JP6738181B2 - Resin composition and heat recovery article - Google Patents

Description

The present invention relates to a resin composition and a heat recovery article.

Fluororesin is widely used as a main component of heat recovery articles for covering and protecting connection parts such as electric wires and pipes because it has excellent heat resistance, chemical resistance, and insulation and can be extruded. There is.

Since a heat recovery article containing a fluororesin has relatively high rigidity, for example, fluororubber is mixed with the heat recovery article in applications where flexibility is required (see JP-A-2015-39843).

JP, 2015-39843, A

When a heat recovery article is manufactured by extrusion using a resin composition mixed with fluororubber or the like, the slipperiness of the extruded product tends to deteriorate. When the slipperiness of the extruded product is poor as described above, adherence of die scum to the heat recovery article and rough appearance of the heat recovery article are likely to occur.

The adhesion of die scum to the heat recovery article and the rough appearance of the heat recovery article can be suppressed by adding a lubricant. However, common lubricants are more susceptible to aging than fluoropolymers. Therefore, the heat recovery article containing the lubricant easily causes deterioration over time. In order to prevent this deterioration over time, a fluorine-based lubricant is used as the lubricant.

Since the fluorine-based lubricant has a polarity close to that of the fluoropolymer that is the main component of the heat recovery article, bleed-out that migrates to the surface of the heat recovery article during extrusion molding is unlikely to occur, and it is difficult to obtain a sufficient sliding effect. Therefore, in a heat recovery article that requires aging resistance, by reducing the extrusion linear velocity during extrusion molding, the appearance roughness is reduced, and the extrusion is periodically interrupted to remove the die scum accumulated in the die. As a result, the adhesion of the dicus to the heat recovery article is suppressed. Therefore, there is room for improvement in the production efficiency of heat recovery articles requiring aging resistance.

The present invention has been made based on the above circumstances, and an object thereof is to provide a resin composition capable of efficiently extrusion-molding a heat recovery article having excellent aging resistance and a heat recovery article using this resin composition. And

The resin composition according to one embodiment of the present invention is a resin composition for forming a heat recovery article by an extrusion molding method, and contains a fluoropolymer as a main component and an additive, and as the additive, A compound having a melting point of 220° C. or less and a functional group capable of capturing a radical is included.

A heat recovery article according to another aspect of the present invention is a heat recovery article using the resin composition.

By using the resin composition of the present invention, a heat recovery article having excellent aging resistance can be efficiently extrusion-molded. Therefore, the heat recovery article using the resin composition of the present invention is excellent in aging resistance and production efficiency.

It is a perspective view of the heat recovery article of one embodiment of the present invention.

[Description of Embodiments of the Present Invention]
The resin composition according to one embodiment of the present invention is a resin composition for forming a heat recovery article by an extrusion molding method, and contains a fluoropolymer as a main component and an additive, and as the additive, A compound having a melting point of 220° C. or less and a functional group capable of capturing a radical is included.

Since the resin composition contains a compound having a functional group capable of capturing radicals as an additive, the heat recovery article produced by using the resin composition suppresses aging by capturing radicals by the functional group. To be done. Further, since the above compound has a melting point of 220° C. or less, it easily melts when a heat recovery article is extrusion-molded using the resin composition, and since it has a different polarity from the fluoropolymer, it functions as a lubricant by bleeding out. .. Therefore, it is possible to suppress the decrease in the extrusion linear velocity when the heat recovery article is extrusion-molded using the resin composition, and to reduce the interruption time of the extrusion for removing the die scum accumulated in the die. .. Therefore, by using the resin composition, a heat recovery article having excellent aging resistance and production efficiency can be extruded.

The compound may be a hindered phenol compound or a hindered amine compound. Hindered refers to a structure in which a bulky functional group is located at the ortho position of a phenolic hydroxyl group or an amino group. The hindered phenol compound and the hindered amine compound stabilize the radical trapped by the phenolic hydroxyl group or amino group by this bulky functional group. Therefore, radicals that cause aging are difficult to transfer to other molecules. Therefore, the aging resistance can be improved by using the above compound as a hindered phenol compound or a hindered amine compound.

