JP5726505B2 - Resin foam, cylindrical body, molded body - Google Patents

Description

  The present invention relates to a resin foam that is optimal for covering and insulating a copper pipe.

  Resin foam is a material widely used in the field of heat insulation for piping of air conditioning equipment and heat insulation for preventing freezing of water pipes.

  However, it has been found that a thermoplastic resin foam sheet or molded article using azodicarbonamide as a pyrolytic chemical foaming agent contains a residual ammonia concentration of about 1500 to 3000 ppm (mass basis).

  On the other hand, when copper pipes are used for piping, depending on the usage environment and period of use, corrosion may occur due to residual ammonia derived from the resin foam from the outer surface of the copper pipes in 5 to 20 years. There was a problem of developing and causing great damage.

  A method of obtaining a thermoplastic resin composition for foam molding without ammonia odor by adding burned alum to a resin foam (see Patent Document 1), or a method of suppressing the generation of crystals in a fogging test is disclosed (Patent) Reference 2).

Japanese Patent Laid-Open No. 06-345888 JP 2008-156620 A

  The inventions described in Patent Documents 1 and 2 which disclose a method for obtaining a thermoplastic resin composition for foam molding without ammonia odor and a method for suppressing the generation of crystals in a fogging test are excellent in heat retaining performance and can be easily molded. It was difficult to obtain a foam stably.

  The present invention employs the following means in order to solve such problems. That is, the resin foam is characterized in that it contains at least calcined alum as an ammonia adsorbent in the resin foam, can be easily molded with excellent heat retention performance, and does not cause copper corrosion.

The above object of the present invention has been basically achieved by the following invention. That is, the present invention is as follows.
1) A resin foam which is a crosslinked foam having an apparent density of 20 to 40 kg / m ³ and an ammonia concentration of 200 ppm to 1000 ppm (mass basis).
2) A molded body made of the resin foam.
3) A cylindrical body made of the resin foam.

  By using the foam of the present invention, it is possible to prevent copper damage while maintaining heat insulation performance, and it is possible to maintain stable performance for a long period of time as a heat insulating material for piping. In addition, construction is possible without taking measures against water leakage and condensation, which is effective in reducing the total cost of reducing the number of constructions and eliminating the need for measures against water condensation.

The example of the calorie | heat amount of fusion measurement by the differential scanning calorimetry apparatus of the resin foam of this invention.

The resin foam of the present invention has an apparent density of 20 to 40 kg / m ³ and an ammonia concentration of 200 ppm to 1000 ppm (mass basis). Further, the resin foam of the present invention contains an ammonia adsorbent in the foam in order to reduce the ammonia concentration in the resin foam to a certain amount (to control the ammonia concentration to 200 ppm to 1000 ppm (mass basis)). It is preferable. Such an ammonia adsorbent has an effect of adsorbing ammonia generated from the pyrolytic chemical foaming agent used in the production of the foam, and can reduce the ammonia concentration of the foam.

  The resin foam in the present invention preferably contains mainly a thermoplastic resin. Here, mainly including means that the thermoplastic resin is contained in an amount of 50% by mass to 100% by mass in 100% by mass of all components of the resin foam.

  The thermoplastic resin is a resin having a characteristic of being softened by heating and solidified by cooling. The thermoplastic resin is not particularly limited. For example, polyolefin resin, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polylactic acid, polyamide, polycarbonate, polytetrafluoroethylene, polyurethane, polystyrene, polyester, ABS resin, acrylic resin And a polyacetal resin or a copolymer of the resin. Among these, it is preferable to use at least one kind, and a plurality of them may be mixed.

  In the resin foam of the present invention, it is preferable to use a polyolefin resin as the thermoplastic resin. Examples of the polyolefin resin used in the present invention include low density, medium to high density, and linear low density polyethylene resins, copolymers of ethylene and vinyl acetate or alkyl acrylate, propylene, and homo or copolymer. Examples thereof include polypropylene, chlorinated polyethylene and the like alone or as a mixture. As the polyolefin resin, polypropylene or polyethylene is particularly preferable, and polyethylene is more preferable. These polyolefin-based resins may be further mixed with two or more other resins as long as they do not adversely affect the foam. As the polyethylene resin, for example, low density, medium density, or high density polyethylene, polyethylene copolymer copolymerized with α-olefin, or a copolymer with vinyl acetate or acrylate ester mainly composed of ethylene is mixed. Also good. The resin foam of the present invention preferably uses a polyolefin resin as the thermoplastic resin, but preferably uses a polyethylene resin as the polyolefin resin.

  The resin foam of the present invention preferably contains 50% by mass or more and 100% by mass or less of a polyolefin resin in 100% by mass of a thermoplastic resin, more preferably 70% by mass or more and 99.95% by mass or less of a polyolefin resin. Is to include. When 100% by mass of the thermoplastic resin in the resin foam is less than 50% by mass of polyethylene resin, the resin foam is molded into a cylindrical body, etc., and the resistance increases when inserted into the pipe, allowing smooth construction. It may not be possible.

  The resin foam referred to in the present invention is a mixture of resin and gas, and its production method is not particularly limited, but an extrusion foaming method in which a gas or a solvent to be vaporized is melted in an extruder and foamed while being extruded under high pressure, Solvent gas such as a bead foaming method in which resin particles containing a gas or a solvent to be vaporized are pre-foamed and further foamed and fused in a mold, and a gas impregnation method in which a gas is dissolved in a resin in a high-pressure vessel and heated at normal pressure to foam Or the normal pressure foaming method in which a resin and a pyrolytic chemical foaming agent are melted and kneaded and foamed by normal pressure heating, and the thermal decomposable chemical foaming agent is thermally decomposed and extruded under high pressure in an extruder. Examples thereof include a foaming method and a foaming agent decomposition method such as a press foaming method in which a thermally decomposable chemical foaming agent is thermally decomposed in a press mold and foamed while reducing pressure. Among these, foaming methods such as a bead foaming method using a gas and a solvent diffusion method such as a gas impregnation method are collectively referred to as gas foaming, and the obtained resin foam is referred to as a gas foam. Among these production methods, there is a concern about the decrease in thermal conductivity due to bubble coarsening in foaming using gas. Therefore, the foaming agent decomposition method is particularly suitable in the present invention.

