Formamide reducing additive for blowing agents and blowing agent composition containing the same

Abstract

The present invention provides a formamide-reducing additive for blowing agents that can significantly reduce the concentration of formamide generated during foaming of ADCA and also reduce the concentration of formamide remaining in the finished foam, and a blowing agent composition using the same.

Description

[Technical Field]

[0001] The present invention relates to a formamide-reducing additive for a blowing agent, such as ADCA, that can reduce the concentration of formamide generated from the blowing agent and the concentration of residual formamide in the finished foam, and to a blowing agent composition containing the same. [Background technology]

[0002] The foaming agent is a synthetic resin additive that is mixed with a synthetic resin to produce a porous foam, and is a substance that supplies gas to form bubbles during foam molding.

[0003] Among the foaming agents, azodicarbonamide (hereinafter referred to as ADCA) is used as an additive for various plastics such as EVA, PE, PVC, and PP, and is a chemical foaming agent that dominates the foaming agent market due to its many advantages such as high expansion ratio, low unit cost, and efficient decomposition temperature control.

[0004] However, in the case of commonly used ADCA, when it is thermally decomposed during foaming, a large amount of formamide is generated along with N2 gas, which causes problems in the working environment, and when it is commercialized, the release of formamide causes environmental problems.

[0005] Therefore, in order to remove formamide generated from ADCA, physical removal using adsorbents, chemical removal, and acidic substances using acid-base reactions are used.

[0006] However, ADCA foams at high temperatures of 200-230°C, so in the case of an ACDA adsorbent, formamide is adsorbed and then desorbed again at high temperatures. Furthermore, existing adsorbents have poor performance because the formamide reduction concentration varies depending on the foaming conditions. Furthermore, there is a problem that poor foaming can occur when using acids or bases.

[0007] In this regard, Korean Patent Registration No. 10-1915690 discloses a method for capturing and reducing harmful substances generated during the thermal decomposition of azo foaming compounds using porous metal oxides. However, although this method is effective in reducing formamide, it has the problem of causing side effects in the foam and changing the foam properties.

[0008] In addition, Korean Patent Publication Nos. 2005-0101689, 2017-0103764, and 2005-0069178 disclose methods for removing toxic gases by impregnating a porous material with a metal, but these methods are intended to remove toxic gases such as combustion exhaust gas and carbon monoxide, and do not recognize a method for reducing formamide, a harmful substance, from ADCA. Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a formamide reducing additive for a blowing agent that can more effectively reduce formamide from a blowing agent by impregnating a porous material such as zeolite with one or more metals including Cu metal.

[0010] The present invention also provides a foam composition and a foam produced therefrom in which the formamide concentration of the foam is effectively reduced by using the formamide reducing additive for a blowing agent. [Means for solving the problem]

[0011] As used herein, the term "zeolite" refers to a porous zeolite having a plurality of pores, a metal containing a first metal impregnated in some or all of the pores, and

[0012] The present invention provides a formamide reducing additive for blowing agents comprising:

[0013] Also, according to another embodiment of the present specification,

[0014] A blowing agent composition is provided that includes a blowing agent and the formamide reducing additive.

[0015] Furthermore, according to the present specification, there is provided a foaming composition comprising the foaming agent composition and a resin to be foamed, wherein the resin to be foamed comprises any one selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polystyrene, polyamide, acetal, styrene-butadiene rubber, ethylene-vinyl acetate copolymer (EVA), ethylene-propylene rubber, thermoplastic elastomers, thermoplastic polyurethanes, thermoplastic rubbers, ABS resins, rubbers, epoxy resins, and acrylic resins.

[0016]

[0017] The present invention will be described in more detail below. The terms and phrases used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical concept of the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to best describe his / her invention.

[0018] Additionally, the meaning of "comprise" as used herein embodies certain properties, regions, integers, steps, operations, elements and / or components, and does not exclude the presence or addition of other properties, regions, integers, steps, operations, elements and / or components.

[0019] As used herein, "formamide reducing additive for blowing agents" refers to an additive that removes residual formamide in foam and reduces its concentration.