Fluorine rubber may be included as the fluoropolymer. In this way, by including the fluororubber as the fluoropolymer, the flexibility of the heat recovery article produced is excellent. When fluororubber is included as the fluoropolymer, the adhesion of die scum to the heat recovery article and the appearance roughness of the heat recovery article tend to be remarkable. Even when using a fluoropolymer containing such a fluororubber, the resin composition is for suppressing the decrease in the extrusion linear velocity during extrusion molding of the heat recovery article, and for removing the die scum accumulated in the die. The interruption time of extrusion can be reduced. Therefore, a heat recovery article having excellent aging resistance and production efficiency and excellent flexibility can be extruded.

The content of the above compound with respect to 100 parts by mass of the fluoropolymer is preferably 0.1 part by mass or more and 6 parts by mass or less. By setting the content of the above compound within the above range, it is possible to stably perform extrusion molding while suppressing the adhesion of die scum to the heat recovery article and the rough appearance of the heat recovery article.

A heat recovery article according to another aspect of the present invention is a heat recovery article using the resin composition.

The said heat recovery article uses the said resin composition. Since the resin composition contains a compound having a functional group capable of capturing radicals as an additive, aging of the heat recovery article is suppressed by capturing the radicals by the functional group. In addition, in the heat recovery article, when the heat recovery article is formed by the extrusion molding method, it is difficult for the heat recovery article to be attached with the dicus and the heat recovery article to be rough. For this reason, it is possible to suppress a decrease in the extrusion linear velocity during extrusion molding and reduce the interruption time of extrusion for removing the die scum accumulated in the die. Therefore, the heat recovery article is excellent in aging resistance and production efficiency.

Here, the "main component" is a component having the highest content, for example, a component having a content of 50% by mass or more.

[Details of the embodiment of the present invention]
Hereinafter, the resin composition and the heat recovery article according to the embodiment of the present invention will be described in detail.

[Resin composition]
The resin composition is a resin composition for forming a heat recovery article by an extrusion molding method, and contains a fluoropolymer as a main component and an additive.

<Fluoropolymer>
Fluoropolymers are those in which at least one hydrogen atom bonded to a carbon atom that constitutes a repeating unit of a polymer chain is substituted with a fluorine atom or an organic group having a fluorine atom (hereinafter also referred to as "fluorine atom-containing group"). Say. The fluorine atom-containing group is a linear or branched organic group in which at least one hydrogen atom is substituted with a fluorine atom, and examples thereof include a fluoroalkyl group, a fluoroalkoxy group, and a fluoropolyether group. ..

The “fluoroalkyl group” means an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and includes a “perfluoroalkyl group”. Specifically, a "fluoroalkyl group" is a group in which all the hydrogen atoms of the alkyl group are replaced with fluorine atoms, and all the hydrogen atoms except one hydrogen atom at the end of the alkyl group are replaced with fluorine atoms. Groups and the like.

The “fluoroalkoxy group” means an alkoxy group in which at least one hydrogen atom is substituted with a fluorine atom, and includes “perfluoroalkoxy group”. Specifically, the "fluoroalkoxy group" is a group in which all the hydrogen atoms of the alkoxy group are substituted with fluorine atoms, and all the hydrogen atoms other than one hydrogen atom at the end of the alkoxy group are substituted with fluorine atoms. Groups and the like.

The “fluoropolyether group” is a monovalent group having a plurality of alkylene oxide chains as a repeating unit and having an alkyl group or a hydrogen atom at a terminal, the alkylene oxide chain and/or a terminal alkyl group or hydrogen. It means a monovalent group having a group in which at least one hydrogen atom in the atom is substituted with a fluorine atom. The "fluoropolyether group" includes a "perfluoropolyether group" having a plurality of perfluoroalkylene oxide chains as a repeating unit.

Examples of the fluoropolymer include polyvinylidene fluoride (PVDF), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-ethylene copolymer (ETFE), polychloro. Examples thereof include trifluoroethylene (PCTFE) and fluororubber (FKM). Among them, PVDF and PFA, which have excellent extrusion processability, are preferable.