  The resin foam of the present invention preferably contains an ammonia adsorbent. Such an ammonia adsorbent is not limited as long as it has an ammonia adsorption effect, but is preferably a sulfate containing an alkali metal excellent in the amount of adsorption of ammonia, more preferably alum, and still more preferably. Is a baked alum. Mixing with an oxide of a transition metal element such as zinc oxide is also effective. As long as the said ammonia adsorption agent does not inhibit the characteristic of this invention, you may mix 2 or more types of ammonia adsorption agents.

  The content of the ammonia adsorbent in the resin composition used for producing the resin foam is preferably 0.3 to 5 parts by mass, more preferably 1 to 3 parts by mass with respect to 100 parts by mass of the thermoplastic resin. . If the content of the ammonia adsorbent in the resin composition used for producing the resin foam is less than 0.3 parts by mass relative to 100 parts by mass of the thermoplastic resin, ammonia adsorption of the resulting resin foam The performance may be inferior or uniform dispersion may be difficult. On the other hand, when the content of the ammonia adsorbent in the resin composition used for producing the resin foam exceeds 5 parts by mass with respect to 100 parts by mass of the thermoplastic resin, bleeding to the surface of the obtained foam is performed. When the amount increases, the long-term ammonia adsorption performance may deteriorate, or there may be problems such as poor dispersion during heat-melt processing, poor kneading, and process instability due to adhesion to various rolls of processing equipment.

  As the foaming agent, there are a physical foaming agent that foams by a physical change such as a pressure release of a compressed gas or a gas, and a chemical foaming agent that generates a gas due to thermal decomposition or a chemical reaction. Among these, a chemical foaming agent that generates nitrogen gas or carbon dioxide gas by thermal decomposition is referred to as a thermal decomposition type chemical foaming agent. A foaming method using a thermal decomposition type chemical foaming agent is called a foaming agent decomposition method.

  The thermally decomposable chemical blowing agent used in the blowing agent decomposition method is a compound that is liquid or solid at room temperature and decomposes or vaporizes when heated. The pyrolytic chemical foaming agent is preferably one that does not substantially interfere with the sheeting or crosslinking reaction of the thermoplastic resin, and the decomposition temperature of the pyrolytic chemical foaming agent is preferably 180 to 250 ° C. Examples of such pyrolytic chemical foaming agents include azodicarbonamide, azodicarboxylic acid metal salts, dinitrosopentamethylenetetramine, N, N-dinitrosopentamethylenetetramine, 4,4-oxybis, bistetrazole and diammonium. Illustrated. As the pyrolytic chemical foaming agent, azodicarbonamide is preferable.

  In producing the resin foam of the present invention by the foaming agent decomposing method, the resin composition used for producing the resin foam contains 2 to 25 pyrolytic chemical foaming agents with respect to 100 parts by mass of the thermoplastic resin. It is preferable to contain a mass part, and it is further preferable to contain 15-20 mass parts. In producing the resin foam of the present invention by the foaming agent decomposing method, the resin composition used for producing the resin foam is less than 2 parts by mass with respect to 100 parts by mass of the thermoplastic resin. When only containing, the resin foam of this invention obtained may become inadequate foaming and it may become impossible to obtain a favorable foam. On the other hand, in producing the resin foam of the present invention by the foaming agent decomposing method, the resin composition used for producing the resin foam has a thermal decomposition type chemical composition exceeding 25 parts by mass with respect to 100 parts by mass of the thermoplastic resin. When a foaming agent is contained, foaming of the obtained resin foam of the present invention becomes non-uniform, and it may not be possible to obtain a good foam.

  Depending on the type of pyrolytic chemical foaming agent and the apparent density of the desired resin foam, the amount of pyrolytic chemical foaming agent added to the resin composition used to produce the resin foam can be arbitrarily changed. I can do it. As long as the said thermal decomposition type chemical foaming agent does not inhibit the characteristic of this invention, you may mix 2 or more types of thermal decomposition type foaming agents.

  In the resin foam used in the present invention, the total area of heat of fusion at 120 ° C. or less is preferably 60% or more, more preferably 65%, when the total area of heat of fusion by a differential scanning calorimeter is 100%. Above, particularly preferably 90% or more. In addition, the upper limit of the total area of heat of fusion at 120 ° C. or lower is 100% when the total area of heat of fusion by the differential scanning calorimeter is 100%. When the total area of heat of fusion at 120 ° C. or lower is less than 60%, the resin foam of the present invention has a high rigidity, making it difficult to mold into a cylindrical body, or the cylindrical body into a teardrop shape. There is a possibility of condensation during construction. The heat of fusion shown here is obtained from the DSC curve measured by differential scanning calorimetry, and the measurement method is as shown in the examples.

It is important that the apparent density of the resin foam of the present invention is in the range of 20 to 40 kg / m ³ . Preferably it is the range of 25-35 kg / m < ³ >. When the apparent density is less than 20 kg / m ³ , the mechanical properties such as compression properties and strength / elongation may decrease and the heat insulation performance and processing characteristics may be deficient. On the other hand, the apparent density exceeds 40 kg / m ³ In addition, the heat insulation performance is remarkably deteriorated, and the required heat insulation and cold insulation temperature characteristics may not be satisfied, and the efficiency may be deteriorated when molding or construction is performed. The apparent density shown here indicates a numerical value measured by a measurement method according to JIS K 7222 (described in the 2001 edition of the JIS handbook).

Although the method of adjusting the apparent density of the resin foam in the present invention to a range of 20 to 40 kg / m ³ is not particularly limited, an example is given as an achievement method. An apparent density of 20 to 20 is obtained by foaming a resin composition containing 2 to 25 parts by mass of azodicarbonamide, which is a pyrolytic chemical foaming agent, at a temperature of 200 to 250 ° C. with respect to 100 parts by mass of the thermoplastic resin. A resin foam controlled in the range of 40 kg / m ³ can be obtained.

