JP2012183504A - Oil-adsorbing material made of ionomer resin foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil-adsorbing material resolved with the defect of a usual polypropylene nonwoven, an inorganic fiber material and polyurethane foam, and excellent in recyclability, lightness and oil adsorbing performance.SOLUTION: In the oil-adsorbing material made of a foam formed out of at least an ionomer resin, the ionomer resin is an ionomer resin (X1) formed out of 100 pts.mass of an olefin polymer (A) having a 2-20C α-olefin-derived constitutional unit and a functional group (a), and 0.01 to 100 pts.mass of a metal salt (B) having two functional groups (b) or more containing a metal component (provided carbonate is excluded).

Description

  The present invention relates to an oil absorbent material made of a foam of ionomer resin.

  Conventionally, polypropylene nonwoven fabrics have been used for applications that require oil absorption performance (see, for example, Patent Document 1). However, the polypropylene nonwoven fabric has oil absorption performance itself, but lacks oil retention with respect to pressure, and lacks rigidity because it is a flexible material. Moreover, inorganic fiber materials, such as glass wool and a cement porous body, are known for the said use (for example, refer patent document 2). However, these inorganic fiber materials lack recyclability and are inferior in lightness.

  On the other hand, foams made of polyurethane (polyurethane foam) are difficult to re-melt and therefore lack recyclability, and the range of application may be limited due to the hygroscopic nature of the material itself.

  In addition, foams of specific ionomer resins are known (see, for example, Patent Document 3). However, there is room for further study on applications that require oil absorption performance.

Patent No. 2,804,772 JP 2010-000472 A International Publication No. 2010/024286 Pamphlet

  An object of the present invention is to provide an oil absorbent material excellent in recyclability, light weight, and oil absorption performance, in which the disadvantages of conventional polypropylene nonwoven fabrics, inorganic fiber materials, and polyurethane foams are eliminated.

The present inventors have intensively studied to solve the above problems. As a result, the present inventors have found that an oil absorbent material composed of a foam having the following configuration can solve the above-mentioned problems, and has completed the present invention. That is, the present invention and preferred embodiments thereof relate to the following [1] to [12].
[1] An oil-absorbing material comprising a foam formed from at least an ionomer resin, wherein the ionomer resin has (A) a structural unit derived from an α-olefin having 2 to 20 carbon atoms, and a functional group ( It is formed from 100 parts by mass of an olefin polymer having a) and (B) 0.01 to 100 parts by mass of a metal salt (excluding carbonate) having two or more functional groups (b) containing a metal component. An oil absorbent, which is an ionomer resin (X1).
[2] The oil absorbent according to [1], wherein the functional group (a) is at least one selected from a structural unit derived from an acid compound and a structural unit derived from an acid anhydride.
[3] The functional group (b) is at least selected from a group formed by neutralizing an acid functional group of an organic acid with a metal component and a group formed by neutralizing an acid functional group of an inorganic acid with a metal component. The oil absorbent material according to [1] or [2], which is one type.
[4] The [1] to [3], wherein the olefin polymer (A) is a graft-modified product of an olefin polymer (A-1) having a structural unit derived from an α-olefin having 2 to 20 carbon atoms. ] The oil-absorbing material according to any one of the above.
[5] The oil absorbent according to [4], wherein the olefin polymer (A-1) is a propylene polymer in which the content of structural units derived from propylene is 51 mol% or more.
[6] The above [4], wherein the olefin polymer (A-1) is a 4-methylpentene-1 polymer in which the content of structural units derived from 4-methylpentene-1 is 51 mol% or more. Oil absorbing material as described in 2.

[7] The oil absorbent according to [4], wherein the olefin polymer (A-1) is a butene-1 polymer having a content of structural units derived from butene-1 of 51 mol% or more. .
[8] In the olefin polymer (A), the functional group (a) is introduced in an amount of 0.01 to 50 parts by mass with respect to 100 parts by mass of the olefin polymer (A-1). The oil absorbent material according to any one of [4] to [7].
[9] The foam is a foam of the resin composition (X2) formed from the ionomer resin (X1) and an olefin polymer (C) different from the olefin polymer (A). The oil absorbent material according to any one of [1] to [8].
[10] The oil absorption according to [9], wherein a mass ratio of the ionomer resin (X1) to the olefin polymer (C) is (X1) :( C) = 1: 99 to 99: 1. Wood.
[11] The oil absorbent according to [9] or [10], wherein the olefin polymer (C) is an olefin polymer having a structural unit derived from an α-olefin having 2 to 20 carbon atoms.
[12] The oil absorbent according to any one of claims 1 to 11, wherein the foam satisfies the following requirements (1) to (4): (1) Method A of ASTM D792 (in-water replacement method) The density measured according to the above is 0.0090 to 0.20 g / cm ³ . (2) The closed cell ratio measured according to ASTM D2856 C method is 0% or more and less than 60%. (3) The average diameter of the cells is 10 μm or more and 1000 μm or less. (4) The average diameter of the holes penetrating the wall surface between the cells is 0.1 to 90% of the average diameter of the cells.

  ADVANTAGE OF THE INVENTION According to this invention, the oil absorbent material excellent in recyclability, lightweight property, and oil absorption performance in which the fault of the conventional polypropylene nonwoven fabric, inorganic fiber material, and polyurethane foam was eliminated can be provided.

Hereinafter, the oil absorbent material of the present invention will be described in detail including preferred embodiments.
The oil absorbing material of the present invention is made of a foam formed from at least an ionomer resin (X1) described later. The foam is preferably a foam formed from an ionomer resin composition (X2) containing an ionomer resin (X1) and an olefin polymer (C) described later.

[Foam]
The foam used in the present invention is formed of at least an ionomer resin (X1). The foam is preferably a foam formed from an ionomer resin composition (X2) containing an ionomer resin (X1) and an olefin polymer (C) described later.

<Ionomer resin (X1)>
The ionomer resin (X1) is a resin formed from a functional group-containing olefin polymer (A) and a metal salt (B) described later. Due to various physical properties of the ionomer resin (X1) (for example, reduction in MFR, increase in extensional viscosity, expression of strain hardening), at least a part of the functional group-containing olefin polymer (A) is introduced via the metal salt (B). It is presumed that a crosslinked structure is formed (see International Publication No. 2010/024286 pamphlet for details).

<< Functional Group-Containing Olefin Polymer (A) >>
The functional group-containing olefin polymer (A) has a structural unit derived from an α-olefin having 2 to 20, preferably 3 to 20, more preferably 3 to 10 carbon atoms, and has a functional group (a). It is a polymer. The functional group-containing olefin polymer (A) is, for example, a graft modified product of the olefin polymer (A-1) described later.

  The polystyrene-reduced mass average molecular weight (Mw) measured by size exclusion chromatography (SEC) of the functional group-containing olefin polymer (A) is not particularly limited, and is, for example, 1000 to 1000000 depending on the intended use and required characteristics. It can design suitably in the range of a grade. For example, a low molecular weight region is preferable for increasing fluidity, and a high molecular weight region is preferable for increasing mechanical strength.

Although the crystallinity degree of a functional group containing olefin polymer (A) does not have a restriction | limiting in particular, Usually, it is 10 to 90%, Preferably it is 12 to 80%, More preferably, it is 15 to 75%. When the crystallinity of the olefin polymer (A) is in the above range, a foam excellent in oil resistance can be obtained. The crystallinity of the functional group-containing olefin polymer (A) and the olefin polymer (A-1) and olefin polymer (C) described later is measured by the XRD (X-ray diffraction) method.
In the present invention, “olefin polymer” is used to collectively refer to olefin homopolymers and copolymers, and “polymerization” is used to refer to both homopolymerization and copolymerization.

(Olefin polymer (A-1))
The olefin polymer (A-1) is a polymer having a structural unit derived from an α-olefin having 2 to 20, preferably 3 to 20, more preferably 3 to 10 carbon atoms. The olefin polymer (A-1) can be obtained by polymerizing at least one selected from the α-olefins. As the raw material for the olefin polymer (A-1), other compounds may be used together with the α-olefin.

  Examples of the α-olefin include ethylene, propylene, butene-1, pentene-1, 2-methylbutene-1, 3-methylbutene-1, hexene-1, 3-methylpentene-1, 4-methylpentene-1, 3,3-dimethylpentene-1, heptene-1, methylhexene-1, dimethylpentene-1, trimethylbutene-1, ethylpentene-1, octene-1, methylpentene-1, dimethylhexene-1, trimethylpentene- 1, ethylhexene-1, methylethylpentene-1, diethylbutene-1, propylpentene-1, decene-1, methylnonene-1, dimethyloctene-1, trimethylheptene-1, ethyloctene-1, methylethylhept Ten-1, diethylhexene-1, dodecene-1, tetradecene-1, hexadecene 1 include octadecene-1.

  The olefin polymer (A-1) has a structural unit derived from an α-olefin, usually 50 mol% or more, preferably 80 mol% or more, particularly preferably 90 mol% or more. The content of the structural unit derived from the α-olefin may be 100 mol%. The olefin polymer (A-1) is preferably a crystalline polyolefin from the viewpoints of heat resistance, mechanical strength, moisture resistance, chemical resistance, and the like.

  Although the crystallinity degree of an olefin polymer (A-1) does not have a restriction | limiting in particular, Usually, it is 10 to 90%, Preferably it is 12 to 80%, More preferably, it is 15 to 75%. When the crystallinity of the olefin polymer (A-1) is in the above range, a foam excellent in oil resistance can be obtained.

  Preferred use forms of α-olefins are propylene alone, butene-1 alone, 4-methylpentene-1 alone, mixed α-olefins containing propylene as the main component, mixed α-olefins containing butene-1 as the main component, 4 -A mixed α-olefin mainly composed of methylpentene-1. In the present invention, the “main component” means that the concentration of the component in the total α-olefin is 30 mol% or more, preferably 51 mol% or more.