As a minimum of content of a fluoropolymer in a resin composition, 60 mass% is preferred, 80 mass% is more preferred, and 90 mass% is still more preferred. On the other hand, the upper limit of the content of the fluoropolymer is preferably 99% by mass, more preferably 98% by mass. If the content of the above-mentioned fluoropolymer is less than the above lower limit, the heat shrinkage force of the produced heat recovery article is reduced, and thus the insulated wire or the like may not be sufficiently covered. Further, the heat-resistant, oil-resistant, flame-retardant and other properties peculiar to the fluoropolymer may not be sufficiently exhibited in the manufactured heat recovery article. On the other hand, when the content of the fluoropolymer exceeds the upper limit, the content of the compound having a radically scavengable functional group becomes insufficient, so that the adhesion of the dicus to the heat recovery article formed by extrusion molding. The effect of suppressing the appearance roughness of the heat recovery article may be insufficient.

The upper limit of the melting point of the fluoropolymer is preferably 215°C, more preferably 200°C, and even more preferably 160°C. If the melting point of the fluoropolymer exceeds the upper limit, the shrinking temperature at which the manufactured heat recovery article is shrunk by heat becomes high, so that the insulated wire or the like covered may be damaged by heat. On the other hand, the lower limit of the melting point of the fluoropolymer is not particularly limited as long as it is a temperature at which the heat recovery article does not soften or melt at the time of use, but can be 100° C., for example.

Further, the above-mentioned fluoropolymer may include fluororubber (FKM). In this way, by including the fluororubber as the fluoropolymer, the flexibility of the heat recovery article produced is excellent. When fluororubber is included as the fluoropolymer, the adhesion of die scum to the heat recovery article and the appearance roughness of the heat recovery article tend to be remarkable. Even when using a fluoropolymer containing such a fluororubber, the resin composition is for suppressing the decrease in the extrusion linear velocity during extrusion molding of the heat recovery article, and for removing the die scum accumulated in the die. The interruption time of extrusion can be reduced. Therefore, a heat recovery article having excellent aging resistance and production efficiency and excellent flexibility can be extruded.

The lower limit of the content of the fluororubber in the fluoropolymer is preferably 20% by mass, more preferably 40% by mass. On the other hand, the upper limit of the content of the fluororubber is preferably 80% by mass, more preferably 60% by mass. When the content of the fluororubber is less than the above lower limit, the effect of improving flexibility of the heat recovery article formed may be insufficient. On the other hand, when the content of the fluororubber exceeds the upper limit, it is difficult to maintain the shape, and thus it may be difficult to mold the heat recovery article.

<Additive>
The resin composition contains a compound having a functional group capable of capturing radicals as an additive. Such compounds are not particularly limited as long as they have a functional group capable of capturing radicals, and examples thereof include phenol compounds, amine compounds, hindered amine compounds, hindered phenol compounds, salicylic acid derivatives, benzophenone compounds, and benzotriazole. System compounds and the like. Of these, hindered phenol compounds and hindered amine compounds are preferable. In the hindered phenol compound and the hindered amine compound, since the bulky functional group is located at the ortho position of the functional group capable of capturing a radical, the radical can be captured and it is difficult to transfer to another molecule even after the radical capturing. Therefore, by using the hindered phenol compound and the hindered amine compound, aging due to radicals can be suppressed. Therefore, the aging resistance can be improved by using the above compound as a hindered phenol compound or a hindered amine compound.

Examples of the hindered phenol compound include tetrakis[methylene-3-(3,6-di-t-butyl-4-hydroxyphenyl)propionate]methane and 4,4butylidenebis-(3-methyl-6-t-butylphenol). , Triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate, and the like.

Further, as the hindered amine compound, tetrakis(2,2,6,6,-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, bis(2,2,6,6,6) -Tetramethyl-4 piperidyl) sebacic acid and the like can be mentioned.

