JP2017095637A - Polypropylene resin composition for deformation recovery heat resistant structure and deformation recovery heat resistant structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propylene resin composition for deformation recovery heat resistant structure excellent in deformation recovery property under high temperature and having heat resistance and a deformation recovery heat resistant structure.SOLUTION: There is provided a polypropylene resin composition for deformation recovery heat resistant structure containing a polypropylene resin composition (X) consisting of a component (A) of 1 to 99 pts.wt. and a component (B) of 1 to 99 pts.wt., wherein total of the component (A) and the component (B) is 100 pts.wt., as an essential component and having melt flow rate (MFR:230°C and 2.16 kg load), melting peak temperature and flexural modulus satisfying specific ranges. There is provided a deformation recovery heat resistant structure having a three-dimensional net structure by bending a plurality of strands obtained by extrusion molding with three-dimensional loop and fusing a part of connection part of the loop. Component (A): one or more kind of propylene single polymer and/or propylene-α-olefin copolymer having the melting peak temperature, the MFR and the density satisfying specific ranges. Component (B):one or more kind of propylene copolymer having the density and the MFR satisfying specific ranges.SELECTED DRAWING: None

Description

  The present invention relates to a polypropylene-based resin composition for deformation-recoverable heat-resistant structures and a deformation-recoverable heat-resistant structure, and in particular, has heat resistance that can maintain a shape even at high temperatures, preferably 121 ° C. or higher. In addition, the present invention relates to a polypropylene resin composition that constitutes a structure having deformation recovery properties when the load is removed after being continuously deformed by a continuous load, and a deformation recovery heat resistant structure comprising the same.

  Conventionally, deformation-recoverable structures, for example, bedding such as beds, cushion materials for homes, vehicles, ships, aircraft seats, etc., have been made of urethane foam, non-elastic crimped cotton, and non-elastic crimped fibers. Bonded resin cotton or hard cotton has been used.

In recent years, an attempt has been made to use a three-dimensional network structure obtained by extruding a thermoplastic resin in a loop shape by extrusion molding, heat-bonding the strands, and cooling and solidifying the strands as the cushioning material. As the thermoplastic resin, it is known to use a polyester-based elastomer, a polyurethane-based elastomer, or a polyamide-based elastomer (for example, see Patent Document 1: Japanese Patent Laid-Open No. 7-068061). However, these resins are expensive and difficult to recycle.
On the other hand, Patent Document 2 (Japanese Patent Laid-Open No. 2004-218116) and Patent Document 3 (Japanese Patent Laid-Open No. 2006-2001117) describe an ethylene-vinyl acetate copolymer (EVA) and an ethylene / α-olefin copolymer. Certain polyethylene-based resins are disclosed and widely used. However, although three-dimensional network structures using these polyethylene-based resins have excellent performance, they place importance on flexibility and thermal adhesiveness. There is a problem that the melting point of the resin is lowered and the deformation recovery property at a high temperature (for example, 70 ° C.) is poor. For this reason, when a polyethylene-based resin is used, application to automobile cushions, cushioning parts, and bed cushions with a heating function is greatly limited.
In order to solve this problem, for example, in Patent Document 4 (Japanese Patent Laid-Open No. 2013-181117), a specific ethylenically unsaturated silane compound is grafted to a specific ethylene polymer, and the resulting graft reaction product is grafted. A method of imparting heat resistance by a method in which a silanol condensation catalyst-containing material is stored in a room in which warm water at 40 ° C. is sprayed in a mist for one week after crosslinking and a crosslinking treatment is disclosed. The cross-linking treatment took a long time of one week, resulting in poor productivity, and the cross-linking treatment was inferior in recyclability.

Furthermore, in recent years, hospitals and the like have a need for cleaning the cushion itself and, in some cases, sterilizing treatment, and there is a demand for resistance to steam sterilization treatment at high temperatures, preferably 121 ° C. or higher.
Those using a polyethylene resin composition melt during steam sterilization, making it difficult to maintain the shape. Examples of the resin that can withstand the steam sterilization treatment include a polypropylene-based resin. However, since polypropylene causes plastic deformation, there is a problem of poor deformation recovery.
In order to solve this problem, for example, Patent Document 5 (Japanese Patent Laid-Open No. 2002-061059) discloses a three-dimensional structure in which 5 to 30% by weight of SBS is blended with polypropylene. It is unclear whether it can withstand steam sterilization, and the compression residual strain that shows deformation recovery is only shown in the test results without holding time at room temperature. However, after being continuously deformed by a continuous load, it is impossible to know the deformation recovery property when the load is removed and the deformation recovery property at high temperatures.

Japanese Patent Laid-Open No. 7-068061 JP 2004-218116 A JP 2006-200117 A JP 2013-181117 A JP 2002-061059 A

  In view of the above-mentioned problems of the prior art, the object of the present invention is to provide heat resistance that is flexible and excellent in deformation recovery at high temperature, and that can retain its shape even under high temperature, preferably at 121 ° C. or higher. The present invention provides a polypropylene resin composition for deformation-recoverable heat-resistant structures and a deformation-recoverable heat-resistant structure comprising the same.

As a result of intensive studies to solve the above problems, the present inventor has found that a polypropylene containing a specific propylene polymer component (A) and a specific propylene-α-olefin copolymer (B) in a specific ratio. The structural body obtained by using the polypropylene resin composition (Y) for a heat-resisting structure having a deformation-recovering heat-resisting structure having the resin-based resin composition (X) as an essential component is excellent even at a high temperature of, for example, 70 ° C. It has been found that it exhibits an unprecedented characteristic that it exhibits deformation recovery and can retain its shape even at a high temperature of 121 ° C. or higher, and the present invention has been completed.
The present invention provides the following polypropylene resin composition for deformation-recoverable heat-resistant structures and a deformation-recoverable heat-resistant structure comprising the same.

