JPH0686543B2 - Open-cell type crosslinked ethylene resin foam composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composition for open-cell type crosslinked ethylene resin foam.

More specifically, the present invention relates to a composition for producing a foam that adheres well to a material to be packaged, is more supple, and has a better texture and touch. In addition, this composition can be used for producing an open-cell type crosslinked ethylene-based resin foam provided with a moisture absorption / dehumidification action or flame retardancy by utilizing its characteristics.

(Prior Art) First, in the Japanese Examined Patent Publication No. 60-49657, the present inventors have excellent breathability, water absorption, weather resistance, and since they are open-cell type, they are more flexible, textured, and tactile than the closed-cell type. , Developed a method for producing pure white foam. That is, according to JP-B-60-49657, it was possible to obtain an open-cell body composed of bubbles having an average bubble diameter of 0.2 mm ± 0.03 mm. However, when the foam sheet manufactured according to JP-B-60-49657 is used as a packaging material, a cover or a supporter material for elbows and knees, it is more closely attached to the material to be packaged, and it is more supple and has a better texture and touch. I was sometimes asked for foam.

In addition, zeolite, cristobalite and other silica-based porous materials have been conventionally known as materials that strongly adsorb gases such as ammonia and also have a moisture absorption / desorption effect. Its use as a material for controlling moisture inside objects is being investigated, but if silica-based porous substance powder or pellets are used as they are in a container, they will spill or take up space, making handling very inconvenient. It was. Therefore, a method of wrapping powder or pellet of silica-based porous material in cloth or paper and using it has been devised, but it is difficult to mold it into a certain shape or cut it into various shapes. . Moreover, a sheet-shaped product obtained by simply mixing powder of a silica-based porous material or pellets with a resin such as polyethylene has almost no moisture permeability or air permeability, and the moisture-absorbing / dehumidifying action and gas of the silica-based porous material are eliminated. It was impossible to take advantage of the adsorptivity.

Furthermore, when the open-cell foam is used as a cushion for building materials, a cushion for automobile interior walls, a sheet for packaging materials, etc.
It was sometimes required to impart flame retardancy.

(Problems to be Solved by the Invention) The present invention is superior to the open-cell type crosslinked ethylene resin foam produced by Japanese Patent Publication No. The present invention aims to obtain a composition for producing a foam, and further utilizes the characteristics of the composition to substantially retain the adsorption / desorption effect of a silica-based porous material, and Composition for producing an open-cell crosslinked ethylene resin foam for producing a composite material capable of molding a powder or pellet of a porous porous material into a certain shape or cutting it into various shapes The present invention is intended to obtain a composition for producing an object and an open-cell type crosslinked ethylene resin foam provided with flame retardancy.

(Means and Actions for Solving Problems) In the method of Japanese Patent Publication No. 60-49657, a cross-linked foaming composition comprising an ethylene resin, an organic peroxide and a foaming agent (half-temperature of organic peroxide and foaming) is used. The relationship of the foaming temperature of the agent is limited), whereas the composition containing the “trifunctional monomer and silicone oil” is used as the composition for the open-cell type crosslinked ethylene resin foam, but in the present invention, By using "one or more compounds selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide" instead of "functional monomer and silicone oil", finer bubbles are formed. It is intended to obtain an open-cell type crosslinked ethylene resin foam.

That is, the present invention is based on 100 parts by weight of an ethylene resin, a foaming agent 1
To 30 parts by weight and 0.2 to 10 parts by weight of an organic peroxide as a cross-linking agent, and one or two selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide.
0.1 to 10 parts by weight of one or more compounds is added, the 10-minute half-life temperature (Tp) of the organic peroxide is 100 to 220 ° C, and the foaming temperature (Tf) of the foaming agent is 90 to 220 ° C. And to obtain a composition for an open-cell type crosslinked ethylene resin foam (hereinafter referred to as the present composition) characterized by satisfying the following formula −10 ° C. ≦ Tp−Tf ≦ 50 ° C. is there.

Further, the present invention, relative to 100 parts by weight of the present composition, 1 to 3000
By blending parts by weight of the silica-based porous material, the absorption and dehumidification effect of the silica-based porous material can be substantially maintained and the powder and pellet of the silica-based porous material can be molded into a certain shape or various shapes. The present invention is intended to obtain a composition for an open-cell type crosslinked ethylene resin foam for producing a composite material that can be cut into the above shape.

