JPH1121364A - Blowing agent composition and expandable thermoplastic polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blowing agent composition that can form fine and uniform cells and is noncorrosive, and to provide an expandable thermoplastic polymer composition. SOLUTION: These are a blowing agent composition comprising 0.1-50 wt.% azodicarbonamide (A), 1-80 wt.% p,p'-oxybis(benzenesulfonohydrazide) (B), 1-30 wt.% sodium hydrogen carbonate or potassium hydrogen carbonate (C), 0.05-30 wt.% citric acid or its salt (D) and 2-80 wt.% higher fatty acid salt, and an expandable thermoplastic polymer composition prepared by adding 0.01-0.2 wt.% above composition to a thermoplastic polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-corrosive blowing agent composition having fine and uniform expanded cell particles, and a foamable thermoplastic polymer composition using the same.

[0002]

2. Description of the Related Art Conventionally, as a foaming agent for a thermoplastic polymer, azodicarbonamide (ADCA) or p, p'-oxybis (benzenesulfonohydrazide) (ADC) has been used as a typical one as an organic foaming agent. OBSH) and sodium bicarbonate (sodium hydrogen carbonate) as an inorganic blowing agent
Citric acid-based blowing agents are known. However, since the azodicarbonamide (ADCA) is easily colored,
It may be used as a foaming agent in combination with p, p'-oxybis (benzenesulfonylhydrazide) (OBSH) or a baking soda-citric acid-based foaming agent. Further, the baking soda-citric acid-based blowing agent has an advantage that the cell density is small and the particle diameter is constant, but since the generated gas pressure is low,
p, p'-oxybis (benzenesulfonohydrazide)
It may be used as a foaming agent in combination with (OBSH).

[0003]

However, the above-mentioned azodicarbonamide (ADCA) mainly generates nitrogen gas at the time of foaming, and this generated gas contains a small amount of ammonia gas. Since the gas is corrosive, azodicarbonamide (ADC)
The foamed molded article of the thermoplastic polymer foamed according to A)
There is a problem in packaging easily corrosive products such as electronic components. Therefore, an aging step of heating a thermoplastic polymer foam molded article made of azodicarbonamide (ADCA) at a temperature of about 40 to 70 ° C. to prevent corrosion is essential. However, even if such an aging step is performed, it is practically impossible to completely remove ammonia, so that it is insufficient for packaging of easily corroded products such as precision electronic parts. It is azodicarbonamide (A
After the foaming of DCA), corrosive siamide or cyanuric acid is formed in the residue, and it is virtually impossible to remove the corrosive siamide or cyanuric acid from the thermoplastic polymer foam molded article. Therefore, there is a problem in packaging of easily corroded products such as electronic parts. On the other hand, since the baking soda-citric acid-based blowing agent also uses citric acid, there was a slight problem in the corrosiveness of the thermoplastic polymer foam molded article using the baking soda-citric acid-based blowing agent.

[0004]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the above problems, and as a result, used various foaming agents in combination.
Based on the finding that a blowing agent composition containing them in a specific quantitative ratio and containing a higher fatty acid salt in order to prevent corrosiveness can significantly reduce corrosiveness, the present invention has been completed. It has been reached. That is, the blowing agent composition of the present invention is characterized by comprising the following components (A) to (E). Component (A): Azodicarbonamide (ADCA) 0.1 to 50% by weight Component (B): p, p′-oxybis (benzenesulfonohydrazide) (OBSH) 1 to 80% by weight Component (C): carbonic acid Sodium hydrogen or potassium hydrogen carbonate 1 to 30% by weight Component (D): citric acid or a salt thereof 0.05 to 30% by weight Component (E): Higher fatty acid salt 2 to 80% by weight