[0020] In this specification, the concentration of residual formamide refers to the concentration measured in a blowing agent composition containing a blowing agent and a formamide-reducing additive for a blowing agent without mixing it with a resin to be foamed.

[0021] The concentration of residual formamide in the foamed resin (i.e., the concentration of residual formamide in the foam) means the concentration measured after mixing the resin to be foamed with the foaming composition.

[0022]

[0023] Hereinafter, a formamide reducing additive for a blowing agent according to an embodiment of the present invention, a blowing agent composition using the same, and a foam will be described in more detail.

[0024]

[0025] According to one embodiment of the present invention, there is provided a formamide reducing additive for a blowing agent, comprising: a porous zeolite having a plurality of pores; and a metal including a first metal impregnated in some or all of the pores.

[0026] The metal may include metal ions, and the pores of the porous zeolite may be partially or entirely impregnated with the metal ions.

[0027] The present inventors have developed a formamide-reducing additive in which one or more metals, including Cu, are impregnated (supported) in a porous material such as zeolite. They have confirmed that when this additive is applied to a blowing agent and a finished foam, it is possible to significantly reduce the concentration of formamide remaining in not only the blowing agent but also the foam, thereby completing the present invention.

[0028] Therefore, the present invention is characterized by providing a formamide-reducing additive for blowing agents in the form of a support in which one or more metals are impregnated (supported) in the form of ions in some or all of the multiple pores of a porous zeolite, which can effectively remove formamide specifically from among harmful substances that are generated during the foaming of a blowing agent (for example, ADCA) and remain in the foam, and reduce its concentration.

[0029] The foaming agent generates N2, carbon monoxide, and ammonia through thermal decomposition during foaming. When the formamide-reducing additive is added, the carbon monoxide is oxidized to carbon dioxide, and the porous zeolite traps moisture, suppressing the generation of formamide without any side effects from the foaming agent or foam.

[0030] The formamide reducing additive is a non-catalytic additive specifically used to remove and reduce formamide in blowing agents and foams containing blowing agents.

[0031] Such formamide reducing additives may include a Group 11 metal as the first metal.

[0032] In addition, the formamide-reducing additive may further include one or more second metals in addition to the first metal. When the second metal is included in addition to the first metal, the second metal may lower the activation energy, thereby providing additional synergistic effects such as temperature control for formamide concentration reduction and improvement of foaming ratio.

[0033] That is, the formamide reducing additive is prepared by applying a carrier (e.g., CuMnA) in which two or more metals are impregnated in porous zeolite having a plurality of pores to the blowing agent, which has fewer side effects on the final foam compared to methods in which metal oxides are applied, and can effectively reduce formamide.

[0034] Specifically, the first metal may include at least one metal selected from the metals of Group 11. The first metal may be included in the form of a first metal ion, and the first metal ion may be impregnated into some or all of the pores of the porous zeolite.

[0035] More specifically, the first metal may be at least one selected from the group consisting of Cu and Ag. For example, the first metal may include Cu. When the first metal essentially includes Cu, it is effectively impregnated into the pores of the porous zeolite, thereby exhibiting a very high performance in reducing formamide generated during foaming of ADCA.

[0036] The metal may further include a second metal different from the first metal. Like the first metal, the second metal may be included in the form of a second metal ion, and the second metal ion may be impregnated into some or all of the pores of the porous zeolite together with the first metal ion.

[0037] The second metal may be one or more metals selected from the group consisting of metals of Groups 1, 3 to 10, 12, and 13. More specifically, the second metal may include one or more metals selected from the group consisting of Mn, Si, Cr, Ce, Cs, Fe, Co, Zn, Ni, Zr, and Al.

[0038] In addition, the present invention can effectively improve the reduction rate of formamide without side effects by adjusting the weight ratio between one or more metals impregnated in the porous material.

[0039] The first metal and the second metal may be contained in a weight ratio of 1:9 to 17:0 based on the total content of metal ions.

