaded. It is necessary to add a master batch prepared in advance.

  By doing so, the hydrophobic zeolite is uniformly dispersed in the resin forming the foamed molded product, and thus a molded product uniformly foamed when molded. Accordingly, even in a food container obtained by heating and pressing the molded body, the uniform foamed state is maintained, so that a food container having excellent impact resistance can be obtained.

  However, the quality of hydrophobic zeolite varies due to complicated manufacturing processes, and in practical use, the deodorizing effect is stabilized by confirming the deodorizing property for each production lot of hydrophobic zeolite and adjusting the particle size. In addition, it was necessary to achieve uniform dispersibility in the resin.

  Furthermore, when using as a masterbatch as mentioned above, the process of manufacturing a masterbatch is required and there exists a problem that a manufacturing process increases and it is not economical compared with the method of adding in a powder state directly.

Japanese Patent No. 4699327

  It is an object of the present invention to provide a sheet-like deodorant foam molded article in which the odor of a foam molded article formed from a resin composition containing a polystyrene resin and polyphenylene ether is suppressed and the strength is maintained. It is said.

Moreover, this invention aims at providing the method of manufacturing the above sheet-like deodorant foaming moldings.
Another object of the present invention is to provide a defoamed foamed food container formed into a desired shape using the above sheet-like deodorant foam molded article.

  In the sheet-like deodorant foam molded article of the present invention, at least one kind of deodorant inorganic powder selected from the group consisting of magnesium hydroxide, calcium oxide and zinc oxide is mainly composed of polystyrene resin and polyphenylene ether. It is formed by injecting a volatile foaming agent into a thermoplastic resin that is blended in a powder state in an amount within the range of 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the thermoplastic resin and uniformly dispersed. Sheet-like deodorant foam molded article, the deodorant inorganic powder is not surface-treated, and the average particle diameter of primary particles of the deodorant inorganic powder is 0.5 to 2.5 μm It is characterized by being within range.

  The sheet-like deodorant foam molded article of the present invention preferably contains polyphenylene ether in an amount in the range of 5 to 230 parts by weight with respect to 100 parts by weight of the polystyrene resin.

The sheet-like deodorant foam molded article of the present invention may further contain 10 to 100 parts by weight of hydrophobic zeolite with respect to 100 parts by weight of the deodorant inorganic powder.
The method for producing the sheet-like deodorant foam molded article of the present invention comprises at least one deodorant inorganic powder selected from the group consisting of magnesium hydroxide, calcium oxide and zinc oxide, mainly comprising polystyrene resin and polyphenylene ether. A sheet obtained by press-fitting a volatile blowing agent into the thermoplastic resin obtained by mixing in an amount in the range of 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the thermoplastic resin as a component. The deodorant inorganic powder is not surface-treated, and the average particle diameter of the primary particles of the deodorant inorganic powder is in the range of 0.5 to 2.5 μm. The deodorant inorganic powder is preferably added to the molten resin in a powder state.

  In the manufacturing method of the sheet-like deodorant foam molding of this invention, it is preferable to mix | blend polyphenylene ether in the quantity within the range of 5-230 weight part with respect to 100 weight part of said polystyrene-type resins.

  In the method for producing a sheet-like deodorant foam of the present invention, the sheet-like deodorant foam-molded product further comprises 10 to 100 parts by weight of hydrophobic zeolite with respect to 100 parts by weight of the deodorant inorganic powder. Can be contained.

  In the foamed food container of the present invention, at least one deodorant inorganic powder selected from the group consisting of magnesium hydroxide, calcium oxide and zinc oxide is a thermoplastic resin having a polystyrene resin and a polyphenylene ether as a main component. A sheet-like eraser formed by press-fitting a volatile foaming agent into a thermoplastic resin that is blended in a powdered state in an amount within the range of 0.1 to 2.0 parts by weight with respect to parts, and uniformly dispersed. A foamed food container obtained by foam-molding a odorous foamed molded product into a desired shape under heating, wherein the deodorant inorganic powder is not surface-treated, and primary particles of the deodorant inorganic powder The average particle diameter of the material is in the range of 0.5 to 2.5 μm.

