JP2005200579A - Polyolefin-based resin composition and method for producing polyolefin-based resin foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyolefin-based resin composition, in which occurrence of a foreign matter is suppressed, enabling stable production for a long time, making a curing step such as heat treatment unnecessary and excellent in productivity in production of a polyolefin-based resin foam and to provide a method for producing the polyolefin-based resin foam by using the resin composition. <P>SOLUTION: The method for producing the polyolefin-based resin foam comprises reacting a polyolefin-based resin composition comprising 100 pts. wt. resin component mainly composed of a polyolefin-based resin, 0.05-5 pts. wt. quinone dioxime compound and a polyfunctional acrylic monomer in an amount of 50-200 wt.% based on the quionedioxime compound while melt-kneading the resin composition to modify the resin component, adding a heat composition type chemical foaming agent to the modified resin component and heating the resultant foaming resin composition to a temperature not lower than decomposition temperature of the foaming agent to expand the resin composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyolefin resin composition and a method for producing a polyolefin resin foam using the same.

  Polyolefin resin foams such as polyethylene and polypropylene are excellent in lightness, heat insulation, flexibility, etc., and thus various studies have been made as suitable materials widely used for various heat insulating materials, cushioning materials, levitation materials, and the like. .

  For example, Patent Document 1 describes a method for producing a polyolefin resin foamable composite sheet using a polyolefin resin, an oxime compound, an acrylic compound, and the like. A polyolefin resin, a dioxime compound, a bismaleimide compound, allyl A modification monomer selected from the group consisting of a polyfunctional monomer, a (meth) acrylic polyfunctional monomer, a quinone compound, and a combination of two or more of these, and modifying the resin, The resulting modified resin is kneaded with a pyrolytic chemical foaming agent, the resulting foamable resin composition is shaped into a sheet, and the resulting foamable resin sheet is heated on at least one side. Polyolefin-based resin foaming property, characterized by laminating sheet-like materials having strength capable of suppressing foaming in the in-plane direction when foaming Discloses such method of manufacturing a case sheet, the obtained modified resin are also disclosed process for producing a polyolefin resin foam composite sheet to blend this same type or unmodified polyolefin resin heterologous. By these methods, a polyolefin resin foamable composite sheet having both foamability and moldability can be produced.

  On the other hand, Patent Document 2 discloses a step of obtaining a partially crosslinked polypropylene resin by melting and mixing a composition containing a polypropylene resin, an organic peroxide, and an oxime compound, and a polypropylene resin containing the partially crosslinked polypropylene resin. A polypropylene-based resin foam comprising a step of supplying a mixed composition and a volatile foam to an extruder to obtain a uniform molten mixture, and a step of foaming the molten mixture while being extruded from the extruder into a low-pressure zone A manufacturing method is disclosed. In this method, a polypropylene resin foam excellent in closed cell properties can be produced.

  Further, Patent Document 3 discloses that in a method of modifying a crystalline polypropylene with an organic peroxide and a crosslinking aid to obtain a modified polypropylene, diacrylate and / or triacrylate as an organic peroxide and the crosslinking aid. The melt tension (MS) and the intrinsic viscosity [η] satisfy a specific relationship, and the boiling xylene extraction residual ratio is within a specific range, characterized in that A method for producing a modified polypropylene is disclosed. In this method, a polypropylene resin composition excellent in melt tension can be obtained.

Japanese Patent No. 3117678 Japanese Examined Patent Publication No. 4-64536 JP-A-7-304815

  However, according to the study of the present inventor, in the method of Patent Document 1, when a quinonedioxime compound is used as a modification monomer, good foamability is obtained due to its high reactivity, When a large amount of phenylenediamine is generated, the mold is likely to be clogged during shaping, or blackening due to adhesion to the roll is likely to occur, and it is difficult to stably produce for a long time. there were. In addition, when an acrylic polyfunctional monomer is used as the modifying monomer, the modification ability of the polyolefin resin is likely to be insufficient, and the melt tension of the resin to ensure foamability is less likely to be exhibited. There is a problem that it is difficult to produce a foam having a magnification, and in order to ensure sufficient foamability, a curing process with hot water or the like may be required for the obtained sheet. In some cases, the productivity is remarkably lowered, for example, it is necessary to perform heating for about 5 to 20 minutes in the vicinity of ° C.