[0040] According to a preferred embodiment, the first metal and the second metal may be contained in a weight ratio of 1:9 to 16.9:0.1 with respect to the total content of the metals. That is, when the metal further includes a second metal, the first metal and the second metal may be contained in a weight ratio of 1:0.006 to 1:9 with respect to the total content of the metals.

[0041] As the amount of the first metal increases, the formamide reduction rate increases, but crosslinking is inhibited, causing the foam to collapse or a significant reduction in the amount of gas. Furthermore, if the content of the first metal is too low, the formamide removal effect is minimal. Therefore, the first metal and second metal must be within the above ranges to reduce the formamide concentration in the foaming agent and foam without side effects.

[0042] In addition, the reduction rate of formamide and the side effects of the foam can be adjusted according to each situation. For example, the weight ratio of the first metal to the second metal can be adjusted to 1:0.05 to 1:0.1, 1:0.5 to 1:1, 1:2 to 1:3, 1:4 to 1:9, or 2:1 to 9:1.

[0043] In one embodiment, the weight ratio of the first metal to the second metal may be 1: 1. When preparing the formamide-reducing additive, the first metal to the second metal impregnated into the porous zeolite material may exhibit the lowest side effects and the highest formamide reduction rate when applied at a ratio of 1:1.

[0044] The formamide reducing additive for a blowing agent contains 83 to 99% by weight of the porous zeolite and 1 to 17% by weight of the metal ions.

[0045] If the metal ion content is less than 1 wt%, the amount of metal ions impregnated into the porous zeolite is too small, resulting in a problem of poor formamide removal effect of the blowing agent, whereas if the metal ion content exceeds 17 wt%, the metal ions are not impregnated into the zeolite but remain in the solution used to prepare the formamide-reducing additive, resulting in the entire solution being discarded as wastewater.

[0046] The porous zeolite may have an average particle size of 1 to 20 μm, or may have a particle size of 2 to 5 μm, and the porosity of the porous zeolite measured by BET analysis may be 3 Å to 10 Å.

[0047] The porous zeolite can be commercially available as a product such as zeolite 4A.

[0048]

[0049] The formamide reducing additive for a blowing agent can be prepared in the form of particles by mixing an aqueous solution of a metal sulfur compound with porous zeolite.

[0050] Specifically, when preparing the formamide-reducing additive, the material for impregnating the zeolite with a metal in an ionic form can be selected from a metal-containing nitric acid aqueous solution and a sulfur compound aqueous solution. However, it is preferable to use a metal sulfide aqueous solution in terms of stability, ease of handling, and economy.

[0051] That is, since metal-containing nitric acid aqueous solutions contain substances that are treated as hazardous materials, they are difficult to store and there is a possibility that problems may arise in mass production.In contrast, aqueous solutions using metal sulfur compounds are cheaper than metal-containing nitric acid aqueous solutions and are not considered hazardous or harmful materials, so they are advantageous for application.

[0052] The formamide-reducing additive can be prepared by preparing an aqueous solution of a metal-containing sulfur compound, adding a porous material, and stirring the mixture, thereby impregnating one or more metals in the form of ions into the pores of porous zeolite and supporting the metals.

[0053] The metal sulfur compound may be at least one selected from metal sulfate compounds such as CuSO4, MnSO4, CeSO4, and FeSO4.

[0054] In the stirring step, the stirring means is not particularly limited, and any commonly known method can be used.

[0055] The mixed solution of the aqueous metal sulfur compound solution and the porous material may be stirred at 25°C to 50°C or 40°C to 50°C for 30 minutes to 2 hours or 45 minutes to 1 hour.

[0056] After the stirring step, the mixed solution may be filtered and washed, and then the solid content may be dried.

[0057] The drying step can be carried out at a temperature of 120° C. or higher, 130° C. or higher, or 120° C. to 200° C. The drying means may be, but is not limited to, an oven or a thermal drying ribbon mixer.

[0058] According to another embodiment of the present invention, there is provided a blowing agent composition comprising a blowing agent and the formamide reducing additive.