The foamable thermoplastic polymer composition according to another aspect of the present invention comprises a thermoplastic polymer and a foaming agent composition comprising the following components (A) to (E): ~
It is characterized by being blended at a ratio of 0.2% by weight. Component (A): Azodicarbonamide (ADCA) 0.1 to 50% by weight Component (B): p, p′-oxybis (benzenesulfonohydrazide) (OBSH) 1 to 80% by weight Component (C): carbonic acid Sodium hydrogen or potassium hydrogen carbonate 1 to 30% by weight Component (D): citric acid or a salt thereof 0.05 to 30% by weight Component (E): Higher fatty acid salt 2 to 80% by weight

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

[I] Blowing agent composition (1) Constituent component (a) Azodicarbonamide (ADCA) [Component (A)] As the azodicarbonamide (ADCA), a commercially available azodicarbonamide can be used. Azodicarbonamide (ADCA) is commercially available as “DS25” manufactured by Eiwa Chemical Co., Ltd. This azodicarbonamide can generate nitrogen gas by being decomposed at a temperature of about 180 to 205 ° C., but also generates a small amount of ammonia gas at the same time. Therefore, in order to remove the ammonia gas after foaming, generally 40 to 70 ° C.
By performing so-called aging treatment, which is left while heating at the above temperature, the corrosiveness due to ammonia gas is reduced. However, even after such aging treatment, some of the foamed thermoplastic polymer after foaming contains
Since azodicarbonamide (ADCA) is decomposed to produce thamelide or cyanuric acid, which remains as a residue in the foamed thermoplastic polymer, the foamed thermoplastic polymer is usually It is corrosive even after aging. Therefore, in the present invention,
It is important to neutralize thiamelide and cyanuric acid generated by the decomposition of azodicarbonamide (ADCA) with a higher fatty acid metal salt described later.

(B) p, p'-Oxybis (benzenesulfonohydrazide) (OBSH) [Component (B)] As the above p, p'-oxybis (benzenesulfonohydrazide) (OBSH), commercially available p, p'-oxybis (benzenesulfonohydrazide) (OBSH) is used. p'-Oxybis (benzenesulfonohydrazide) (OBSH) can be used. This p, p'-oxybis (benzenesulfonohydrazide) (OBSH) is 140 to 16
Decomposes at a temperature of about 0 ° C. to generate nitrogen gas. This p,
p'-oxybis (benzenesulfonohydrazide) (O
When BSH) is used alone, the foam is hardly colored, but the bubbles tend to be coarse.

(C) Sodium hydrogen carbonate or potassium hydrogen carbonate [Component (C)] Examples of the sodium hydrogen carbonate or potassium hydrogen carbonate include sodium hydrogen carbonate and potassium hydrogen carbonate. Among them, it is preferable to use sodium hydrogen carbonate and potassium hydrogen carbonate. In particular, it is preferable to use sodium hydrogen carbonate. Even when sodium hydrogencarbonate or potassium hydrogencarbonate is used in combination with citric acid, the generated gas pressure is low and the cell density is low.

(D) Citric acid or a salt thereof [Component (D)] As the citric acid or a salt thereof, citric acid or a salt of citric acid and various metals, specifically, citric acid and sodium or potassium And / or salts with 2 to 3, for example, sodium citrate, potassium citrate, calcium citrate and the like. Generally, commercially available citric acid can be used. The citric acid can decompose the sodium hydrogencarbonate or potassium hydrogencarbonate to generate carbon dioxide gas.

(E) Higher Fatty Acid Salt [Component (E)] The higher fatty acid metal salt is an aliphatic carboxylic acid having 6 to 20 carbon atoms, preferably 6 to 18 carbon atoms, and a periodic table IIA to II.
A metal salt with Group IIIB is used. In particular, stearic acid,
Caprylic acid, lauric acid, palmitic acid, linoleic acid,
It is a salt of linolenic acid or the like with calcium, magnesium, barium, zinc, boron, aluminum or the like. Specific examples include calcium stearate and magnesium stearate. Among these, it is particularly preferable to use calcium stearate. By blending these higher fatty acid metal salts, neutralization of ammonia gas, which is a corrosive substance generated at the time of gas generation of the above components (A) to (D), and siamide and cyanuric acid remaining as residues are neutralized. And fine and uniform expanded cell particles can be obtained.

