JP2015086246A - Polyolefin-based elastomer composition and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyolefin-based elastomer composition good in surface appearance, and capable of achieving a molded body having no odor, stickiness nor oozing.SOLUTION: There is provided a polyolefin-based elastomer composition can be obtained at least by melting and mixing (A) olefin-based elastomer of 100 pts.mass, (B) a polypropylene resin of 70 to 210 pts.mass, (C) hydrocarbon oil having an average molecular weight of 400 to 1000 and the content of a component having molecular weight of 400 or less of 30 mass% of 3 to 300 pts.mass. There is also provided a polyolefin-based elastomer composition having a polymer aggregate of 1 to 150 with 0.3 to 0.5 mm and 1 to 150 with 0.5 to 1.0 mm when the polyolefin-based elastomer composition is compression molded to a film having 0.1 mm thickness, light is radiated to one side surface of the film and a 5 cm×5 cm region of another side surface.

Description

  The present invention relates to a polyolefin elastomer composition and a method for producing the same.

  Conventionally, hydrocarbon oil (paraffin oil) has been added to a dynamically crosslinked thermoplastic polyolefin-based elastomer composition in order to improve fluidity. Molded articles obtained by injection molding of such polyolefin-based elastomer compositions are used in various applications. Since the molded body itself has rubber properties, it is widely used, for example, in automobile interior parts, OA equipment members, solar power generation module members, daily miscellaneous goods, and the like. Patent Documents 1 to 4 disclose techniques related to such a polyolefin-based elastomer composition.

JP2012-224865A JP 2010-285528 A International Publication No. 2009/072553 Pamphlet Japanese Patent No. 3540118

  However, neither of Patent Documents 1 and 2 has been studied on the stickiness and oil bleeding on the surface of the molded body. Patent Literature 3 discloses fogging and solidity, but does not disclose improvement of both stickiness and oil bleeding. Patent Document 4 also does not disclose improving both stickiness and oil bleeding. As described above, regarding the polyolefin elastomer composition, there is still room for improvement with respect to making it possible to suppress at least both stickiness and oil bleeding at a high level.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a polyolefin-based elastomer composition capable of realizing a molded article having a good surface appearance and free from odor, stickiness, and oil bleeding.

  As a result of intensive studies to solve the above problems, the present inventors have (A) 100 parts by mass of an olefin elastomer, (B) 70 to 210 parts by mass of a polypropylene resin, and (C) an average molecular weight of 400 to 1000. And a polyolefin elastomer composition obtained by melt-kneading at least 3 to 300 parts by mass of a hydrocarbon oil having a molecular weight of 400 or less and a content of a component having a molecular weight of 400 or less. The knowledge of satisfying specific conditions when compression-molded into a film was obtained, and the present invention was made.