[0059] According to yet another embodiment, there is provided a foam composition comprising a resin and the foaming agent composition. Specifically, there is provided a foam composition comprising the foaming agent composition and a resin to be foamed, the resin to be foamed being any one selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polystyrene, polyamide, acetal, styrene-butadiene rubber, ethylene-vinyl acetate copolymer (EVA), ethylene-propylene rubber, thermoplastic elastomers, thermoplastic polyurethane, thermoplastic rubber, ABS resin, rubber, epoxy resin, and acrylic resin.

[0060] The formamide reducing additive can be included in the blowing agent to reduce the concentration of formamide in the blowing agent itself.

[0061] In addition, when the foaming agent composition is applied to a resin to be foamed, the concentration of residual formamide in the foamed resin can also be reduced after foaming of the resin to be foamed.

[0062] In one embodiment of the invention, the foaming agent composition may have a residual formamide concentration of 10,000 ppm or less, and the foamed resin in the foam may have a residual formamide concentration of 900 ppm or less.

[0063] The foaming agent composition contains 85 to 98% by weight of the foaming agent and 2 to 15% by weight of the formamide-reducing additive.

[0064] That is, the formamide reducing additive may be contained in an amount of 2 to 15 wt % based on the total weight of the foaming agent composition. In the present invention, by containing the formamide reducing additive within the above content range, side effects are reduced compared to the amount added, and the reduction of formamide can be maximized.

[0065] If the content of the formamide reducing additive is less than 2 wt%, the reduction in formamide concentration will be insufficient, while if the content exceeds 15 wt%, the amount of foaming agent gas will be reduced even if the reduction in formamide concentration is increased, resulting in a decrease in the foam volume and inhibiting crosslinking, resulting in changes in physical properties.

[0066] Specifically, the formamide reducing additive can be contained in an amount of 2 to 10% by weight based on the total weight of the foaming agent composition, which can minimize side effects and increase the extent of formamide reduction.

[0067] The foaming agent may be azodicarbonamide (ADCA) particles having an average particle size of 1 to 20 μm, specifically, ADCA particles having an average particle size of 2 to 15 μm.

[0068] If the average particle size of the blowing agent is less than 1 μm, the blowing agent may decompose prematurely, and if the average particle size of the blowing agent is more than 20 μm, the cells of the foam may become non-uniform.

[0069] The resin is a resin to be foamed using a foaming agent, and can be any of various synthetic or natural resins, such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polycarbonate (PC), polystyrene (PS), polyamide, acetal, styrene butadiene rubber (SBR), ethylene vinyl acetate copolymer (EVA), ethylene propylene diene monomer rubber (EPDM), thermoplastic elastomer (TPE), thermoplastic polyurethane (TPU), thermoplastic rubber (TPR), ABS resin (acrylonitrile butadiene styrene copolymer), rubber, epoxy resin, and acrylic resin. Specifically, the resin to be foamed may be EVA. In one embodiment of the present invention, the foaming agent composition may further include an additive.

[0070] Examples of the additives include calcium compounds such as calcium stearate and calcium carbonate (CAS No. 471-34-1), zinc compounds such as zinc oxide and zinc stearate, titanium or tin compounds such as titanium dioxide and tin methoxy maleate, barium compounds such as barium stearate and barium ricinoleate, magnesium compounds such as magnesium oxide, talc, monosodium citrate, urea, silica, dicyclohexyl phthalate, and stearic acid. The calcium compound can improve the flowability of the foaming agent, the zinc compound can accelerate the decomposition temperature, and the titanium or tin compound can improve the whiteness of the foam.

[0071] The content of the additive is not particularly limited since it can be used within a range well known in this field, and may be, for example, 0.1 to 10 parts by weight per 100 parts by weight of the foaming agent composition.

[0072]

[0073] Meanwhile, according to still another embodiment of the present invention, there is provided a foam in which the concentration of residual formamide in the foamed resin obtained by foaming the foaming composition is 900 ppm or less.