(2) Amount ratio The azodicarbonamide (ADCA) of component (A) is 0.1 to 50% by weight, preferably 0.2 to 5% by weight, particularly preferably 0.3 to 1% by weight. It is blended in a ratio. If the compounding amount of azodicarbonamide (ADCA) is less than the above range, the amount of generated gas is reduced, resulting in a drawback of insufficient foaming. Further, when the ratio exceeds the above range, there are disadvantages in that coloring, cell density becomes coarse, and corrosiveness cannot be suppressed. P, p of the above component (B)
'-Oxybis (benzenesulfonohydrazide) (OB
SH) is blended in an amount of 1 to 80% by weight, preferably 0.2 to 5% by weight, particularly preferably 0.3 to 1% by weight. When the amount of the above p, p'-oxybis (benzenesulfonohydrazide) (OBSH) is less than the above range, there are disadvantages such as coloring and a decrease in cell density. In addition, when it exceeds the above range, there is a disadvantage that the cell density becomes coarse.

The component (C) sodium bicarbonate or potassium bicarbonate is 1 to 30% by weight, preferably 0.2 to 30% by weight.
-5% by weight, particularly preferably 0.3-1% by weight. If the blending amount of the sodium hydrogencarbonate or potassium hydrogencarbonate is less than the above range, there is a disadvantage that coloring occurs. On the other hand, if it exceeds the above range, the amount of generated gas is reduced, resulting in insufficient foaming and a disadvantage that the cell density becomes coarse. The citric acid of the component (D) is 0.05 to
30% by weight, preferably 0.2 to 1% by weight. If the amount of the citric acid is small, coloring tends to occur. On the other hand, if it exceeds the above range, the amount of generated gas is reduced, resulting in insufficient foaming and a disadvantage that the cell density becomes coarse. The higher fatty acid salt of the above-mentioned component (E) is 0.1%.
It is blended at a ratio of 2 to 80% by weight, preferably 1 to 5% by weight. If the amount of the higher fatty acid salt is less than the above range, the corrosiveness increases, and the cell density becomes poor. On the other hand, if it exceeds the above range, the amount of generated gas is reduced, resulting in insufficient foaming and a disadvantage that the cell density becomes coarse.

(3) Preparation of a foaming agent composition A foaming agent composition is obtained by blending and mixing the above components (A) to (E) in the above-mentioned quantitative ratios. As described later, this foaming agent composition is blended with a thermoplastic polymer, and the foamed molded article is used as a packaging material for easily corrosive electronic parts.
Even if CA) decomposes to form corrosive cyamelide or cyanuric acid, or contains citric acid, it is neutralized and rendered harmless because it contains higher fatty acid salts. No corrosion of parts.

[II] Foamable thermoplastic polymer composition (1) Thermoplastic polymer The thermoplastic polymer used in the foamable thermoplastic polymer composition of the present invention includes high-density polyethylene, low-density polyethylene, Linear low-density polyethylene, ethylene-based polymer such as ethylene-acrylate copolymer, propylene homopolymer, propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-ethylene-butene random Propylene-based polymers such as copolymers, homo- or copolymers of α-olefins such as butene-based polymers, styrene-based polymers such as polystyrene, acrylonitrile-butadiene-styrene copolymer (ABS), polyurethane resins, Thermoplastic resin such as vinyl chloride resin or ethylene-propylene copolymer rubber (EP
R), ethylene-propylene-diene copolymer rubber (EP
DM) and thermoplastic rubbers such as styrene-butadiene rubber (SBR). Among them, high-density polyethylene, low-density polyethylene, ethylene-based polymer resins such as linear low-density polyethylene, propylene homopolymer, propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene It is preferable to use a propylene-based polymer resin such as an ethylene-butene random copolymer, a styrene-based polymer resin such as polystyrene and acrylonitrile-butadiene-styrene copolymer (ABS), and particularly an ethylene-based polymer resin and It is preferable to use a propylene-based polymer resin.