  Examples of other compounds that can be used with the α-olefin include polyene compounds such as chain polyene compounds and cyclic polyene compounds; and cyclic monoene compounds. The polyene compound has two or more conjugated or non-conjugated olefinic double bonds.

  Examples of the chain polyene compound include 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, 2,4,6-octatriene, 1,3,7-octatriene. 1,5,9-decatriene.

  Examples of the cyclic polyene compound include 1,3-cyclopentadiene, 1,3-cyclohexadiene, 5-ethyl-1,3-cyclohexadiene, 1,3-cycloheptadiene, dicyclopentadiene, dicyclohexadiene, 5 -Ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-vinyl-2-norbornene, 5-isopropylidene-2-norbornene, methylhydroindene, 2,3-diisopropylidene-5-norbornene, 2- Examples include ethylidene-3-isopropylidene-5-norbornene and 2-propenyl-2,5-norbornadiene.

Examples of cyclic monoene compounds include monocycloalkenes such as cyclopropene, cyclobutene, cyclopentene, cyclohexene, 3-methylcyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclododecene, cyclotetradecene, cyclooctadecene, and cycloeicocene; norbornene, 5-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-isobutyl-2-norbornene, 5,6-dimethyl-2-norbornene, 5,5,6-trimethyl-2-norbornene, 2-bornene, etc. A tricycloalkene such as 2,3,3a, 7a-tetrahydro-4,7-methano-1H-indene, 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene; , 4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene;
2-methyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-ethyl-1,4,5,8-dimethano-1, 2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-propyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydro Naphthalene, 2-hexyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-stearyl-1,4,5,8-dimethano- 1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2,3-dimethyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8, 8a-octahydronaphthalene, 2-methyl-3-ethyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-chloro-1, 4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-bromo-1,4,5,8-dimethano-1,2,3,4, 4a, 5,8,8a-octahydronaphthalene, 2-fluoro-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octa Mud naphthalene and 2,3-dichloro-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-tetramethyl cycloalkenes such octahydronaphthalene;
Hexacyclo [6,6,1,1 ^3.6 , 1 ^10.13 , 0 ^2.7 , 0 ^9.14 ] heptadecene-4, pentacyclo [8,8,1 ^2.9 , 1 ^4.7 , 1 ^11.18 , 0,0 ^3.8 , 0 ^12.17 ] Henicosen-5 , Polycycloalkenes such as octacyclo [8,8,1 ^2.9 , 1 ^4.7 , 1 ^11.18 , 1 ^13.16 , 0,0 ^3.8 , 0 ^12.17 ] docosene-5;
Is mentioned.

  As the olefin polymer (A-1), from the viewpoints of heat resistance and mechanical strength, propylene polymers such as propylene homopolymer and propylene copolymer, butene-1 homopolymer and butene-1 copolymer 4-methylpentene-1 polymers such as butene-1 polymer, 4-methylpentene-1 homopolymer and 4-methylpentene-1 copolymer are preferred.

Propylene Polymer As the propylene homopolymer , any propylene homopolymer such as isotactic, atactic and syndiotactic can be used.

  As the propylene copolymer, any propylene copolymer such as a random copolymer of propylene and an α-olefin other than propylene and a block copolymer can be used.

  The propylene copolymer usually has a structural unit derived from propylene of 51 mol% or more, preferably 80 mol% or more, particularly preferably 90 mol% or more, and is derived from an α-olefin other than propylene and / or other compounds. It is a copolymer having the remaining amount of the structural unit. It is also one of the preferable aspects that content of the structural unit derived from the alpha olefin containing propylene is 100 mol%.

As the propylene polymer, a propylene polymer obtained by a method for industrially producing polyolefins, or a propylene polymer widely available on the market can also be used.
The melting point of the propylene polymer measured by differential scanning calorimetry (DSC) is preferably 100 to 180 ° C, more preferably 110 to 170 ° C, from the viewpoint of the rigidity of the foam.

  The melt flow rate (MFR) of the propylene polymer is preferably 0.1 to 500 g / 10 minutes, more preferably 0.2 to 0.2, under the measurement conditions of a temperature of 230 ° C. and a load of 2.16 kg in accordance with ASTM D1238. 300 g / 10 min, more preferably 0.3 to 100 g / 10 min. If the MFR is not more than the above upper limit value, the resulting polymer has a sufficiently high melt viscosity and excellent moldability, and if the MFR is not less than the above lower limit value, the resulting polymer has sufficient mechanical strength.

  As the molecular weight of the propylene polymer, the intrinsic viscosity can be used as a guide, and the intrinsic viscosity (hereinafter also referred to as “[η]”) measured with a tetralin solution at 135 ° C. is usually 0.1 to 10 dl / g. is there.

  Examples of the catalyst used in the production of the propylene polymer include a titanium trichloride catalyst, a promoter component (alkyl aluminum, etc.) and a catalyst component (magnesium compound supported by a titanium compound such as titanium trichloride or titanium tetrachloride). And a catalyst component). Furthermore, a metal complex belonging to Group 3 and Group 4 of the periodic table having a cyclopentadienyl compound as a ligand as represented by a combination of dicyclopentadienylzirconium dichloride and an aluminoxane or boron compound, and an aluminoxane compound Or a homogeneous catalyst using a metal cation complex belonging to Group 3 or Group 4 of the periodic table having a cyclopentadienyl compound as a ligand.

Examples of the polymerization method include conventionally known methods such as a solvent polymerization method, a bulk polymerization method substantially free of a solvent, and a gas phase polymerization method. As the polymerization conditions, the reaction temperature is usually from room temperature to 200 ° C. The pressure is normal pressure to 50 kgf / cm ² .

Butene-1 Polymer As the butene-1 homopolymer , any butene-1 homopolymer such as isotactic and atactic can be used.

  As the butene-1 copolymer, any butene-1 copolymer such as a random copolymer of butene-1 and an α-olefin other than butene-1 and a block copolymer can be used.

  The butene-1 copolymer has a structural unit derived from butene-1 of usually 51 mol% or more, preferably 80 mol% or more, more preferably 85 mol% or more, particularly preferably 90 mol% or more. It is a copolymer having a remaining amount of structural units derived from an α-olefin other than 1 and / or other compounds. It is also one of the preferable aspects that content of the structural unit derived from the alpha olefin containing butene-1 is 100 mol%.

  Among the α-olefins, ethylene, propylene, hexene-1, octene-1, decene-1, tetradecene-1, and octadecene-1 are preferable as the α-olefin other than butene-1.

The melting point of the butene-1 polymer measured by differential scanning calorimetry (DSC) is preferably 50 to 150 ° C, more preferably 60 to 140 ° C, from the viewpoint of the rigidity of the foam.
The melt flow rate (MFR) of the butene-1 polymer is preferably 0.5 to 200 g / 10 min, more preferably 5 to 5 ° C. under measurement conditions of a temperature of 190 ° C. and a load of 2.16 kg in accordance with ASTM D1238. 100 g / 10 min. If the MFR is not more than the above upper limit value, the resulting polymer has a sufficiently high melt viscosity and excellent moldability, and if the MFR is not less than the above lower limit value, the resulting polymer has sufficient mechanical strength.

  The 4-methylpentene-1 polymer can be produced by a conventionally known method. For example, it can be obtained by polymerizing butene-1 and, if necessary, the α-olefin in the presence of a Ziegler catalyst. .

4-methylpentene-1 polymer As the 4-methylpentene-1 homopolymer, any methylpentene homopolymer such as isotactic, atactic and syndiotactic can be used.

  As the 4-methylpentene-1 copolymer, any methylpentene copolymer such as a random copolymer of 4-methylpentene-1 and an α-olefin other than 4-methylpentene-1 and a block copolymer Can also be used.

  The 4-methylpentene-1 copolymer is usually 51 mol% or more, preferably 80 mol% or more, more preferably 85 mol% or more, particularly preferably 90 mol%, of a structural unit derived from 4-methylpentene-1. It is a copolymer having the remaining amount of structural units derived from an α-olefin other than 4-methylpentene-1 and / or other compounds. It is also one of the preferable aspects that content of the structural unit derived from the alpha olefin containing 4-methyl-1-pentene is 100 mol%.

  As the α-olefin other than 4-methylpentene-1, among the α-olefins, ethylene, propylene, butene-1, hexene-1, octene-1, decene-1, tetradecene-1 and octadecene-1 are preferable. Decene-1, tetradecene-1, and octadecene-1 are particularly preferable because a copolymer having good copolymerizability with 4-methylpentene-1 and good toughness can be obtained.

  The melting point of the 4-methylpentene-1 polymer measured by differential scanning calorimetry (DSC) is preferably 220 to 240 ° C, more preferably 225 to 240 ° C, from the viewpoint of the rigidity of the foam.

  The melt flow rate (MFR) of 4-methylpentene-1 polymer is preferably 0.5 to 200 g / 10 minutes, more preferably, under the measurement conditions of a temperature of 260 ° C. and a load of 5.0 kg, in accordance with ASTM D1238. Is 5 to 100 g / 10 min. If the MFR is not more than the above upper limit value, the resulting polymer has a sufficiently high melt viscosity and excellent moldability, and if the MFR is not less than the above lower limit value, the resulting polymer has sufficient mechanical strength.

  The 4-methylpentene-1 polymer can be produced by a conventionally known method. For example, as described in JP-A No. 59-206418, 4-methylpentene-1 polymer can be produced in the presence of a catalyst. If necessary, it can be obtained by polymerizing the α-olefin.