[0074] When foams are produced using the formamide-reducing additive for blowing agents according to the present invention, the content of formamide remaining in the foam can be reduced more effectively than conventional additives to the industry-required level of 1,000 ppm or less, without causing any side effects or changes in the foam properties.

[0075] Specifically, the concentration of residual formamide in the foamed resin in the foam can be reduced to 900 ppm or less, 850 ppm or less, 600 ppm or less, 500 ppm or less, 400 ppm or less, 350 ppm or less, 300 ppm or less, 250 ppm or less, 200 ppm or less, 100 ppm or less, 50 ppm or less, 40 ppm or less, or 30 ppm or less. [Effects of the Invention]

[0076] The formamide reducing additive for blowing agents according to the present invention can significantly reduce the concentration of formamide generated during foaming of a blowing agent (for example, ADCA) by impregnating porous zeolite with one or more metals.

[0077] In addition, the formamide reducing additive can reduce the concentration of formamide remaining in a finished foam containing a blowing agent (e.g., ADCA) and a resin to 900 ppm or less, thereby reducing environmental problems caused by formamide emissions. DETAILED DESCRIPTION OF THE INVENTION

[0078] Examples are presented below to aid in understanding the present invention, but the following examples are merely for illustrative purposes and are not intended to limit the present invention.

[0079]

[0080] <Examples 1 to 20 and Comparative Examples 1 to 7: Production of Formamide-Reducing Additives for Foaming Agents>

[0081] Metal sulfate compounds of CuSO4, MnSO4, CeSO4, FeSO4, Cs2SO4, CoSO4·H2O, ZnSO4, NiSO4, Zr(SO4)2, Al2(SO4)3, and Si(SO4)2 were prepared.

[0082] Next, the metal sulfate compound was dissolved in water so that the first metal or the first and second metals were contained in the zeolite weight ratio according to the composition and content shown in Table 1, and then the solution was stirred for 30 minutes to dissolve the metal sulfate compound completely, thereby preparing a metal sulfate aqueous solution containing one or two metals.

[0083] Then, zeolite 4A (product of Cosmo Catalyst Co., Ltd.) was added to the metal sulfate aqueous solution and stirred for 2 hours, and the resultant was filtered and washed with water.

[0084] Once the metals were completely impregnated into the zeolite, the zeolite and wastewater were checked for discoloration, and the filtered and washed zeolite was dried in a vacuum oven at a temperature of 130°C or higher for 4 hours or more to produce the additive.

[0085] When two types of metals were contained, the two types of metal sulfate aqueous solutions were mixed and then zeolite was added.

[0086] In Comparative Example 4, a method was used in which an aqueous solution of silicon (IV) chloride and an aqueous solution of CoSO4*H2O were mixed together, and then zeolite was added.

[0087]

[0088] <Examples 21 to 42 and Comparative Examples 8 to 17: Preparation of Foaming Agent Compositions>

[0089] The blowing agent compositions of Examples 21 to 42 and Comparative Examples 8 to 17 were produced using the following azodicarbonamide (ADCA) and formamide-reducing additives of Examples 1 to 20 and Comparative Examples 1 to 7 in the compositions and contents shown in Table 2.

[0090] *Azodicarbonamide (ADCA): 100% purity of dry product, particle size 6~9um (Unicell D600, manufacturer: Dongjin Semichem), foaming properties DT: 206GV: 240mL / g210

[0091] Thereafter, each foam was produced by the following method.

[0092]

[0093] Comparative Example 8

[0094] 5 parts by weight (phr) of a foaming agent composition consisting of ADCA alone was added to 100 parts by weight of EVA sole, and then 10 parts by weight (phr) of hard carbon, 1 part by weight (phr), 1 part by weight (phr) of ZnO, 1 part by weight (phr) of stearic acid, and 1 part by weight (phr) of a crosslinking agent were added to the foaming composition (EVA composition) as additives. The foaming composition was then rolled into a sheet. The sheet was then rolled under a pressure of 150 kgf / cm. 2 The mixture was foamed at 175°C for 12 minutes using a press with a pressure of 1.0.