The upper limit of the melting point of the compound is 220°C, more preferably 200°C and even more preferably 150°C. When the melting point of the compound exceeds the upper limit, it is difficult for the compound to melt when a heat recovery article is extrusion-molded using the resin composition. Therefore, the effect of the above compound as a lubricant may be insufficient. On the other hand, the lower limit of the melting point of the compound is not particularly limited, but 50° C. is preferable from the viewpoint of easy handling.

As a minimum of content of the above-mentioned compound to 100 mass parts of fluoropolymers, 0.1 mass part is preferred, 0.5 mass part is more preferred, and 1 mass part is still more preferred. On the other hand, the upper limit of the content of the compound is preferably 6 parts by mass, more preferably 5 parts by mass, and further preferably 4 parts by mass. If the content of the compound is less than the lower limit, the effect of suppressing the adhesion of die scum to the heat recovery article formed by extrusion molding and the appearance roughness of the heat recovery article may be insufficient. On the contrary, when the content of the compound exceeds the upper limit, the amount of the compound bleeding out during extrusion increases, so that the extrusion molded article slips at the die part, and it may not be possible to perform extrusion stably. is there.

Moreover, you may add another additive to the said resin composition further as needed. Examples of such additives include flame retardants, copper damage inhibitors, colorants, heat stabilizers, and ultraviolet absorbers.

[Heat recovery article]
The heat recovery article of FIG. 1 is used, for example, as a coating for connection between insulated wires, terminals of wiring, protection of metal pipes, insulation, waterproofing, and corrosion prevention. This heat recovery article comprises a tubular base material layer 1. Further, in the heat recovery article, the base material layer 1 is formed of the resin composition.

The base material layer 1 is formed as a tube whose diameter is reduced by being heated. The average inner diameter and the average thickness of the base material layer 1 are appropriately selected according to the application and the like. The average inner diameter of the base material layer 1 before heat shrinkage can be, for example, 1 mm or more and 60 mm or less. The average inner diameter of the base material layer 1 after heat shrinkage can be, for example, 30% or more and 50% or less of the average inner diameter before heat shrinkage. The average thickness of the base material layer 1 can be, for example, 0.1 mm or more and 5 mm or less.

The upper limit of the secant modulus of the heat recovery article is preferably 200 MPa, more preferably 160 MPa, further preferably 100 MPa. If the secant modulus exceeds the upper limit, the flexibility of the heat recovery article is insufficient, since the portion of the insulated wire covered with the heat recovery article cannot be bent, it may be difficult to handle the insulated wire. is there. On the other hand, the lower limit of the secant modulus of the heat recovery article is not particularly limited, but is usually about 30 MPa. The secant modulus is a value measured based on ASTM-D5223-92.

The upper limit of the rate of decrease in tensile strength after heating the heat-recovered article at 250° C. for 7 days before heating is preferably 30%, more preferably 20%, and even more preferably 10%. If the rate of decrease in tensile strength exceeds the upper limit, the aging resistance of the heat recovery article may be insufficient. On the other hand, the lower limit of the reduction rate of the tensile strength is not particularly limited and may be 0%. The tensile strength of the heat recovery article is a value measured according to JIS-K-7162 (1994).

The upper limit of the rate of decrease in elongation after heating the heat-recovered article at 250°C for 7 days before heating is preferably 50%, more preferably 40%, and even more preferably 30%. If the rate of decrease in elongation exceeds the upper limit, the aging resistance of the heat recovery article may be insufficient. On the other hand, the lower limit of the elongation reduction rate is not particularly limited and may be 0%. The elongation of the heat recovery article is a value measured according to JIS-K-7162 (1994).

[Method of manufacturing heat recovery article]
The method for producing the heat recovery article is a method for producing a heat recovery article including the base material layer 1 using the resin composition, and includes a step of forming the base material layer 1 by an extrusion molding method. Specifically, the method for manufacturing the heat recovery article includes the following steps.
(1) A step of preparing a base material layer forming material for forming the base material layer 1 (2) A step of forming an extrusion molded article by extruding the base material layer forming material using a melt extruder ( 3) A step of expanding the diameter of the extruded product to obtain a heat recovery article.