Further, the present invention is based on 100 parts by weight of the present composition, 5 to 200 parts by weight of a halogen-containing flame retardant and 1 to 50 parts of antimony trioxide.
It is intended to obtain a composition for flame-retardant open-cell crosslinked ethylene-based resin foam by adding parts by weight, further, with respect to 100 parts by weight of the present composition, the surface-treated metal hydroxide 1 to 200 parts by weight is added to obtain a flame-retardant open-cell type crosslinked ethylene resin foam composition.

In the present invention, instead of the "trifunctional monomer and silicone oil" of the composition of Japanese Patent Publication No. 60-49657, "1 selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide.
It is intended to obtain an open-cell type crosslinked ethylene-based resin foam comprising finer cells by using one kind or two or more kinds of compounds. For example, as shown in Example 1, the average cell diameter is A bubble of 0.08 mm ± 0.02 mm can be obtained. However, it is not always clear why the production of such a uniform and fine open-cell type crosslinked ethylene resin foam is possible.

However, considering the factors, a suitable polarity of polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide,
That is, the balance between hydrophilic groups and lipophilic groups and the fact that a reaction mechanism that is completely opposite to the method for selecting a foaming agent and a crosslinking agent designed to foam after conventional crosslinking is used is an organic combination. It is presumed that it has become possible to reach.

In the present invention, the ethylene-based resin is a polymer containing ethylene as a main component, and high-pressure polyethylene, low-pressure low-density polyethylene, linear low-density polyethylene (LLDPE),
An ethylene-vinyl ester copolymer, an ethylene-alkyl acrylate copolymer, an ethylene-α olefin-based copolymer and the like.

The organic peroxide used in the present invention has a decomposition temperature of 100 to 220 ° C. with a half-life of 10 minutes, and the following may be mentioned as examples. However, in parentheses, decomposition temperature (℃)
Is.

Succinic acid peroxide (110), benzoyl oxide (1
10), t-butylperoxy-2-ethylhexanoate (113), p-chlorobenzoyl peroxide (11)
5), t-butylperoxyisobutyrate (115), t
-Butyl peroxyisopropyl carbonate (13
5), t-butylperoxylaurate (140), 2,5-
Dimethyl-2,5-di (benzoylperoxy) hexane (140), t-butylperoxyacetate (140), di-t-butyldiperoxyphthalate (140), t-butylperoxymaleic acid (140), cyclohexanone peroxide ( 145), t-butyl peroxybenzoate (145), methyl ethyl ketone peroxide (15)
0), dicumyl peroxide (150), 2,5-dimethyl-
2,5-di (t-butylperoxy) hexane (155), t
-Butyl cumyl peroxide (155), t-butyl hydroperoxide (158), di-t-butyl peroxide (160), 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne 3 (170) , Di-isopropylbenzene hydroperoxide (170), p-menthane hydroperoxide (180), 2,5-dimethylhexane-2,5-dihydroperoxide (213).

The foaming agent used in the present invention has a foaming temperature of 90 ° C. to 220 ° C., and includes those having a decomposition temperature adjusted to this range by using an accelerator or an auxiliary agent together. Examples include:

Azobisisobutyronitrile, diazocarbonamide,
p-toluenesulphonyl hydrazide, 4,4'-oxybis (benzenesulphonyl hydrazide), n-heptane, n-octane, n-nonane, n-decane.

The molecular weight of polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide usable in the present invention is preferably 1,000 or more. If it is less than 1000, it is difficult to mix, and after molding, bleeding may occur on the surface of the product.

In the present invention, the 10-minute half-life temperature (Tp) of organic peroxide is
100 ~ 220 ℃, foaming temperature (Tf) of foaming agent is 90 ~ 220
A combination of an organic peroxide and a foaming agent which satisfies the following formula −10 ° C. ≦ Tp−Tf ≦ 50 ° C. is desirable. That is, combining this cross-linking agent and a foaming agent,
When a composition obtained by adding one or more compounds selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide to an ethylene-based resin is heated, almost simultaneously with foaming, or slightly. Crosslinking starts afterwards, gradually progresses, and the crosslink density rises sharply after or immediately before the completion of foaming, resulting in uniform open cells or open cells containing some closed cells. The body stabilizes, and if it cools, it becomes immobilized.

When Tp-Tf <-10 ° C, when the composition is heated, the crosslinking preferentially proceeds, and foaming hardly occurs.
Even if it happens, it will become a closed cell foam.

When Tp-Tf> 50 ° C, foaming proceeds preferentially, and bubbles are not stabilized. In the present invention, one kind or two or more kinds of compounds selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide is effective in giving a foam having uniform and fine cells.

The composition ratio of each component of the present composition used in the present invention will be described.