[0095]

[0096] Comparative Example 9

[0097] A foam was produced in the same manner as in Comparative Example 8, except that a blowing agent composition containing 84 wt. % ADCA and 16 wt. % of the formamide reducing additive of Example 8 was used.

[0098] However, in Comparative Example 9, a decrease in the expansion ratio and a defective foam due to poor crosslinking were observed.

[0099]

[0100] Comparative Example 10

[0101] A foam was produced in the same manner as in Comparative Example 8, except that a blowing agent composition containing 99 wt % ADCA and 1 wt % of the formamide reducing additive of Example 8 was used.

[0102]

[0103] Comparative Examples 11 to 17

[0104] Foams were produced in the same manner as in Comparative Example 8, except that a blowing agent composition containing ADCA and a formamide-reducing additive of Comparative Examples 1 to 7 according to the composition and content in Table 2 below was used.

[0105]

[0106] Example 21

[0107] A blowing agent composition was prepared by mixing 90% by weight of ADCA and 10% by weight of the formamide reducing additive of Example 1.

[0108] 5 parts by weight (phr) of the foaming agent composition was added to 100 parts by weight of EVA sole, and then 10 parts by weight of hard carbon, 1 part by weight of ZnO, 1 part by weight of stearic acid, and 1 part by weight of a crosslinking agent were added to the foaming composition (EVA composition) as additives. The foaming composition was then rolled into a sheet. The sheet was then rolled under a pressure of 150 kgf / cm. 2 The mixture was foamed at 175°C for 12 minutes using a press with a pressure of 1.0.

[0109]

[0110] Examples 22 to 42

[0111] Foams were produced in the same manner as in Example 21, except that a blowing agent composition containing ADCA and the formamide-reducing additives of Examples 2 to 12 according to the composition and content in Table 2 below was used.

[0112]

[0113] <Experimental Example>

[0114] Analytical method for formamide

[0115] The concentrations of residual formamide in the blowing agent compositions and foams of Examples 22 to 42 and Comparative Examples 8 to 17, and the concentrations of residual formamide in the EVA foams were analyzed by the following method, and the results are shown in Table 2.

[0116] 1) The expanded foam was cut into small pieces of 5 mm x 5 mm, and 2 g of the foam was placed in 20 mL of acetone solvent.

[0117] 2) The sample prepared in 1) above was dispersed in water at 40°C for 1 hour using a sonicator.

[0118] 3) A small amount of acetone was sampled from the dispersion liquid of 2) above, and the concentration of formamide was analyzed using GC-MS.

[0119]

[0120] *Concentration of residual formamide:

[0121] Analytical concentration of formamide remaining when the ACDA blowing agent composition itself is foamed without applying ADCA to the resin.

[0122] *EVA foam residual formamide concentration:

[0123] The concentration of formamide remaining in the foam produced when EVA is mixed with ADCA and foamed (i.e., the concentration of formamide remaining in the foam when foamed after mixing EVA with the blowing agent composition)

[0124]

[0125] [Table 1]

[0126] [Table 2]

[0127] As shown in Table 2, Examples 21 to 42 used the formamide-reducing additives of Examples 1 to 20, in which zeolite was impregnated with Cu ions as the first metal within a specific content range, and thus had lower residual formamide concentrations overall than Comparative Examples 8 to 17. Furthermore, the residual formamide concentrations in EVA foams were all 900 ppm or less, satisfying the industry requirement of 1000 ppm or less. In contrast, Comparative Example 8 contained only ADCA, and both the residual formamide concentration and the residual formamide concentration in EVA were high.

[0128] In Comparative Example 9, although the formamide-reducing additive of Example 8 was used and the residual formamide concentration and EVA residual formamide concentration were reduced, the formamide-reducing additive content was 16 wt%, which was excessively high and exceeded the range of the present invention, resulting in a reduced expansion ratio and poor crosslinking. Therefore, Comparative Example 9 caused the foam to collapse and fail to perform its functions properly.