[1] A polypropylene resin comprising 1 to 99 parts by weight of the following component (A) and 1 to 99 parts by weight of the following component (B) (provided that the total of the component (A) and the component (B) is 100 parts by weight) A polypropylene resin composition for deformation-recoverable heat-resistant structures, which contains the composition (X) as an essential component and satisfies the following characteristics (y1) to (y3).
(Y1) The melt flow rate (MFR: 230 ° C., 2.16 kg load) is 1.0 to 100 g / 10 minutes.
(Y2) Melting peak temperature (Tm) is 121-170 degreeC.
(Y3) The bending elastic modulus is 10 to 200 MPa.
Component (A): One or more propylene homopolymers and / or propylene-α-olefin copolymers satisfying the following (a1) to (a3).
(A1) The melting peak temperature (Tm) is 121 to 170 ° C.
(A2) The melt flow rate (MFR: 230 ° C., 2.16 kg load) is 0.1 to 500 g / 10 minutes.
(A3) The density is 0.89 g / cm ³ or more.
Component (B): at least one propylene-based copolymer satisfying the following (b1) to (b2).
(B1) The density is 0.88 g / cm ³ or less.
(B2) MFR is 1.0 to 100 g / 10 min.

[2] A deformation-recoverable heat-resistant structure comprising the polypropylene-based resin composition (Y) for deformation-recoverable heat-resistant structure according to [1].
[3] The deformation-recoverable heat-resistant structure is formed by twisting a continuous linear body made of a plurality of strands obtained by extrusion molding into a three-dimensional random loop, and at least a part of contact portions of the plurality of loops is fused. The deformation-recoverable heat-resistant structure according to [2] above, which is a network structure having a three-dimensional network structure.

  The polypropylene resin composition for deformation-recoverable heat-resistant structures of the present invention provides a structure having excellent deformation-recovery properties and heat resistance.

The polypropylene resin composition (Y) for deformation-recoverable heat-resistant structures of the present invention (hereinafter also simply referred to as “polypropylene resin composition (Y)”) comprises 1 to 99 parts by weight of the following components (A) and the following components: (B) A polypropylene resin composition (X) comprising 1 to 99 parts by weight (provided that the total of the component (A) and the component (B) is 100 parts by weight) is contained as an essential component, and the following characteristics ( It is a polypropylene resin composition for deformation-recoverable heat-resistant structures characterized by satisfying y1) to (y3).
(Y1) The melt flow rate (MFR: 230 ° C., 2.16 kg load) is 1.0 to 100 g / 10 minutes.
(Y2) Melting peak temperature (Tm) is 121-170 degreeC.
(Y3) The bending elastic modulus is 10 to 200 MPa.
Component (A): One or more propylene homopolymers and / or propylene-α-olefin copolymers satisfying the following (a1) to (a3).
(A1) The melting peak temperature (Tm) is 121 to 170 ° C.
(A2) The melt flow rate (MFR: 230 ° C., 2.16 kg load) is 0.1 to 500 g / 10 minutes.
(A3) The density is 0.89 g / cm ³ or more.
Component (B): at least one propylene-based copolymer satisfying the following (b1) to (b2).
(B1) The density is 0.88 g / cm ³ or less.
(B2) MFR is 1.0 to 100 g / 10 min.
Hereinafter, each item will be described in detail.

[Component (A)]
The component (A) used in the present invention satisfies the above characteristics (a1), (a2), and (a3).
Each of the above characteristics will be specifically described below.

Characteristic (a1): Melting peak temperature (Tm)
The melting peak temperature (Tm) of the component (A) used in the present invention is 121 to 170 ° C.
Component (A) is composed of one or two or more types of propylene homopolymer and / or propylene-α-olefin copolymer. When the component (A) is composed of two or more components, a blend of two or more components is used. The melting peak temperature is 121 ° C to 170 ° C. As the propylene-α-olefin copolymer, a propylene-α-olefin random copolymer and a propylene-α-olefin block copolymer are preferable.
When the melting peak temperature is 121 ° C. or higher, the deformation-recoverable heat-resistant structure of the present invention can exhibit heat resistance sufficient to maintain its shape at a high temperature, for example, in an environment of 121 ° C. or higher. Moreover, the thing whose melting peak temperature is 170 degrees C or less is easy to acquire.
The preferable range of the melting peak temperature is 125 ° C to 170 ° C, more preferably 130 ° C to 170 ° C, and still more preferably 135 ° C to 170 ° C.

Characteristic (a2): Melt flow rate (MFR: 230 ° C., 2.16 kg load)
The melt flow rate (MFR) of the component (A) used for this invention is 0.1-500 g / 10min.
Component (A) is composed of one or two or more types of propylene homopolymer and / or propylene-α-olefin copolymer as described above. As a blend of the components, the MFR is 0.1 to 500 g / 10 min. As the propylene-α-olefin copolymer, a propylene-α-olefin random copolymer and a propylene-α-olefin block copolymer are preferable.
Here, MFR is measured according to JIS K7210: 1999 method A, condition M (230 ° C., 2.16 kg load).
When the MFR is 0.1 g / 10 min or more, it becomes easy to adjust the MFR of the polypropylene resin composition (Y) of the present invention to 1.0 g / 10 min or more, which increases the load during molding. However, the molded body itself can be easily molded. Further, when the MFR is 500 g / 10 min or less, it becomes easy to make the MFR of the polypropylene resin composition (Y) of the present invention 100 g / 10 min or less. Good molding stability when used.
The preferable range of MFR is 1.0 to 500 g / 10 minutes, more preferably 5.0 to 200 g / 10 minutes, still more preferably 5.0 to 100 g / 10 minutes.

Property (a3): Density (Unit: g / cm ³ )
The density of the component (A) used in the present invention is 0.89 g / cm ³ or more.
The component (A) is composed of one or more propylene homopolymers and / or propylene-α-olefin copolymers as described above, but when composed of two or more components, As a blend of the components, the density may be 0.89 g / cm ³ or more. As the propylene-α-olefin copolymer, a propylene-α-olefin random copolymer and a propylene-α-olefin block copolymer are preferable.
If the density is 0.89 g / cm ³ or more, the crystal component necessary for maintaining the shape at high temperature is sufficiently present, so that the heat resistance is good.
The upper limit of the density is not particularly defined, but generally the density of the propylene polymer is 0.92 or less.