The amount of the organic peroxide needs to be 0.2 to 10 parts by weight with respect to 100 parts by weight of the ethylene resin. If the amount is less than 0.2 parts by weight, the viscosity of the resin layer will hardly increase upon heating the composition, and the resin layer will sag. Even if it is more than 10 parts by weight, the improvement of the crosslinking efficiency is little.

The amount of foaming agent is required to be 1 to 30 parts by weight. If it is less than 1 part by weight, there is almost no effect of foaming, and if it is more than 30 parts by weight, the amount of the decomposed product of the foaming agent wastefully escaping into the atmosphere at the time of foaming increases, resulting in poor efficiency.

The amount of one or more compounds selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide is 0.1.
~ 10 parts by weight is required. If it is less than 0.1 part by weight, bubbles having a uniform fine structure cannot be obtained, and if it is more than 10 parts by weight, oozing may occur.

Next, the silica-based porous material that can be used in the present invention refers to, for example, zeolite, cristobalite, and semi-synthetic or synthetic products thereof. Examples of cristobalite-based substances include Chris Barr (manufactured by Nittetsu Mining) and Builder Clay (manufactured by Nittetsu Mining). The silica-based porous material may be in the form of powder, pellets or other molded products. However, in the case of powder having a diameter of 250 μm or less, a composite of a silica-based porous substance and an open-cell type crosslinked ethylene-based resin foam, which is uniform at an addition amount of 1 to 100 parts by weight with respect to 100 parts by weight of the present composition Is obtained. Also, the diameter is 250μ
100 to 3000 parts by weight for powders or pellets of m or more, especially pellets or other molded articles with a diameter of 0.5 mm or more,
It is preferable to add 1000 to 3000 parts by weight to obtain a molded product in a sintered state or close to this.

If the amount of silica-based porous material is less than 1 part by weight, a substantial effect of moisture absorption and desorption cannot be expected, and if it is more than 3000 parts by weight, the resin layer does not serve as a binder, and the powder of silica-based porous material is used. Alternatively, pellets and other molded products may be separated from each other.

The composite of the silica-based porous material and the open-cell type crosslinked ethylene-based resin foam obtained according to the present invention can be molded into a certain shape or cut into various shapes.

Next, as the first method of making the open-cell type crosslinked ethylene resin foam of the present invention flame-retardant, a halogen-containing flame retardant is used as a flame-retardant imparting agent and added in combination with antimony trioxide. That is, the halogen-containing flame retardant generates a hydrogen halide when exposed to a flame, and this hydrogen halide dilutes a combustible gas generated by thermal decomposition of the resin, or a combustion reaction that proceeds by a radical mechanism. There is a flame retarding effect by stopping the chain reaction. Further, the combined use of antimony trioxide with the halogen-containing flame retardant increases the flame retardant effect.

Examples of the halogen-containing flame retardant that can be used in the present invention are given below.

Chlorinated paraffin, chlorinated polyethylene, tetrabromobisphenol A, tetrabromoethane, tetrabromobutane, decabromobiphenyl ether, hexabromobiphenyl ether, pentabromoethylbenzene and others.

The amount of the halogen-containing flame retardant is preferably 5 to 200 parts by weight with respect to 100 parts by weight of the present composition. If the amount is less than 5 parts by weight, a substantial flame retardant effect cannot be expected, and if the amount is more than 200 parts by weight, a uniform foam cannot be obtained at the time of foam molding of the composition, and at times, gas escapes and almost no foaming occurs. It may not happen.

The amount of antimony trioxide is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the present composition.

Next, as a second method of making the open-cell type crosslinked ethylene resin foam of the present invention flame-retardant, a surface-treated metal hydroxide is added. Examples of the metal hydroxide used in the composition of the present invention include aluminum hydroxide, magnesium hydroxide and the like. These metal hydroxides contain water of crystallization, and at the combustion temperature of ethylene-based resin, the metal hydroxide thermally decomposes to release water of crystallization and absorb heat energy, which itself is a metal. It becomes an oxide and combines with the carbonized products on the surface of the burning resin to form a protective film that blocks the penetration of thermal energy and oxygen, and at the same time the water vapor released from the metal hydroxide is a combustible gas in the gas phase. It is said that the flame retarding action is promoted by the diluting effect of. Also,
These metal hydroxides are safe because they do not generate toxic gas or corrosive gas at high temperature.

The metal hydroxide used in the present invention is preferably surface-treated. If the surface treatment is not performed, voids occur due to poor compatibility between the metal hydroxide and ethylene resin during foam molding of the composition, and a uniform foam cannot be obtained. In some cases, foaming hardly occurs. As the surface treatment agent, a silicone coupling agent or a surfactant is used.