[0129] In Comparative Example 10, even though the concentration of residual formamide in EVA was 1000 ppm or less, the content of the formamide reducing additive was too low at 1 wt %, so the reduction value of formamide was lower than in the Examples, and the formamide removal effect was insignificant.

[0130] In addition, in Comparative Example 11, the additive of Comparative Example 1 was used, in which the content of the first metal, Cu, was impregnated at an excessively low level of 0.5 wt% (i.e., a formamide-reducing additive in which 99.5 wt% of zeolite 4A was impregnated with 0.5 wt% of the first metal, Cu, in ionic form), and the formamide reduction value was low.

[0131] In Comparative Example 12, the additive of Comparative Example 2 was used, in which the content ratio of the first metal, Cu, was impregnated at an excessively high level of 18 wt% (i.e., a formamide reduction additive in which 82 wt% of zeolite 4A was impregnated with 18 wt% of the first metal, Cu, in ionic form), but impregnation was not achieved to more than 17%, and more than 1% of Cu remained in the waste liquid.

[0132] Comparative Examples 13 to 16 showed EVA residual formamide concentrations of 1100 ppm or more by using the formamide reducing additives of Comparative Examples 3 to 6 in which the first metal impregnated in the zeolite did not contain Cu ions.

[0133] In Comparative Example 17, a formamide reduction additive was used in which 90 wt% of zeolite 4A from Comparative Example 7 was impregnated with 0.5 wt% of the first metal Cu and 9.5 wt% of the second metal Mn in ionic form. Although the reduction additive contained Mn ions as the second metal ions, the proportion of the first metal Cu ions was excessively low at less than 1 wt%, and the reduction concentration of EVA residue formamide was poorer than in Comparative Example 11.

Claims

1. a porous zeolite containing a plurality of pores; a metal containing a first metal contained in and impregnated into some or all of the pores; Formamide reducing additive for blowing agents comprising:

2. 2. The formamide reducing additive for a blowing agent according to claim 1, wherein the first metal comprises at least one metal selected from Group 11 metals.

3. 2. The formamide reducing additive for a blowing agent according to claim 1, wherein the first metal comprises Cu.

4. 10. The formamide reducing additive for a blowing agent according to claim 1, wherein the metal further comprises a second metal different from the first metal.

5. 5. The formamide reducing additive for a blowing agent according to claim 4, wherein the second metal comprises one or more metals selected from the group consisting of metals of Groups 1, 3 to 10, 12, and 13.

6. 5. The formamide reducing additive for a blowing agent according to claim 4, wherein the second metal comprises one or more selected from the group consisting of Mn, Si, Cr, Ce, Cs, Fe, Co, Zn, Ni, Zr and Al.

7. 5. The formamide reducing additive for a blowing agent according to claim 4, wherein the first metal and the second metal are contained in a weight ratio of 1:9 to 16.9:0.1 based on the total content of the metals.

8. 83 to 99 wt % of the porous zeolite; 1 to 17 wt. % of the metal; 2. The formamide reducing additive for blowing agents of claim 1, comprising:

9. 2. The formamide reducing additive for a blowing agent according to claim 1, wherein the porous zeolite has an average particle size of 1 to 20 μm.

10. A blowing agent composition comprising a blowing agent and the formamide reducing additive of claim 1.

11. 11. The blowing agent composition of claim 10 comprising 85 to 98 weight percent of said blowing agent and 2 to 15 weight percent of said formamide reducing additive.

12. 11. The blowing agent composition of claim 10, wherein the blowing agent comprises azodicarbonamide (ADCA) having an average particle size of 1 to 20 μm.

13. A foaming agent composition comprising the foaming agent composition according to claim 10 and a resin to be foamed, The resin to be foamed is any one selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polystyrene, polyamide, acetal, styrene butadiene rubber, ethylene-vinyl acetate copolymer (EVA), ethylene propylene rubber, thermoplastic elastomers, thermoplastic polyurethanes, thermoplastic rubbers, ABS resins, rubbers, epoxy resins, and acrylic resins.

Images