  The thermal conductivity of the resin foam of the present invention is preferably in the range of 0.03 to 0.04 W / mK. When the thermal conductivity is less than 0.03 W / mK, the heat insulation performance is satisfied, but problems such as a decrease in productivity and a price increase may occur. On the other hand, when the thermal conductivity exceeds 0.04 W / mK, it is necessary to increase the necessary heat insulation thickness, and the efficiency may deteriorate when molding or construction is performed. The thermal conductivity shown here indicates a numerical value measured by a measurement method according to JIS A 1412-2 (described in the 2001 edition of the JIS handbook).

In order to control the thermal conductivity of the resin foam within the range of 0.03 to 0.04 W / mK, the apparent density of the resin foam obtained by the foaming agent decomposition method is set within the range of 20 to 40 kg / m ^3. Is possible.

  The resin foam of the present invention preferably has a crosslinked structure. That is, the resin foam of the present invention is preferably a crosslinked foam. When it does not have a crosslinked structure, sheet breakage may occur frequently. Further, when the production method is gas foaming or the like, it is preferable to crosslink because there is a concern about a decrease in heat resistance. Examples of a method for obtaining a crosslinked foam by introducing a crosslinked structure include: electron beam crosslinking method in which ionizing radiation is irradiated for crosslinking, dicumyl peroxide, tertiary butyl perbenzoate, and di-tert-butyl peroxide. Methods such as chemical crosslinking method in which organic peroxides such as kneaded are decomposed and foamed during foaming, and silane crosslinking method in which polyolefin resin having silane group is mixed and heated to contact with moisture May be used, and the electron beam crosslinking method is preferred.

  The resin composition used for producing the resin foam of the present invention is 0.3 to 5 parts by mass of an ammonia adsorbent and 2 to 25 parts by mass of a pyrolytic chemical foaming agent with respect to 100 parts by mass of the thermoplastic resin. However, the method of mixing such a resin composition is not particularly limited. Preferably, it is a method of melting, mixing and kneading using various extruders such as a single screw extruder and a twin screw extruder, or a mixer such as a kneader or a calender roll, at or above a temperature at which the thermoplastic resin is softened.

  The ammonia concentration of the resin foam of the present invention needs to be set in the range of 200 to 1000 ppm (mass basis). If the ammonia concentration is less than 200 ppm on a mass basis, the amount of ammonia adsorbent added must be increased, resulting in a problem that costs are increased and efficient production is not possible. In the case of a gas foam, if the ammonia concentration is less than 200 ppm on a mass basis, in addition to the above reasons, there is a concern about a decrease in thermal conductivity due to bubble coarsening. On the other hand, when it exceeds 1000 ppm on the mass basis, corrosion may occur frequently in copper, which is the main material of piping. The ammonia concentration shown here indicates a numerical value measured by an ion chromatograph shown in Appendix 1 (normative) of 2001 edition JIS K 0102 42.5.

  In order to adjust the ammonia concentration of the resin foam in the present invention to a range of 200 to 1000 ppm (mass basis), 0.3 to 5 parts by mass of an ammonia adsorbent is included with respect to 100 parts by mass of the thermoplastic resin. Thus, it is possible to obtain a resin foam controlled in the ammonia concentration range of 200 to 1000 ppm (mass basis).

  The thickness of the resin foam of the present invention is preferably 1 to 100 mm, and more preferably 5 to 80 mm. If the thickness is less than 1 mm, the heat insulation performance is remarkably deteriorated and the required heat insulation and cold insulation temperature characteristics may not be satisfied. On the other hand, if the thickness exceeds 100 mm, the heat insulation performance is satisfied, but the processing characteristics and productivity are low. There are cases where problems such as price declines and price increases occur. The thickness shown here indicates a numerical value measured by a measuring method according to JIS K 7222 (described in the 2001 edition of the JIS handbook).

  The resin foam of the present invention is a cylindrical body capable of covering in accordance with the pipe shape in order to efficiently keep warm, cool, and prevent condensation of fluid objects such as gas and liquid flowing in the pipe. It is desirable. The method of making the foam into a cylindrical body is not particularly limited. For example, the foam produced by the above method is cut into a width corresponding to the diameter of the cylinder, and the foam is removed with a known heat source such as hot air or an infrared heater. A method of passing a conical base while heating, or cutting a resin foam into a width corresponding to the diameter of the cylinder, and passing the conical base while heating the foam with a known heat source such as hot air or an infrared heater After forming a cylindrical body, the polyolefin resin layer formed into an unstretched film cut to an appropriate width is bonded with a solvent-based, water-based liquid, gel-like, solid-state known adhesive or a known pressure-sensitive adhesive tape. The method of doing is illustrated.

  The types of pipes covering the resin foam of the present invention include refrigerant pipes used for residential air conditioning equipment, water pipes used for water supply and hot water supply, and connecting pipes for hot water storage type hot water heaters. Examples of the material of the pipe include a vinyl chloride pipe, a crosslinked polyethylene pipe, a polybutene pipe, a vinyl chloride lining pipe, a copper pipe, and a stainless steel pipe. The resin foam has a remarkably low residual ammonia concentration and is effective in preventing corrosion of the copper tube.

  In addition, pipes that have a different shape from the cylindrical body, such as a curved part of a pipe, a joint part, and a flow rate adjusting part such as a valve, should be molded into a predetermined shape that is equivalent to the part of the pipe. Is desirable. A method for forming the foam into a predetermined shape is not particularly limited. For example, the foam is heated with a known heat source such as a circulating hot air oven or an infrared heater, and then made of metal or wood having fine holes. An example is a method in which the foam is placed on a predetermined mold, air is extracted from the fine holes, and the foam and the predetermined mold are brought into close contact with each other.

  Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are merely examples and are not particularly limited.

The evaluation method of the resin foam in the present invention is as follows.
"Ammonia concentration measurement"
It was measured according to the ion chromatograph of the ammonia concentration measuring method described in Appendix 1 (normative) of 2001 edition JIS K 0102 42.5.