The metal hydroxide used in the present invention is preferably a powder having a particle size of 100 μm or less.

The amount of metal hydroxide was 10 parts by weight based on 100 parts by weight of the composition.
~ 200 parts by weight is desirable. If it is less than 10 parts by weight, a substantial flame retardant effect cannot be expected, and if it is more than 200 parts by weight, a uniform foam cannot be obtained at the time of foam molding of the composition, and at times, gas escapes and almost no foaming occurs. It may not happen.

In the present invention, the composition, if necessary, oxidation stabilizer, ultraviolet stabilizer, other inorganic fillers, pigments, other flame retardants,
Plasticizers, rubbers and the like can be added.

The open-cell type crosslinked ethylene resin foam can be produced by a single step of heating the composition, for example, a pellet, a powder or film, a sheet or other molded article, and heating and cooling the composition.

In the present invention, the temperature at which the composition is heated is equal to or higher than the temperature required for foaming and crosslinking, and specifically, it is between 120 and 300 ° C.

In the present invention, the decomposition temperature of the organic peroxide is shown as the temperature at which the half-life of the pure product is 10 minutes, so that crosslinking proceeds even below this temperature.

In the present invention, the heating time of the composition is the time required to produce a foam having open cells, and specifically 1 to
It is in the range of 60 minutes.

In the present invention, the structure is fixed by heating the composition and then cooling the foam. The cooling temperature is preferably 50 ° C or lower.

As a heating method, heating gas such as air, direct or indirect contact with a heated metal such as iron or aluminum, external heating by infrared rays, burners, electric heating, etc., as well as internal heating such as high frequency heating can be applied. .

Further, depending on the purpose, heating may be performed under normal pressure or under pressure.

Examples will be given below.

(Example) Example 1 Melt index 30, ethylene-vinyl acetate copolymer having a vinyl acetate content of 35 weight percent (manufactured by Nippon Unicar)
To 100 parts, 4 parts of azodicarbonamide type foaming agent "Celmic CAP" (foaming temperature 130 ° C: Sankyo Kasei), 1 part of dicumyl peroxide (decomposition temperature 150 ° C: made by NOF Corporation),
Polyethylene glycol (Molecular weight 20,000: Wako Pure Chemical Industries)
One part was kneaded with a roll mill at 70 ° C. for 40 minutes and pelletized.

The pellet was formed into a 0.2 mm thick sheet at 80 ° C. by a compression molding method. Pressure and time are 100kg / cm ² , 5 respectively
It was a minute. When this sheet was placed on a polyester sheet and placed in an oven at 180 ° C., it foamed uniformly in 5 minutes. When this foam was taken out and allowed to cool to room temperature, a white foam having a thickness of 0.7 mm and a cell size of 0.08 mm ± 0.02 mm and having soft and open cells with good feel was obtained. The apparent density of this foam was 0.30 g / cm ³ , and when it was made to absorb water, 1 cm ³ of the foam contained 0.62 g of water. This sheet is Sunshine Inn Weather Meter WE
Irradiated with L-SUN-HC (manufactured by Suga Test Instruments) for 450 hours,
The crack did not enter.

Example 2 Ethylene-vinyl acetate copolymer having a melt index of 20 and a vinyl acetate content of 28% by weight (manufactured by Nippon Unicar)
Was crushed to obtain a powder having an average particle size of 40 mesh. This powder
Azodicarbonamide-based foaming agent "Celmic CAP-149" (foaming temperature 125 ° C: Sankyo Kasei Co., Ltd.) 7 parts, t-butylperoxyisobutyl carbonate (decomposition temperature 135 ° C: Japan Oil and fat) 1 part, propylene glycol (diol type, molecular weight 20,000 Wako Pure Chemical Industries)
One part was stirred with a super mixer for 15 minutes and left for 1 day.

6g of this powder is put in a dish and placed in an oven at 180 ° C for 8
After heating for 1 minute and allowing to cool, the diameter is 7 cm and the thickness is 2 cm.
A foam having open cells of was obtained. The average cell diameter of this foam was 0.15 mm ± 0.03 mm.

Example 3 100 parts of an ethylene-ethyl acrylate copolymer having a melt index of 20 and an ethyl acrylate content of 20% by weight (manufactured by Nihon Unicar) was used, and an azodicarbonamide type foaming agent "Celmic CAP" (foaming temperature 130 ° C.) was used. : Sankyo Kasei)
8 parts of 4 parts, 1 part of dicumyl peroxide (decomposition temperature 150 ° C .: manufactured by NOF Corporation), 1 part of ethylene oxide-propylene oxide copolymer (molecular weight 10,000: manufactured by Union Carbide)
The mixture was kneaded with a roll mill at 0 ° C for 10 minutes and pelletized.