  In relation to the above, Patent Document 2 discloses that a quinone dioxime compound is used as an oxime compound, a melt elastic modulus of a polypropylene resin is improved, and 1, 1, 2, 2-tetrafluorodichloroethane is used as a volatile foaming agent. Although it is described that the foamability is improved and a good closed cell ratio is obtained, according to the study of the present inventor, since a large amount of phenylenediamine that causes foreign matters is generated as described above, There was a problem that it was difficult to produce stably.

  Patent Document 3 describes that a modified polypropylene excellent in melt tension is obtained by heat treatment at a temperature of 180 to 300 ° C. using an acrylic monomer as a modification aid. As long as a process is required, there is a problem that productivity is remarkably lowered as described above.

  The object of the present invention is to solve the above-mentioned problems, and in the production of polyolefin resin foams, the generation of foreign substances is suppressed and production can be performed stably for a long time, and a curing process such as heat treatment is not required and the productivity is increased. Another object of the present invention is to provide a polyolefin resin composition excellent in the above and a method for producing a polyolefin resin foam using the same.

  The polyolefin resin composition according to claim 1, wherein 100 parts by weight of a resin component mainly composed of a polyolefin resin, 0.05 to 5 parts by weight of a quinonedioxime compound, and 50 to 50 parts by weight of the quinonedioxime compound. It is characterized by comprising 200% by weight of a polyfunctional acrylic monomer.

  According to a second aspect of the present invention, there is provided a method for producing a polyolefin-based resin foam, wherein the polyolefin-based resin composition according to the first aspect is reacted while being melt-kneaded to modify a resin component, and the modified resin component is thermally decomposed by chemical foaming. The resulting foamable resin composition is heated to a temperature equal to or higher than the decomposition temperature of the foaming agent and foamed.

Hereinafter, the present invention will be described in detail.
The polyolefin resin as the main component of the resin component in the present invention is not particularly limited as long as it is a homopolymer of an olefin monomer or a copolymer containing the same as a main component. Polyethylene such as high-density polyethylene and linear low-density polyethylene, propylene homopolymer, propylene random polymer, propylene block polymer and other polypropylene, polybutene, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer, Examples of the copolymer include ethylene-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer and other ethylene-based copolymers. Among them, polyethylene and polypropylene are preferably used. These polyolefin resin may be used independently and 2 or more types may be used together.

  In the present invention, the resin component refers to a resin composition in which the proportion of the polyolefin resin is 70 to 100% by weight. Resins other than the polyolefin resin constituting the resin component are not limited, and examples thereof include polystyrene and styrene elastomer. If the proportion of the polyolefin resin in the resin component is less than 70% by weight, not only the light weight, chemical resistance, flexibility, elasticity, etc. that are characteristic of the polyolefin resin can be exhibited, but also the melt viscosity necessary for foaming is secured. This is not preferable because it may be difficult. Resins other than the polyolefin-based resin may be used alone or in combination of two or more.

  The quinonedioxime compound in the present invention is not particularly limited as long as it is a compound having two oxime groups (including one in which a hydrogen atom bonded to an oxygen atom is substituted with another atomic group) having a benzene ring as a nucleus. Examples thereof include p-quinone dioxime and p, p-dibenzoylquinone dioxime. The quinone dioxime compound can be used in combination of two or more.

The polyfunctional acrylic monomer used in the present invention means a compound having two or more (meth) acryloyloxy groups [sometimes referred to as (meth) acrylic groups] in the molecule. For example, (meth) acryloyl As compounds having two oxy groups, alkanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, ethylene glycol adduct di (meth) acrylate of bisphenol A, propylene glycol adduct di (meth) acrylate of bisphenol A Examples of the compound having three acryloyloxy groups include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane ethylene oxide-added tri (meth) acrylate, glycerin propylene oxide-added tri (Meth) acrylate, tri (meth) acryloyloxyethyl phosphate, and the like. Examples of the compound having four (meth) acryloyloxy groups include pentaerythritol tetra (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate. Can be mentioned. The said polyfunctional acrylic monomer may be used independently and 2 or more types may be used together.
The above “(meth) acryloyloxy group” means “acryloyloxy group” or “methacryloyloxy group”, and “(meth) acrylic group” means “acrylic group” or “methacrylic group”. To do.

  The composition of the polyolefin resin composition of the present invention is 0.05 to 5 parts by weight of the quinonedioxime compound with respect to 100 parts by weight of the resin component, and the polyfunctional acrylic monomer is the quinonedioxime compound. The amount is 50 to 200% by weight.