  1 g of a sample cut into 5 mm pieces is accurately weighed and placed in a 100 ml sealed bottle. After adding 40 ml of distilled water and sealing it, it is allowed to stand at 90 ° C. for 24 hours. After cooling, the extract was taken out and subjected to ion analysis.

The equipment used was DX-320J manufactured by Nippon Dionex, and IonPac CG12A and IonPac CS12A were used for the guard column and separation column, respectively. Methanesulfonic acid as an eluent is allowed to flow through the separation column at 1 ml / min, 25 μl of the sample is injected into the ion chromatograph, and an ion chromatogram is recorded.
"Apparent density"
It measured by the measuring method according to JISK7222 (2001 version JIS handbook description). A sample is cut into 15 cm × 15 cm, and the length, width, and thickness are measured with a digital caliper, and the volume is obtained. The caliper used was CD-20 manufactured by Mitutoyo. Subsequently, the mass of each sample was determined using AUW220D manufactured by SHIMADZU. The apparent density was calculated from the obtained volume and mass.
"DSC"
A DSC 2920 manufactured by Seiko Instruments is used as a differential scanning calorimeter. The temperature was raised between −50 ° C. and 200 ° C. at a rate of 10 ° C./min and held for 5 minutes, then the temperature was lowered between 200 ° C. and −50 ° C. at a rate of 10 ° C./min and held for another 5 minutes. The DSC curve obtained in the second temperature raising process when the temperature is raised at a rate of 10 ° C./min between −50 ° C. and 200 ° C. is used.

  First, in the DSC curve, a line segment (ab) connecting a point a on the DSC curve corresponding to the melting start temperature T1 of the resin foam and a point b on the DSC curve corresponding to the melting end temperature T2 of the resin foam. )pull. Next, a straight line parallel to the vertical axis of the graph is drawn from the point c corresponding to 120 ° C., and a point where the DSC curve intersects is defined as d (a point where the DSC curve intersects the vertical axis indicating 120 ° C.). Further, a straight line parallel to the vertical axis of the graph is drawn from the point c corresponding to 120 ° C., and a point intersecting with the line segment (a−b) is represented by e (line segment (ab) and the vertical axis indicating 120 ° C. Intersection).

The total area of 100% of the heat of fusion measured by the differential scanning calorimeter is the area of the part surrounded by the curve from a to b along the DSC curve and the line segment (ab). On the other hand, the total area of heat of fusion at 120 ° C. or lower is defined as the area of the portion surrounded by the curve from a to d along the DSC curve and the line segment (d−e). The melting start temperature T1 and the melting end temperature T2 are the intersections of the DSC curve, the low temperature side baseline, and the high temperature side baseline.
"Thermal conductivity"
It measured by the measuring method according to the measuring method of the heat conductivity as described in JIS A 1412-2 (2001 version JIS handbook description). A sample is cut into 30 cm × 30 cm, and the length, width, and thickness are measured with a digital caliper, and the volume is obtained. The apparent density was calculated from the volume and mass of the sample. A heat flow meter made by HOROMERIX, RAPID-K was used, and the temperature difference between the top and bottom of the sample and the heat flow rate were measured, and the thermal conductivity was calculated. The room temperature at which the measurement was performed is 23 ° C.
"appearance"
The surface state of the resin foam was visually confirmed.
If the surface roughness is severe and wide, (x), if the surface roughness is small and there is no problem in use (△), and if there is no problem on the surface (◯).
"Formability (flatness)"
The resin foam was cut into a width of 110 mm, and a cylindrical body having an inner diameter of 18 mm was obtained through a conical base while heating the resin foam with hot air of 300 ° C.
The numerical value obtained by the minor axis / major axis x 100 of the cylindrical body is defined as the flatness ratio. When the ratio is less than 85%, (x), when 85-90% is (△), and when it is greater than 90%, (◯). .
"Workability"
When a heat insulating material formed into a cylindrical body is applied to a copper tube having a nominal diameter of 15A (outer diameter of 15.88 mm) and a wall thickness of 1.02 mm, the heat insulating material cannot be passed through and cannot be used at all (×). If there is a slight resistance but it can be used by pushing it in, (△).
"Heat retention"
The resin foam is wound around a cylindrical steel tank having a diameter of 80 mm and a height of 150 mm without any gap. A 100 ° C. hot water and a thermocouple were placed in the tank, and the time for the hot water to cool to 50 ° C. was measured. The room temperature at which the measurement was performed is 23 ° C.
"Copper pipe corrosion"
The resin foam and the copper plate are each cut into a size of 5 cm × 5 cm. The sample is bonded to a copper plate and stored in a dryer at 100 ° C. for 180 days. After completion of the test, the surface state was observed, and when corrosion due to copper occurred, the size of the corroded portion was measured with a caliper manufactured by Mitutoyo, CD-20.

[Example 1]
After pulverizing 100% by mass of a high-pressure low-density polyethylene resin (Petrocene 310 manufactured by Tosoh Corporation) having an MFR of 3.6 g / 10 min and a density of 0.922 g / cm ³ to 2 mm or less, a thermoplastic resin Is 10 parts by mass of pyrolytic chemical foaming agent azodicarbonamide (Vinole AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.), 0.2 parts by mass of Irganox 1010 as a stabilizer, and calcined as an ammonia adsorbent. After mixing 0.5 parts by mass of alum with a super mixer and forming it into a long sheet with a thickness of 1.8 mm using a T-die with a 90 mmφ single screw extruder heated to 140 to 160 ° C., an electron of 70 kGy After irradiating the wire with an acceleration voltage of 800 kV and crosslinking, salt foaming is performed at 200 to 250 ° C., and heating with an infrared heater is performed from the top to obtain a resin foam. It was.

  The resin foam obtained above was cut into a width corresponding to the diameter of the cylinder (18 mm), and a cylindrical heat insulating material was obtained through a conical base while heating the resin foam with hot air at 300 ° C.