The foamed food container of the present invention preferably contains polyphenylene ether in an amount in the range of 5 to 230 parts by weight with respect to 100 parts by weight of the polystyrene resin.
In the foamed food container of the present invention, the sheet-like deodorant foamed molded product may further contain 10 to 100 parts by weight of hydrophobic zeolite with respect to 100 parts by weight of the deodorant inorganic powder.

  When the sheet-like deodorant foam molded article of the present invention is further heat-molded, this sheet-like deodorant foam molded article has a deodorizing property.

  The sheet-like deodorant foam molded article of the present invention comprises at least one deodorant inorganic powder selected from the group consisting of magnesium hydroxide, calcium oxide and zinc oxide as a resin component consisting of polystyrene resin and polyphenylene ether. It mixes with a powder state and forms a sheet-like foaming fabrication object. Thus, since the base resin used in the present invention contains polyphenylene ether, it has a unique odor attributed to polyphenylene ether. In the present invention, the odor attributed to polyphenylene ether is specifically eliminated. Deodorization can be achieved by using odorous inorganic powder.

  In addition, the specific debrominated inorganic powder blended in the sheet-shaped molded body also acts as a debromating agent when the foamed molded body is further heated to produce a foamed food container having a desired shape. To do.

Therefore, in this invention, although the polystyrene resin is modified with polyphenylene ether, the generation of odor derived from polyphenylene ether can be suppressed.
Further, by blending polyphenylene ether, it has excellent heat resistance that cannot be achieved with polystyrene resins.

Therefore, it is possible to provide a foamed food container corresponding to a new eating habit of directly heating at high frequency from a frozen state without going through a thawing step.
The resin contained in the sheet-like foamed molded article for producing the foamed food container of the present invention is a direct kneading of a polystyrene resin, polyphenylene ether, and a specific powdery deodorant inorganic powder without using a masterbatch. Therefore, an economical sheet-like deodorized molded body and a foamed food molded body with few manufacturing processes can be obtained.

FIG. 1 is a conceptual diagram showing an apparatus for measuring the impact strength of a sheet-like deodorant foam molded article of the present invention.

Next, the sheet-like deodorant foam molded article of the present invention, its production method, and the foamed food container will be described.
The sheet-like deodorant foam molded article of the present invention uses a thermoplastic resin mainly composed of a polystyrene resin and polyphenylene ether as a resin component.

  Examples of polystyrene resins used here include styrene homopolymers, styrene α-methylstyrene copolymers, styrene / butadiene copolymers, styrene / acrylonitrile copolymers, and styrene / acrylic acid copolymers. Can do. These can be used alone or in combination.

  In the sheet-like deodorant foam molded article of the present invention, a polyphenylene ether resin represented by the following formula is blended and used as a resin component as described above.

上記式においてＲ₁およびＲ₂はそれぞれ独立に炭素数１〜４のアルキル基またはハロゲン原子を表し、ｎは重合度を表す正の整数である。

In the above formula, R ₁ and R ₂ each independently represents an alkyl group having 1 to 4 carbon atoms or a halogen atom, and n is a positive integer representing the degree of polymerization.

  Examples of such polyphenylene ether resins include poly-2,6-dimethylphenylene-1,4-ether, poly-2,6-diethylphenylene-1,4-ether, poly-2,6-dichloro. Mention may be made of phenylene-1,4-ether. In the above formula, n is usually 10 to 5000. The above polyphenylene ether polymers can be used alone or in combination.

In the sheet-like deodorant foam molded article of the present invention, polyphenylene ether is usually used in an amount in the range of 5 to 230 parts by weight with respect to 100 parts by weight of the polystyrene resin.
By using polystyrene resin and polyphenylene ether in the amounts as described above, a sheet-like deodorant foam molded body capable of forming a foamed food container having excellent heat resistance can be formed.

  When used in a large amount outside the above range, the properties of the sheet-like deodorant foam molded article of the present invention using a polystyrene resin and polyphenylene ether as the main component of the resin may be deteriorated.

  The resin component that forms the sheet-like deodorant foam molded article of the present invention comprises the above polystyrene-based resin and polyphenylene ether as essential resin components, but is compatible with the polystyrene-based resin and polyphenylene ether. In order to improve the above, other resins can be blended within the range not impairing the object of the present invention. In addition, in order to improve the dispersibility of the deodorant inorganic powder used in the present invention, not only styrene homopolymer but also styrene such as butadiene or a copolymer of styrene and butadiene is grafted with an elastic resin forming component. Impact-resistant polystyrene (HIPS), α-methylstyrene and styrene copolymer, styrene and acrylonitrile copolymer, styrene and (meth) acrylic acid copolymer, styrene and (meth) acrylic Examples include copolymers with acid esters. These can be used alone or in combination. In particular, in the present invention, it is preferable to use a styrene homopolymer (GPPS), or a combination of a styrene homopolymer and high-impact polystyrene (HIPS).