That is, the present invention is as follows.
[1]
(A) 100 parts by mass of an olefin elastomer,
(B) 70 to 210 parts by mass of a polypropylene resin;
(C) 3 to 300 parts by mass of a hydrocarbon oil having an average molecular weight of 400 to 1000 and a content of a component having a molecular weight of 400 or less, of 30% by mass or less;
Is a polyolefin-based elastomer composition obtained by melt-kneading at least,
When the polyolefin elastomer composition is compression-molded into a film having a thickness of 0.1 mm, light is applied from one surface of the film, and an area of 5 cm × 5 cm on the surface opposite to the surface is observed, A polyolefin-based elastomer composition that satisfies the following conditions (1) and (2);
(1) There are 1 or more and 150 or less polymer aggregates of 0.3 mm or more and less than 0.5 mm.
(2) There are 1 or more and 150 or less polymer aggregates of 0.5 mm or more and less than 1.0 mm.
[2]
The melt-kneading has a step of at least simultaneously crosslinking the component (A) and decomposing the component (B), and during and / or after the step, The polyolefin elastomer composition according to [1], wherein component C) is added to the reaction system.
[3]
In the melt-kneading, the component (A), the component (B), and the component (C) are composed of one or more first metal meshes having an opening of 0.2 to 1 mm and an opening of 0.05. The polyolefin-based elastomer composition according to [1] or [2], which has at least a step of passing through a second wire mesh having a diameter of 0.17 mm to two or more sheets in random order.
[4]
The condition (1) is that there are 1 or more and 100 or less polymer aggregates of 0.3 mm or more and less than 0.5 mm;
[1] to [3], wherein the condition (2) is that there are 1 or more and 100 or less polymer aggregates of 0.5 mm or more and less than 1.0 mm. Polyolefin elastomer composition.
[5]
The condition (1) is that there are 1 or more and 50 or less polymer aggregates of 0.3 mm or more and less than 0.5 mm;
[1] to [3], wherein the condition (2) is that there are 1 or more and 50 or less polymer aggregates of 0.5 mm or more and less than 1.0 mm. Polyolefin elastomer composition.
[6]
The component (A) is an ethylene- (α-olefin having 3 to 12 carbon atoms) copolymer and / or an ethylene- (α-olefin having 3 to 12 carbon atoms) -nonconjugated diene copolymer. [1] to [5] The polyolefin elastomer composition according to any one of [5].
[7]
The polyolefin elastomer composition according to any one of [1] to [6], wherein the component (B) is homopolypropylene.
[8]
The polyolefin elastomer composition according to any one of [1] to [7], wherein the resin composition is a polyolefin elastomer composition for skin.
[9]
A step of melt-kneading the component (A), the component (B), and the component (C);
The melt-kneading has a step of performing at least simultaneously the crosslinking of the component (A) and the decomposition of the component (B), and
During the process and / or after the process, the component (C) is added to the reaction system, and then one or more first wire meshes having a mesh opening of 0.2 to 1 mm and a mesh opening of 0.05. Having a step of passing through a second wire mesh of ~ 0.17 mm in two or more, in random order;
The manufacturing method of the polyolefin-type elastomer composition as described in any one of [1]-[8].
[10]
The method for producing a polyolefin-based elastomer composition according to [9], wherein the first wire mesh and the second wire mesh are both plain weave wire meshes.
[11]
[1] A molded product obtained by injection molding the polyolefin elastomer composition according to any one of [8].

  ADVANTAGE OF THE INVENTION According to this invention, the surface appearance is favorable and can provide the polyolefin-type elastomer composition which can implement | achieve the molded object which does not have an odor, stickiness, and oil bleeding.

It is a conceptual diagram which shows the outline of a structure of the manufacturing apparatus of the resin composition used by the present Example.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.

The resin composition of this embodiment includes (A) 100 parts by mass of an olefin elastomer, (B) 70 to 210 parts by mass of a polypropylene resin, (C) an average molecular weight of 400 to 1000, and a molecular weight of 400 or less. Is a polyolefin-based elastomer composition obtained by melt-kneading at least 3 to 300 parts by mass of a hydrocarbon oil having a content of 30% by mass or less. When compression-molding into a 1 mm film and applying light from one surface of the film and observing a 5 cm × 5 cm region on the surface opposite the surface, the following conditions (1) and (2) are satisfied: A polyolefin-based elastomer composition;
(1) There are 1 or more and 150 or less polymer aggregates of 0.3 mm or more and less than 0.5 mm.
(2) There are 1 or more and 150 or less polymer aggregates of 0.5 mm or more and less than 1.0 mm.

  The present inventors considered that it would be necessary to be able to form a state in which the hydrocarbon oil to be added is held by the resin component in order to obtain a molded product free from stickiness and oil bleeding. And in order to form such a state, it was thought that it was important to form a specific polymer aggregate obtained by melting and kneading the raw material under a specific condition under a certain condition. And as a result of earnest research based on such knowledge, surprisingly, the polyolefin-based elastomer composition of the present embodiment satisfying such conditions has a good surface appearance and is free from odor, stickiness and oil bleeding. I found out that it could be realized.

  The reason why a molded article having a good surface appearance and free from odor, stickiness, and oil bleeding can be obtained from the polyolefin-based elastomer composition of the present embodiment is not clear, but is estimated as follows. First, the above-mentioned polymer aggregate absorbs the hydrocarbon oil which is the component (C) and retains the oil component as it is. This is considered to be because the component (A) is cross-linked and becomes a bowl-like shape, and the oil component taken in can be retained. When the component (A) is not sufficiently crosslinked, it is considered that the incorporated oil component cannot be sufficiently retained and oil bleeding is generated. On the other hand, when the generated polymer aggregate is destroyed and reduced by shearing in a filtration step (described later) performed inside the extruder, the crosslinking point is also destroyed, so that the absorbed oil component cannot be retained, This is considered to cause oil bleeding. Therefore, in order to obtain a molded article having a good surface appearance and free from odor, stickiness and oil bleeding, it is necessary to control the number and size of polymer aggregates based on these findings.