This pellet was compressed into a sheet having a thickness of 1 mm at 90 ° C. Pressure and time are 100kg / cm ² , 5 respectively
It was a minute. This sheet was placed on a wire mesh of 200 mesh, heated in an oven at 180 ° C for 7 minutes, and then allowed to cool. A white foam having a thickness of 3 mm and an average diameter of 0.3 mm, which had a soft feel and was flexible open cells I got a body.

Example 4 Melt index 5, ethylene-α with a density of 0.895 g / cm ³
Azodicarbonamide foaming agent "Celmic CAP5" for 100 parts of olefin copolymer (made by Union Carbide)
00 "(foaming temperature 150 ° C: Sankyo Kasei) 10 parts, perhexin 25B (decomposition temperature 170 ° C: made by NOF Corporation), 1 part polyethylene glycol (molecular weight 20,000: made by Wako Pure Chemical Industries) at 125 ° C with a Banbury mixer After kneading for 10 minutes, it was pelletized. This pellet was compression molded into a 2 mm thick sheet, placed on an aluminum plate, and placed in a pine oven at 200 ° C for 5 minutes.
After heating for a minute, it was taken out and allowed to cool. The obtained foam was a uniform void-free foam having a thickness of 8 mm and an average cell diameter of 0.20 mm and an apparent density of 0.25 g / cm ³ .

Comparative Example 1 In the same manner as in Example 1, 1 part of triallyl cyanurate and silicone oil L- were used instead of polyethylene glycol.
The bubble diameter of the foamed sheet obtained by adding 1 part of 45 (10CS: manufactured by Nippon Unicar) was 0.18 mm ± 0.03 mm.

Comparative Example 2 In the same manner as in Example 2, instead of polypropylene glycol, 1 part of triallyl cyanurate and silicone oil L were used.
The bubble diameter of the bubble sheet obtained by adding 1 part of −45 (10CS: made by Nippon Unicar) was 0.20 mm ± 0.03 mm.

Comparative Example 3 In the same manner as in Example 3, instead of the ethylene oxide-propylene oxide copolymer, triallyl cyanurate 1 was used.
Parts and silicone oil L-45 (10CS: Nippon Unicar) 1
The bubble diameter of the bubble sheet obtained by adding the parts was 0.60 mm.

Example 5 Melt index 30, ethylene-vinyl acetate copolymer having a vinyl acetate content of 35% by weight (manufactured by Nippon Unicar)
To 100 parts, 4 parts of azodicarbonamide type foaming agent "Celmic CAP" (foaming temperature 130 ° C: Sankyo Kasei), 1 part of dicumyl peroxide (decomposition temperature 150 ° C: made by NOF Corporation),
Polyethylene glycol (Molecular weight 20,000: Wako Pure Chemical Industries)
After kneading 1 part with a Banbury mixer at 80 ° C for 10 minutes,
Granular Crispearl (made by Nittetsu Mining Co., Ltd.) with a diameter of 3 mm and a length of 5 mm
Add 00 parts, knead for another 10 minutes, and press with a hot press.
The mixture was heated at 180 ° C. for 10 minutes and gradually cooled to room temperature over 1 hour to obtain a plate-shaped foam molded product having a thickness of 15 mm, a length of 550 mm, and a width of 580 mm. When this plate-shaped foam molded article was made to absorb water,
It contained 45 g of water per 0 g. The plate-shaped foamed product was dropped from the height of 1 m on the floor, but it was not damaged.

Example 6 100 parts of an ethylene-ethyl acrylate copolymer having a melt index of 20 and an ethyl acrylate content of 20 wt% (manufactured by Nippon Unicar) was used, and an azodicarbonamide-based foaming agent "Celmic CAP" (foaming temperature 130 ° C) was used. : Sankyo Kasei)
4 parts, dicumyl peroxide (decomposition temperature 150 ° C: made by NOF Corporation) 1 part, propylene glycol (diol type,
(Molecular weight 2,000: Wako Pure Chemical Industries, Ltd.) 1 part with a roll mill at 80 ℃
After kneading for 25 minutes, 25 parts by weight of builder clay (manufactured by Nittetsu Mining Co., Ltd.) having an average particle size of 1000 mesh was added, and the mixture was kneaded for 10 minutes, and pelletized.