Other characteristics:
The component (A) used in the present invention may satisfy the above characteristics (a1), (a2) and (a3), but when a propylene-α-olefin copolymer is used as the component (A), the component (A) preferably has a propylene content of more than 85% by weight and less than 100% by weight, and an α-olefin content of more than 0% by weight and less than 15% by weight.
When a propylene-α-olefin copolymer is used as the component (A), the α-olefin is preferably ethylene and / or butene.
The manufacturing method of a component (A) is not specifically limited, It can select suitably from a commercially available propylene homopolymer, a propylene-alpha-olefin copolymer, and a propylene-alpha-olefin block copolymer. Specific examples include the trade name “Novatech PP”, the trade name “Wintech”, the trade name “Newcon”, and the trade name “Wellnex” manufactured by Nippon Polypro Co., Ltd.

[Component (B)]
The component (B) used in the present invention is composed of one or more propylene polymers that satisfy the above characteristics (b1) and (b2).
The above characteristics will be specifically described below.

Characteristic (b1): density (unit: g / cm ³ )
The component (B) used in the present invention is 0.88 g / cm ³ or less.
Component (B) is composed of one or two or more types of propylene-based copolymers, and when composed of two or more components, as a blend of two or more components, the density is 0.88 g / cm ³ or less. I just need it.
If the density is 0.88 g / cm ³ or less, it is easy to adjust the flexural modulus of the polypropylene resin composition (Y) of the present invention to 200 MPa or less, and it is obtained from the polypropylene resin composition (Y) of the present invention. The deformation-recoverable heat-resistant structure tends to be excellent in flexibility. In addition, when the density is 0.88 g / cm ³ or less, the component (B) is less likely to cause plastic deformation at the time of deformation, and thus the deformation-recoverable heat-resistant structure obtained from the polypropylene resin composition (Y) of the present invention. It tends to be excellent in deformation recovery.
The preferred range of density is at 0.875 g / cm ³ or less, more preferably 0.87 g / cm ³ or less. The lower limit of the density is not particularly defined, but is preferably 0.85 g / cm ³ or more from the viewpoint of handling properties.

Characteristic (b2): Melt flow rate (MFR: 230 ° C., 2.16 kg load)
The melt flow rate (MFR) of the component (B) used in the present invention is 1.0 to 100 g / 10 min.
Component (B) is composed of one or two or more types of propylene-based copolymers, and when composed of two or more types of components, the MFR is 1.0 to 100 g / 10 min as a blend of two or more types of components. If it is.
If the MFR is 1.0 g / 10 min or more, it becomes easy to adjust the MFR of the polypropylene resin composition (Y) of the present invention to 1.0 g / 10 min or more, and the load during molding increases. However, the molded body itself can be easily molded. Further, when the MFR is 100 g / 10 min or less, it becomes easy to make the MFR of the polypropylene resin composition (Y) of the present invention 100 g / 10 min or less, and the stability of molding, particularly for extrusion molding. Good molding stability when used.
The preferable range of MFR is 1.0 to 80 g / 10 minutes, more preferably 2.0 to 50 g / 10 minutes, and still more preferably 5.0 to 50 g / 10 minutes.

Other characteristics:
The component (B) used in the present invention may satisfy the above characteristics (b1) and (b2), but is preferably a propylene-α-olefin copolymer. The α-olefin is preferably ethylene and / or butene.
The manufacturing method of a component (B) is not specifically limited, It can select suitably from a commercially available propylene-type copolymer. Specifically, ExxonMobil brand name “Vistamaxx”, Dow Chemical brand name “Versify”, Mitsui Chemicals brand name “Toughmer PN”, “Notio SN”, “Toughmer XM”, Sumitomo Chemical The brand name “Tough Selenium” manufactured by the company may be mentioned.

[Polypropylene resin composition (X)]
The polypropylene resin composition (X) used in the present invention comprises 1 to 99 parts by weight of the component (A) and 1 to 99 parts by weight of the component (B). However, the total of the component (A) and the component (B) is 100 parts by weight.
If the component (A) is 1 part by weight or more, the structure obtained from the polypropylene resin composition (Y) of the present invention has a heat resistance sufficient to maintain its shape at a high temperature, preferably 121 ° C. or higher. It becomes easy to express. Further, if the component (A) is 99 parts by weight or less, it is difficult to cause plastic deformation during deformation, and the deformation recovery heat-resistant structure obtained from the polypropylene resin composition (Y) of the present invention has excellent deformation recovery properties. It tends to be a thing.
The preferred range of component (A) in the polypropylene resin composition (X) is 1 to 75 parts by weight, more preferably 10 to 60 parts by weight, and even more preferably 25 to 50 parts by weight.

[Polypropylene resin composition (Y)]
The polypropylene resin composition (Y) of the present invention comprises the polypropylene resin composition (X) as an essential component and satisfies the above characteristics (y1), (y2), and (y3).

Characteristic (y1): Melt flow rate (MFR: 230 ° C., 2.16 kg load)
The melt flow rate (MFR) of the polypropylene resin composition (Y) of the present invention is 1.0 to 100 g / 10 min.
Here, MFR is measured according to JIS K7210: 1999 method A, condition M (230 ° C., 2.16 kg load).
When MFR is 0.1 g / 10 min or more, the load during molding does not increase, and molding of the molded body is easy. Further, when the MFR is 100 g / 10 min or less, the molding stability, particularly, the molding stability when used for extrusion molding is good.
The melt flow rate (MFR) of the polypropylene resin composition (Y) considers the MFR of the component (A), and the MFR of the component (B) and the third component MFR other than the polypropylene resin composition (X). Can be adjusted by appropriate selection.
The preferable range of the melt flow rate (MFR) of the polypropylene resin composition (Y) is 2.0 to 50 g / 10 minutes, more preferably 5.0 to 50 g / 10 minutes, and particularly preferably 5.0 to 40 g / minute. 10 minutes.

Characteristic (y2): Melting peak temperature The melting peak temperature of the polypropylene resin composition (Y) of the present invention is 121 to 170 ° C.
When the melting peak temperature is 121 ° C. or higher, the deformation-recoverable heat-resistant structure of the present invention can exhibit heat resistance sufficient to maintain its shape at a high temperature, for example, in an environment of 121 ° C. or higher. Moreover, the thing whose melting peak temperature is 170 degrees C or less is easy to acquire.
The preferable range of the melting peak temperature is 125 to 170 ° C, more preferably 130 to 170 ° C.