  In the above, when the amount of the quinonedioxime compound is less than 0.05 parts by weight, the reactivity when modifying the polyolefin resin becomes insufficient, and it becomes difficult to obtain a good foam. On the other hand, when the amount exceeds 5 parts by weight, phenylenediamine causing foreign matter is likely to be generated, the resin viscosity becomes excessive, and shaping by extrusion or the like becomes difficult.

  Further, when the polyfunctional acrylic monomer is less than 50% by weight or more than 200% by weight based on the quinonedioxime compound, in any case, the reactivity when modifying the polyolefin resin (hereinafter referred to as “modified”). The effect ”is also insufficient, and it becomes difficult to obtain a good foam. That is, since a sufficient modification effect is exhibited only when the polyfunctional acrylic monomer is 50 to 200% by weight with respect to the quinonedioxime compound, the quinonedioxime compound is contained in a small amount (100 parts by weight of the resin component). Even if it is 0.05 to 5 parts by weight), it becomes possible to obtain a good foam, and it is possible to produce stably for a long time with little generation of foreign matter. Although this effect is not necessarily clear, it is presumed that components that do not contribute to denaturation bleed out.

  The method for producing a polyolefin resin foam using the polyolefin resin composition of the present invention is not particularly limited. For example, the resin component is modified by reacting while melting and kneading the polyolefin resin composition, A method in which a thermally decomposable chemical foaming agent is added to the modified resin component and the resulting foamable resin composition is heated to a temperature equal to or higher than the decomposition temperature of the foaming agent or foamed, or volatilized in the modified resin component. Examples thereof include a method in which a foaming agent composition is added and foamed while shaping the obtained foamable resin composition.

  Among these, the former method using a pyrolytic chemical foaming agent is preferable in that it is easy to control foaming properties depending on heating conditions.

The volatile foaming agent is not particularly limited, and examples thereof include hydrocarbons such as propane, butane, pentane, and hexane, methyl chloride, ethylene chloride trichlorofluoromethane, dichlorofluoromethane, difluorochloromethane, and 1, 1.2. -Halogenated carbons such as 2-tetrafluorodichloroethane, 1,1,2-trifluorotrichloroethane, or inert gases such as CO ₂ and N ₂ .

  The pyrolytic chemical foaming agent is not particularly limited, and examples thereof include azodicarbonamide (ADCA), benzenesulfonyl hydrazide, dinitrosopentamethylenetetramine, toluenesulfonyl hydrazide, and 4,4-oxybis (benzenesulfonyl hydrazide). Among them, ADCA is more preferably used. These pyrolytic chemical foaming agents may be used alone or in combination of two or more.

  As a method for modifying the resin component, for example, a method in which the resin component, a quinonedioxime compound, and a polyfunctional acrylic monomer are charged into a kneading apparatus such as a screw extruder or a kneader and melt-kneaded is employed. This melt-kneading temperature is 170 ° C. or higher and below the decomposition temperature of the polyolefin resin, and preferably 200 ° C. to 250 ° C. If the melt-kneading temperature is less than 170 ° C., the resulting resin tends to be insufficiently modified, and if it exceeds 250 ° C., the polyolefin resin tends to be decomposed.

  When using a thermally decomposable chemical foaming agent, the foamable resin composition may be produced, for example, by adding a thermally decomposable chemical foaming agent to the modified resin component, at a temperature at which the foaming agent does not decompose, and the resin. Examples thereof include a method for producing a foamable resin composition by kneading within a melting temperature range.

  The obtained expandable resin composition is kneaded by an apparatus such as a screw extruder or a kneader, and then shaped into a predetermined shape by a mold, a press or the like and heated and foamed. The temperature during the kneading and shaping is preferably 150 to 200 ° C, more preferably 160 to 185 ° C. The temperature at the time of foaming is usually within a temperature range from a temperature higher than the decomposition temperature of the thermal decomposition type chemical blowing agent to a temperature lower than the thermal decomposition temperature of the polyolefin resin.

  For example, a sheet-like shaped body (hereinafter also referred to as “foamable sheet”) obtained by shaping the foamable resin composition in the above is heated to a temperature equal to or higher than the decomposition temperature of the foaming agent. It is preferably carried out using a continuous foaming apparatus. The foaming method using the continuous foaming apparatus is not particularly limited. For example, a take-up foaming machine that continuously foams the foamable sheet while taking the sheet at the outlet side of the heating furnace, A method of foaming using a belt-type foaming machine, a vertical foaming furnace, a horizontal foaming furnace, a hot air thermostat, or a method of foaming in a hot bath such as an oil bath, a metal bath, a salt bath, etc. Can be mentioned.