(1) Base Layer Forming Material Preparation Step In the method for manufacturing the heat recovery article, the resin composition is used as the base layer forming material. The resin composition is obtained by adding a fluoropolymer as a main component, a compound having a melting point of 220° C. or less as an additive, and a radically scavengable functional group, and other additives as necessary, For example, it can be prepared by mixing with a melt mixer. As the melt mixer, a known mixer such as an open roll, a Banbury mixer, a pressure kneader, a single-screw mixer or a multi-screw mixer can be used.

(2) Extrusion Molding Step An extrusion molded article is formed by extruding the base material layer forming material using a known melt extrusion molding machine. The heat resistance of the extruded product may be improved by crosslinking the constituent materials of the base material layer forming material. Examples of the crosslinking method include crosslinking by irradiation with ionizing radiation, chemical crosslinking, and thermal crosslinking.

The die temperature in the extrusion molding step is not particularly limited, but may be, for example, a temperature higher by 10° C. or more and 100° C. or less than the melting point of the fluoropolymer contained in the resin composition as a forming material.

The lower limit of the linear extrusion speed in the extrusion step is preferably 5 m/min, more preferably 8 m/min. If the extrusion linear velocity is less than the lower limit, the productivity of the heat recovery article may be insufficient. On the other hand, the upper limit of the extrusion linear velocity is not particularly limited, but is usually about 15 m/min.

(3) Expanding process of extruded product Expanding the extruded product to a specified inner diameter by introducing compressed air into the extruded product while heating it to a temperature above its melting point. After that, cooling is performed to fix the shape. The diameter expansion of such an extrusion-molded product is performed so that the inner diameter of the extrusion-molded product is, for example, 2 times or more and 4 times or less. In this way, the heat-recovered article is obtained by expanding the diameter of the extruded product and fixing its shape.

〔advantage〕
Since the resin composition contains a compound having a functional group capable of capturing radicals as an additive, the heat recovery article produced by using the resin composition suppresses aging by capturing radicals by the functional group. To be done. Further, since the above compound has a melting point of 220° C. or less, it easily melts when a heat recovery article is extrusion-molded using the resin composition, and since it has a different polarity from the fluoropolymer, it functions as a lubricant by bleeding out. .. Therefore, it is possible to suppress the decrease in the extrusion linear velocity when the heat recovery article is extrusion-molded using the resin composition, and to reduce the interruption time of the extrusion for removing the die scum accumulated in the die. .. Therefore, by using the resin composition, a heat recovery article having excellent aging resistance and production efficiency can be extruded.

[Other Embodiments]
The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configurations of the above-described embodiments, but is shown by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope. It

The heat recovery article of the present invention is not limited to the tube-shaped heat recovery article shown in FIG. 1, but may be, for example, a cap-shaped heat recovery article. Such a heat recovery article can be manufactured by heat-shrinking and closing one end of the tubular heat recovery article. This heat recovery article can be suitably used, for example, for terminal treatment of wiring.

Further, the heat recovery article of the present invention may include an adhesive layer laminated on the inner peripheral surface of the base material layer. This adhesive layer is for enhancing the adhesiveness between the adhered portion and the base material layer and improving the waterproof property and the like.

As the main component of this adhesive layer, for example, polyamide or the like can be used. This polyamide may be crosslinked by irradiation with ionizing radiation. Further, the adhesive layer may contain additives such as a viscosity characteristic improver, a deterioration suppressor, a flame retardant, a lubricant, a coloring agent, a heat stabilizer, an ultraviolet absorber and an adhesive.

The average thickness and average length of the adhesive layer can secure an amount of adhesive that can fill the inside of the base material layer after contraction, and ensure an inner diameter that allows an insulated wire or the like to pass through inside the heat recovery article. It is decided to be done. From this point of view, for example, the average thickness of the adhesive layer can be 2% or more and 8% or less of the average inner diameter of the base material layer. The average length of the adhesive layer can be equal to the average length of the base material layer.