Property (y3): Flexural modulus (unit: MPa)
The polypropylene resin composition (Y) for deformation-recoverable heat-resistant structures of the present invention has a flexural modulus of 10 to 200 MPa, preferably 40 to 200 MPa, more preferably 50 to 150 MPa.
If the flexural modulus is 10 MPa or more, the deformation-recoverable heat-resistant structure obtained from the polypropylene resin composition (Y) of the present invention has sufficient rigidity to maintain its shape. Moreover, if a bending elastic modulus is 200 Mpa or less, it can be said that the deformation | transformation heat-resistant structure obtained from the polypropylene resin composition (Y) of this invention has a preferable softness | flexibility.
The flexural modulus can be adjusted to a desired value by appropriately selecting the composition of component (A) and component (B), the blending ratio, the blending amount of the following other components, and the like.

Other characteristics:
The polypropylene resin composition (Y) for deformation-recoverable heat-resistant structures of the present invention preferably has a tensile yield stress of 20 MPa or less, more preferably 15 MPa or less, still more preferably 12 MPa or less, and particularly preferably 10 MPa or less. Yes, most preferably not observed. If the tensile yield stress is within the above range, it is easy to develop deformation recovery properties, which is preferable.

[Other ingredients]
The polypropylene resin composition (Y) of the present invention is a resin composition containing the above-mentioned polypropylene resin composition (X) as an essential component, but other resins or additives within the range not impairing the object of the present invention. Various other components such as an agent can be added and used.

(1) Additives In the polypropylene resin composition (Y) of the present invention, additives such as an antioxidant that can be added to the polypropylene resin can be appropriately blended as long as the effects of the present invention are not hindered.
Specifically, 2,6-di-t-butyl-p-cresol (BHT), tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (BASF Japan) And trade name “IRGANOX 1010”) and n-octadecyl-3- (4′-hydroxy-3,5′-di-t-butylphenyl) propionate (trade name “IRGANOX 1076” manufactured by BASF Japan). Phenol stabilizers such as bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite and tris (2,4-di-t-butylphenyl) phosphite Lubricants represented by higher fatty acid amides such as oleic acid amide and erucic acid amide, higher fatty acid esters and silicone oils, Antistatic agent represented by glycerin ester, sorbitan acid ester, polyethylene glycol ester and the like of fatty acid having 8 to 22 carbon atoms, sorbitol nucleating agent (for example, trade name “Gelol MD” manufactured by Shin Nippon Rika Co., Ltd.), aroma Group phosphates (for example, trade names “NA-21” and “NA-11” manufactured by ADEKA), trade name “Millad” series manufactured by Milliken, brand name “Hyperform” manufactured by Milliken, manufactured by Shin Nippon Rika Co., Ltd. Trade name "NJ Star NU-100", nucleating agent represented by talc, high-density polyethylene, etc., molecular weight adjustment represented by anti-blocking agent represented by silica, calcium carbonate, talc, organic peroxide, etc. For higher fatty acid metal salts and hydrotalcites, such as agents, crosslinking aids, calcium stearate Neutralizing agent, light stabilizer, UV absorber, metal deactivator, peroxide, filler, antibacterial and antifungal agent, antibacterial agent, antibacterial agent, fluorescent whitening agent, antifogging agent, flame retardant Coloring agents, pigments, natural oils, synthetic oils, waxes, and organic and inorganic flame retardants may be added depending on the intended use.

  Examples of organic flame retardants include brominated flame retardants and phosphorus flame retardants, and it is preferable to use a flame retardant aid such as antimony trioxide as necessary. For example, the content of the brominated flame retardant may be appropriately adjusted according to the desired flame retardant performance, but 0.1 to 10% by weight is contained in the polypropylene resin composition (Y) of the present invention, Moreover, it can be illustrated that the flame retardant aid contains about 1/4 to 1/2 amount of the brominated flame retardant. Furthermore, the content of the phosphorus-based flame retardant may be appropriately adjusted according to the desired flame retardant performance, but it is contained in the polypropylene resin composition (Y) of the present invention in an amount of about 1 to 30% by weight. It can be illustrated.

  As antibacterial and antibacterial agents, the brand name “Novalon” manufactured by Toagosei Co., Ltd., the brand name “Zeomic” manufactured by Sinanen Zeomic Co., the brand name “Bacte Killer” manufactured by Fuji Chemical Co., Ltd., and the brand name “Ion Pure” manufactured by Ishizuka Glass Examples include silver antibacterial agents, organic antibacterial agents exemplified by trade name “Royal Guard” manufactured by ADEKA and trade name “Wasaolo” manufactured by Mitsubishi Chemical Foods, Inc. The use of antibacterial agents is preferred. The content of the antibacterial agent and antibacterial agent may be appropriately adjusted according to the desired antibacterial and antibacterial performance, but is about 0.1 to 10% by weight in the polypropylene resin composition (Y) of the present invention. It can be exemplified.

(2) Other polymers The polypropylene resin composition (Y) for a heat-recoverable structure for deformation recovery of the present invention can be added to a polypropylene resin as long as the effects of the present invention are not hindered. A modifier such as a hydrogen resin can be appropriately contained.
The content of the other polymer is not particularly limited as long as the effects of the present invention are not hindered, but is usually 100 parts by weight or less with respect to 100 parts by weight of the polypropylene resin composition (X).

  Specifically, ethylene-α-olefin copolymers, such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polyethylene-based resins represented by ethylene-based elastomers and ethylene-vinyl acetate copolymers, 1-butene homopolymer, 1-butene-propylene copolymer, 1-butene-ethylene copolymer, and other polyolefins. In addition, alicyclic hydrocarbon resins represented by petroleum resins, terpene resins, rosin resins, coumarone indene resins, hydrogenated derivatives thereof, and the like, for example, product names Apel and Polyplastics manufactured by Mitsui Chemicals, Inc. You may add the cyclic | annular olefin (co) polymer represented by brand name TOPAS, the brand name ZEONOR, a ZEONEX by Nippon Zeon, etc.