(Functional group (a))
Examples of the functional group (a) possessed by the olefin polymer (A) include a structural unit derived from an acid compound (hereinafter also referred to as “acid group”, eg, carboxylic acid group, sulfonic acid group), and derivatives of acid compounds. Derived structural units (hereinafter also referred to as “acid derivative groups”, eg, acid anhydride groups such as carboxylic acid anhydride groups and sulfonic acid anhydride groups), halogen groups, hydroxyl groups, thiol groups, sulfide groups, disulfide groups, aldehydes Group, amino group, imino group, epoxy group, nitrile group, nitro group, isocyanate group, thioisocyanate group, azo group, diazo group. The olefin polymer (A) may have two or more functional groups (a).

  In the present invention, the structural unit derived from an acid compound refers to a group represented by the following formula (1) if, for example, maleic acid, and the structural unit derived from a derivative of an acid compound includes, for example, maleic anhydride. If present, it refers to a group represented by the following formula (2).

これらの中でも、酸化合物に由来する構成単位および酸無水物に由来する構成単位が好ましく、カルボン酸化合物に由来する構成単位およびカルボン酸無水物に由来する構成単位がより好ましく、不飽和カルボン酸化合物に由来する構成単位および不飽和カルボン酸無水物に由来する構成単位がより好ましく、マレイン酸、ナジック酸（登録商標）、これらの酸無水物に由来する構成単位が特に好ましい。また、スルホン酸化合物に由来する構成単位およびスルホン酸無水物に由来する構成単位も好ましい。

Among these, a structural unit derived from an acid compound and a structural unit derived from an acid anhydride are preferable, a structural unit derived from a carboxylic acid compound and a structural unit derived from a carboxylic acid anhydride are more preferable, and an unsaturated carboxylic acid compound The structural unit derived from the above and the structural unit derived from the unsaturated carboxylic acid anhydride are more preferable, and the structural unit derived from maleic acid, nadic acid (registered trademark), and these acid anhydrides are particularly preferable. Further, a structural unit derived from a sulfonic acid compound and a structural unit derived from a sulfonic acid anhydride are also preferable.

  Examples of the carboxylic acid compound include unsaturated acids such as maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acid (registered trademark), sorbic acid, acrylic acid, and methacrylic acid. Carboxylic acid is mentioned.

  Examples of the derivative of the carboxylic acid compound include acid anhydrides, imides, amides, and esters of the unsaturated carboxylic acid. Specific examples of the derivative include maleic anhydride, citraconic anhydride, maleimide, monomethyl maleate, and glycidyl malate.

  In the olefin polymer (A), the functional group (a) is, for example, when the functional group (a) is a structural unit derived from an acid compound and / or a structural unit derived from a derivative of an acid compound. A-1) (that is, the polymer chain derived from the olefin (A-1)) is usually from 0.01 to 50 parts by mass, preferably from 0.05 to 40 parts by mass, more preferably from 0.1 to 100 parts by mass. It is introduced in an amount of 1 to 30 parts by mass.

  If the content of the functional group (a) is not less than the above lower limit value, the strain curability of the ionomer resin tends to be good, and if the content of the functional group (a) is not more than the above upper limit value, for example, grafting Along with the reaction, due to the action of heat or a radical initiator (hereinafter also referred to as “radical generator”), the decomposition reaction of the main chain skeleton of the olefin polymer is relatively difficult to occur, and the molecular weight of the olefin polymer (A) is extremely low. It is less likely to become smaller, and as a result, deterioration of mechanical properties and coloring are unlikely to occur.

  When the functional group (a) is not a structural unit derived from an acid compound or a structural unit derived from a derivative of an acid compound, the functional group (a) is usually 0.1 to 100 mass% of the olefin polymer (A). Occupies 30% by mass.

As a method for introducing the functional group (a) into the olefin polymer (A-1), for example,
(Method 1) Method of graft-modifying the olefin polymer (A-1);
(Method 2) When a structural unit derived from a chain polyene compound or a cyclic polyene compound is contained in the olefin polymer (A-1), a carbon-carbon double bond derived from the polyene compound is treated with an appropriate treatment agent. A method of reacting;
(Method 3) After carrying out the graft modification of Method 1, the obtained graft modified product is further reacted with an appropriate treating agent, and the functional group in the obtained graft modified product is converted into a functional group (a). how to;
Is mentioned.

  Hereinafter, each method will be described in detail by taking, as an example, a case where a structural unit derived from an acid compound and / or a structural unit derived from a derivative of an acid compound is introduced as a functional group (a) into the olefin polymer (A-1). .

(Method 1)
The method 1 includes, for example, a method of grafting an acid compound and / or a derivative of an acid compound (hereinafter also referred to as “graft monomer”) to the olefin polymer (A-1), and there is no limitation on a conventionally known method. Can be used. For example, the graft monomer is usually 0.01 to 50 parts by weight, preferably 0.05 to 40 parts by weight, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the olefin polymer (A-1). Graft modification may be performed.

  For example, when a propylene polymer is used as the olefin polymer (A-1), a melt modification method in which the propylene polymer is melted and a graft monomer is added and graft copolymerized, the propylene polymer is dissolved in a solvent, and the graft monomer is dissolved. A solution modification method in which is added and graft copolymerized.

  The graft reaction is preferably carried out in the presence of a radical initiator from the viewpoint of efficiently grafting the graft monomer to the olefin polymer (A-1). In this case, the graft reaction is usually performed at a temperature of 60 to 350 ° C. Is called. The usage-amount of a radical initiator is 0.001-2 mass parts normally with respect to 100 mass parts of olefin polymers (A-1).

  Examples of the radical initiator include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, 2,5-dimethyl-2,5. -Organic peroxides such as di (tert-butylperoxy) hexane, 1,4-bis (tert-butylperoxyisopropyl) benzene, and t-butylperoxybenzoate are preferred. A radical initiator may be used individually by 1 type, and may use 2 or more types together.

(Method 2)
As the method 2, for example, a method described in JP-A-2006-137873 can be mentioned. When maleic anhydride groups are introduced into the olefin polymer (A-1), for example, the olefin polymer (A-1) and maleic anhydride are reacted under acidic conditions. When introducing a sulfonic acid group into the olefin polymer (A-1), for example, the olefin polymer (A-1) is reacted with a reaction agent such as sulfuric acid-acetic anhydride or fuming sulfuric acid.

(Method 3)
Examples of the method 3 include a method of converting a functional group into a sulfonic acid group by reacting the obtained graft-modified product with aminosulfonic acid after the graft modification treatment of the method 1 is performed.

  Examples of aminosulfonic acid include p-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, o-aminobenzenesulfonic acid, and 2-aminoethanesulfonic acid. Aminosulfonic acid may be used alone or in combination of two or more.

<Metal salt (B)>
The metal salt (B) has two or more functional groups (b) containing a metal component. Here, the functional group (b) containing a metal component is a functional group (eg, reactive site) that can interact (eg, react) with the functional group (a). That is, the metal salt (B) has two or more “functional groups (b) containing a metal component” that can interact with the functional group (a) of the olefin polymer (A). For example, in the case of disodium succinate, one —COONa group is one functional group.

However, carbonate is excluded from the metal salt (B). The reason why carbonate is excluded from the metal salt (B) in the present invention is based on the following idea. For example, when potassium carbonate is used, it is considered that potassium (K ⁺ : cation part) remains in the ionomer resin, but the carbonic acid part (CO ₃ ²⁻ : anion part) volatilizes as CO ₂ and does not remain. On the other hand, when metal salts of inorganic acids other than carbonates, such as phosphates and borates, are used, the phosphoric acid part and boric acid part (anion part) remain in the ionomer resin. It is considered that the effect of improving the melt tension and the like is manifested.

  Regardless of whether it is reversible or irreversible, the olefin polymers (A) are at least partially formed through the metal salt (B) due to intermolecular interactions such as a covalent bond, an ionic bond, a coordinate bond, and a hydrogen bond. By forming a cross-linked structure, it is presumed that the excellent physical properties of the present invention (eg, low closed cell ratio, high oil absorption performance) are developed.

  Examples of the metal component (ion) in the metal salt (B) include lithium, sodium, potassium, aluminum, zirconium, magnesium, calcium, barium, cesium, strontium, rubidium, titanium, zinc, copper, iron, tin, and lead. Examples include metals of Groups 1 to 16 of the periodic table. Among these, sodium, potassium, magnesium, calcium, zirconium, zinc, and aluminum are preferable, and from the viewpoint of promoting molecular chain crosslinking of the olefin polymer (A), monovalent metal components (ions) are preferable, and sodium, potassium Is more preferable, and potassium is particularly preferable.

  As the metal salt (B), a metal salt of an organic acid or an inorganic acid is preferable. That is, as the functional group (b) of the metal salt (B), a group obtained by neutralizing an acid functional group of an organic acid with a metal component and an acid functional group of an inorganic acid are neutralized by a metal component. At least one selected from the group is preferred.

Examples of the acid functional group possessed by the organic acid include a carboxyl group (—COOH) and a sulfo group (—SO ₃ H). Examples of the group formed by neutralizing the acid functional group with a metal component include: -COOM, -SO ₃ M (wherein M represents a metal component).

Examples of acid functional groups possessed by inorganic acids include functional groups possessed by phosphoric acid (H ₃ PO ₄ ) and boric acid (B (OH) ₃ ) (POOH, BOH). Examples of the group formed by the addition include groups possessed by phosphates and borates (POOM, BOM; in the formula, M represents a metal component).