(A) Types of Ethylene Polymer Resin The preferred ethylene polymer resin in the present invention is specifically described as follows. A homopolymer of ethylene or ethylene as a main component, and other α -Copolymers with olefins and / or other unsaturated monomers. Examples of the α-olefin include propylene, butene-1,3-methylpentene-1,4-
Examples thereof include α-olefins having about 3 to 12 carbon atoms, preferably 3 to 8 carbon atoms, such as methylpentene-1, hexene-1, and octene-1. Examples of the other unsaturated monomers include, for example, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, and maleic anhydride, and derivatives thereof; vinyl acetate, vinyl butyrate, and the like. Esters; styrene, methylstyrene,
Unsaturated aromatic monomers such as divinylbenzene; and vinylsilanes such as vinyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane.

Among these, ethylene polymer resins which are preferable in terms of foam moldability and vacuum moldability include a low-density ethylene homopolymer produced by a high-pressure method, ethylene and vinyl acetate containing mainly ethylene, acrylic acid, and acrylate. , A copolymer of methacrylic acid, methacrylate, and the like; a high-density ethylene homopolymer produced by a medium-low pressure method, ethylene containing ethylene as a main component, and other α-olefins (propylene, butene-1, hexene-1, And octene-1 etc.). These copolymers are not limited to binary copolymers, but may be terpolymers or more. Among these, particularly preferred ethylene polymer resins are low-density ethylene homopolymer (LDPE) and ethylene / vinyl acetate copolymer (EV) produced by a high-pressure method.
A), a high-density ethylene homopolymer (HDPE) produced by a medium-low pressure method, and a linear copolymer of ethylene and another α-olefin (L-LDPE). The content of the α-olefin and / or other unsaturated monomer in the ethylene polymer resin in the ethylene polymer resin may be in a range in which ethylene is the largest component as long as the effects of the present invention are not significantly impaired. However, it is generally preferably 30% by weight or less, particularly preferably 15% by weight or less.

Physical properties of the above ethylene polymer resin are such that the MFR (melt flow rate) is generally 0.1 to 10 g / 10 min, more preferably 0.2 to 8 g / 10 min, especially 0.3 to 6 g / min. 10
In general, the MT (melt tension) is preferably 2 to 20 g, more preferably 3 to 16 g, and particularly preferably 4 to 12 g. Further, ethylene polymer resin has Q
Value (molecular weight distribution) is generally 2 to 9, more preferably 3 to 9.
8, particularly preferably 4 to 7. If the value of the MFR is too low, the surface gloss of the foam tends to deteriorate, while if it is too high, the mechanical strength tends to deteriorate. Also, if the MT value is too low, it tends to be difficult to obtain a high magnification foam, while if it is too high, the foam cells tend to be rough. If the value of the Q value is too low, vacuum formability tends to decrease, while if it is too high, the impact strength of the foam tends to deteriorate.

[0018] (b) Stated the preferred propylene polymer resins specifically the propylene polymer resin species such the present invention, a propylene homopolymer or a propylene as a main component, this and other Α-
Copolymers with olefins can be mentioned. The above α
-As the olefin, for example, ethylene, butene-
1,3-methylpentene-1,4-methylpentene-
1, 2 or 4 carbon atoms such as hexene-1 and octene-1
About 12 and preferably 2 or 4 to 8 α-olefins can be mentioned. Specific examples include propylene homopolymer, propylene / ethylene random copolymer, propylene / ethylene block copolymer, propylene / ethylene / butene random copolymer, and the like.
Ethylene and / or α in the propylene polymer resin
The content of the olefin in the propylene-based polymer resin is within the range in which propylene is the largest component as long as the effects of the present invention are not significantly impaired, and may be within the range of exhibiting crystallinity. Olefin content is 35% by weight
It is preferably at most 30% by weight or less. As the propylene-based polymer resin, a crystalline resin obtained by homopolymerization or random or block copolymerization in the presence of a stereoregular catalyst such as a Ziegler catalyst or a metallocene catalyst is used.