  Further, a styrene-based elastomer can be added, and the styrene-based elastomer can be appropriately selected from commercially available ones. For example, as a hydrogenated product of a styrene-butadiene block copolymer, Kraton “Clayton G” from Polymer Japan Co., Ltd., “Tough Tech” from Asahi Kasei Chemicals, Inc., “Septon” from Kuraray Co., Ltd. As a hydrogenated product of styrene-vinylated polyisoprene block copolymer, Kuraray Co., Ltd. under the trade name “Hibler”, and as a hydrogenated product of styrene-butadiene random copolymer, “Dynalon” from JSR Co., Ltd. The product is sold under the product name. It may be.

[Production Method of Polypropylene Resin Composition (Y)]
The polypropylene resin composition (Y) of the present invention comprises components (A) and (B) constituting the above-described polypropylene resin composition (X), and, if necessary, other additives and polymer components. It can be obtained by mixing with a Henschel mixer, V blender, ribbon blender, tumbler blender or the like. Further, if necessary, it can also be obtained by a method of melt-kneading with a kneader such as a single-screw extruder, a multi-screw extruder, a kneader, a Banbury mixer after the mixing step.
Moreover, each component may be mixed and / or melt-kneaded at the same time, or may be mixed and / or melt-kneaded after making a part of the master batch.

[Deformation-resistant heat-resistant structure]
The deformation-recoverable heat-resistant structure of the present invention is excellent in deformation recovery property at high temperatures, and has heat resistance that allows the shape to be maintained at high temperatures, preferably even in an environment of 121 ° C. or higher.
The shape, forming method, and use of the structure are not particularly limited, but are used for applications that require deformation recovery when the load is removed after being continuously deformed by a continuous load.
For example, by injection molding or extrusion molding, a flat body, rod shape, spiral shape, or a molded body having an irregular cross section or hollow cross section is applied to an application similar to a buffer spring, or applied to a support such as a cushion. Cases.
Moreover, it can also be used as one component of the structure which has a core-sheath structure or has a side-by-side structure.
As an example of a suitable application form, a continuous linear body composed of a plurality of strands obtained by extrusion is twisted into a three-dimensional random loop, and at least a part of contact portions of the plurality of loops is fused. Examples thereof include a network structure having a three-dimensional network structure, and a structure made of a fiber assembly exemplified in Japanese Patent Application Laid-Open No. 2012-112072, and Japanese Patent Application Laid-Open No. 5-163657.

As a particularly preferred application form, a continuous linear body made of a plurality of strands obtained by extrusion molding is twisted into a three-dimensional random loop, and at least a part of contact portions of the plurality of loops is fused. Examples thereof include a network structure having a three-dimensional network structure.
The net-like structure may be used, for example, as a bedding such as a bed, or a cushioning material for a home, vehicle, ship or aircraft seat. In these applications, a person lies down or sits down for a long time. Therefore, it is continuously deformed by the continued load. In addition, after removing the load, in order to use it again as a cushioning material, it is necessary to recover the deformation to such an extent that there is no practical problem.
Furthermore, since there are cases where a load is applied at a high temperature (for example, 70 ° C.) in an automobile cushion, a cushioning part, a bed cushion with a heating function, etc., a deformation recovery property at a high temperature is also required.
In recent years, hospitals and the like have a need to clean the cushion itself and, in some cases, sterilization treatment, and there is a demand for resistance to steam sterilization treatment at high temperatures, preferably 121 ° C. or higher, and the polypropylene resin of the present invention. It can be said that the deformation recovery heat resistant structure to which the composition (Y) is applied is a particularly suitable application form.

  In addition to the above, the polypropylene resin of the present invention is also used for civil engineering materials, building materials, industrial materials, etc. that are buried or laid on the ground for the purpose of improving drainage, improving air permeability, and retaining earth and sand. A deformation recovery heat resistant structure using the composition (Y) can be suitably used. In these applications, for example, it is assumed that the outdoor environment is in a high temperature environment outdoors during the day and is deformed by a load of a person, vehicle, animal, etc., but the polypropylene resin composition (Y It is expected to easily restore the original shape by using a deformation-recoverable heat-resistant structure using Furthermore, since it has excellent shape retention at high temperatures, preferably 121 ° C. or higher, it can also be applied to cleaning with a steam cleaning machine. Moreover, since the deformation | transformation recoverable heat-resistant structure using the polypropylene resin composition (Y) of this invention is flexible, it also has the followability to various shapes and can anticipate the expansion of an application range.

As a method for producing the network structure, a known method may be appropriately employed. For example, Japanese Patent Application Laid-Open No. 2013-040437, Japanese Patent Application Laid-Open No. 7-173753, Japanese Patent No. 5549438, Japanese Patent No. 5549436, Patent Although the method of 5454733 gazette is mentioned, it is not limited to these.
In addition, when applied to an application in which a load under high temperature is applied, it is molded at a temperature not higher than a temperature at which the shape of the structure can be maintained, preferably at a temperature not lower than an assumed use condition temperature and not higher than a temperature at which the shape of the structure can be maintained. It is preferable to adjust the state of the structure for about 10 seconds to 1 day since deformation recovery at high temperatures is more likely to be improved.
In the case of the deformation recovery heat resistant structure of the present invention, for example, 40 ° C., 50 ° C., 60 ° C., 70 ° C., 80 ° C., 90 ° C., 100 ° C., 110 ° C., 120 ° C., 130 ° C., 140 ° C., 150 ° C., A temperature condition such as 160 ° C. can be exemplified.

In addition, when the molded body is applied to a use similar to a buffer spring, when applied to a support such as a cushion, and further, in any case of applying the network structure to a cushion material, A deformation form that is continuously deformed by a continuous load is a bending deformation.
For example, in the case of the network structure, the seemingly deformed form tends to be seen as a compressive deformation. However, if attention is paid to each filament constituting the network structure, the deformed form is a bending deformation.
Therefore, it is possible to sufficiently analogize the deformation recoverability of the various structures listed in the above example by continuously bending and deforming with the continued load, and then evaluating the deformation recovery when the load is removed. it can.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited only to these Examples.
In addition, the various properties of the polypropylene resin compositions used in Examples and Comparative Examples, their constituent components, and deformation-recoverable heat-resistant structures were measured and evaluated according to the following evaluation methods.