As shown in Table 1, the resin foam obtained by the above method has a density of 34 kg / m ³ , an ammonia concentration of 750 ppm (mass basis), a thermal conductivity of 0.036 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 2]
A resin foam was obtained in the same manner as in Example 1 except that 4 parts by mass of calcined alum was used as the ammonia adsorbent.

As shown in Table 1, the resin foam obtained by the above method has a density of 36 kg / m ³ , an ammonia concentration of 350 ppm (mass basis), a thermal conductivity of 0.034 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 3]
A resin foam was obtained in the same manner as in Example 1 except that 10 parts by mass of calcined alum was used as the ammonia adsorbent.

As shown in Table 1, the resin foam obtained by the above method has a density of 33 kg / m ³ , an ammonia concentration of 450 ppm (mass basis), a thermal conductivity of 0.035 W / mK, heat retention, and copper tube corrosion. There is no problem. Appearance defects occurred due to the bleed-out of the adsorbent, but there was no problem in use.

[Example 4]
Resin foaming in the same manner as in Example 1, except that 20 parts by mass of the pyrolytic chemical foaming agent azodicarbonamide (Vinole AC # 1 manufactured by Eiwa Chemical Industry Co., Ltd.) and 0.5 parts by mass of baked alum as the ammonia adsorbent were used. Got the body.

As shown in Table 1, the resin foam obtained by the above method has a density of 25 kg / m ³ , an ammonia concentration of 1000 ppm (mass basis), a thermal conductivity of 0.040 W / mK, heat retention, copper tube corrosion There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 5]
A resin foam was obtained in the same manner as in Example 1, except that 20 parts by mass of the pyrolytic chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.) and 4 parts by mass of baked alum as the ammonia adsorbent were used. Obtained.

As shown in Table 2, the resin foam obtained by the above method has a density of 23 kg / m ³ , an ammonia concentration of 700 ppm (mass basis), a thermal conductivity of 0.038 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 6]
A resin foam was obtained in the same manner as in Example 1 except that 20 parts by mass of the thermal decomposition type chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Chemical Industry Co., Ltd.) and 10 parts by mass of baked alum as the ammonia adsorbent were used. Obtained.

As shown in Table 2, the resin foam obtained by the above method has a density of 25 kg / m ³ , an ammonia concentration of 850 ppm (mass basis), a thermal conductivity of 0.036 W / mK, heat retention, copper pipe corrosion There is no problem. Appearance defects occurred due to the bleed-out of the adsorbent, but there was no problem in use.

[Example 7]
A resin foam was obtained in the same manner as in Example 1 except that 0.5 parts by mass of calcined alum and 0.1 parts by mass of zinc oxide were mixed as an ammonia adsorbent.

As shown in Table 2, the resin foam obtained by the above method has a density of 32 kg / m ³ , an ammonia concentration of 600 ppm (mass basis), a thermal conductivity of 0.036 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 8]
A resin foam was obtained in the same manner as in Example 1 except that 4 parts by mass of calcined alum and 1 part by mass of zinc oxide were mixed as an ammonia adsorbent.

As shown in Table 2, the resin foam obtained by the above method has a density of 35 kg / m ³ , an ammonia concentration of 450 ppm (mass basis), a thermal conductivity of 0.036 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 9]
50% by mass of high-pressure low-density polyethylene resin (Petrocene 310 manufactured by Tosoh Corporation) having an MFR of 3.6 g / 10 min and a density of 0.922 g / cm ^3, an MFR of 2.0 g / 10 min, and a density of 0.909 g / Cm ³ linear low density polyethylene resin (Ultzex 1020L manufactured by Prime Polymer Co., Ltd.) 50% by mass, respectively, pulverized to 2 mm or less using a pulverizer, and then thermally decomposed when the thermoplastic resin is 100 parts by mass. 10 parts by weight of a chemical foaming agent azodicarbonamide (Vinole AC # 1 from Eiwa Kasei Kogyo Co., Ltd.), 0.2 parts by weight of Irganox 1010 as a stabilizer, and 4 parts by weight of baked alum as an ammonia adsorbent were mixed with a super mixer. After forming into a long sheet with a thickness of 1.8 mm using a T-die with a 90 mmφ single screw extruder heated to 140 to 160 ° C. After irradiation with an electron beam of 70 kGy at an acceleration voltage of 800 kV and crosslinking, salt foaming was performed at 200 to 250 ° C., and heating with an infrared heater was performed from the top to obtain a resin foam.

  The resin foam obtained above was cut into a width corresponding to the diameter of the cylinder (18 mm), and a cylindrical heat insulating material was obtained through a conical base while heating the resin foam with hot air at 300 ° C.

As shown in Table 3, the resin foam obtained by the above method has a density of 35 kg / m ³ , an ammonia concentration of 200 ppm (mass basis), a thermal conductivity of 0.035 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 10]
A resin foam was obtained in the same manner as in Example 9, except that 4 parts by mass of calcined alum and 1 part by mass of zinc oxide were mixed as an ammonia adsorbent.

As shown in Table 3, the resin foam obtained by the above method has a density of 39 kg / m ³ , an ammonia concentration of 400 ppm (mass basis), a thermal conductivity of 0.033 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 11]
A resin foam was obtained in the same manner as in Example 9 except that 0.5 parts by mass of calcined alum was used as the ammonia adsorbent.

As shown in Table 3, the resin foam obtained by the above method has a density of 34 kg / m ³ , an ammonia concentration of 800 ppm (mass basis), a thermal conductivity of 0.033 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 12]
A resin foam was obtained in the same manner as in Example 9 except that 0.5 parts by mass of calcined alum and 0.1 parts by mass of zinc oxide were mixed as an ammonia adsorbent.