This pellet was compressed into a sheet having a thickness of 1 mm at 90 ° C. Pressure and time are 100kg / cm ² , 5 respectively
It was a minute. This sheet was placed on a wire mesh of 200 mesh, heated in an oven at 180 ° C for 7 minutes, and then allowed to cool. As a result, a foam having a soft texture and a continuous open cell with a thickness of 3 mm and an average diameter of 0.3 mm was formed. Was obtained. The air permeability of this foam was 40 when the air passage speed of the B5 filter paper was 100. This foam was vacuum dried at room temperature for 24 hours, then placed in a desiccator and placed in an atmosphere with a relative humidity of 90%. After 24 hours, the weight of the foam increased by 8 g per 100 g of the foam. Similarly, when placed in an ammonia gas atmosphere, a weight increase of 60 mg per 100 g of the foam was observed after 24 hours. This foam could be easily cut with scissors.

Example 7 Melt index 5, ethylene-α with a density of 0.895 g / cm ³
Azodicarbonamide foaming agent "Celmic CAP5" for 100 parts of olefin copolymer (made by Union Carbide)
00 "(foaming temperature 150 ° C: Sankyo Kasei) 10 parts, Perhexin 25B (decomposition temperature 170 ° C: Nippon Oil & Fats) 1 part, ethylene oxide and propylene oxide (molecular weight 10,000: Union Carbide) 1 part with a bumper mixer 10 at 125 ° C
After kneading for 30 minutes, 30 parts by weight of builder clay having an average particle size of 50 mesh (manufactured by Nittetsu Mining Co., Ltd.) was added, and the mixture was kneaded for 10 minutes, and pelletized. The pellet was compression-molded into a sheet having a thickness of 2 mm, placed on an aluminum plate, heated in a pine oven at 200 ° C. for 5 minutes, taken out, and allowed to cool. The obtained foam was an open-cell type foam having a thickness of 8 mm and 0.30 g / cm ³ . This foam could be easily cut with scissors.

Comparative Example 4 In the same manner as in Example 6, the foam obtained without adding the builder clay was vacuum dried at room temperature for 24 hours, then placed in a desiccator and placed in an atmosphere having a relative humidity of 90%. After 24 hours, There was a weight gain of 1.5 g per 100 g of foam. Similarly, when placed in an ammonia gas atmosphere, a weight increase of 5 mg per 100 g of the foam was observed after 24 hours.

Example 8 Ethylene-vinyl acetate copolymer having a melt index of 30 and a vinyl acetate content of 35% by weight (manufactured by Nippon Unicar)
To 100 parts, 4 parts of azodicarbonamide type foaming agent "Celmic CAP" (foaming temperature 130 ° C: Sankyo Kasei), 1 part of dicumyl peroxide (decomposition temperature 150 ° C: made by NOF Corporation),
Polyethylene glycol (Molecular weight 20,000: Wako Pure Chemical Industries)
After mixing 1 part and 0.1 part of the antioxidant Irganox 1010 (manufactured by Ciba Geigy) with a Banbury mixer at 80 ° C for 10 minutes, paraffin chloride (40% chlorination: Wako Pure Chemical Industries) 15
By weight, 5 parts by weight of antimony trioxide (manufactured by Wako Pure Chemical Industries, Ltd.) were added, and the mixture was further kneaded for 10 minutes, and then a sheet having a thickness of 1 mm was formed by compression molding at 90 ° C. This sheet was placed on a polyester sheet and placed in an oven at 180 ° C., whereupon it foamed uniformly in 8 minutes. Take out this foam,
When left to cool to room temperature, it has a thickness of 3 mm and a bubble size of 0.2.
A mm open cell foam was obtained. The oxygen index of this foam was 26.

Example 9 100 parts of an ethylene-ethyl acrylate copolymer having a melt index of 20 and an ethyl acrylate content of 20% by weight (manufactured by Nippon Unicar) was used, and an azodicarbonamide-based foaming agent "Celmic CAP" (foaming temperature 130 ° C.) was used. : Sankyo Kasei)
4 parts, dicumyl peroxide (decomposition temperature 150 ° C: made by NOF Corporation) 1 part, propylene glycol (diol type,
(Molecular weight 2,000: Wako Pure Chemical Industries, Ltd.) 1 part and antioxidant Irganox 1010 (manufactured by Ciba Geigy) were kneaded with a roll mill at 80 ° C for 10 minutes, and then 12 parts by weight of decabromophenyl ether (manufactured by Hexel) and trioxide. 5 parts by weight of antimony (manufactured by Wako Pure Chemical Industries, Ltd.) was added and kneaded for 10 minutes, and pelletized. This pellet was compressed into a sheet having a thickness of 1 mm at 90 ° C. The pressure and time were 100 kg / cm ² and 5 minutes, respectively.