In the resin component forming the sheet-like deodorant foam molded article of the present invention, a specific deodorant inorganic powder is added and dispersed in a powder state.
The deodorant inorganic powder used in the present invention is at least one inorganic powder selected from the group consisting of magnesium hydroxide, calcium oxide and zinc oxide. Moreover, these inorganic powders are not surface-treated, and the primary particles have an average particle diameter in the range of 0.5 to 2.5 μm, preferably 0.5 to 2.0 μm. The average particle size is measured with a transmission electron microscope.

Furthermore, the specific surface area of such anti bromide inorganic powder is usually 1 to 10 m ² / g, preferably in the range of 2 to 8 m ² / g. By using an inorganic powder having a large specific surface area in this way, the amount of deodorant powder to be used can be reduced, and the design of the properties of the resulting deodorized and deodorized sheet-like foamed molded article can be easily performed. Become. The non-surface area is measured by the BET method.

  In addition, when mixing an inorganic oxide or an inorganic hydroxide with a resin, in order to disperse uniformly or to prevent the photocatalytic action, basic action, etc. from affecting the resin, these inorganic oxides and inorganic hydroxides are used. In general, the product is asserted with a coupling agent or the like. Therefore, as a resin additive, when there is no description of the presence or absence of surface treatment in general patent documents and other documents, it is considered that this inorganic oxide or inorganic hydroxide is mostly surface-treated. It is done.

In the present invention, since the deodorant inorganic powder is not surface-treated, it can be easily selectively reacted with a specific odor substance or adsorbed.
Magnesium hydroxide, zinc oxide and calcium oxide used as deodorant inorganic powder here are compounds that exhibit weak basicity, and are considered to react with or adsorb acidic substances or similar substances. It is done. In the present invention, the odor-causing substance is not clearly specified, but the balance of the odorous substance in the odor is lost due to reaction or adsorption removal of a certain substance, and as a result, it is not perceived as odor. Inferred.

  This is similar to the phenomenon in which the smell of fragrance is not added by adding a small amount of fragrance in the odorous substance in the same way as pairing deodorization, but the odor is felt to decrease. I can say that.

  In addition to the three compounds, many inorganic compounds showing weak basicity as described above are known as inorganic compounds. However, although the reason was unknown among the inventors, the three compounds showed a remarkable deodorizing effect on polyphenylene ether.

  Strictly comparing the deodorizing effect of the deodorant inorganic powder used in the present invention, magnesium hydroxide is the best, followed by zinc oxide, and calcium oxide has the same deodorizing effect compared to both. Or it tends to be somewhat inferior.

  The deodorant inorganic powder used here is in the state of powder, in the range of 0.1 to 2.0 parts by weight with respect to the amount of the resin component, that is, 100 parts by weight of the total amount of polystyrene resin and polyphenylene ether. The resin component is melted and kneaded at the same time, and at the same time, the deodorant inorganic powder is uniformly dispersed in the molten resin.

  By dispersing the deodorant inorganic powder in the resin component in the powder state in this way, substances that become odor sources such as unreacted substances and thermal decomposition substances presumed to be contained in the polyphenylene ether that is the resin component are added. It can be captured with deodorant inorganic powder while melt kneading.

  Particularly in the present invention, a specific deodorant inorganic powder is brought into contact with a molten resin in a powder state and molded into a sheet shape. When the resin forming the sheet-like deodorant molded body is melted and mixed, the active site on the surface of the deodorant inorganic powder has a very high activity because it contacts the molten resin for the first time. ing. For this reason, when a component that becomes an odor source generated when the resin is melted is generated in the molten resin, it is adsorbed and removed at an extremely early stage by the deodorant inorganic powder, and the odor source diffuses outside the molten resin. The amount becomes extremely small, and the concentration of the compound that becomes an odor source in the work environment can be kept low.