  Examples of organic acid metal salts include aliphatic polyvalent carboxylates such as succinates, adipates, and butanetetracarboxylates, phthalates, isophthalates, terephthalates, hemimelates, trimellites, Aromatic polybasic carboxylates such as trimesinate, merophanate, planite, pyromellitic acid and melitrate, hydroxy polyvalent carboxylates such as citrate, iminodiacetate, nitrilotriacetate Nitrogen atom-containing polyvalent carboxylates such as ethylenediaminetetraacetate and diethylenetriaminepentaacetate. Cost, availability, workability, molding stability during production, and balance of physical properties of the resulting ionomer resin composition. From the viewpoint, succinate, citrate, iminodiacetate, nitrilotriacetate, ethylenediaminetetraacetate, diethylenetriamide Pentaacetic acid salts are preferred. Specific examples of the organic acid metal salt include, for example, potassium salt, dipotassium succinate, tripotassium citrate, dipotassium iminodiacetic acid, tripotassium nitrilotriacetate, tetrapotassium ethylenediaminetetraacetate, pentapotassium diethylenetriaminepentaacetate Is mentioned. An organic acid metal salt may be used individually by 1 type, and may use 2 or more types together.

  As the inorganic acid metal salt, phosphates and borates are preferable because decomposition hardly occurs even when heating or the like is performed, and they tend to remain in the ionomer resin. Specific examples of the inorganic acid metal salt include tripotassium phosphate and potassium tetraborate. However, as described above, carbonates are excluded from inorganic acid metal salts. An inorganic acid metal salt may be used individually by 1 type, and may use 2 or more types together.

  When there are three or more acid functional groups per molecule, all the acid functional groups may be neutralized by the metal component, or two even if one or more acid functional groups are not neutralized by the metal component. The above acid functional group should just be neutralized with the metal component. Preferably, it is a compound in which all acid functional groups are neutralized with a metal component.

  In the formation of the ionomer resin (X1), the use ratio of the metal salt (B) is usually 0.01 to 100 parts by mass, preferably 0.05 to 50 parts by mass with respect to 100 parts by mass of the olefin polymer (A). Especially preferably, it is 0.1-10 mass parts. When the use ratio is less than the lower limit, an ionomer resin having a low crosslinking density and insufficient strain curability is easily obtained. When the use ratio exceeds the upper limit, the resulting ionomer resin has a too high crosslink density, the melt fluidity is significantly deteriorated, the moldability is deteriorated, and the dispersibility of the metal salt in the ionomer resin is reduced. It will deteriorate remarkably and will lead to problems such as poor appearance of the finally obtained foam.

<< Olefin polymer (C) >>
The foam used in the present invention is a foam of the ionomer resin composition (X2) formed from the ionomer resin (X1) and the olefin polymer (C) different from the functional group-containing olefin polymer (A). Good.

  Unlike the functional group-containing olefin polymer (A), the olefin polymer (C) is an olefin polymer having no functional group (a). As the olefin polymer (C), for example, the olefin polymer (A-1) described above and having no functional group (a) is preferable.

  The olefin polymer (C) has a structural unit derived from an α-olefin in an amount of usually 50 mol% or more, preferably 80 mol% or more, particularly preferably 100 mol%. The content of the structural unit derived from the α-olefin may be 100 mol%. The olefin polymer (C) is preferably a crystalline polyolefin from the viewpoint of heat resistance, mechanical strength, moisture resistance, chemical resistance, and the like.

  Although the crystallinity degree of an olefin polymer (C) does not have a restriction | limiting in particular, Usually, it is 10 to 90%, Preferably it is 12 to 80%, More preferably, it is 15 to 75%. When the crystallinity of the olefin polymer (C) is in the above range, a foam excellent in oil resistance can be obtained.

  The details of the olefin polymer (C) are the same as those of the olefin polymer (A-1), and the preferred range is also the same as that of the olefin polymer (A-1). In particular, from the viewpoints of heat resistance and mechanical strength, propylene polymers such as propylene homopolymer and propylene copolymer, butene-1 polymers such as butene-1 homopolymer and butene-1 copolymer, 4- 4-methylpentene-1 polymers such as methylpentene-1 homopolymer and 4-methylpentene-1 copolymer are preferred.

  The mixing ratio ((X1) :( C)) of the ionomer resin (X1) and the olefin polymer (C) is usually 1:99 to 99: 1, preferably 5:95 to 80:20, in mass ratio. More preferably, it is 10: 90-50: 50, More preferably, it is 10: 90-30: 70.

  The addition amount of the olefin polymer (C) is usually 1 to 99%, preferably 20 to 95%, more preferably 50 to 90%, based on the mass, with respect to the entire ionomer resin composition (X2) after mixing. More preferably, it is 70 to 90%.

  The weight average molecular weight (Mw) in terms of polystyrene measured by size exclusion chromatography of the olefin polymer (C) is usually 1000 to 5000000, preferably 10000 to 3000000.

《Other ingredients》
In the ionomer resin (X1) or the ionomer resin composition (X2), various additives such as a flame retardant, a heat stabilizer, an oxidation stabilizer, a weathering stabilizer, an antistatic agent, a lubricant, and a plasticizer are added as desired. It can mix | blend in the range which does not impair the effect of this invention.

<Method for Producing Ionomer Resin (X1) and Ionomer Resin Composition (X2)>
The ionomer resin (X1) can be obtained, for example, by melt-kneading the functional group-containing olefin polymer (A) in the presence of the metal salt (B). “Melt kneading” refers to a process in which shearing and heating are performed simultaneously. The melt kneading can be performed, for example, using a general melt kneading apparatus used for processing a thermoplastic resin. The melt kneader may be a batch type or a continuous type. Specific examples of the melt kneader include batch type melt kneaders such as a Banbury mixer and a kneader; and continuous melt kneaders such as a co-rotating continuous twin screw extruder.

  Examples of the method of adding the olefin polymer (C) include (1) a method of melt-kneading the ionomer resin (X1) and the olefin polymer (C), and (2) a functional group in the presence of the metal salt (B). Method of Melting and Kneading Containing Olefin Polymer (A) and Olefin Polymer (C) Simultaneously (Method of Simultaneously Forming Ionomer Resin (X1) and Melting and Kneading Ionomer Resin (X1) and Olefin Polymer (C) ). In any method, the ionomer resin composition (X2) formed from the ionomer resin (X1) and the olefin polymer (C) can be obtained.

  Any of these two methods may be used. From the viewpoint of easily controlling the crosslinking density of the ionomer resin, there is a method in which only the ionomer resin (X1) is once produced as described above, and then the ionomer resin (X1) and the olefin polymer (C) are melt-kneaded. preferable. From the viewpoint of production cost, a method in which the functional group-containing olefin polymer (A) and the olefin polymer (C) are simultaneously melt-kneaded in the presence of the metal salt (B) is preferable.

  The melt-kneading is preferably performed on the functional group-containing olefin polymer (A), the metal salt (B), and, if necessary, a mixture containing the olefin polymer (C). Examples of the method include (I) and (II).

  Method (I): Melting continuously for a mixture containing a functional group-containing olefin polymer (A), a metal salt (B) and, if necessary, an olefin polymer (C) using a twin screw extruder Kneading method.

  Method (II): A method of melt-kneading a mixture containing the functional group-containing olefin polymer (A), the metal salt (B) and, if necessary, the olefin polymer (C) using a batch kneader.

  The melt kneading conditions vary depending on the melting point or glass transition temperature of the functional group-containing olefin polymer (A), the type of metal salt (B), the type of melt kneader, etc., but the processing temperature is usually 80 to 350 ° C., preferably Is 100 to 320 ° C., and the treatment time is usually 30 seconds to 30 minutes, preferably 60 seconds to 10 minutes.

  If the treatment temperature is too low, the time required to sufficiently react the functional group-containing olefin polymer (A) and the metal salt (B) becomes long, which may be a problem from the viewpoint of productivity. If the treatment temperature is too high, it will be difficult to react the functional group-containing olefin polymer (A) and the metal salt (B) uniformly, and the crosslink density in the ionomer resin (X1) finally obtained will be coarse and dense. It may become noticeable, and may lead to deterioration of the mechanical characteristics.

  The metal salt (B) is preferably mixed with the functional group-containing olefin polymer (A) and, if necessary, the olefin polymer (C) in a liquid form such as an aqueous solution. This is particularly advantageous when the polymer (A) is an olefin polymer grafted with an acid anhydride. This is because the water contained in the aqueous solution is used to hydrolyze the acid anhydride into a dibasic acid.

  The melt fluidity that is an index of the average molecular weight of the ionomer resin (X1) is as follows. That is, when the olefin polymer (A-1) is a propylene polymer, the MFR of the ionomer resin (X1) under a load of 2.16 kg at 230 ° C., the olefin polymer (A-1) is a butene-1 polymer. When the MFR of the ionomer resin (X1) under a load of 190 ° C. and 2.16 kg and the olefin polymer (A-1) is a 4-methylpentene-1 polymer, the load is 260 ° C. under a load of 5.0 kg. The MFR of the ionomer resin (X1) is usually 0.01 to 500 g / 10 minutes, preferably 0.1 to 200 g / 10 minutes, more preferably 0.1 to 50 g / 10 minutes.

  The ionomer resin (X1) and the ionomer resin composition (X2) have an improved extensional viscosity. These are excellent in chemical resistance, heat resistance, balance of mechanical properties, moldability, dimensional stability, electrical insulation, low dielectric properties, light weight, etc. Is preferably used.

[Production of foam]
The foam can be obtained by foaming the above-mentioned ionomer resin (X1) or ionomer resin composition (X2) (hereinafter also referred to as “molding material”), and extrusion foaming is preferred. The foam production method includes, for example, a step of melt-kneading a molding material in an extruder, and a step of extruding and foaming the molding material in a low pressure region.