[Physical properties of various polypropylene resins]
(1) Melt flow rate (MFR, unit: g / 10 minutes)
Measured in accordance with JIS K7210: 1999, Method A, Condition M (230 ° C., 2.16 kg load).
(2) Melting peak temperature (melting point) (Tm, unit: ° C)
Using a differential scanning calorimeter (DSC), once the temperature was raised to 200 ° C. and the heat history was erased, the temperature was lowered to 40 ° C. at a temperature lowering rate of 10 ° C./min, and the temperature rising rate was 10 ° C./min again. The temperature at the top of the endothermic peak at the time of measurement was taken as the melting peak temperature (melting point) (Tm).
(3) Density (unit: g / cm ³ )
Measured in accordance with method A of JIS K7112: 1999.

(4) Residual strain (unit:%)
(I) Preparation of sample The polypropylene resin composition (Y) was molded into a sheet by a compression molding method.
Spacers used: length 200 mm, width 200 mm, thickness 1 mm.
Compression molding conditions:
(A) Preheating process: preheating time 7 minutes, preheating temperature 200 ° C., preheating pressure 0.1 MPa
(A) Pressurization step: pressurization time 3 minutes, pressurization temperature 200 ° C., pressurization pressure 8 MPa
(C) Cooling step: Cooling time 3 minutes, cooling temperature 30 ° C., cooling pressure 12 MPa
The sheet obtained by molding under the above-mentioned conditions is subjected to condition adjustment for 48 hours or more under the conditions of 23 ° C. and 50% relative humidity, and in some cases, further in a gear oven, 70 ° C. or 90 ° C. Or after adjusting the condition under conditions of 100 ° C., 1 hour or 10 minutes, and further adjusting the condition for 48 hours or more under the conditions of 23 ° C. and 50% relative humidity, it is cut out with a cutter knife, 140 mm in length and 10 mm in width. A structure having a thickness of 1 mm was prepared and subjected to the following test.
(Ii) Constant displacement bending test Two glass plates having a length of 220 mm, a width of 150 mm, and a thickness of 3 mm were arranged in parallel on a work table with an interval of 100 mm.
A marked line is attached to each position of 20 mm from both ends in the length direction of the structure prepared by the above-described method (that is, the distance between marked lines is 100 mm), and the structure is attached to each of the opposite ends of the glass plate. The structure was placed so that the marked lines coincided with each other, and the portion where the structure and the glass plate overlap was firmly fixed with cellophane tape. The glass plates on which the structures were fixed were overlapped through a spacer having a thickness of 50 mm so that the surfaces fixed with cellophane tape faced each other and the four corners of the glass plates overlapped.
In this state, the structure is bent so that the gap between the marked lines becomes 50 mm through the space, and the deformation amount of 50% is given to the original length between the marked lines of 100 mm. . In addition, 3 sheets per sample and 1 to 5 types of samples were fixed to a set of glass plates.
Then, in the gear oven adjusted to 23 ° C. and 50% relative humidity or 40 ° C. or in the gear oven adjusted to 70 ° C. for 22 hours, the same conditions are applied. Then, the vicinity of the marked line of the structure attached to the glass plate was cut with sharp scissors or a cutter knife to remove the load.
The cut structure was immediately brought into a constant temperature and humidity chamber at 23 ° C. and 50% relative humidity, and the condition was adjusted for 30 minutes. The cut structure remained bent to some extent, and the distance between both ends cut in the bent state was measured using a ruler. This distance was set to L1.
Further, the bending deformation of the structure cut on the workbench was extended so as to be parallel to the workbench, and the lengths of the cut ends were measured using a ruler. This length was defined as L0.
Residual strain was determined using the following formula. Residual strain is an index of deformation recovery, and the smaller the value, the better the deformation recovery.
Residual strain = (L0−L1) / L0 × 100 (%)

(5) Flexural modulus (unit: MPa)
The bending elastic modulus of the injection molded product was measured according to JIS K7171.
(6) Tensile yield stress (unit: MPa)
The tensile yield stress of the injection molded product was measured according to JIS K7162.

(7) Heat resistance From the both ends in the length direction to the structure of 140 mm in length, 10 mm in width, and 1 mm in thickness obtained in the above-mentioned sample preparation section (conditions are adjusted at 23 ° C. and 50% relative humidity). , Each marked with a marked line at a position of 20 mm (that is, distance between marked lines is 100 mm).
The end of the structure was sandwiched between clips and placed in a gear oven adjusted to 100 ° C. or 121 ° C. in a suspended state, and the state was adjusted for 15 minutes.
After completion of the condition adjustment, it was taken out from the gear oven, immediately brought into a constant temperature and humidity chamber at 23 ° C. and 50% relative humidity, and the length (L2) between the marked lines was immediately measured for the unmelted structure.
Those that contract during the condition adjustment have an L2 of less than 100 mm, and those that sag due to expansion or dead weight have an L2 greater than 100 mm. For those melted by the above-mentioned condition adjustment, there was no heat resistance, and for those not melted, the absolute value of the amount of change (%) from the original distance between the marked lines of 100 mm was used as the heat resistance index, and the value was The smaller the value, the better the heat resistance.

(8) Solid viscoelasticity measurement A 10 mm wide × 18 mm long strip cut out from a 2 mm thick sheet obtained by press molding under the following conditions was used. The apparatus used was ARES manufactured by Rheometric Scientific. The frequency is 1 Hz. The measurement temperature was raised stepwise from −60 ° C., and the measurement was performed until the sample melted and became impossible to measure. The strain was performed in the range of 0.1 to 0.5%. From the obtained stress, the storage elastic modulus G ′ and the loss elastic modulus G ″ are obtained by a known method, and the loss tangent (= loss elastic modulus / storage elastic modulus) defined by this ratio is plotted against the temperature. The peak of the tan δ curve at 0 ° C. or lower generally observes the glass transition of the amorphous part, and in the present invention, this peak temperature is expressed as the glass transition temperature Tg (° C. It can be used as a reference index for suitability for use in cold weather, and it is desirable that the temperature is 0 ° C. or lower, preferably −5 ° C. or lower, because it is difficult to be destroyed when a load is applied during cold weather.
Press molding:
Preheat at 230 ° C for 5 minutes, then pressurize at the same temperature for 3 minutes at a pressure of 50 kgf / cm ² and immediately apply a pressure of 100 kgf / cm ² with a press machine adjusted to 30 ° C for cooling and solidification. The press sheet of thickness 2mm was obtained.
(9) Vicat softening point temperature Measurement was performed based on the A50 method of JIS K7206: 1999 except that a 4 mm thick injection molded piece was used and the load was changed to 5N. It can be used as a reference index related to heat resistance, and it is desirable that the temperature is 70 ° C. or higher, preferably 80 ° C. or higher.
(10) Durometer hardness Type D hardness was measured in accordance with JIS K7215-1986. It can be used as an index other than the flexural modulus related to flexibility, and is desirably 50 or less, preferably 45 or less as a guide.