  When foaming is performed using a volatile foaming agent, for example, in the above-described method for modifying a resin component, the resin component, the quinone dioxime compound, and the polyfunctional acrylic monomer are extruded and melted using a screw extruder. A method in which the volatile foaming agent is injected under pressure from a pressure inlet provided in the middle of the machine and foamed while being extruded under low pressure is suitable.

  The polyolefin resin composition of the present invention comprises 100 parts by weight of a resin component mainly composed of a polyolefin resin, 0.05 to 5 parts by weight of a quinone dioxime compound, and 50 to 200 parts by weight based on the quinone dioxime compound. % Of polyfunctional acrylic monomer, so that the production of polyolefin resin foam can suppress the generation of foreign substances and can be produced stably for a long time, and no curing process such as heat treatment is required. It will be excellent in productivity.

  Further, the method for producing a polyolefin resin foam of the present invention comprises modifying the resin component by reacting while melting and kneading the polyolefin resin composition, and adding a pyrolytic chemical foaming agent to the modified resin component. The foamable resin composition obtained is characterized in that it is heated to a temperature equal to or higher than the decomposition temperature of the foaming agent and foamed. It is possible to provide a method for producing a polyolefin resin foam excellent in productivity without requiring a curing step such as heat treatment.

The present invention will be specifically described below by showing examples and comparative examples.
In addition, this invention is not limited only to the following Example.
(Example 1)
Preparation and modification of polyolefin resin composition As a screw extruder for reaction, BT40 (manufactured by Plastics Engineering Laboratory Co., Ltd.) co-rotating twin screw extruder was used. This is equipped with a self-wiping double thread, L / D is 35 and D is 39 mm. The cylinder barrel is composed of first to fourth barrels from the upstream side to the downstream side of the extruder, the die is a three-hole strand die, and a vacuum vent is installed in the fourth barrel to collect volatile components.

The operating conditions are as follows.
・ Screw rotation speed: 200rpm
・ Cylinder barrel set temperature: 1st barrel; 180 ℃
2nd barrel; 220 ° C
3rd barrel; 220 ° C
4th barrel; 220 ° C
Die: 220 ° C

  First, the polyolefin resin and the quinone dioxime compound are separately fed from the rear end hopper to the reaction screw extruder having the above-described configuration with a screw feeder, and the polyfunctional acrylic monomer is injected into the extruder with a metering pump. A polyolefin resin composition comprising a polyolefin resin, a quinonedioxime compound, and a polyfunctional acrylic monomer is reacted while melt-mixed in the extruder to modify the polyolefin resin, and the resin modified in the extruder A component (hereinafter also referred to as “modified resin composition”) was obtained. At this time, the volatile matter generated in the extruder was evacuated by a vacuum vent.

The polyolefin resin was a polypropylene random copolymer (“EG8” manufactured by Mitsubishi Chemical Corporation, MI; 0.8 g / 10 min, density: 0.9 g / cm ³ ), and the supply amount was 10 kg / h.

  The quinone dioxime compound was p-quinone dioxime (“Barunok GM-P” manufactured by Ouchi Shinsei Chemical Co., Ltd.), and its supply amount was 0.8 parts by weight with respect to 100 parts by weight of the polyolefin resin.

  The polyfunctional acrylic monomer was trimethylolpropane trimethacrylate (trifunctional acrylic monomer TMPTMA, manufactured by Kyowa Kasei Co., Ltd.), and the supply amount thereof was the same as that of the quinonedioxime compound.

  The modified resin composition obtained in the extruder as described above was discharged from a strand die attached to the extruder, cooled with water, and cut with a pelletizer to obtain pellets of the modified resin composition.

Preparation of foamable resin sheet The screw extruder for foaming agent kneading is a TEX-44 type (manufactured by Nippon Steel Works) co-rotating twin screw extruder, which is equipped with a self-wiping twin screw and its L / D Is 45.5 and D is 47 mm. The cylinder barrel is composed of 1st to 12th barrels from the upstream side to the downstream side of the extruder, and the forming die is a 7-hole strand die.