  In the present invention, a batch-type foaming method and a continuous-type foaming method can be used, but it is particularly preferable to use the continuous-type foaming method because a foam suitable for the oil absorbent material of the present invention can be obtained. The batch-type foaming method and the continuous-type foaming method are described, for example, in “Resin Foam Molding Technology and Application Examples Focusing on Application to Automotive Parts” (Technical Information Association, issued on October 30, 2009).

As a manufacturing apparatus manufacturing apparatus, for example, a known extrusion foaming apparatus capable of heating a molding material in a molten state, kneading while applying an appropriate shear stress, and extruding and foaming from a die can be mentioned. As the extruder constituting the production apparatus, either a single screw extruder or a twin screw extruder can be used. As such an extrusion foam molding apparatus, for example, a tandem extrusion foam molding apparatus disclosed in Japanese Patent Application Laid-Open No. 2004-237729, in which two extruders are connected, can be cited.

  The melting temperature in an extruder is 100-350 degreeC normally, Preferably it is 120-300 degreeC. When a physical foaming agent in a supercritical state is used as the foaming agent, the melting and diffusion of the physical foaming agent in the molding material is greatly enhanced, allowing it to penetrate into the molding material in a short time. It is preferred to maintain the temperature above the critical pressure of the physical blowing agent and above the critical temperature.

  When a supercritical physical foaming agent is used as the foaming agent, the physical foaming agent is heated and pressurized in the extruder to the supercritical state, or the physical foaming agent is heated and heated before being supplied to the extruder. It is preferable to supply to the extruder after raising the pressure to the supercritical state.

  The resin temperature (the temperature of the molding material) at the die exit is usually 50 to 250 ° C., preferably 60 to 240 ° C., from the viewpoint of foam moldability. The molding material is cooled to the above temperature range and adjusted to a viscosity suitable for subsequent foaming. For example, when the olefin polymer (A-1) in the ionomer resin (X1) is a propylene polymer and a nucleating agent is used, the resin temperature at the die outlet is from the viewpoint of adjusting the average diameter of the through holes. For example, 130-160 degreeC is preferable.

  The shape of the foam is appropriately set according to the shape of the oil absorbing material, and examples thereof include known shapes such as a plate shape, a columnar shape, a rectangular shape, a convex shape, and a concave shape. The shape of the foam is determined by the shape of the die outlet formed in the die.

<Fine strips>
As a method for producing the foam, a so-called strip converging body, in which the foams extruded from a plurality of die outlets are converged into one foam, can be preferably employed. For example, a plurality of strips are extruded and foamed from a die assembly constituted by a plurality of extrusion dies, or a plurality of strips are extruded and foamed from an extrusion die formed with a plurality of extrusion holes. There is a method of obtaining an extruded foam (strip converging body) in which a plurality of strips are bundled by fusing the strips together in the longitudinal direction. In the strip, a plurality of foam cells are present at random.

  In the strip bundle, the expansion ratio of the extruded foam can be increased, and the extruded foam having a sufficient thickness can be easily formed in various shapes. Details of the method for producing the strip-shaped bundle are described in, for example, Japanese Patent Application Laid-Open No. 53-1262.

  The shape of the strip depends on the shape of the extrusion die and the shape of the extrusion hole formed in the extrusion die. The shape of the extrusion die and the extrusion hole can be any shape such as a circle, a diamond, or a slit. The shapes and sizes of the extrusion die and the extrusion holes may all be the same shape and the same size, or extrusion holes of various types and sizes may be formed in one extrusion die.

  The extruded foam may have a portion (non-striped portion) where no strip is formed. In order to form a non-striped portion, if a part that does not partially form an extrusion hole is provided for an extrusion die in which a plurality of extrusion holes are formed, the strip is not extruded from the part, and a gap is formed. The non-striped part which consists of will be formed suitably.

<Foaming means>
Examples of the foaming means for the molding material include physical foaming in which a physical foaming agent (fluid) is injected into the molten molding material during molding, and chemical foaming in which a chemical foaming agent is mixed into the molding material.

  Examples of the physical foaming agent include inert gases such as carbon dioxide (carbon dioxide gas) and nitrogen gas, and carbon dioxide gas and nitrogen gas in a supercritical state are particularly preferable. From the viewpoint of adjusting the expansion ratio, the physical foaming agent is preferably injected in an amount of 1 to 20% by mass, more preferably 2 to 15% by mass based on a total of 100% by mass of the molding material and the physical foaming agent. preferable. For example, when the olefin polymer (A-1) in the ionomer resin (X1) is a propylene polymer and a nucleating agent is used, from the viewpoint of adjusting the average diameter of the through holes, the physical foaming agent is a molding material. It is preferable to inject, for example, 3.0 to 10.0% by mass with respect to the total of 100% by mass of the physical foaming agent.

  The physical foaming agent can be injected, for example, into a molten molding material in an extruder. In the case of a tandem extrusion foaming molding apparatus, the physical foaming agent is injected into a molten molding material in an upstream extruder. do it.

  Examples of the chemical foaming agent include inorganic chemical foaming agents such as sodium bicarbonate and ammonium carbonate; and organic chemical foaming agents such as azodicarbonamide, azobisisobutyronitrile, and N, N-dinitrosopentatetramine. It is done. Among these, an inorganic chemical foaming agent is preferable.

  The addition amount of the inorganic chemical foaming agent is usually 0.1 to 40 parts by mass, preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the molding material. The addition amount of the organic chemical foaming agent is usually 0.1 to 40 parts by mass, preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the molding material.

  A physical foaming agent may be used individually by 1 type, and may use 2 or more types together. A chemical foaming agent may be used individually by 1 type, and may use 2 or more types together. Moreover, you may use together a physical foaming agent and a chemical foaming agent.

<Additive>
For molding materials, nucleating agents commonly used as additives for polyolefins such as polypropylene (eg, sorbitol nucleating agents, carboxylic acid ester nucleating agents, phosphate ester nucleating agents, β crystal nuclei) The agent may be added in a small amount as long as various physical properties such as foamability are not impaired.

  As a result, the molten molding material extruded from the die outlet is accelerated by the solidification of the cell wall during the cooling process, and at the same time, is subjected to expansion deformation accompanying foaming. As a result, as in the case of producing a microporous sheet by stretching polypropylene, the average diameter of the through-holes on the cell wall surface is reduced and the number density is increased, and therefore the oil absorption performance is further improved. Be expected. This is because the total area (specific surface area) of the cell walls inside the foam that can absorb oil increases, and the average diameter of the through-holes is small, so the oil flow between cells using capillarity is easy. Therefore, the reason is that the oil can more efficiently penetrate the entire inside of the foam.

  The addition amount of the nucleating agent in 100% by mass of the molding material is preferably 0.001 to 0.1% by mass, more preferably 0.01 to 0.1% by mass. When the addition amount of the nucleating agent is within the above range, a small through hole suitable for the object of the present invention can be obtained. In the present invention, the amount of nucleating agent added can be reduced as compared with ordinary polyolefins. This is presumably because the ionomer resin is thought to have a branched polymer or star-like polymer-like molecular structure and can itself act as a nucleating agent.

<Preferred requirements for foam>
The foam preferably satisfies the following requirements (1) to (4).
(1) Density measured according to ASTM D792 A method (underwater substitution method)
0.0090 to 0.20 g / cm ³ .
(2) The closed cell ratio measured according to ASTM D2856 C method is
0% or more and less than 60%.
(3) The average diameter of the cells is 10 μm or more and 1000 μm or less.
(4) The average diameter of the holes penetrating the wall surface between the cells is 0.1 to 90% of the average diameter of the cells (in the present specification, the holes are also referred to as “through holes”). .)
Hereinafter, preferable requirements for the foam will be described.

Requirement (1): Density The density of the foam is measured in accordance with ASTM D792 Method A (submersion method), preferably 0.0090 to 0.20 g / cm ³ , more preferably 0.00. 0090 to 0.20 g / cm ³ , more preferably 0.010 to 0.20 g / cm ³ . When the density is not more than the above upper limit value, the oil absorbability is good, and when it is not less than the above lower limit value, the thickness of the cell wall is not too thin, and dissolution by oil and reduction in rigidity are small.

Requirement (2): Closed cell ratio The closed cell ratio measured in accordance with ASTM D2856 method C of the foam is preferably 0% or more and less than 60%, more preferably 0 to 55%. More preferably, it is 0 to 50%. When the closed cell ratio is in the above range, the oil absorbability is excellent.

Requirement (3): Average cell diameter The average cell diameter (average cell diameter) of the foam is preferably 10 µm or more and 1000 µm or less, preferably 30 to 800 µm, more preferably 50 to 600 µm. When the average cell diameter is in the above range, the total area (specific surface area) of the cell wall inside the foam capable of absorbing oil is large, so that the oil can efficiently penetrate into the entire inside of the foam. If the average cell diameter is equal to or greater than the lower limit, the foam is sufficiently flexible and breakage is less likely to occur when the foam is bent. If the average cell diameter is less than or equal to the above upper limit value, mechanical strength such as rigidity is less likely to be reduced, and it is easy to be self-supporting when the foam body is upright, and lamination with a highly rigid plate such as a steel plate is not necessarily required. It is no longer necessary, and there is a tendency to reduce process costs and material costs, and there is little deterioration in physical properties due to moisture absorption.

Requirement (4): Average diameter of through-holes The average diameter of the through-holes of the foam is smaller than the average diameter of the cells, and is usually 0.1 to 99%, preferably 0.1 to 50% of the average diameter of the cells. More preferably, it is 0.1 to 40%. The average diameter of the through holes is, for example, 0.5 μm or more, preferably 0.5 μm or more and 10 μm or less. When the average diameter of the through holes is within the above range, the oil can easily flow between the cells using the capillary phenomenon, so that the oil can efficiently penetrate the entire inside of the foam. Become. If the average diameter of the through holes is equal to or greater than the lower limit, the oil absorbability is good. When the average diameter of the through holes is not more than the above upper limit value, the oil absorption performance is good, the mechanical strength such as rigidity is hardly reduced, and the physical properties are not lowered due to moisture absorption.