The product of the physical properties of the propylene polymer resin has a melt flow rate (MFR) is generally 0.1 to 20 g / 10 min, preferably in the range of 0.5 to 10 g / 10 min.

(2) Blowing agent composition As the blowing agent used in the expandable thermoplastic polymer composition of the present invention, the components (A) to (C) described in the section of the blowing agent are used.
The foaming agent composition comprising (E) is used.

(3) Other optional components In the thermoplastic polymer constituting the expandable thermoplastic polymer composition of the present invention, other thermoplastic components other than the above-mentioned essential components are included within a range not to significantly impair the effects of the present invention. Optional components can be blended. As this optional component, for example, for the purpose of adjusting physical properties and appearance, etc., an elastomer component or another resin component, or an antioxidant, a heat stabilizer, a light stabilizer, a coloring agent, an antistatic agent, an antibacterial agent, Antifungal agent, rust inhibitor, conductivity-imparting agent, foam regulator (foaming accelerator), foaming agent decomposition temperature regulator, neutralizer, dispersant, molecular weight regulator (radical generator, etc.), crosslinking agent, crosslinking Auxiliaries, nucleating agents, fillers, lubricants, flame retardants, flame retardant auxiliaries, processing aids, heavy metal deactivators, plasticizers,
Various additive components such as a fluorescent whitening agent, a releasing agent, a softening agent, and a gloss-imparting agent can be exemplified.

(4) Amount ratio The blowing agent composition comprising the above components (A) to (E) is used in an amount of 0.01 to 0.2% by weight, preferably 0.02 to 0.2% by weight, based on the thermoplastic polymer. 1% by weight, particularly preferably 0.02 to
It is blended at a ratio of 0.07% by weight.

[III] Production of foamable thermoplastic polymer composition [0023] Each of the above components is mixed with a conventional kneading extruder, for example, a single screw extruder.
In a twin screw extruder or the like, the resin temperature is generally 170 to 240 ° C,
Preferably, the foamable thermoplastic polymer composition can be produced by melt-kneading under a temperature condition of 180 to 230 ° C.

[IV] Molding (1) Production of Sheet-like Molded Article of Expandable Thermoplastic Polymer Composition To produce a sheet-shaped molded article of foamable thermoplastic polymer composition, the above kneading extruder By extruding the foamable thermoplastic polymer composition from the slit of the die, the foaming ratio is expanded to 1.03 times, preferably 1.1 times to 2 times, particularly preferably 1.3 times to 1.8 times. And the thickness is generally 0.
A low foamed ethylene polymer resin sheet (low foamed sheet) of 1 to 5 mm, preferably 0.2 to 3 mm is produced. This sheet is obtained as a non-crosslinked low foam sheet. If the expansion ratio is too low, the resin may be inferior in flexibility, and beautiful shaping may not be performed in the next thermoforming step. On the other hand, if the expansion ratio is too high, molding will be defective in the next thermoforming step. The low-foamed sheet obtained here can be molded without pulling it while maintaining a good foamed state even during the thermoforming described below, so that the drawn shape can be clearly formed, which is preferable. The production of the sheet-like molded body produces a large number of foam cells in the low foam, and the foam cells are fine and uniform, and the average size of the foam cells is generally 0.05 to
What is in the range of 0.5 mm, preferably 0.1 to 0.4 mm, particularly preferably 0.15 to 0.3 mm, the foamed cells are hardly broken even when thermoformed, and the foaming state is good. It is preferable because the aperture shape can be clearly obtained while maintaining the aperture value. The average size of such a foam cell can be adjusted by appropriately selecting the type and amount of the foaming agent, and the conditions at the time of compounding.

(2) Thermoforming The thermoforming of the low-foaming sheet layer into various molded articles is preferably performed by the following vacuum forming method, pressure forming method, vacuum / pressure forming method, embossing method, or the like. After being heated and softened by various thermoforming methods, the sheet is deformed by applying an external force to the sheet by means of vacuum or pressure, and is shaped into various shapes. A molded article is obtained.