  Of the deodorant inorganic powder of the present invention, magnesium hydroxide is also used as a flame retardant for resin, but in this case, it is generally used after being surface-treated. If it is not added in an amount of more than% by weight, the flame retardant effect will not be exhibited.

Zinc oxide is also used as an ultraviolet shielding agent for resins. However, since it has a photocatalytic action, it deteriorates the resin if it is not surface-treated.
Calcium oxide accelerates the deterioration of the resin because the surface activity is particularly strong when it is not surface-treated.

  In the present invention, the blending amount of these deodorant inorganic powders is optimized as described above so that the amount is within the range of 0.1 to 2.0 parts by weight based on the total resin (100 parts by weight). Therefore, it is possible to minimize the deterioration of the resin even if the surface treatment is not performed.

  In addition, the inorganic powder as described above may be used as a crystal nucleating agent for the resin, but it is not necessary to increase the crystallinity of the resin when producing a polystyrene resin or polyphenylene ether resin foam. In the resin foam, the inorganic powder does not act as a crystal nucleating agent.

  In the present invention, the specific deodorant inorganic powder is dispersed in the molten resin component in the powder state as described above, and a hydrophobic zeolite may be used in addition to the specific deodorant inorganic powder. it can.

The structure of the hydrophobic zeolite used here is a complex, crystalline inorganic polymer in which the AlO ₄ tetrahedron and the SiO ₄ tetrahedron are connected to each other while sharing oxygen ions, and the skeleton is infinitely widened. It is. And the higher the silica / alumina ratio of the zeolite, the higher the hydrophobicity. Specifically, hydrophobic Y-type zeolite can be produced by removing alumina by subjecting the Y-type zeolite to steam treatment. In addition, the manufacturing method of Y type hydrophobic zeolite itself is already well-known, and also in this invention, Y type hydrophobic zeolite can be manufactured according to a well-known method.

  In the present invention, when used in combination with at least one deodorant inorganic powder selected from the group consisting of magnesium hydroxide, zinc oxide and calcium oxide, and hydrophobic zeolite, the deodorant inorganic powder and hydrophobic Zeolite is used in a weight ratio, usually in an amount in the range of 10: 0.1 to 10:20, preferably in an amount in the range of 10: 1 to 10:10.

In the present invention, in addition to the hydrophobic zeolite, a commonly used inorganic powder can be used.
The sheet-like deodorant foam-molded article of the present invention comprises the above-mentioned polystyrene resin, polyphenylene ether and, if necessary, other resin in a molten state, and a powdery deodorant inorganic powder and optionally a hydrophobic zeolite. In addition, melt kneading, then adjusting the temperature of the resin component to a temperature suitable for foaming, and manufacturing by extruding and foaming from a extruder while pressing a volatile foaming agent into the resin melted by the extruder Can do.

  The volatile blowing agent used here is usually a saturated aliphatic hydrocarbon having 3 to 5 carbon atoms, and specific examples include propane, butane, normal butane, isobutane, pentane and neopentane. These volatile blowing agents can be used alone or in combination. In the present invention, it is particularly preferable to use a combination of normal butane and isobutane.

The usage-amount of these foaming agents is 1-5 weight part normally with respect to 100 weight part of resin which forms a sheet | seat.
The deodorizing effect of the deodorant inorganic powder tends to increase in the foamed molded product. This is because the odorous substance derived from polyphenylene ether is trapped inside the bubbles, This is thought to be due to easy contact with the deodorant inorganic powder when passing through a thin film.

By setting the amount of the volatile foaming agent in the above range, the expansion ratio of the sheet-like deodorant foamed molded product can be 5 to 20 times, preferably 7 to 15 times.
As described above, the sheet-like deodorant foam molded article of the present invention is prepared by adding a deodorant inorganic powder and, if necessary, a hydrophobic zeolite to a resin component containing a polystyrene resin and polyphenylene ether. A volatile foaming agent is press-fitted into a melt obtained by mixing in a powder state and kneading under heating, kneading, and extrusion-molding. In this extrusion foaming, a single extruder can be used, but it is preferable to combine a plurality of extruders. When using a plurality of extruders, in the first-stage extruder, the resin component, the specific deodorant inorganic powder, etc. are kneaded, or the specific deodorant inorganic powder is kneaded into the molten resin. This second extruder is used to supply a kneaded product obtained by press-fitting a volatile foaming agent into a highly kneadable zone arranged near the exit of the extruder of the second stage via a connecting pipe. Preferably, the temperature of the kneaded product is set to a temperature suitable for foaming, and extrusion molding is performed from a die disposed at the tip of the second extruder.