  In the present invention, for example, by increasing the functional group (a) content per molecule of the olefin polymer (A) described later and the number of metal atoms per molecule of the metal salt (B), the closed cell ratio is lowered, An average cell diameter can be made small and the average diameter of a through-hole can be made small.

  Further, the average cell diameter can be increased by reducing the resin pressure loss (ΔP) at the die portion during foam molding. Specifically, in the case of a circular die, ΔP can be reduced by increasing the die diameter and shortening the land length. Also, the average cell diameter can be increased by slowing down the cooling rate of the foamed resin coming out of the die. Specifically, an average cell diameter can be controlled by installing a tank capable of adjusting the temperature at the die outlet and passing the foamed resin from the die through the die.

[Use of oil absorbing material]
The oil-absorbing material of the present invention is excellent in oil-absorbing performance and is formed from an ionomer resin. Therefore, the oil-absorbing material is recyclable and various substrates (eg, a substrate composed of polyethylene terephthalate, a group composed of an ethylene / vinyl alcohol copolymer). Excellent adhesion to resin base materials such as materials and metal base materials such as aluminum sheets). In addition, it has an excellent balance of heat resistance, chemical resistance, light weight, and mechanical properties. In addition, the oil absorbent material of the present invention is more efficient and remarkably more effective than conventional technology, which is advantageous in foam molding, and exhibits “strain hardenability” in which the viscosity increases with strain when uniaxially stretched. This is advantageous from the viewpoint of moldability because it can be obtained by using an ionomer resin that can be produced as a raw material.

  The oil absorbing material of the present invention includes organic solvents such as toluene and cyclohexane, silicon oil, petroleum wax, kerosene, light oil, heavy oil A, heavy fuel oil C, heavy oil JIS3, sebum, crude oil, gasoline, mineral oil, vegetable oil. (Castor oil, tung oil, linseed oil, tempura oil, salad oil, white squeezed oil, corn oil, sesame oil, rapeseed oil, sunflower oil, rice bran oil, coconut oil, coconut oil, palm oil, palm oil, cottonseed oil, hemp seed oil, olive oil, peanut oil , Almond oil, cacao butter, coffee bean oil, tincture oil, wood wax, etc., animal oil (lard, beef tallow, bone fat, fish oil, chicken oil, duck oil, coconut oil, etc.), industrial oil (lubricating oil, spindle oil, etc.) , Dynamo oil, Cylinder oil, Turbine oil, Hydraulic oil, Bearing oil, Gear oil, Sliding surface lubricating oil, Refrigerator oil, Compressor oil, Heat medium oil, Heat treatment oil, Grease, Engine Oil, cutting oil, an insulating oil), cosmetic oil (hair oil, Bintsukeabura, silver out oil, pomade) can be suitably used as an absorbent, such as. Moreover, the oil absorbent material of the present invention can also be suitably used as an absorbent for aqueous liquids such as water.

The oil absorbing material of the present invention can be suitably used for applications that require absorption of the liquid.
Examples of the application include the following.
・ Recovered oil leaked to the surface of the ocean, lakes, rivers, etc., recovered oil leaked on the road, U-shaped grooves, fields etc. due to accidents, recovered oil leaked at gas stations, factories, etc., and flowed into the sewer Oil absorbers used for recovery of oil leaked or waste oil leaked at every location, such as oil recovery and waste oil treatment / recovery with grease traps.

・ Attaching / absorbing oil that has leaked to the sea, rivers, lakes, etc., floating on the water or in the water due to inflow of various wastewater or other causes An oil absorber used to attach and remove oil.
・ Hydraulic machine maintenance / disassembly / assembly factory, automobile maintenance factory, machine maintenance factory, refinery, in-vessel, ship maintenance area, aircraft maintenance area, traffic accident handling site, and other oil handling areas Absorber. The target oils include engine oil, gasoline, kerosene, light oil, cutting oil, hydraulic oil, lubricating oil, jet fuel, oil-based ink, gear oil, vegetable oil, animal oil, general liquid oil including crude oil, and other chemicals including hydrocarbons. Goods.

・ Oil spill recovery, floating oil recovery, oil recovery in wastewater, emulsion breaker, waste oil treatment, edible waste oil treatment, machine oil waste oil treatment, chemical cleaning cloth, water treatment filter, oil mist filter, household waste oil treatment, industrial use Waste oil treatment, oil spill treatment, waste water treatment, pits, harbors, floating oil treatment material that has flowed out to lakes and seas, cosmetics to absorb sebum, spilled oil and waste oil absorbent (collecting agent), fragrance, Cosmetics for external use on skin and hair, such as sustained release bases for oil components such as insecticides and fungicides, makeup cosmetics, skin care cosmetics, antiperspirant cosmetics, UV protection cosmetics and hair cosmetics Raw material, oil absorber around kitchen, cleaning (oil stain removal) sheet.

The present invention will be described more specifically with reference to examples.
In the present invention, each physical property was measured by the following method.

Melt flow rate (MFR)
The melt flow rate (MFR) of various resins is in accordance with ASTM D1238 under conditions of a temperature of 230 ° C. and a load of 2.16 kg when a propylene polymer is used, and a temperature when a butene-1 polymer is used. When 4-methylpentene-1 polymer was used under the conditions of 190 ° C. and a load of 2.16 kg, the measurement was performed under the conditions of a temperature of 260 ° C. and a load of 5.0 kg.

Average molecular weight (Mw, Mn)
The average molecular weights (Mw, Mn) of various polymers were measured by size exclusion chromatography (SEC) and performed under the following conditions. Calibration curves of elution volume and molecular weight were prepared using standard polystyrene manufactured by Tosoh Corporation. Using the calibration curve, the polystyrene-equivalent weight average molecular weight (Mw) and number average molecular weight (Mn) of the specimen were determined. In some cases, they were converted to polypropylene to give Mw and Mn.
-SEC: Alliance GPC2000 type manufactured by Waters-Column: TSK gel GMH ₆ -HT 2 manufactured by Tosoh Corporation-Sample amount: 500 μl (polymer concentration 0.15% by mass)
・ Flow rate: 1ml / min ・ Temperature: 140 ℃
Solvent: o-dichlorobenzene

The density density of the foam was measured in accordance with ASTM D792 Method A (submersion method).
The closed cell ratio of the foam was measured according to ASTM D2856, C method.
Average cell diameter of foam (average cell diameter)
The foams obtained in the examples, comparative examples, and reference examples were cut in an arbitrary cross section, and one section of approximately 7 mm × 7 mm × 1 mm was cut out from the cross section. After depositing platinum on the surface of the section, the surface structure was observed with a scanning electron microscope (JSM-651OLV manufactured by JEOL Ltd.). Three surface photographs (three sheets) that were photographed at an arbitrary magnification selected from 30 to 500 times and different from each other and that did not overlap each other were prepared. Ten arbitrary cells were selected from each photograph, the longest axis and the shortest axis of the cell were measured, and the average value was taken as the diameter of the cell. This operation was performed on a total of 30 cells selected above, and the average value was defined as the “average cell diameter” of the foam.

Average diameter (average diameter) of through-holes in foam cell wall
Three cells were arbitrarily selected from each of the three photographs prepared above, and the diameters of all the through-holes existing on each cell wall surface were measured. The diameter of each through hole was the average value of the longest axis and the shortest axis, as described above. This operation was performed for all the through holes, and the average value thereof was defined as the average diameter of the through holes in the cell of interest. The evaluation work for the average diameter of the through holes was performed on a total of nine selected cells, and the average value thereof was defined as the “average diameter of the through holes” of the foam.

Water absorption rate, oil absorption rate (method for evaluating liquid absorbency)
A rectangular parallelepiped sample piece having a size of approximately 3.0 cm × 2.0 cm × 2.0 cm was used. This sample piece was kept at 23 ° C. in a state where the sample piece was completely impregnated in the liquid, and was allowed to stand in this state for 24 hours. After the elapse of 24 hours, the sample piece was taken out from the liquid, and the liquid adhering to the surface of the sample piece was removed with a cloth such as an exposed cloth, and its weight w (g) was measured. When the weight of the test piece before impregnating the liquid is w ₀ (g), the liquid absorbency is calculated by the following equation.
Liquid absorption characteristic = {(w−w ₀ ) / w ₀ } × 100 (%)

[Synthesis Example 1] Synthesis of Syndiotactic Polypropylene (s-PP) 1000 L of n-heptane was charged into a reaction vessel having an internal volume of 3.0 m ³ which had been sufficiently purged with nitrogen, and a toluene solution of methylaluminoxane (Al = 1.53 mol / L) was added dropwise to 610 ml (0.93 mol).

  On the other hand, a magnetic stirrer was placed in a 5 L-branched flask that had been sufficiently purged with nitrogen. To this, 610 ml (0.93 mol) of a toluene solution of methylaluminoxane (Al = 1.53 mol / L) and then dibenzylmethylene ( A toluene solution of 1.30 g (1.86 mmol) of cyclopentadienyl) (2,7-diphenyl-3,6-ditert-butylfluorenyl) zirconium dichloride was added and stirred for 20 minutes.