A polymer aggregate is produced | generated when (A) component bridge | crosslinks, for example. The size of the polymer agglomerate refers to a long diameter that is obtained by compression-molding a polyolefin-based elastomer composition into a sheet having a thickness of 0.1 mm, and observing visually by applying light from the back of the sheet. The polyolefin elastomer composition of the present embodiment satisfies the following conditions (1) and (2). If the conditions (1) and (2) are not satisfied, a molded product free from stickiness and oil bleeding cannot be obtained.
(1) There are 1 or more and 150 or less polymer aggregates of 0.3 mm or more and less than 0.5 mm.
(2) The number of polymer aggregates of 0.5 mm or more and less than 1 mm is 1 or more and 150 or less.

  Furthermore, the surface appearance is further improved by controlling the number of polymer aggregates having a size of 0.3 mm or more and less than 0.5 mm to 150 or less. The surface appearance is further improved by controlling the number of polymer aggregates of 0.5 mm or more and less than 1 mm to 150 or less.

Regarding condition (1), it is preferable that the number of polymer aggregates in the condition (1a) 0.3 mm or more and less than 0.5 mm is 1 or more and 100 or less, and the condition (1b) 0.3 mm or more and less than 0.5 mm. It is preferable that the polymer aggregate is 1 or more and 50 or less.
Regarding condition (2), the condition (2a) is preferably 1 or more and 100 or less polymer aggregates of 0.5 mm or more and less than 1.0 mm, and condition (2b) is 0.5 mm or more and less than 1 mm. The number of polymer aggregates is preferably 1 or more and 50 or less.
And it is more preferable to satisfy | fill both conditions (1a) and (2a), and it is still more preferable to satisfy | fill both conditions (1b) and (2b).

  The polyolefin-based elastomer composition of the present embodiment is obtained by melt-kneading at least 100 parts by weight of component (A), 70 to 210 parts by weight of component (B), and 3 to 300 parts by weight of component (C). Can do. At that time, the crosslinking of the components (I) and (A) and the decomposition of the components (II) and (B) proceed simultaneously, and during the reaction of the components (III) (A) and (B), (C ) Component is also preferably uniformly kneaded.

  As a suitable example for realizing such a process, for example, the melt-kneading includes at least a step of simultaneously crosslinking at least the component (A) and decomposing the component (B), and In the process and / or after the process, the component (C) may be added to the reaction system. As a suitable example, a radical generator that generates radicals in advance with the component (A) and the component (B) before the above components are melted and kneaded in an extruder or a resin kneader, for example. It is preferable to mix and then melt the resin or the like. More preferably, the radical generator is mixed with the component (A) and the component (B) by dry blending at room temperature.

  As a specific method, the (A) component and the (B) component are uniformly mixed in advance with a blender. The radical generator is added to this at room temperature and then mixed again. Examples thereof include a method in which this is introduced into a melt kneader (kneader) to simultaneously crosslink the component (A) and decompose the component (B), and further knead them uniformly. At this time, a crosslinking aid may be added to the mixture of the component (A) and the component (B) as necessary. When the radical generator alone or both radical generator and crosslinking aid are mixed uniformly, amorphous silicon dioxide or calcium carbonate is impregnated with the radical generator alone or both radical generator and crosslinking aid in advance. It is also possible to add the mixture to the mixture of the component (A) and the component (B) and mix them. As a mixing means, a tumbler or the like can be used.

  As a means for dissolving the resin or the resin composition, a Banbury mixer, an extruder or the like can be used. When the above process is carried out continuously, it is preferable to use a twin screw extruder having a twin screw, and the diameter of the screw is preferably 40 mm or more from the viewpoint of productivity (discharge amount). At this time, in order to efficiently perform the crosslinking of the component (A) and the decomposition of the component (B), the kneading part (zone) is L / D (screw length L / screw diameter) = 4-6. It is preferable to provide in the range. The kneading part is more preferably one kind or a combination of two or more kinds of kneading disks and one kind or a combination of two or more kinds of rotors.