This sheet was placed on a wire mesh of 200 mesh, heated in an oven at 180 ° C for 7 minutes, and then allowed to cool. As a result, a foam having a soft texture and a continuous open cell with a thickness of 3 mm and an average diameter of 0.3 mm was formed. Was obtained. When it was made to absorb water, it contained 0.60 g of water per cm ³ . The air permeability of B5 filter paper was 40 when the air passage speed was 100. The oxygen index of this foam was 25.

Example 10 Melt index 5, ethylene-α with a density of 0.895 g / cm ³
Azodicarbonamide foaming agent "Celmic CAP5" for 100 parts of olefin copolymer (made by Union Carbide)
00 "(foaming temperature 150 ° C: Sankyo Kasei) 10 parts, Perhexin 25B (decomposition temperature 170 ° C: manufactured by NOF CORPORATION), copolymer of ethylene oxide and propylene oxide (molecular weight 10,0
00: Union Carbide) 1 part and antioxidant Irganox 1010 (Ciba Geigy) 0.1 part were kneaded with a Banbury mixer at 125 ° C. for 10 minutes, then Fire Card 2000 (brominated aromatic compound, Teijin Kasei) 15 weight Parts and 5 parts by weight of antimony trioxide (manufactured by Wako Pure Chemical Industries, Ltd.) were added and kneaded for 10 minutes, and pelletized. The pellet was compression-molded into a sheet having a thickness of 2 mm, placed on an aluminum plate, heated in a pine oven at 200 ° C. for 5 minutes, taken out, and allowed to cool. The resulting foam has a thickness of 8 mm
It was an open-cell type foam. When it absorbs water, 1 cm
^It contained 0.65 g of water per ³ . The oxygen index of this foam is
It was 26.

Comparative Example 5 The oxygen index of the foam obtained in the same manner as in Example 8 except that paraffin chloride and antimony trioxide were not used was 17.

Example 11 Melt index 30, ethylene-vinyl acetate copolymer having a vinyl acetate content of 35 weight percent (manufactured by Nippon Unicar)
To 100 parts, 4 parts of azodicarbonamide type foaming agent "Celmic CAP" (foaming temperature 130 ° C: Sankyo Kasei), 1 part of dicumyl peroxide (decomposition temperature 150 ° C: made by NOF Corporation),
Polyethylene glycol (Molecular weight 20,000: Wako Pure Chemical Industries)
After kneading 1 part and 0.1 part of the antioxidant Irganox 1010 (manufactured by Ciba Geigy) with a Banbury mixer at 80 ° C. for 10 minutes, the surface was treated with a silicone coupling agent A-174 (manufactured by Nippon Unicar) with an average particle size of 0.7 μ. After adding 60 parts of magnesium hydroxide (manufactured by Kyowa Chemical Industry Co., Ltd.) and kneading for 10 minutes, a sheet having a thickness of 1 mm was formed by compression molding at 90 ° C. This sheet was placed on a polyester sheet and placed in an oven at 180 ° C., whereupon it foamed uniformly in 8 minutes. When this foam was taken out and allowed to cool to room temperature, an open-cell foam having a diameter of 3 mm and a cell size of 0.2 mm was obtained. The oxygen index of this foam was 23.

Example 12 100 parts of an ethylene-ethyl acrylate copolymer having a melt index of 20 and an ethyl acrylate content of 20% by weight (manufactured by Nippon Unicar Co., Ltd.) was used as an azodicarbonamide-based foaming agent "Celmic CAP" (foaming temperature 130 ° C). : Sankyo Kasei)
4 parts, dicumyl peroxide (decomposition temperature 150 ° C: made by NOF Corporation) 1 part, propylene glycol (diol type,
Molecular weight 2,000: Wako Pure Chemical Industries, Ltd.) 1 part and antioxidant Irganox 1010 (manufactured by Ciba Geigy) 0.1 part were kneaded with a roll mill at 80 ° C. for 10 minutes, and then hydroxylated with an average particle size of 6 μm and surface-treated with sodium oleate. 60 aluminum
What was added by weight and kneaded for 10 minutes was pelletized. This pellet was compressed into a sheet having a thickness of 1 mm at 90 ° C. Pressure and time are 100kg / cm ² respectively
And 5 minutes.

This sheet was placed on a wire mesh of 200 mesh, heated in an oven at 180 ° C for 7 minutes, and then allowed to cool. As a result, a foam having a soft texture and a continuous open cell with a thickness of 3 mm and an average diameter of 0.3 mm was formed. Was obtained. When it was made to absorb water, it contained 0.60 g of water per cm ³ . The air permeability of B5 filter paper was 40 when the air passage speed was 100. The oxygen index of this foam was 23.