The temperature setting categories are as follows.
1st barrel is always cooled 1st zone; 2nd to 4th barrel 2nd zone; 5th to 8th barrel 3rd zone; 9th to 12th barrel 4th zone; Die and adapter part

  A side feeder is installed in the sixth barrel for supplying the foaming agent, and a vacuum vent is installed in the eleventh barrel for recovering volatile components.

The operating conditions are as follows.
-Screw rotation speed: 40rpm
・ Cylinder barrel set temperature: 1st zone; 150 ℃
Second zone: 170 ° C
Third zone: 180 ° C
Zone 4; 160 ° C

The pellet of the modified resin composition obtained as described above and an unmodified polypropylene random copolymer (“EG7” manufactured by Mitsubishi Chemical, MI; 1.2 g / 10 min, density: 0.9 g / cm ³ ) Were dry blended at a weight ratio of 1: 1 and fed to a foam extruder kneading screw extruder. The pellet supply rate was 20 kg / h. Moreover, the foaming agent was supplied to the same extruder from the side feeder and dispersed. The blowing agent was azodicarbonamide (ADCA), and the supply amount was 1.2 kg / h.

  The foamable resin composition obtained in the extruder by kneading the modified resin component and the foaming agent is discharged from a T die attached to the extruder, shaped into a sheet using a cooling roll, and the width A foamable resin sheet having a thickness of 1000 mm and a thickness of 0.6 mm was obtained.

Preparation of resin foam A square sample with a side of 100 mm was cut out from the obtained foamable resin sheet and foamed on a stainless steel vat with foam talc laid under a hot air oven at 220 ° C to obtain a polypropylene resin foam. Obtained.

Performance evaluation In the above, the following performance evaluation was performed.
(Extrusion operability)
In order to evaluate whether or not stable production is possible for a long time, in the adjustment of the foamable resin sheet, the time from the start of extrusion to the break of the sheet due to the generation of foreign matters was measured.
(Foaming)
About the resin foam obtained by the above, the expansion ratio was measured based on JISK6767.

(Example 2)
In obtaining the modified resin composition, the same as Example 1 except that the supply amount of trimethylolpropane trimethacrylate as a polyfunctional acrylic monomer was 0.6 parts by weight (75% by weight with respect to the quinonedioxime compound). Then, a resin foam was prepared, and extrusion operability and foamability were evaluated.

(Comparative Example 1)
In obtaining the modified resin composition, the resin foaming was carried out in the same manner as in Example 1 except that the polyfunctional acrylic monomer was not used and the supply amount of P-quinonedioxime as the quinonedioxime compound was 1.6 parts by weight. A body was prepared, and extrusion operability and foamability were evaluated.

(Comparative Example 2)
In obtaining a modified resin composition, a resin foam was prepared in the same manner as in Example 1 except that 2 parts by weight of trimethylolpropane trimethacrylate was used as a polyfunctional acrylic monomer without using a quinonedioxime compound. Extrusion operability and foamability were evaluated.
The evaluation results are shown in Table 1.

(Example 3)
As a reaction screw extruder, BT40 (Plastics Engineering Laboratory Co., Ltd.) co-rotating twin screw extruder was used. This is equipped with a self-wiping double thread, L / D is 35 and D is 39 mm.

The operating conditions are as follows.
・ Screw rotation speed: 200rpm
・ Cylinder barrel set temperature: 1st barrel; 180 ℃
2nd barrel; 220 ° C
3rd barrel; 200 ° C
4th barrel; 180 ° C
Die: 150 ° C

  First, the polyolefin resin and the quinone dioxime compound are separately fed from the rear end hopper to the reaction screw extruder having the above-described configuration with a screw feeder, and the polyfunctional acrylic monomer is injected into the extruder with a metering pump. A polyolefin resin composition composed of a polyolefin resin, a quinonedioxime compound, and a polyfunctional acrylic monomer is reacted while being melted and mixed in an extruder to modify the polyolefin resin, and the modified resin composition in the extruder The foamable resin composition obtained in the extruder by injecting a volatile foaming agent through a press-fitting hole provided in the middle of the extruder and further kneading the modified resin composition and the foaming agent Discharge from a one-hole nozzle-shaped die (φ5mm, length 50mm) attached to the extruder, and release by pressure release after discharge It is to obtain a polyolefin resin foam.

The polyolefin resin is a polypropylene random copolymer (“EG8” manufactured by Mitsubishi Chemical, MI; 0.8 g / 10 min, density; 0.9 g / cm ³ , melting point 143 ° C.), and the supply amount thereof is 10 kg / h. did.