[Component (A)]
(A-1) Trade name “Wellnex RMG02” manufactured by Nippon Polypro Co., Ltd.
(MFR 20 g / 10 min, melting point 130 ° C., density 0.89 g / cm ³ , flexural modulus 350 MPa)
(A-2) Trade name “Wellnex RFG4VM”, manufactured by Nippon Polypro Co., Ltd.
(MFR 6 g / 10 min, melting point 130 ° C., density 0.89 g / cm ³ , flexural modulus 280 MPa)
(A-3) Made by Nippon Polypro Co., Ltd., trade name “Wintech WFW4M” (MFR 7 g / 10 min, melting point 135 ° C., density 0.9 g / cm ³ , flexural modulus 1000 MPa)

[Propylene copolymer (B)]
(B-1) Trade name “Versify 3300” manufactured by Dow Chemical Co., Ltd.
(Propylene-ethylene copolymer, MFR 8 g / 10 min, density 0.87 g / cm ³ )
(B-2) Trade name “Tuffmer PN2070” manufactured by Mitsui Chemicals, Inc.
(Propylene copolymer, MFR 7 g / 10 min, density 0.87 g / cm ³ )
(B-3) Trade name “Vistamaxx 6102” manufactured by ExxonMobil Corporation
(Propylene copolymer, MFR ³ g / 10 min, density 0.86 g / cm ³ )

[Other resin components]
(PE-1) manufactured by Nippon Polyethylene Co., Ltd., trade name “Kernel KS571”
(Ethylene-α-olefin copolymer by metallocene catalyst, MFR 12 g / 10 min (however, 190 ° C., 2.16 kg load), density 0.91 g / cm ³ )
(PE-2) manufactured by Nippon Polyethylene Co., Ltd., trade name “Kernel KS340T”
(Ethylene-α-olefin copolymer by metallocene catalyst, MFR 3.5 g / 10 min (however, 190 ° C., 2.16 kg load), density 0.88 g / cm ³ )
(C-1) Trade name “Clayton G1657MO” manufactured by Kraton Polymer Co., Ltd.
(Hydrogenated product of styrene-butadiene block copolymer)

[Example 1]
50% by weight of component A (A-1) and 50% by weight of propylene copolymer (B-1) as component B were blended in a Henschel mixer to obtain a polypropylene resin composition (X-1). Using a single screw extruder of φ30 mm, melt kneading was performed under the conditions of a cylinder temperature of 200 ° C. and a discharge rate of 6 kg / hour to obtain polypropylene resin composition (Y-1) pellets.
The obtained pellets were molded into a sheet by the compression molding method by the above-described method, and the structure was obtained by the above-mentioned method without adjusting the state at 70 ° C., 90 ° C., or 100 ° C.
The evaluation results of the obtained structure are summarized in Table 1.

[Example 2]
50% by weight of component A (A-1) and 50% by weight of propylene copolymer (B-2) as component B were blended in a Henschel mixer to obtain a polypropylene resin composition (X-2). Using a single screw extruder of φ30 mm, melt kneading was performed under the conditions of a cylinder temperature of 200 ° C. and a discharge rate of 6 kg / hour to obtain polypropylene-based resin composition (Y-2) pellets.
The obtained pellets were molded into a sheet by the compression molding method by the above-described method, and the structure was obtained by the above-mentioned method without adjusting the state at 70 ° C., 90 ° C., or 100 ° C.
The evaluation results of the obtained structure are summarized in Table 1.
The Vicat softening point temperature was 87 ° C. The glass transition temperature was −17 ° C. The durometer hardness (type D) was 40.

[Example 3]
In Example 1, the same operation as in Example 1 was performed except that the state of the sheet obtained by the compression molding method was adjusted at 70 ° C. for 1 hour.
The evaluation results are summarized in Table 1. Compared to Example 1, the deformation recoverability (residual strain) at 40 ° C. and 70 ° C. was further improved.

[Example 4]
In Example 2, the same operation as in Example 2 was performed, except that the state of the sheet obtained by the compression molding method was adjusted at 70 ° C. for 1 hour.
The evaluation results are summarized in Table 1. Compared to Example 2, deformation recoverability (residual strain) at 40 ° C. and 70 ° C. was further improved.

[Example 5]
In Example 3, the same operation as in Example 1 was performed, except that the state of the sheet obtained by the compression molding method was adjusted at 100 ° C. for 1 hour.
The evaluation results are summarized in Table 1. Compared to Example 3, the 70 ° C. deformation recovery property (residual strain) was further improved.

[Example 6]
In Example 4, the same operation as in Example 4 was performed, except that the state of the sheet obtained by the compression molding method was adjusted at 100 ° C. for 1 hour.
The evaluation results are summarized in Table 1. Compared to Example 4, the deformation recovery property (residual strain) at 70 ° C. was further improved.

[Example 7]
In Example 2, the same operation as in Example 2 was performed, except that the state of the sheet obtained by the compression molding method was adjusted at 90 ° C. for 10 minutes.
The evaluation results are summarized in Table 1. Compared to Example 2, deformation recoverability (residual strain) at 40 ° C. and 70 ° C. was further improved.

[Example 8]
25% by weight of component A (A-3) and 75% by weight of propylene copolymer (B-2) as component B were blended in a Henschel mixer to obtain a polypropylene resin composition (X-3). Using a single screw extruder of φ30 mm, melt kneading was performed under conditions of a cylinder temperature of 200 ° C. and a discharge rate of 6 kg / hour to obtain polypropylene resin composition (Y-3) pellets.
The obtained pellets were molded into a sheet shape by the compression molding method by the above-described method, the state was adjusted at 100 ° C. for 1 hour, and the structure was obtained by the above-described method.
The evaluation results of the obtained structure are summarized in Table 1.