This solution was added to the reaction vessel, and then 3200 NL of hydrogen was supplied at 19 Nm ³ / h for 10 minutes. Thereafter, polymerization was started while supplying propylene in an amount of 65 kg / h. Propylene is continuously supplied in an amount of 65 kg / h while maintaining a gas phase concentration of 53 mol% in a hydrogen reaction tank, polymerization is carried out at 25 ° C. for 4 hours, and then a small amount of diethylene glycol monoisopropyl ether is added for polymerization. Stopped. The obtained polymer was washed with 1.8 m ³ of heptane and dried under reduced pressure at 80 ° C. for 15 hours. As a result, 100 kg of polymer was obtained.

The polymerization activity was 14 kg-PP / mmol-Zr · Hr, the polymer obtained [η] was 1.96 dl / g, the melting point measured by DSC was Tm ₁ = 152.8 ° C., Tm ₂ = 159. It was 3 ° C., MFR = 6.0 g / 10 min, rrrr = 0.95, and the amount of n-decane soluble part was not more than the lower limit of measurement (0.5% by mass). The syndiotactic polypropylene thus obtained is hereinafter abbreviated as s-PP.

Functional group-containing olefin polymer (A)
[Preparation Example 1]
100 parts by mass of homopolypropylene (manufactured by Prime Polymer, trade name: J105G) as the olefin polymer (A-1), 0.7 parts by mass of maleic anhydride as a graft monomer, and t-butylperoxybenzoate ( A product obtained by dissolving 0.2 parts by mass of Nippon Oil & Fats, trade name: Perbutyl Z) in 10 parts by mass of acetone was dry blended.

  Thereafter, melt modification was performed using a biaxial kneader (trade name: KZW15, manufactured by Technobel Co., Ltd.) under conditions of a resin temperature of 180 ° C., a screw rotation speed of 200 rpm, and a discharge rate of 25 g / min. During extrusion, the radical initiator, solvent and unreacted maleic anhydride were vacuum degassed.

  The extruded strand in the molten state was cooled and pelletized to obtain a maleic acid-modified propylene polymer having a graft amount (content of groups derived from maleic anhydride) of 0.5% by mass.

[Preparation Examples 2 to 9]
The same as Preparation Example 1 except that in Preparation Example 1, the types and blending amounts of the olefin polymer (A-1) and the graft monomer, the blending amount of the initiator, and the melt modification conditions were changed as shown in Table 1. Thus, a functional group-containing olefin polymer was obtained.

アイオノマー樹脂（Ｘ１）
〔製造例１〕
１５ｍｍφ二軸押出機を用いて、シリンダー温度２３０℃、ダイス温度２３０℃、スクリュー回転数２００ｒｐｍの条件で、官能基含有オレフィン重合体（Ａ）として調製例１で調製したマレイン酸変性プロピレン重合体１００質量部と金属塩（Ｂ）としてエチレンジアミン四酢酸四カリウム０．５質量部とを溶融混合し、ペレタイザーにてペレット化を行い、アイオノマー樹脂のペレットを得た。（Ｂ）成分は、任意の濃度の水溶液とした後、（Ａ）成分とは独立の高圧注入ゾーンからシリンダーに供給した。

Ionomer resin (X1)
[Production Example 1]
Maleic acid-modified propylene polymer 100 prepared in Preparation Example 1 as a functional group-containing olefin polymer (A) under the conditions of a cylinder temperature of 230 ° C., a die temperature of 230 ° C., and a screw rotation speed of 200 rpm using a 15 mmφ twin screw extruder. Mass parts and 0.5 parts by mass of tetrapotassium ethylenediaminetetraacetate as a metal salt (B) were melt-mixed and pelletized with a pelletizer to obtain ionomer resin pellets. (B) Component was made into the aqueous solution of arbitrary density | concentrations, Then, it supplied to the cylinder from the high pressure injection zone independent of (A) component.

[Production Examples 2-9, Comparative Production Examples 1-7]
Ionomer resin pellets in the same manner as in Production Example 1 except that the type and amount of the functional group-containing olefin polymer (A) and metal salt (B) were changed as shown in Table 2 in Production Example 1. Got.

In addition, in the said manufacture example and comparative manufacture example, melt mixing was performed according to the following conditions according to the kind of olefin polymer (A-1) which comprises a functional group containing olefin polymer (A).
(1) h-PP: cylinder temperature 230 ° C., die temperature 230 ° C., screw rotation speed 200 rpm
(2) r-PP: cylinder temperature 180 ° C, die temperature 180 ° C, screw rotation speed 200rpm
(3) s-PP: cylinder temperature 200 ° C, die temperature 200 ° C, screw rotation speed 200rpm
(4) P4MP1: Cylinder temperature 260 ° C, die temperature 260 ° C, screw rotation speed 200rpm
(5) i-PB: Cylinder temperature 160 ° C, die temperature 160 ° C, screw rotation speed 200rpm

オレフィン重合体（Ｃ）
実施例で用いたオレフィン重合体（Ｃ）を表３に示す。

Olefin polymer (C)
Table 3 shows the olefin polymer (C) used in the examples.

［実施例１］：連続発泡
１５ｍｍφ二軸押出機を用いて、シリンダー温度２３０℃、ダイス温度２３０℃、スクリュー回転数２００ｒｐｍの条件で、オレフィン重合体（Ｃ）としてホモポリプロピレン（プライムポリマー製、商品名：Ｆ１１３Ｇ）とアイオノマー樹脂（Ｘ１）として製造例１で製造したアイオノマー樹脂のペレットとを質量比が（Ｃ）／（Ｘ１）＝９０／１０の割合で溶融混合し、ペレタイザーにてペレット化を行い、成形材料を得た。

[Example 1]: Continuous foaming Using a 15 mmφ twin screw extruder, homopolypropylene (manufactured by Prime Polymer, commercial product) as an olefin polymer (C) under conditions of a cylinder temperature of 230 ° C., a die temperature of 230 ° C., and a screw rotation speed of 200 rpm. Name: F113G) and the ionomer resin pellet produced in Production Example 1 as the ionomer resin (X1) are melt-mixed at a mass ratio of (C) / (X1) = 90/10, and pelletized with a pelletizer. A molding material was obtained.

  Using the obtained molding material, a tandem extrusion foaming molding apparatus (manufactured by Frontier Co., Ltd., the above-mentioned apparatus is a single screw extruder having a screw diameter of φ50 mm and a single screw extruder having a screw diameter of φ65 mm). Using a combination of a large number of circular extrusion holes (circular die, cross-sectional areas are all substantially the same) as a die, by the following method (manufacturing condition 1). A foam was produced which was a plate-like extruded foam (strip converging body) formed by concentrating a large number of foamed cylindrical strips.

Specifically, while melting the molding material with a φ50 mm single screw extruder, a CO ₂ supercritical fluid is injected to sufficiently dissolve the fluid uniformly in the molten molding material, and then φ50 mm From a φ65 mm single screw extruder connected to a single screw extruder, a molding material is extruded so that the resin temperature at the die outlet in the φ65 mm single screw extruder is 155 ° C., and a large number of strips are converged to form a plate shape An extruded foam (strip bundle) was produced.

[Examples 2 to 13, Comparative Examples 1 to 7]: Continuous foaming In Example 1, the types and blending amounts of the ionomer resin (X1) pellets and the olefin polymer (C), and the production conditions are shown in Tables 4 and 5. A foam was produced in the same manner as in Example 1 except that it was changed as described in 1. However, in Example 5, the ionomer resin (X1) was directly used as a molding material.

ＣＯ₂超臨界流体の質量基準は、樹脂成分とＣＯ₂との合計質量である。

The mass reference of the CO ₂ supercritical fluid is the total mass of the resin component and CO ₂ .

  As the resin temperature at the die outlet of the φ65 mm single screw extruder, for example, a value measured by a thermocouple thermometer may be adopted, and this resin temperature can be considered as the temperature of the molten resin extruded while foaming.

[Reference Example 1]
Polypropylene resin (manufactured by Prime Polymer Co., Ltd., homopolypropylene, grade F113G, MFR = 3.0 g / 10 min) was vacuum-pressed at a machine (manufactured by Kansai Roll Co., Ltd.) at 230 ° C. under a pressure of 10 MPa. Pressurized for minutes. Then, the press sheet of thickness 3mm, length 80mm, and width 80mm was obtained by pressurizing for 5 minutes under 20 degreeC and pressure 10MPa under normal pressure. A 40 mm × 10 mm × 3 mm rectangular parallelepiped sample was cut out from this press sheet and used for evaluation of liquid absorbency.

[Reference Examples 2 to 4]
In Reference Example 1, instead of polypropylene resin, s-PP (Reference Example 2), P4MP1 (Reference Example 3), i-PB (Reference Example 4) (using the abbreviations in Table 3) were used, and pressure conditions “After pressurizing under vacuum at 230 ° C. and a pressure of 10 MPa for 5 minutes, then pressurizing under normal pressure at 20 ° C. and a pressure of 10 MPa for 5 minutes” (Reference Example 2), “Pressurized under vacuum at 280 ° C. and a pressure of 10 MPa for 5 minutes. Then, pressurize at 20 ° C. under normal pressure for 5 minutes at 10 MPa ”(Reference Example 3),“ pressurize at 180 ° C. under vacuum for 5 minutes at 10 MPa, then pressurize at 20 ° C. under normal pressure for 5 minutes at 10 MPa ” A press sheet and a sample were obtained in the same manner as in Reference Example 1 except that it was changed to (Reference Example 4).

[Reference Examples 5 and 6]
(1) Production of flexible polyurethane foam Polyol A: polyether polyol having a hydroxyl group value of 54 kgKOH / g obtained by addition polymerization of propylene oxide and ethylene oxide to glycerin.
-TEDA: triethylenediamine.
DMEA: N, N-dimethylethanolamine.
L-5740s: Silicone foaming agent manufactured by Nippon Unicar Company.
BLDMC: benzyl, lauryl, dimethylammonium chloride.
・ TDI-80: 80% by mass of 2,4-tolylene diisocyanate
Mixture with 20% by weight of 2,6-tolylene diisocyanate.