  The kneading temperature of the resin in the first stage extruder when producing the sheet-like deodorant foam molded article may be a temperature at which the resin used melts, and the cylinder temperature of the first stage extruder is usually 150. By adjusting the temperature within the range of ˜300 ° C., the resin temperature is usually set within the range of 200-280 ° C. If the resin temperature is too high, the resin may be decomposed or deteriorated. If the temperature is too low, the deodorant inorganic powder cannot be uniformly dispersed.

  A highly kneadable single screw extruder for press-fitting a volatile foaming agent is arranged near the outlet of the first stage extruder and melt kneaded in the first stage extruder using this single screw extruder. A volatile foaming agent is pressed into the resin kneaded product.

Thus, the resin kneaded material into which the volatile foaming agent is press-fitted is supplied to the second-stage extruder through the connecting pipe.
In this second stage extruder, a die cap is arranged at the tip on the outlet side, and the resin kneaded material supplied to the second stage extruder is suitable for foaming by this second stage extruder. Adjust to the correct temperature. Specifically, the resin temperature is usually within the range of 130 to 170 ° C. by adjusting the cylinder temperature within the range of 100 to 180 ° C. Next, the temperature of the resin is cooled to a temperature suitable for foaming, and the die pressure is set in the range of 150 to 250 kg / cm ² to perform extrusion foam molding.

By extruding and foam-molding under the above conditions, the sheet-like deodorant foam-molded article of the present invention can be produced.
The sheet-like deodorant foam molded article produced as described above is wound into a roll and cured at room temperature usually for 14 to 90 days.

  During this curing period, a part of the foaming agent is volatilized to make the amount of foaming agent suitable for molding. The volatile foaming agent remains in an amount in the range of 1 to 5 parts by weight in the sheet-like deodorant foam molded article after curing at room temperature for 30 days, which is a normal curing period. Thus, by leaving in the sheet-like deodorant foam molded article of the present invention, this sheet-like deodorant foam molded article has a desired shape under heating using a mold having a desired shape. A container can be formed.

  The foamed food container of the present invention uses the volatile foaming agent present in the sheet-like deodorant foam molded article as a foaming agent after curing the foamed sheet while being deodorized as described above. It can be obtained by molding into a desired shape.

  In addition, a sheet-like deodorant foam molded product or foamed food container produced by carrying out the present invention is laminated with a polyethylene film, a polypropylene film, or a polystyrene film on the surface for imparting designability or improving impact resistance. You may do it.

EXAMPLES Next, the present invention will be described in more detail with reference to examples of the present invention, but the present invention is not limited thereto.
[Example 1]
As the deodorant inorganic powder, magnesium hydroxide having an average primary particle diameter of 0.8 μm was prepared. This magnesium hydroxide was not surface-treated, and the specific surface area was 2 m ² / g.

Apart from this, a hydrophobic zeolite (trade name “Absents” manufactured by Union Showa Co., Ltd.) was prepared.
100 parts by weight of magnesium hydroxide as the deodorant inorganic powder and 50 parts by weight of hydrophobic zeolite were mixed well to prepare an inorganic powder for addition.

43 parts by weight of polyphenylene ether (SMBIC Innovative Plastics Co., Ltd., trade name “Noryl ^™ EFN4230”) modified with 30% by weight of polystyrene (100 parts by weight of polystyrene (trade name “HRM26”, manufactured by Toyo Styrene Co., Ltd.)) Parts were mixed and supplied to the extruder together with 1.14 parts by weight of deodorant inorganic powder prepared as described above.

The first-stage extruder was a high-kneading extruder and was adjusted to a cylinder temperature of 190 to 270 ° C., a resin temperature of 240 to 245 ° C., and a pressure of 140 to 200 kg / cm ² .
As a volatile foaming agent, a mixture of 55% by weight of isobutane and 45% by weight of normal butane was press-fitted while controlling the foaming ratio to be 10 ± 1 times. In addition, the press-fitting part of the foaming agent in the extruder was set near the outlet, and a single-screw extruder equipped with a screw capable of high kneading was arranged near the outlet. The molten resin kneaded by the first-stage extruder was supplied to the second-stage extruder via a connecting pipe. In the second-stage extruder, the cylinder temperature was 115 to 165 ° C., the resin temperature was 155 to 165 ° C., and the pressure was adjusted to 160 to 170 kg / cm ² .