As shown in Table 3, the resin foam obtained by the above method has a density of 32 kg / m ³ , an ammonia concentration of 700 ppm (mass basis), a thermal conductivity of 0.038 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 13]
50% by mass of high-pressure low-density polyethylene resin (Petrocene 310 manufactured by Tosoh Corporation) having an MFR of 3.6 g / 10 min and a density of 0.922 g / cm ^3, an MFR of 2.4 g / 10 min, and a density of 0.9 g / Cm ³ homopolypropylene (Novatech PPFY6C, manufactured by Nippon Polypro Co., Ltd.) 50% by mass, respectively, using a pulverizer, pulverized to 2 mm or less, and then 100 parts by mass of the thermoplastic resin, azodicarboxylic pyrolytic chemical foaming agent 10 parts by weight of amide (Binhole AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.), 4 parts by weight of divinylbenzene as a crosslinking aid, 0.2 parts by weight of Irganox 1010 as a stabilizer, and 0.5 parts by weight of baked alum as an ammonia adsorbent Was mixed with a super mixer and heated to 140-160 ° C. with a 90 mmφ single-screw extruder using a T die with a thickness of 1.8 mm. After forming into a long sheet shape, 70 kGy electron beam was irradiated at an acceleration voltage of 800 kV, and after crosslinking, salt foaming was performed at 200 to 250 ° C., and heating with an infrared heater was performed from the top to obtain a resin foam. .

  The resin foam obtained above was cut into a width corresponding to the diameter of the cylinder (18 mm), and a cylindrical heat insulating material was obtained through a conical base while heating the resin foam with hot air at 300 ° C.

As shown in Table 4, the resin foam obtained by the above method has a density of 36 kg / m ³ , an ammonia concentration of 750 ppm (mass basis), a thermal conductivity of 0.034 W / mK, heat retention, copper tube corrosion There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 14]
A resin foam was obtained in the same manner as in Example 13 except that 4 parts by mass of calcined alum was used as the ammonia adsorbent.

As shown in Table 4, the resin foam obtained by the above method has a density of 34 kg / m ³ , an ammonia concentration of 400 ppm (mass basis), a thermal conductivity of 0.036 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 15]
A resin foam was obtained in the same manner as in Example 13 except that 20 parts by mass of the thermal decomposition type chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Chemical Industry Co., Ltd.) was used.

As shown in Table 4, the resin foam obtained by the above method has a density of 22 kg / m ³ , an ammonia concentration of 900 ppm (mass basis), a thermal conductivity of 0.039 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 16]
Except for using 20 parts by mass of pyrolytic chemical foaming agent azodicarbonamide (Binhoy AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.), 4 parts by mass of calcined alum and 1 part by mass of zinc oxide as an ammonia adsorbent, the same as in Example 13. Thus, a resin foam was obtained.

As shown in Table 4, the resin foam obtained by the above method has a density of 20 kg / m ³ , an ammonia concentration of 650 ppm (mass basis), a thermal conductivity of 0.039 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 17]
A resin foam was obtained in the same manner as in Example 13 except that 0.5 parts by mass of calcined alum and 0.1 parts by mass of zinc oxide were mixed as an ammonia adsorbent.

As shown in Table 5, the resin foam obtained by the above method has a density of 35 kg / m ³ , an ammonia concentration of 800 ppm (mass basis), a thermal conductivity of 0.036 W / mK, heat retention, and copper tube corrosion. There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 18]
A resin foam was obtained in the same manner as in Example 13 except that 4 parts by mass of calcined alum and 1 part by mass of zinc oxide were mixed as an ammonia adsorbent.

As shown in Table 5, the resin foam obtained by the above method has a density of 38 kg / m ³ , an ammonia concentration of 250 ppm (mass basis), a thermal conductivity of 0.035 W / mK, heat retention, copper pipe corrosion There is no problem. Moreover, the moldability to the cylindrical heat insulating material and the workability to the piping were good.

[Example 19]
40% by mass of an ethylene propylene block copolymer (Prime Polypro E185-G manufactured by Prime Polymer Co., Ltd.) having an MFR of 0.3 g / 10 min and a density of 0.9 g / cm ³ and an MFR of 7.0 g / 10 min, a density There an ethylene-propylene random copolymer 0.9 g / cm ³ (Japan Polypropylene Corp. WINTEC WFX4TA) 40 wt% and an MFR of 2.0 g / 10 min, linear density 0.909 g / cm ³ low After pulverizing 20% by mass of a density polyethylene resin (Ultzex 1020L manufactured by Prime Polymer Co., Ltd.) to 2 mm or less using a pulverizer, when the thermoplastic resin was 100 parts by mass, the pyrolytic chemical foaming agent azodicarbonamide ( Eiwa Chemical Industry Co., Ltd., VINYHALL AC # 1) 10 parts by mass, divinylbenzene 4 parts by mass as a crosslinking aid, Add 0.2 parts by weight of Irganox 1010 as a settling agent, mix 4 parts by weight of baked alum as an ammonia adsorbent with a super mixer, and use a T die with a 90mmφ single screw extruder heated to 140-160 ° C. After forming into a long sheet of 8 mm, 70 kGy electron beam is irradiated at an acceleration voltage of 800 kV, and after crosslinking, salt foaming is performed at 200 to 250 ° C., and heating with an infrared heater is performed from the top to form a resin foam Got.

  The resin foam obtained above was cut into a width corresponding to the diameter of the cylinder (18 mm), and a cylindrical heat insulating material was obtained through a conical base while heating the resin foam with hot air at 300 ° C.

As shown in Table 5, the resin foam obtained by the above method has a density of 33 kg / m ³ , an ammonia concentration of 800 ppm (mass basis), a thermal conductivity of 0.036 W / mK, heat retention, and copper tube corrosion. There is no problem. Further, the flatness was 87% when molded into a cylindrical body, and although it had a slight resistance when applied to piping, it could be used by being pushed in.