  A more preferred means for forming a polymer aggregate satisfying the above conditions (1) and (2) includes a method of simultaneously adding a radical generator and a crosslinking aid.

  In the crosslinking aid, for example, the thermal radicals generated by the radical generator are once stored in the crosslinking aid, and then effectively act on the component (A) to generate a reaction, thereby causing the polymer aggregate to grow. It is thought that there exists an effect | action which arranges so that it may become the score of the above polymer aggregates (however, the effect | action of this embodiment is not limited to these). As a method of adding a crosslinking aid, a method of adding a crosslinking aid when adding a radical generating agent when mixing the component (A) and the component (B); Examples include a method of adding a radical generator from the middle of the extruder before the components (A) and (B) are melted. It is preferable that the addition amount of a crosslinking adjuvant is 1-5 mass parts with respect to 100 mass parts of component (A) component from a viewpoint of residual control in resin or a resin composition.

  As a means for aligning the scores of the polymer aggregates, it is preferable that the crosslinking of the component (A) and the decomposition of the component (B) do not proceed rapidly in the extruder. As a method for controlling this reaction, for example, (1) a method of setting the extruder temperature at which crosslinking and decomposition occur to 200 ° C. or less, and (2) an extrusion rotation speed of 400 rpm or less to suppress shearing heat generation. (3) A method of adding a stabilizer (described later) such as a hindered amine (HALS) stabilizer, a phosphorus stabilizer, a sulfur stabilizer, or a phenol stabilizer at the same time when the radical generator is added. , Etc. By these, the radical reaction including a rapid crosslinking reaction can be relaxed, and the number of polymer aggregates can be more efficiently aligned. Further, it is effective for stabilizing the strands during granulation. As a method for adding the stabilizer, for example, the components (A) and (B) can be added together when they are mixed with a tumbler or the like.

  The component (C) is preferably added by liquid addition after the resin component (resin or resin composition) is dissolved. The liquid addition can be performed by injecting the component (C) with a liquid addition nozzle while increasing the pressure using a plunger pump or a gear pump.

  In order to make the number of the polymer aggregates even more efficiently, for example, during the melt-kneading, the step of crosslinking the component (A) and decomposing the component (B) at least simultaneously and / or Or after the said process, (C) component is added to a reaction system, and the 1 or more 1st metal-mesh with an opening of 0.2-1 mm after that, and an opening of 0.05-0.17 mm It is preferable to perform a process of passing a certain second wire mesh through two or more sheets in any order. Specifically, the molten resin (eg, the component (A), the component (B), the component (C), etc.) before granulation in which the crosslinking and decomposition reactions are completed are combined with the first wire net and the second wire. It is more preferable to pass through the wire mesh in random order.

  The number of meshes (JIS G3555 and JIS G3556) of the first wire mesh is preferably 20 to 70. The number of meshes of the second wire mesh is preferably 100 to 300. It is preferable that the gauge pressure at the time of filtering molten resin with a 1st metal mesh and a 2nd metal mesh is 1-10 Mpa. By controlling the gauge pressure in such a range, the molten resin can be forcibly discharged.

  The total number of the first wire mesh and the second wire mesh is preferably three. In this case, the number of meshes is 20/100/20, 40/100/40 along the flow direction of the molten resin. 40, 40/100/100/40, 40/40/100/40, or 40/300/40 wire mesh combinations are more preferred. Examples of the first and second wire meshes include plain weave and twill, but plain weave is preferable in terms of strength.

As one of the roles of this forced filtration process, the following points etc. are mentioned, for example.
(I) removal of large polymer aggregates exceeding 1 mm;
(II) Uniformization of polymer aggregate particles by forcibly passing the polymer aggregate through a wire mesh

  In particular, (II) can be expected to work by forcibly breaking huge polymer aggregates by shearing and aligning the particles of the aggregates.

  By passing through the filtration step, the size of the polymer aggregate can be further controlled. Examples of the filtration device for installing the wire mesh include a die plate and a device equipped with an automatic wire mesh changer (screen changer) capable of continuously replacing the wire mesh. About the preset temperature of the filtration apparatus at this time, it is preferable to control so that it may become a resin temperature of 170 to 250 degreeC.