  After cooling the resin composition to a resin temperature suitable for foaming, the resin composition is transferred from the die base (lip width 40 to 50 mm) attached to the tip (exit side) of the second-stage extruder to 220. Extrusion and foaming were performed at a rate of ˜250 kg / hour.

The die pressure was 200-210 kg / cm ² . The lip diameter is 190 mm and the drum diameter is 668 mm.
As a result, two sheet-like deodorant foam molded articles having a width of 1050 mm were obtained. The thickness of the sheet was 2.00 mm, and the basis weight was 180 to 250 g / m ² . The draw ratio was 2 ± 0.2 times.

The sheet-like deodorant foam molded body obtained as described above was wound into a roll and cured.
The sheet-like deodorant foam molded body wound up in the above-mentioned roll shape was cut into a 1 cm × 1 cm square, and 20 sheets of this sheet were collected and enclosed in a glass container.

The sheet-like deodorant foam molded article enclosed in the glass container was stored under the following conditions I and II, and then an odor test and a sensitivity test were performed.
Condition I: Odor is measured after 24 hours at room temperature.
Condition II: Heated at 100 ° C. for 2 hours and then allowed to cool at room temperature. Measure odor after 24 hours.

Odor Test For samples stored under the above conditions I and II, odor was measured using a odor sensor XP-329III manufactured by Shin Cosmos Electric Co., Ltd.

Sensory test The odor after completion of the odor test was evaluated by a sensory test by ten researchers, and was scored by the following evaluation method.
1: Almost no odor can be felt 2: Odor that does not matter 3: Odor that is slightly anxious 4: Unpleasant odor 5: Unpleasant odor

The polystyrene molded body formed into a sheet shape as described above was cured for 3 weeks, and then a foamed food container was molded using a mold.
The heater temperature of the molding machine at this time was set to 250 ° C., the heating time was 8 seconds, and the mold temperature was set to 20 ° C.
The working environment during the foam molding was not deteriorated by odor.
Moreover, Vicat softening temperature was measured according to JSI K7206 for the resin forming the foamed food container obtained as described above.
Furthermore, the impact strength of the sheet-like deodorant foam molded article obtained as described above was measured by the following method.

Impact strength measurement test The impact resistance of the sheet-like deodorant foam molded article was measured using an apparatus as shown in FIG.
As shown in FIGS. 1 (a), (b), and (c), the measuring apparatus is a sheet prepared in a size of 240 × 240 mm between the frame base 50 and the movable frame 52. The deodorized foam molded body 54 is sandwiched.

In this apparatus, as shown in FIG. 1B, a support pole 57 is erected on the back side of the frame base 50, and a measure plate 58 is provided on the front side of the support pole 57. Yes.
On this support pole 57, a sphere holding arm 59 is installed so as to be movable with respect to the support pole 57, and this sphere holding arm 59 can be fixed to an arbitrary position of the sphere holding arm 59 by a fixture 60. Has been.

  A sphere holding device 61 is disposed at the tip of the sphere holding arm 59. The spherical body holding device 61 is formed so that the spherical body 63 can be dropped at the center of the sheet-like deodorant foam molded body 54 sandwiched between the frame base 50 and the movable frame 52.

  A sphere 63 is held by the sphere holding device 61, and the sphere 63 can be dropped by operating the switch 62. The sphere 63 is usually a metal sphere, and is held by the sphere holding device 61 by a magnetic force or the like. The weight of the sphere 63 is 200 g, and the position of the sphere in the height direction can be measured by the measure plate 58.

About a sheet-like deodorant foaming molding as mentioned above, 20 times of tests are repeated, 50% breaking height is calculated | required, and 50% breaking energy (J) is calculated | required from this value. The measurement temperature is 23 ° C.
Various measurement results are shown in Tables 1 and 2.

[Example 2]
In Example 1, a sheet-like deodorant foamed molded article was produced in the same manner except that zinc oxide (average particle size 0.6 μm) that was not surface-treated was used instead of magnesium hydroxide, and this sheet was further produced. A foamed food container was molded in the same manner except that the deodorant foam molded product was used.
Various measurement results are shown in Tables 1 and 2.