The heat recovery article including the base material layer and the adhesive layer can be formed by, for example, extruding the base material layer and the adhesive layer separately. In this case, the heat recovery article is obtained by disposing the adhesive layer on the inner peripheral surface of the base material layer expanded after extrusion molding, applying this to the adherend, and then shrinking the base material layer. used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[Fluoropolymer]
As the fluoropolymer, fluororubber (FKM; "Viton B202" manufactured by DuPont, specific gravity 1.86, Mooney viscosity 23) and polyvinylidene fluoride (PVDF; "Kainer 2800" manufactured by Arkema, melting point 140°C, specific gravity 1. 78, MFR 5) was prepared.

[Additive]
The following nine kinds of additives were prepared as additives.
(1) Tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane ("IRGANOX 1010" manufactured by BASF, melting point 115°C, molecular weight 1178, hereinafter "phenolic structure" Also called "body 1")
(2) 4,4′-butylidene bis-(3-methyl-6-t-butylphenol (“ADEKA STAB AO-40” manufactured by ADEKA CORPORATION, melting point 210° C., molecular weight 383, hereinafter also referred to as “phenol structure 2”)
(3) 1,5,3-Tris(3,5-di-t-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene (“ADEKA STAB AO-330” manufactured by ADEKA CORPORATION, melting point 245) °C, molecular weight 775, hereinafter also referred to as "phenol structure 3")
(4) Silicone ("Torefil R902A" manufactured by Toray Dow Corning, specific gravity 1.33)
(5) Acrylic polymer ("Metablen L-1000" manufactured by Mitsubishi Rayon)
(6) Stearic acid (“powdered stearic acid Sakura” manufactured by NOF Corporation, melting point 57.5° C., molecular weight 284)
(7) PE wax (“High Wax 420P” manufactured by Mitsui Chemicals, melting point 118° C., molecular weight 4000, density 0.93 g/cm ³ ).
(8) FKM lubricant ("Technoflon NM" manufactured by Solvay)
(9) PVDF lubricant ("Sorev 11010" manufactured by Solvay)

Among the above additives, the phenol structures 1 to 3 are hindered phenol compounds and have a radical-capturing functional group. In addition, all of the structures other than the phenolic structures 1 to 3 are lubricants and have no functional group capable of capturing radicals.

[Manufacture of heat recovery articles]
A resin composition was prepared in which the above-mentioned fluoropolymer and additives were blended in the blending amounts shown in Table 1. A heat recovery article was produced by extrusion molding using this resin composition. For extrusion molding, an extrusion molding die having a die diameter of 8 mm and a point diameter of 4.5 mm was used. The molded body extruded by this molding die had an outer diameter of 6 mm and an inner diameter of 4 mm. The extrusion molding was performed at a die temperature of 220° C. and a linear velocity of 10 m/min. By expanding the diameter of the extrusion-molded product thus obtained and fixing the shape, 1-No. Eighteen heat recovery articles were obtained.

[Evaluation method]
The heat recovery article was evaluated for the presence of die scum in the die, the appearance of the heat recovery article for rough appearance, the secant modulus, and the aging rate.

<Staying of dicus>
In the extrusion molding, the presence or absence of die scum remaining in the die after 500 m extrusion was visually confirmed. The evaluation criteria are as follows. The results are shown in Table 1. In addition, when the die scum is accumulated in the die, if the extrusion molding is continued as it is, the die scum may be attached to the heat recovery article, which may cause a defect of the heat recovery article. Therefore, it is necessary to interrupt the extrusion molding and remove the die scum.
(Evaluation criteria for dicus)
A: No die scum remains in the die, and extrusion molding can be continued.
B: Die scum stays in the die, and it is necessary to interrupt extrusion molding and remove the die scum.

<Rough appearance>
The appearance of each heat recovery article thus obtained was visually confirmed. The evaluation criteria are as follows. The results are shown in Table 1.
(Evaluation criteria for appearance roughness)
A: No rough appearance is observed.
B: Rough appearance is observed.