Example 13 Melt index 5, ethylene-α with a density of 0.895 g / cm ³
Azodicarbonamide foaming agent "Celmic CAP5" for 100 parts of olefin copolymer (made by Union Carbide)
00 "(foaming temperature 150 ° C: Sankyo Kasei) 10 parts, copolymer of ethylene oxide and propylene oxide (molecular weight 10,0
00: Union Carbide) 1 part and antioxidant Irgatnox 1010 (Ciba Geigy) 0.1 part were kneaded with a Banbury mixer at 125 ° C for 10 minutes, and then the average particle size was 0.7μ.
Then, 60 parts of magnesium hydroxide (manufactured by Kyowa Chemical Industry Co., Ltd.) surface-treated with the silicone coupling agent A-174 (manufactured by Nippon Unicar) was added, and the mixture was kneaded for 10 minutes to form a pellet. The pellet was compression-molded into a sheet having a thickness of 2 mm, placed on an aluminum plate, heated in a pine oven at 200 ° C. for 5 minutes, taken out, and allowed to cool. The obtained foam was an open-cell type foam having a thickness of 8 mm. When it was made to absorb water, it contained 0.65 g of water per cm ³ . The oxygen index of this foam was 23.

Comparative Example 6 Magnesium hydroxide which had not been surface-treated was used for heating in an oven in the same manner as in Example 11, but the gas was exhausted and no foam was obtained.

Comparative Example 7 The foam obtained in the same manner as in Example 11 except that magnesium hydroxide was not used had an oxygen index of 17.

(Effect of the Invention) According to the present invention, it is possible to obtain a foam that is more supple, more supple, and more excellent in texture and touch than the open-cell crosslinked ethylene resin foam produced by JP-B-60-49657. It is possible to obtain a composition for producing, further substantially retain the adsorption and desorption effect of the silica-based porous material, and to mold the powder or pellet of the silica-based porous material into a certain shape or various It is possible to obtain a composite material that can be cut into the shape of, and a continuous-cell type crosslinked ethylene-based resin foam with flame retardancy imparted by a halogen-containing flame retardant or a surface-treated metal hydroxide. The body can be manufactured.

Claims (3)

[Claims] 1. An ethylene resin 100 parts by weight, a foaming agent 1 to 30.
1 part or 2 or more compounds selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide are added to a cross-linked foaming composition consisting of 1 part by weight and 0.2 to 10 parts by weight of an organic peroxide as a cross-linking agent. 0.1 to 10 parts by weight, and the 10-minute half-life temperature (Tp) of the organic peroxide is 100 to 220 ℃,
A composition for an open-cell type crosslinked ethylene-based resin foam characterized in that the foaming temperature (Tf) of the foaming agent is 90 to 220 ° C. and the following formula −10 ° C. ≦ Tp−Tf ≦ 50 ° C. is satisfied. object. 2. 100 parts by weight of an ethylene resin, a foaming agent 1 to 30
1 part or 2 or more compounds selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide are added to a cross-linked foaming composition consisting of 1 part by weight and 0.2 to 10 parts by weight of an organic peroxide as a cross-linking agent. Add 1 to 3000 parts by weight of the silica-based porous material to 100 parts by weight of the composition prepared by adding 0.1 to 10 parts by weight, and the 10-minute half-life temperature (Tp) of the organic peroxide is 10 parts by weight.
0 ~ 220 ℃, foaming temperature (Tf) of foaming agent is 90 ~ 220 ℃
A composition for an open-cell type crosslinked ethylene resin foam containing a silica porous material, characterized in that the following formula −10 ° C. ≦ Tp−Tf ≦ 50 ° C. is satisfied. 3. Ethylene resin 100 parts by weight, blowing agent 1-30
1 part or 2 or more compounds selected from polyethylene glycol, polypropylene glycol or a copolymer of ethylene oxide and propylene oxide are added to a cross-linked foaming composition consisting of 1 part by weight and 0.2 to 10 parts by weight of an organic peroxide as a cross-linking agent. A combination of 5 to 200 parts by weight of a halogen-containing flame retardant and 1 to 50 parts by weight of antimony trioxide with respect to 100 parts by weight of a composition obtained by adding 0.1 to 10 parts by weight, or a surface-treated metal hydroxide 1 ~ 200 parts by weight, the 10-minute half-life temperature (Tp) of the organic peroxide is 100-220 ° C, and the foaming temperature (Tf) of the blowing agent is 90-220 ° C. A flame-retardant open-cell crosslinked ethylene resin foam composition, characterized by satisfying the following formula: −10 ° C. ≦ Tp−Tf ≦ 50 ° C.