Example 3
In Example 1, a sheet-like deodorant foam molded article was produced in the same manner except that calcium oxide (average particle size: 1.5 μm) which was not surface-treated was used instead of magnesium hydroxide, and this sheet was further produced. A foamed food container was molded in the same manner except that the deodorant foam molded product was used.
Various measurement results are shown in Tables 1 and 2.

[Comparative Example 1]
In Example 1, a foamed sheet and a foamed food container were produced using general-purpose polystyrene and modified polyphenylene ether without using magnesium hydroxide and hydrophobic zeolite (blank).
Various measurement results are shown in Tables 1 and 2.

50 ... Frame base 52 ... Movable frame 54 ... Sheet-like deodorant foam molding 56 ... Locking tool 57 ... Support pole 58 ... Measure plate 59 ... -Sphere holding arm 60 ... Fixing device 61 ... Sphere holding device 62 ... Switch 63 ... Sphere

Claims (9)

  At least one deodorant inorganic powder selected from the group consisting of magnesium hydroxide, calcium oxide and zinc oxide is 0.1 to 100 parts by weight of a thermoplastic resin mainly composed of polystyrene resin and polyphenylene ether. A sheet-like deodorant foam molded article formed by press-fitting a volatile foaming agent into a thermoplastic resin blended and uniformly dispersed in a powder state in an amount within a range of 2.0 parts by weight, The sheet-like deodorant, wherein the deodorant inorganic powder is not surface-treated, and the average particle diameter of primary particles of the deodorant inorganic powder is in the range of 0.5 to 2.5 μm. Foamed molded article.   2. The sheet-like deodorant foam molded article according to claim 1, comprising polyphenylene ether in an amount in the range of 5 to 230 parts by weight with respect to 100 parts by weight of the polystyrene-based resin.   The sheet-like deodorant foam-molded article according to claim 1, further comprising 10 to 100 parts by weight of a hydrophobic zeolite with respect to 100 parts by weight of the deodorant inorganic powder. Odorous foam. At least one deodorant inorganic powder selected from the group consisting of magnesium hydroxide, calcium oxide and zinc oxide is added in an amount of 0.1 to 100 parts by weight of a thermoplastic resin mainly composed of polystyrene resin and polyphenylene ether. Having a step of press-fitting a volatile foaming agent into the sheet while melting the thermoplastic resin obtained by mixing in an amount within the range of 2.0 parts by weight;
The deodorant inorganic powder is not surface-treated, and the average particle diameter of primary particles of the deodorant inorganic powder is in the range of 0.5 to 2.5 μm. A method for producing a sheet-like deodorant foam molded article, which is added to a molten resin in a state. The method for producing a sheet-like deodorant foam molded article according to claim 4 , wherein polyphenylene ether is contained in an amount in the range of 5 to 230 parts by weight with respect to 100 parts by weight of the polystyrene resin.   The sheet-like deodorant foamed molded article further contains 10 to 100 parts by weight of hydrophobic zeolite with respect to 100 parts by weight of the deodorant inorganic powder. Manufacturing method of odorous foam.   At least one deodorant inorganic powder selected from the group consisting of magnesium hydroxide, calcium oxide and zinc oxide is 0.1 to 100 parts by weight of a thermoplastic resin mainly composed of polystyrene resin and polyphenylene ether. Under heating, a sheet-like deodorant foam molded article formed by press-fitting a volatile foaming agent into a thermoplastic resin blended in a powder state in an amount within a range of 2.0 parts by weight and uniformly dispersed. A foamed food container formed by foaming into a desired shape, wherein the deodorant inorganic powder is not surface-treated, and the average particle size of primary particles of the deodorant inorganic powder is 0.5 to A foamed food container characterized by being in a range of 2.5 μm.   The foamed food container according to claim 7, wherein polyphenylene ether is contained in an amount in the range of 5 to 230 parts by weight with respect to 100 parts by weight of the polystyrene-based resin.   The foamed food container according to claim 7, wherein the sheet-like deodorant foamed molded article further contains 10 to 100 parts by weight of hydrophobic zeolite with respect to 100 parts by weight of the deodorant inorganic powder. .

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