<Second secant>
The secant modulus of each obtained heat recovery article was measured according to ASTM-D5223-92. The results are shown in Table 1. The secant modulus means that the smaller the measured value, the more excellent the flexibility of the heat recovery article.

<Aging rate>
Regarding the aging rate of each heat recovery article obtained, the aging rate of tensile strength and the aging rate of elongation of each heat recovery article were measured. Specifically, the tensile strength and elongation immediately after production and the tensile strength and elongation after heating at 250° C. for 7 days were measured, and the tensile strength and elongation after heating with respect to the tensile strength and elongation before heating and The percentage of elongation was calculated for each. The results are shown in Table 1. The tensile strength [MPa] and the elongation [%] of the heat recovery article were measured according to JIS-K-7162 (1994). The larger the aging rate [%], the more advanced the aging.

In Table 1, “−” in the fluoropolymer and the additive means that the content is 0. Moreover, "-" in the measurement of the aging rate means that it is not measured.

From the results of Table 1, No. 1-No. The heat recovery article obtained by extrusion-molding the resin composition of No. 6 has no retention of die scum in the die, has no rough appearance of the heat recovery article, and has a low aging rate.

On the other hand, No. 7-No. In the heat recovery article of No. 9, since the resin composition does not include an additive, retention of die scum in the die and rough appearance of the heat recovery article occur. In addition, No. In the heat recovery article No. 10, since the phenol structure 3 having a melting point higher than 220° C. was used as the additive of the resin composition, it is considered that the phenol structure 3 does not melt sufficiently at the die temperature (220° C.) during extrusion molding. To be Therefore, it is considered that the phenol structure 3 did not sufficiently bleed out and did not function sufficiently as a lubricant. In addition, No. 11-No. In the heat-recovery article of No. 14, since the lubricant having no radical scavenging function was used as the additive of the resin composition, it is considered that the lubricant itself has aged. In addition, No. When the resin composition of Example 14 was extrusion-molded, a phenomenon was observed in which the extrusion-molded body slipped at the die part and the extrusion was not stable. It is considered that this is because the difference in polarity between the fluoropolymer and the PE wax used as the additive was too large, so that the polymer bleeded out excessively and slipped excessively. Furthermore, No. 15 and No. 15 In the heat recovery article of 16, since a fluorine-based lubricant is used as an additive of the resin composition, since the difference in polarity between the additive and the fluoropolymer is too small, the additive does not sufficiently bleed out and the lubricant It is thought that it did not function sufficiently.

From the above, it can be seen that the heat recovery article excellent in aging resistance can be efficiently produced by the fact that the resin composition contains, as an additive, a compound having a melting point of 220° C. or less and a functional group capable of radical scavenging. ..

In addition, No. 1-No. No. 5 in which the content of the fluororubber with respect to the fluoropolymer was 20% by mass or more and 80% by mass or less, and the content of the fluororubber was 100% by mass. No. 17 in which the content rate of 17 and the fluororubber is 0% by mass. Higher flexibility than 18 When the resin composition contains the fluororubber in the content within the above range, the heat recovery article to be formed has excellent flexibility, and by using the resin composition, adhesion of a dicus or heat recovery article to the heat recovery article It can be seen that the effect of preventing the appearance roughness is exhibited.

By using the resin composition of the present invention, a heat recovery article having excellent aging resistance can be efficiently extrusion-molded. Therefore, the heat recovery article using the resin composition of the present invention is excellent in aging resistance and production efficiency.

1 Base material layer

Claims (2)

A resin composition for forming a heat recovery article by an extrusion molding method,
Contains a fluoropolymer as a main component and an additive,
The additive includes a compound having a melting point of 220° C. or less and a functional group capable of capturing a radical,
Ri der melting point of 215 ° C. or less of the fluoropolymer,
The above compound is a hindered phenol compound or a hindered amine compound,
As the fluoropolymer, 40% by mass or more and 80% by mass or less of fluororubber is contained,
A resin composition in which the content of the compound is 0.1 part by mass or more and 6 parts by mass or less based on 100 parts by mass of the fluoropolymer . A heat recovery article using the resin composition according to claim 1 .

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