(A) Vacuum Forming Method In the above vacuum forming method, only one of a female mold and a male mold is used, and the laminated sheet is heated and softened, and then placed on a mold. Is made into a vacuum, the laminated sheet is brought into close contact with the surface of the mold, and then cooled and molded. Specifically, straight molding, drape molding, plug assist molding, plug assist reverse draw molding, air slip molding, snapback molding, reverse draw molding, plug assist air slip molding, free molding, match molding, plug ring Various known molding methods such as molding, slip molding, and contact heating molding can be employed.

(B) Compressed air forming method The compressed air forming method is a method of forming a laminated sheet heated and softened with compressed air into a mold instead of using the atmospheric pressure in the vacuum forming.

(C) Vacuum / Pressure forming method The vacuum / press forming method is a method in which the above-mentioned vacuum forming and pressure forming are combined.

(D) Embossing Method The embossing method may be a method in which a heat-softened laminated sheet is inserted between upper and lower base plates and pressed by a mold, or the laminated sheet is heated as it is. This is a method of molding by pressing with a mold.

The above-mentioned thermoforming is carried out by a usual thermoforming apparatus according to a conventional method. Deep drawing In general, in sheet thermoforming, it is difficult to perform deep drawing usually to a depth of 30 mm or more so that the drawn shape can be clearly obtained while maintaining a good foaming state. Can be surprisingly deep-drawn to a depth of 30 mm or more, preferably 40 mm or more, particularly preferably 50 mm or more. The deep drawing is
Since the sheet surface and the deeply drawn wall surface can be bent and formed to an angle of about a right angle, or extremely to an inverse taper, the drawn shape can be sharply formed. At this time, advanced deep drawing can be performed because the foamed cells are fine and their dimensions are uniform, so that the foamed cells are not broken even during thermoforming, and a good foamed state is maintained. It is presumed that this is because deep drawing can be performed uniformly without bias in one direction.

[V] Cutting A thermoformed body thermoformed into various shapes is cut so as to conform to various uses, and cut off from a sheet-shaped molded body on a thermoforming machine. It is performed by a method of punching with a blade. At this time, in the ethylene polymer resin raw material,
It is preferable to add a small amount of a polyolefin that is usually used as an anti-blocking agent to the polyolefin in advance, since the blade separation at the time of cutting is good and the punching property is good.

[VI] Applications The expandable thermoplastic polymer composition of the present invention can be applied to various uses because it can be formed into a sheet and low foamed and subjected to deep drawing with a large depth. It can be formed into various thermoformed bodies. Examples of the use of the thermoformed article include not only storage cases for electronic component packaging materials, stuffed toys, ornamental dolls, clothing, animal pet supplies, but also various Sunday items.

[0033]

The present invention will be described more specifically with reference to the following experimental examples. [I] Raw materials (1) Thermoplastic resin LDPE (high-pressure low-density ethylene homopolymer): MFR4
g / 10 minutes, MT5g, Q value 6.2 LDPE (high pressure low density ethylene homopolymer): MFR
0.3 g / 10 min, MT 12 g, Q value 6.0 EVA (ethylene / vinyl acetate copolymer): MFR 0.
5 g / 10 min, MT 11 g, Q value 5.5 HDPE (high density ethylene homopolymer): MFR 0.6
g / 10 min, MT 9 g, Q value 5.6 L-LDPE (copolymer of ethylene and 7 wt% butene-1): MFR 0.8 g / 10 min, MT 5 g, Q value 7.0 PP (polypropylene resin : EC manufactured by Nippon Polychem Co., Ltd.
7): MFR 1.5 g / 10 min, MT 5 g

(2) Blowing agent composition ADCA: azodicarbonamide OBSH: p, p'-oxybis (benzenesulfonohydrazide) CS: 1: 1 mixture of sodium bicarbonate and citric acid StCa: calcium stearate

[II] Evaluation method (1) Resin physical properties The MFR melt flow rate (MFR) was measured in accordance with JIS K7210.
Is a value measured at a temperature of 190 ° C. and a load of 2.16 kgf. M T melt tension (MT) is used Capillograph manufactured by Toyo Seiki Co., melting drop speed 10 mm / min, the extrusion temperature 190 ° C., a value measured by haul-off speed of 4m / min. Q value The Q value (molecular weight distribution) is a value measured by gel permeation chromatography (GPC).