[Example 20]
80% by mass of an ethylene propylene random copolymer (Wintech WFX4TA manufactured by Nippon Polypro Co., Ltd.) having an MFR of 7.0 g / 10 min and a density of 0.9 g / cm ^3, an MFR of 2.0 g / 10 min, and a density of 0 After pulverizing 20% by mass of a linear low density polyethylene resin of .909 g / cm ³ (Ulzex 1020L manufactured by Prime Polymer Co., Ltd.) to 2 mm or less using a pulverizer, the thermoplastic resin was taken as 100 parts by mass, Add 10 parts by mass of pyrolytic chemical foaming agent azodicarbonamide (Vinole AC # 1 manufactured by Eiwa Chemical Industry Co., Ltd.), 4 parts by mass of divinylbenzene as a crosslinking aid, 0.2 parts by mass of Irganox1010 as a stabilizer, and an ammonia adsorbent 90mmφ single screw extrusion mixed with 4 parts by mass of baked alum with a super mixer and heated to 140-160 ° C After forming into a long sheet with a thickness of 1.8 mm using a T-die, 70 kGy electron beam was irradiated at an acceleration voltage of 800 kV and crosslinked, then salt foamed at 200 to 250 ° C., infrared heater from above Heating was performed to obtain a resin foam.

  The resin foam obtained above was cut into a width corresponding to the diameter of the cylinder (18 mm), and a cylindrical heat insulating material was obtained through a conical base while heating the resin foam with hot air at 300 ° C.

As shown in Table 5, the resin foam obtained by the above method has a density of 34 kg / m ³ , an ammonia concentration of 700 ppm (mass basis), a thermal conductivity of 0.034 W / mK, heat retention, and copper tube corrosion. There is no problem. Further, the flatness was 86% when molded into a cylindrical body, and although it had a slight resistance when applied to piping, it could be used by being pushed in.

[Example 21]
After pulverizing 100% by mass of low-pressure high-density polyethylene (Hi-Zex 5000S manufactured by Prime Polymer Co., Ltd.) having an MFR of 0.82 g / 10 min and a density of 0.95 g / cm ³ to 2 mm or less using a pulverizer, a thermoplastic resin Is 10 parts by mass of pyrolytic chemical foaming agent azodicarbonamide (Vinole AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.), 4 parts by mass of divinylbenzene as a crosslinking aid, and Irganox 1010 as a stabilizer. Add 2 parts by mass, mix 4 parts by mass of baked alum as an ammonia adsorbent with a super mixer, and heat it to 140-160 ° C. After being molded into a 70 kGy electron beam at an accelerating voltage of 800 kV and crosslinked, salt foaming is performed at 200 to 250 ° C. By heating with an infrared heater, to obtain a resin foam.

  The resin foam obtained above was cut into a width corresponding to the diameter of the cylinder (18 mm), and a cylindrical heat insulating material was obtained through a conical base while heating the resin foam with hot air at 300 ° C.

As shown in Table 5, the resin foam obtained by the above method has a density of 34 kg / m ³ , an ammonia concentration of 800 ppm (mass basis), a thermal conductivity of 0.034 W / mK, heat retention, and copper tube corrosion. There is no problem. Further, the flatness was 88% when molded into a cylindrical body, and although it had a slight resistance when applied to piping, it could be used by being pushed in.

  “DSC” in the table indicates the total area of heat of fusion at 120 ° C. or lower when the total area of heat of fusion by a differential scanning calorimeter is 100%.

[Comparative Example 1]
A resin foam was obtained in the same manner as in Example 1 except that 1 part by mass of the pyrolytic chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Chemical Industry Co., Ltd.) and 4 parts by mass of calcined alum as the ammonia adsorbent were used. Obtained.

As shown in Table 6, the resin foam obtained by the above method has a density of 84 kg / m ³ , an ammonia concentration of 600 ppm (mass basis), a thermal conductivity of 0.042 W / mK, and is inferior in heat retention. There is no problem with copper pipe corrosion. In addition, it was difficult to form a cylindrical heat insulating material because of its high rigidity, making it difficult to construct pipes.

[Comparative Example 2]
A resin foam was obtained in the same manner as in Example 1 except that 30 parts by mass of pyrolytic chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.) and 4 parts by mass of baked alum as an ammonia adsorbent were used. Obtained.

As shown in Table 6, the resin foam obtained by the above method has a density of 18 kg / m ³ , an ammonia concentration of 3000 ppm (mass basis), a thermal conductivity of 0.045 W / mK, and poor heat retention. In addition, corrosion occurred on the copper plate. During the extrusion, the pyrolytic chemical foaming agent was decomposed, the bubble diameter was not uniform, the appearance was poor, the sheet was cut, and it was unstable.

[Comparative Example 3]
A resin foam was obtained in the same manner as in Example 1 except that no ammonia adsorbent was used.

As shown in Table 6, the resin foam obtained by the above method has a density of 34 kg / m ³ , an ammonia concentration of 2300 ppm (mass basis), a thermal conductivity of 0.033 W / mK, and is poor in heat retention. In addition, corrosion occurred on the copper plate.

[Comparative Example 4]
A resin foam was obtained in the same manner as in Example 1 except that 20 parts by mass of thermal decomposition type chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Chemical Industries Ltd.) and no ammonia adsorbent were used.

As shown in Table 6, the resin foam obtained by the above method has a density of 24 kg / m ³ , an ammonia concentration of 2850 ppm (mass basis), a thermal conductivity of 0.039 W / mK, and is inferior in heat retention. In addition, corrosion occurred on the copper plate.

[Comparative Example 5]
After pulverizing 100% by mass of a high-pressure low-density polyethylene resin (Petrocene 310 manufactured by Tosoh Corporation) having an MFR of 3.6 g / 10 min and a density of 0.922 g / cm ³ to 2 mm or less, a thermoplastic resin Is 10 parts by mass of pyrolytic chemical foaming agent azodicarbonamide (Vinole AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.), 0.2 parts by mass of Irganox 1010 as a stabilizer, and calcined as an ammonia adsorbent. After mixing 4 parts by mass of alum with a super mixer and forming it into a long sheet with a thickness of 1.8 mm using a T-die with a 90 mmφ single screw extruder heated to 140 to 160 ° C., the temperature is 200 to 250 ° C. Salt foaming and heating with an infrared heater from above were performed to obtain a resin foam.

  As shown in Table 7, in the above method, the resin foam frequently cut and could not be produced. Therefore, the resin foam is not evaluated.