[Example 9]
75% by weight of component A (A-1) and 25% by weight of propylene copolymer (B-2) as component B were blended in a Henschel mixer to obtain a polypropylene resin composition (X-4). A polypropylene resin composition (Y-4) pellet was obtained by melt-kneading using a single-screw extruder of φ30 mm under the conditions of a cylinder temperature of 200 ° C. and a discharge rate of 6 kg / hour.
The obtained pellets were molded into a sheet shape by the compression molding method by the above-described method, the state was adjusted at 100 ° C. for 1 hour, and the structure was obtained by the above-described method.
The evaluation results of the obtained structure are summarized in Table 1.

[Comparative Example 1]
As a resin composition other than the polypropylene resin composition (Y) of the present invention, it was molded into a sheet by a compression molding method in the same manner as described above except that PE-1 was used and the molding temperature was changed to 230 ° C. The structure was obtained by the method described above without adjusting the state at 70 ° C., 90 ° C., or 100 ° C.
The evaluation results of the obtained structure are summarized in Table 1. Compared with the one using the polypropylene resin composition (Y) of the present invention, the deformation recovery property (residual strain) at 70 ° C. was greatly deteriorated, and the heat resistance was also significantly inferior.

[Comparative Example 2]
The component (A-1) was a polypropylene resin composition (Y-5).
The polypropylene resin composition (Y-5) was molded into a sheet shape by the compression molding method by the above-described method, the state was adjusted at 100 ° C. for 1 hour, and the structure was obtained by the above-described method.
The evaluation results of the obtained structure are summarized in Table 1. Although it was excellent in deformation recovery (residual strain) and heat resistance at 40 ° C. and 70 ° C. compared with Comparative Example 1, it was more flexible than that using the polypropylene resin composition (Y) of the present invention. Was significantly inferior.

[Comparative Example 3]
Using B-3 as a resin composition other than the polypropylene resin composition (Y) of the present invention, it is molded into a sheet by the compression molding method as described above, and is adjusted at 70 ° C., 90 ° C. or 100 ° C. The structure was obtained by the method described above.
The evaluation results of the obtained structure are summarized in Table 1. The deformation recovery property (residual strain) at 70 ° C. could not be measured, and the heat resistance was significantly inferior.

[Comparative Example 4]
50% by weight of (A-1) as component A and 50% by weight of ethylene-α-olefin copolymer (PE-2) as a component other than component B were blended in a Henschel mixer, and a polypropylene resin composition ( X-6). Using a single screw extruder of φ30 mm, melt kneading was performed under the conditions of a cylinder temperature of 200 ° C. and a discharge rate of 6 kg / hour to obtain polypropylene resin composition (Y-6) pellets.
The obtained pellets were molded into a sheet by the compression molding method by the above-described method, and the structure was obtained by the above-mentioned method without adjusting the state at 70 ° C., 90 ° C., or 100 ° C.
The evaluation results of the obtained structure are summarized in Table 1. Compared with the one using the polypropylene resin composition (Y) of the present invention, the deformation recoverability (residual strain) at 40 ° C. and 70 ° C. was greatly deteriorated.

[Comparative Example 5]
Blending 50% by weight of (A-2) as component A and 50% by weight of hydrogenated styrene-butadiene block copolymer (C-1) as a component other than component B using a Henschel mixer, a polypropylene resin It was set as the composition (X-7). Using a single screw extruder of φ30 mm, melt kneading was performed under the conditions of a cylinder temperature of 200 ° C. and a discharge rate of 6 kg / hour to obtain polypropylene resin composition (Y-7) pellets.
The obtained pellets were molded into a sheet by the compression molding method by the above-described method, and the structure was obtained by the above-mentioned method without adjusting the state at 70 ° C., 90 ° C., or 100 ° C.
The evaluation results of the obtained structure are summarized in Table 1. Compared with the one using the polypropylene resin composition (Y) of the present invention, the deformation recoverability (residual strain) at 40 ° C. and 70 ° C. was greatly deteriorated.

  The polypropylene resin composition for deformation-recoverable heat-resistant structures of the present invention is flexible, excellent in deformation recovery at high temperatures, and has heat resistance that can maintain its shape even in an environment of 121 ° C. or higher. Therefore, it is possible to provide a deformation-recovery heat-resistant structure having deformation recovery property and heat resistance, and the industrial applicability is high.

Claims (3)

1 to 99 parts by weight of the following component (A) and 1 to 99 parts by weight of the following component (B) (provided that the total of the component (A) and the component (B) is 100 parts by weight) ( A polypropylene-based resin composition for deformation-recoverable heat-resistant structures, which contains X) as an essential component and satisfies the following characteristics (y1) to (y3).
(Y1) The melt flow rate (MFR: 230 ° C., 2.16 kg load) is 1.0 to 100 g / 10 minutes.
(Y2) Melting peak temperature (Tm) is 121-170 degreeC.
(Y3) Bending elastic modulus is 10 to 200 MPa Component (A): one or more propylene homopolymers and / or propylene-α-olefin copolymer satisfying the following (a1) to (a3) Coalescence.
(A1) The melting peak temperature (Tm) is 121 to 170 ° C.
(A2) The melt flow rate (MFR: 230 ° C., 2.16 kg load) is 0.1 to 500 g / 10 minutes.
(A3) The density is 0.89 g / cm ³ or more.
Component (B): at least one propylene-based copolymer satisfying the following (b1) to (b2).
(B1) The density is 0.88 g / cm ³ or less.
(B2) MFR is 1.0 to 100 g / 10 min.   A deformation-recoverable heat-resistant structure comprising the polypropylene-based resin composition for a deformation-recoverable heat-resistant structure according to claim 1.   The deformation-recoverable heat-resistant structure is formed by twisting a continuous linear body composed of a plurality of strands obtained by extrusion molding into a three-dimensional random loop shape, and at least a part of contact portions of the plurality of loops is fused. The deformation-recoverable heat-resistant structure according to claim 2, which is a network structure having a three-dimensional network structure.