(2) Evaluation Expansion Ratio The expansion ratio is a value obtained by measuring the densities before and after foaming using a pycnometer and dividing the density before foaming by the density after foaming. Bubble Cell State and Size The state and size of the foam cell were obtained by magnifying and seeing the surface sliced in the thickness direction and the parallel direction of the foam using a microscope, and visually observing the state and size of the bubbles. The corrosiveness was determined by contacting the molten resin with an iron plate and visually observing and determining the corrosiveness. Specifically, it is measured by the following method. After the molten resin is brought into contact with the cold-rolled steel sheet, pressure is applied at 280 ° C. for 13 minutes by compression molding. After cooling, take out and place in a desiccator containing a saturated aqueous solution of ammonium sulfate.
The test plate was allowed to stand for a period of time and visually inspected for corrosion.

[III] Experimental Examples Examples 1 to 3 and Comparative Examples 1 to 3 (1) Production of foamable thermoplastic polymer composition The foaming agent compositions blended in the composition shown in Table 1 are shown in Table 1. The thermoplastic polymer shown was kneaded with a 90 mm diameter twin-screw extruder manufactured by Masculo Co. to obtain a foamable thermoplastic polymer composition. (2) Molding of low-foaming ethylene polymer resin sheet (low-foaming sheet) The foamable thermoplastic polymer composition kneaded with the above-mentioned 90 mm diameter twin-screw extruder manufactured by Masculo Co. was extruded from a die at a molding temperature of 180 ° C. A 1 mm low foam sheet was formed. Next, the expansion ratio, the state and dimensions of the foam cells, and the corrosiveness of the low foam sheet were measured, and the results are shown in Table 1.
The low-foam sheet of the example could be subjected to deep drawing.

[0038]

[Table 1]

[0039]

As described above, the foaming agent composition and the foamable thermoplastic polymer composition of the present invention have a non-corrosive foaming agent composition capable of producing a thermoplastic polymer having fine and uniform foam cells. The foamable thermoplastic polymer composition obtained by using this foaming agent composition can form a low-foamed layer having fine foam cells, uniform dimensions, and appropriate flexibility. For this reason, even when subjected to thermoforming, the foam cells are not broken, and the foaming can be performed uniformly without biasing in one direction while maintaining a good foaming state, so that advanced deep drawing can be performed. The resulting foamed molded product has fine foam cells, uniform and uniform dimensions, is extremely beautiful, has no corrosiveness, and has a buffering property. It does not corrode when used as a packaging material.

Claims (3)

[Claims] 1. A blowing agent composition comprising the following components (A) to (E). Component (A): Azodicarbonamide (ADCA) 0.1 to 50% by weight Component (B): p, p′-oxybis (benzenesulfonohydrazide) (OBSH) 1 to 80% by weight Component (C): carbonic acid Sodium hydrogen or potassium hydrogen carbonate 1 to 30% by weight Component (D): citric acid or a salt thereof 0.05 to 30% by weight Component (E): Higher fatty acid salt 2 to 80% by weight 2. The blowing agent composition according to claim 1, wherein the blowing agent composition is a non-corrosive blowing agent composition. 3. A thermoplastic polymer comprising the following components (A) to
0.01 to 0.2% by weight of a foaming agent composition comprising (E)
The foamable thermoplastic polymer composition characterized by being blended at a ratio of: Component (A): Azodicarbonamide (ADCA) 0.1 to 50% by weight Component (B): p, p′-oxybis (benzenesulfonohydrazide) (OBSH) 1 to 80% by weight Component (C): carbonic acid Sodium hydrogen or potassium hydrogen carbonate 1 to 30% by weight Component (D): citric acid or a salt thereof 0.05 to 30% by weight Component (E): Higher fatty acid salt 2 to 80% by weight