  The quinone dioxime compound is p-quinone dioxime ("Barunok GM-P" manufactured by Ouchi Shinsei Chemical Co., Ltd.), and its supply amount is 0.4 with respect to 100 parts by weight of the resin component mainly composed of polyolefin resin. Part by weight.

  The polyfunctional acrylic monomer was trimethylolpropane trimethacrylate (trifunctional acrylic monomer TMPTMA, manufactured by Kyowa Kasei Co., Ltd.), and the supply amount thereof was the same as that of the quinonedioxime compound.

  The volatile foaming agent is 1,1,2,2-tetrafluorodichloroethane, and its supply amount is 20 parts by weight with respect to 100 parts by weight of the resin component mainly composed of polyolefin resin, and the supply pressure is 5.9 MPa. It was.

As a result of performing the following performance evaluation on the obtained resin foam, the expansion ratio was 25, the closed cell ratio was 80%, and the continuous extrusion time was 10 hours.
(Foaming)
About the resin foam obtained by the above, the expansion ratio was measured based on JISK6767.
(Closed cell rate)
It measured using the air comparison type hydrometer 1000 type | mold (made by Tokyo Science company).
(Continuous extrusion time)
In order to evaluate whether it can be stably produced for a long time, the time from the start of extrusion until the formation of a good foam due to the generation of foreign matter was measured.

(Comparative Example 3)
Instead of the quinonedioxime compound, the following mixture was used, and the supply amount was 4 parts by weight with respect to 100 parts by weight of the resin component mainly composed of a polyolefin resin, and a polyfunctional acrylic monomer was used. A foam was produced in the same manner as in Example 3 except that there was no.
(Mixture composition)
Quinone dioxime: 0.8 part by weight Organic peroxide (DCP): 0.1 part by weight extender [Polyolefin resin (“EG8” manufactured by Mitsubishi Chemical Corporation) molded product): 3.1 parts by weight

  As a result of performing the same performance evaluation as in Example 3 on the obtained resin foam, the foaming ratio was 25 and the closed cell ratio was 80%, but the continuous extrusion time was 4 hours, and when it exceeded 4 hours, the black gel As a result, a good foam could not be produced.

Example 4
The melt tension (MS) of the pellet of the modified resin composition (p-quinonedioxime 0.8 parts by weight) prepared in Example 1 was measured using a melt tension tester (“Capillary rheometer” manufactured by Toyo Seiki Seisakusho). did. The measurement conditions were a nozzle diameter of 2.095 mm, a measurement temperature of 230 ° C., a discharge speed from the nozzle of 20 mm / min, an air gap of 35 cm, and a take-off speed of 3.14 m / min. As a result, the melt tension was 4.1 g.

(Comparative Example 4)
The following mixture was used in place of the quinonedioxime compound, and the supply amount was 7.1 parts by weight with respect to 100 parts by weight of the polyolefin resin, and no polyfunctional acrylic monomer was used. A foam was produced in the same manner as in Example 1.
(Mixture composition)
2,5-dimethyl-2,5-di (t-butylperoxy) -hexane: 0.01 part by weight 1,6-hexanediol acrylate: 0.7 part by weight extender [polyolefin resin (manufactured by Mitsubishi Chemical Corporation) “EG8”) pulverized molded product]: 6.39 parts by weight

  The melt tension of the pellet of the modified resin composition prepared in Comparative Example 4 was measured in the same manner as in Example 4. As a result, the melt tension of the modified resin was 2.3 g.

As described above, in the examples of the present invention, it has been found that the extrudability and foamability are excellent, and it has a high closed cell ratio, a long continuous extrusion time, and a high melt tension level. In the production of polyolefin resin foams, it has been found that the generation of foreign matters is suppressed and production can be performed stably for a long time.

Claims (2)

  100 parts by weight of a resin component mainly composed of a polyolefin-based resin, 0.05 to 5 parts by weight of a quinonedioxime compound, and 50 to 200% by weight of a polyfunctional acrylic monomer based on the quinonedioxime compound. A polyolefin-based resin composition characterized by that. The polyolefin resin composition according to claim 1 is reacted while melt-kneaded to modify the resin component, a pyrolytic chemical foaming agent is added to the modified resin component, and the resulting foamable resin composition is A method for producing a polyolefin-based resin foam, wherein the foam is heated to a temperature equal to or higher than a decomposition temperature of a foaming agent.