[Comparative Example 6]
A resin foam was obtained in the same manner as in Comparative Example 5, except that 20 parts by mass of the thermal decomposition type chemical foaming agent azodicarbonamide (Ebina Kasei Kogyo Co., Ltd., VINYHALL AC # 1) was used.

  As shown in Table 7, in the above method, the resin foam frequently cut and could not be produced. Therefore, the resin foam is not evaluated.

[Comparative Example 7]
A resin foam was obtained in the same manner as in Example 13 except that no ammonia adsorbent was used.

As shown in Table 7, the resin foam obtained by the above method has a density of 35 kg / m ³ , an ammonia concentration of 2500 ppm (mass basis), a thermal conductivity of 0.035 W / mK, and there is no problem with heat retention. In addition, corrosion occurred on the copper plate.

[Comparative Example 8]
A resin foam was obtained in the same manner as in Example 13 except that 20 parts by mass of thermal decomposition type chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Chemical Industry Co., Ltd.) and no ammonia adsorbent were used.

As shown in Table 7, the resin foam obtained by the above method has a density of 23 kg / m ³ , an ammonia concentration of 2700 ppm (mass basis), a thermal conductivity of 0.038 W / mK, and is inferior in heat retention. In addition, corrosion occurred on the copper plate.

[Comparative Example 9]
A resin foam was obtained in the same manner as in Example 13 except that 1 part by mass of the pyrolytic chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.) and 4 parts by mass of baked alum as the ammonia adsorbent. Obtained.

As shown in Table 8, the resin foam obtained by the above method has a density of 88 kg / m ³ , an ammonia concentration of 450 ppm (mass basis), a thermal conductivity of 0.045 W / mK, and is inferior in heat retention. There is no problem with copper pipe corrosion. In addition, it was difficult to form a cylindrical heat insulating material because of its high rigidity, making it difficult to construct pipes.

[Comparative Example 10]
A resin foam was obtained in the same manner as in Example 13 except that 30 parts by mass of the thermal decomposition type chemical foaming agent azodicarbonamide (Vinole AC # 1 manufactured by Eiwa Chemical Industry Co., Ltd.) and 4 parts by mass of baked alum as the ammonia adsorbent were used. Obtained.

As shown in Table 8, the resin foam obtained by the above method has a density of 16 kg / m ³ , an ammonia concentration of 3300 ppm (mass basis), a thermal conductivity of 0.050 W / mK, and poor heat retention. Corrosion occurred on the copper plate. Further, the pyrolytic chemical foaming agent was decomposed during the extrusion, the bubble diameter was not uniform, appearance defect occurred, the sheet was cut and it was unstable.

[Comparative Example 11]
50% by mass of high-pressure low-density polyethylene resin (Petrocene 310 manufactured by Tosoh Corporation) having an MFR of 3.6 g / 10 min and a density of 0.922 g / cm ^3, an MFR of 2.4 g / 10 min, and a density of 0.9 g / Cm ³ homopolypropylene (Novatech PPFY6C, manufactured by Nippon Polypro Co., Ltd.) 50% by mass, respectively, using a pulverizer, pulverized to 2 mm or less, and then 100 parts by mass of the thermoplastic resin, azodicarboxylic pyrolytic chemical foaming agent 10 parts by weight of amide (Einwa Kasei Kogyo Co., Ltd., VINYHALL AC # 1), 4 parts by weight of divinylbenzene as a crosslinking aid, 0.2 parts by weight of Irganox 1010 as a stabilizer, and 4 parts by weight of baked alum as an ammonia adsorbent Long length of 1.8mm using a T-die with a 90mmφ single screw extruder mixed with a mixer and heated to 140-160 ° C After forming into a sheet shape, salt foaming was performed at 200 to 250 ° C., and heating with an infrared heater was performed from above to obtain a resin foam.

  As shown in Table 8, in the above method, the resin foam was frequently cut and could not be produced. Therefore, the resin foam is not evaluated.

[Comparative Example 12]
A resin foam was obtained in the same manner as in Comparative Example 11 except that 20 parts by mass of the thermal decomposition type chemical foaming agent azodicarbonamide (Binhole AC # 1 manufactured by Eiwa Kasei Kogyo Co., Ltd.) was used.

  As shown in Table 8, in the above method, the resin foam was frequently cut and could not be produced. Therefore, the resin foam is not evaluated.

  As described above, the resin foam according to the present invention shown in the examples includes a polyolefin resin having a heat of fusion of 60% or more in the range of 120 ° C. or less as measured by a differential scanning calorimeter, It can be obtained by adding 0.3 to 5 parts by mass of an ammonia adsorbent containing baked alum and 2 to 25 parts by mass of a pyrolytic chemical foaming agent with respect to 100 parts by mass of the plastic resin.

a Melting start temperature b Melting end temperature c 120 ° C
d Point where the DSC curve intersects the vertical axis indicating 120 degrees e Point where the line segment (ab) intersects the vertical axis indicating 120 degrees T temperature T1 melting start temperature T2 melting end temperature Wg heat of fusion

Claims (7)

A resin foam which is a crosslinked foam having an apparent density of 20 to 40 kg / m ³ and an ammonia concentration of 200 ppm to 1000 ppm (mass basis).   The resin foam according to claim 1, wherein the thermal conductivity is 0.03 W / mK to 0.04 W / mK.   The resin foam according to claim 1 or 2, wherein the resin foam contains an ammonia adsorbent.   It is obtained from a resin composition containing 0.3 to 5 parts by mass of an ammonia adsorbent and 2 to 25 parts by mass of a pyrolytic chemical foaming agent with respect to 100 parts by mass of a thermoplastic resin. The resin foam in any one of -3.   The total area of the heat of fusion at 120 ° C. or less is 60% or more when the total area of the heat of fusion by the differential scanning calorimeter is 100%. Resin foam. The molded object which consists of a resin foam in any one of Claims 1-5 . The cylindrical body which consists of a resin foam in any one of Claims 1-5 .

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