  280 parts by weight of polyol A, 14.0 parts by weight of water, 0.233 parts by weight of TEDA, 0.336 parts by weight of DMEA, 3.92 parts by weight of L-5740S, 0.112 parts by weight of BLDMC in advance Then, 0.28 parts by mass of stannous octoate was added thereto, and immediately after high speed mixing, 1.00 part by mass of TDI-80 was added, and further high speed mixing was performed. The mixture was poured into a 70 mm mold, covered and foamed. After being cured by heating in an oven at 160 ° C. for 12 minutes, the foam was taken out of the mold and used as a sample.

(2) Production of rigid polyurethane foam Using a high-pressure foaming machine (CANNON HC-40), a mixed polyol of an aromatic amine-based polyether polyol and a phthalic acid-based polyester polyol, a foam stabilizer, a tertiary amine catalyst, water and A premix composed of cyclopentane and Takenate 4040MC (mixture of polymeric MDI and modified TDI) were mixed, and the resulting mixture was heated to 45 ° C. and a 45 mm thick, 50 cm square aluminum mold. To obtain a panel of rigid polyurethane foam having an overall density of 43 kg / m ³ . After foam molding, the sample was allowed to stand at room temperature for 24 hours, and then a core foam sample having a thickness of 25 mm and a 20 cm square was cut out from the panel and used as a sample.

  Table 6 shows the evaluation results of the above Examples, Comparative Examples, and Reference Examples.

※参考例における「バルク」は、プレスシートを意味する。
※比較例および参考例における「−」は、参考例１〜４では発泡体ではないのでセル径等が測定できないことを表し、比較例１〜７および参考例６では独立気泡率の高い発泡体のため、貫通孔が観察されなかったことを表す。

* "Bulk" in the reference example means a press sheet.
* "-" In Comparative Examples and Reference Examples indicates that cell diameters cannot be measured in Reference Examples 1 to 4 because they are not foams. In Comparative Examples 1 to 7 and Reference Example 6, foams having a high closed cell ratio Therefore, it represents that a through hole was not observed.

Bond strength test of ionomer resin composition Hereinafter, lamination of an ionomer resin composition which is a molding material of the oil absorbing material of the present invention and various base materials (eg, polyethylene terephthalate, ethylene / vinyl alcohol copolymer, aluminum sheet). The manufacturing method and adhesion evaluation result of a body are shown.

[Test Example 1]
As one of the base material layers, the molding material (ionomer resin composition) obtained in Example 2 was subjected to a vacuum press molding machine (manufactured by Kansai Roll Co., Ltd.) for 5 minutes at 230 ° C. under a pressure of 10 MPa. Pressed. Then, press sheet (Q-1) having a thickness of 100 μm, a length of 80 mm, and a width of 15 mm was obtained by pressurizing under normal pressure at 20 ° C. and a pressure of 10 MPa for 3 minutes.

  As another base material layer, polyethylene terephthalate (grade J135T manufactured by Mitsui Chemicals, Inc., hereinafter referred to as “PET”) was dried at a temperature of 80 ° C. for 8 hours, and then at 280 ° C. under vacuum in the vacuum press molding machine. Pressurization was performed at a pressure of 10 MPa for 5 minutes. Then, press sheet (Q-2) having a thickness of 100 μm, a length of 80 mm, and a width of 15 mm was obtained by pressurizing under normal pressure at 20 ° C. and a pressure of 10 MPa for 3 minutes.

  The obtained two kinds of press sheets were stacked in the order of the sheet (Q-1) and the sheet (Q-2), and the heat seal tester set to 240 ° C. (manufactured by Tester Sangyo Co., Ltd., heat seal tester TP-701). -B) was heat-sealed for 20 seconds to produce a laminated structure (T-1-1) composed of the layer (Q-1) and the layer (Q-2).

  About the obtained laminated structure (T-1-1), the interface bond strength of a layer (Q-1) and a layer (Q-2) was used using the tensile testing machine (Instron Japan company make, INSTRON1123). The adhesive strength was 27 N / 15 mm, and the peeled form was cohesive failure, as determined by T-peeling under conditions of a peeling atmosphere temperature of 23 ° C., a peeling speed of 500 mm / min, and a peel width of 15 mm.

[Test Example 2]
As another base material layer, an ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., trade name: EVAL, Grade L101A, hereinafter referred to as “EVOH”) is dried at a temperature of 80 ° C. for 8 hours, and then the above vacuum press The molding machine was pressurized at 220 ° C. and a pressure of 10 MPa for 5 minutes under vacuum. Then, press sheet (Q-3) having a thickness of 100 μm, a length of 80 mm, and a width of 15 mm was obtained by pressurizing under normal pressure at 20 ° C. and a pressure of 10 MPa for 3 minutes.

  In Test Example 1, a laminated structure (T-1-2) was produced in the same manner as in Test Example 1 except that the sheet (Q-3) was used instead of the sheet (Q-2), and the adhesion The strength was measured. As a result, the adhesive strength was 8.8 N / 15 mm, and the peeling form was cohesive failure.

[Test Example 3]
In Test Example 1, a laminated structure (T) was prepared in the same manner as in Test Example 1 except that an aluminum sheet (Q-4) having a thickness of 100 μm, a length of 80 mm, and a width of 15 mm was used instead of the sheet (Q-2). When 1-3-1) was manufactured and the adhesive strength was measured, the adhesive strength was 48 N / 15 mm, and the peeling form was cohesive failure.

[Test Example 4]
As one of the base material layers, a polypropylene resin (manufactured by Prime Polymer Co., Ltd., homopolypropylene, grade F113G, MFR = 3.0 g / 10 min) is vacuumed with a vacuum press molding machine (manufactured by Kansai Roll Co., Ltd.). The pressure was increased at 230 ° C. and a pressure of 10 MPa for 5 minutes. Then, press sheet (Q-5) having a thickness of 100 μm, a length of 80 mm, and a width of 15 mm was obtained by pressurizing under normal pressure at 20 ° C. and a pressure of 10 MPa for 3 minutes.

  In Test Examples 1 to 3, a laminated structure was produced in the same manner as in Test Examples 1 to 3 except that the sheet (Q-5) was used instead of the sheet (Q-1). An adhesive strength test was performed. As a result, the adhesive strength with PET is 0.0 N / 15 mm, the adhesive strength with EVOH is 0.0 N / 15 mm, and the adhesive strength with Al is 0.0 N / 15 mm. Yes, it did not show adhesiveness.

  As is clear from the results of the above Test Examples 1 to 4, the ionomer resin composition, which is the molding material for the oil absorbent material of the present invention, is made of various substrates (eg, polyethylene terephthalate, ethylene / vinyl alcohol copolymer, aluminum). Sheet). Therefore, it turns out that the oil-absorbing material of the present invention is excellent in adhesiveness with various substrates.

Claims (12)

It is an oil absorbing material consisting of a foam formed from at least an ionomer resin,
The ionomer resin has (A) 100 mass parts of an olefin polymer having a structural unit derived from an α-olefin having 2 to 20 carbon atoms and having a functional group (a), and (B) a functional component containing a metal component. An oil absorbent which is an ionomer resin (X1) formed from 0.01 to 100 parts by mass of a metal salt (excluding carbonate) having two or more groups (b).   The oil absorbent according to claim 1, wherein the functional group (a) is at least one selected from a structural unit derived from an acid compound and a structural unit derived from an acid anhydride.   The functional group (b) is at least one selected from a group obtained by neutralizing an acid functional group of an organic acid with a metal component and a group obtained by neutralizing an acid functional group of an inorganic acid with a metal component. The oil-absorbing material according to claim 1 or 2.   The olefin polymer (A) is a graft modified product of an olefin polymer (A-1) having a structural unit derived from an α-olefin having 2 to 20 carbon atoms. Oil absorbing material as described in 2.   The oil-absorbing material according to claim 4, wherein the olefin polymer (A-1) is a propylene polymer in which the content of structural units derived from propylene is 51 mol% or more.   The oil according to claim 4, wherein the olefin polymer (A-1) is a 4-methylpentene-1 polymer in which the content of structural units derived from 4-methylpentene-1 is 51 mol% or more. Absorber.   The oil-absorbing material according to claim 4, wherein the olefin polymer (A-1) is a butene-1 polymer having a content of structural units derived from butene-1 of 51 mol% or more.   The said olefin polymer (A) WHEREIN: The said functional group (a) is introduce | transduced in the quantity of 0.01-50 mass parts with respect to 100 mass parts of said olefin polymers (A-1). The oil absorbent material according to any one of 4 to 7.   The foam is a foam of a resin composition (X2) formed from the ionomer resin (X1) and an olefin polymer (C) different from the olefin polymer (A). The oil absorbent material according to any one of 8.   The oil-absorbing material according to claim 9, wherein a mass ratio of the ionomer resin (X1) to the olefin polymer (C) is (X1) :( C) = 1: 99 to 99: 1.   The oil absorber according to claim 9 or 10, wherein the olefin polymer (C) is an olefin polymer having a structural unit derived from an α-olefin having 2 to 20 carbon atoms. The oil absorbent according to any one of claims 1 to 11, wherein the foam satisfies the following requirements (1) to (4):
(1) Density measured according to ASTM D792 A method (underwater substitution method)
0.0090 to 0.20 g / cm ³ .
(2) The closed cell ratio measured according to ASTM D2856 C method is
0% or more and less than 60%.
(3) The average diameter of the cells is 10 μm or more and 1000 μm or less.
(4) The average diameter of the holes penetrating the wall surface between the cells is
It is 0.1 to 90% of the average diameter of the cell.