((A) Description of olefin elastomer)
(A) The olefin elastomer is an ethylene-α-olefin random copolymer (excluding propylene) containing 40% by mass or more of ethylene, or a terpolymer of ethylene-propylene-nonconjugated diene. It is preferable.

  The carbon number of the α-olefin is preferably 4 to 12 from the viewpoint of elastomeric flexibility when it does not contain a conjugated diene, and the non-conjugated diene is a cyclohexane from the viewpoint of elastomeric flexibility. Pentadiene and ethylidene norbornene are preferred.

  As the component (A), one type described above may be used alone, or two or more types may be used in combination.

  The density of the component (A) is preferably 0.89 g / cc or less from the viewpoint of elastomeric flexibility. The polymerization method for producing the component (A) includes, but is not particularly limited to, a method using a Ziegler-Natta catalyst or a metallocene catalyst.

((B) Description of polypropylene resin)
(B) From the viewpoint of easiness of decomposition due to radicals, the (B) polypropylene resin is preferably a random copolymer and a block copolymer, and a polypropylene homopolymer containing propylene in an amount of preferably 80% by mass or more, more preferably 85% by mass or more. A homopolymer is more preferred. When the propylene content is not less than the above lower limit, decomposition of components by radicals is moderately promoted in the production process, and as a result, the fluidity of the resulting composition can be further improved (however, the effect of this embodiment is Not limited to these.) Examples of these comonomer components include olefins having 2 to 12 carbon atoms excluding propylene. Specific examples include propylene-ethylene-propylene random block copolymers and propylene-ethylene random copolymers.

  The density of the component (B) is preferably more than 0.89 g / cc from the viewpoint of easiness of decomposition by radicals. Although the decomposition of the component (B) can be achieved by adding a radical generator, which will be described later, from the viewpoint of the crosslinking of the component (A) and the efficiency of the decomposition of the component (B), 100 parts by mass of the component (A). The amount of component (B) added to parts is 70 to 210 parts by weight, preferably 100 to 200 parts by weight, and more preferably 120 to 190 parts by weight.

  In the present embodiment, aromatic vinyl block-conjugated diene (provided that 90 mol% or more of the double bond is finally hydrogenated to the components (A) and (B) as necessary. Preferred) block copolymer, aromatic vinyl block-aromatic vinyl conjugated diene random (however, it is preferred that 90 mol% or more of the double bonds are finally hydrogenated) -aromatic vinyl block Styrenic elastomers such as copolymers; polyorganosiloxanes typified by polydimethylsiloxane; one or more selected from the group consisting of inorganic fillers such as calcium carbonate, silicon dioxide (silica), alumina, and talc may be added it can.

((C) Description of hydrocarbon oil)
As hydrocarbon oil, the paraffin oil etc. which are obtained by distilling and refine | purifying petroleum are mentioned, for example. Component (C) has an average molecular weight of 400 to 1000, and the content of a component having a molecular weight of 400 or less is 30% by mass or less.

  The molecular weight refers to a molecular weight determined by a gas chromatograph FID method (GC-FID), and can be specifically measured according to the method described in Examples.

  Since the said measurement is implemented based on GC-FID method, the detected intensity | strength is proportional to the product of the density | concentration and carbon number. This is the weight value detected at each holding time. Since the molecular weight relationship is clarified from the retention time of the gas chromatograph from the calibration curve, the molecular weight distribution of the hydrocarbon oil can be obtained from the gas chromatograph of the hydrocarbon oil. The molecular weight is converted from the retention time with the FID intensity at this time on the vertical axis. An integral distribution map of this distribution is created, and the value at 50% of the integrated value of the intensity ratio is taken as the average molecular weight. In addition, a value having a molecular weight of 400 or less is taken as a value having a molecular weight of 400 or less from the integrated distribution map.

  (C) Hydrocarbon oil has a content of a component having a molecular weight of 400 or less of 30% by mass or less and an average molecular weight of 400 to 1000. When the content of the component having a molecular weight of 400 or less exceeds 30% by mass and the average molecular weight is less than 400, the odor of the molded body and the adhesiveness (stickiness) of the surface of the molded body become worse and oil bleeding occurs. If the average molecular weight exceeds 1000, the hydrocarbon oil is not impregnated with the crosslinked rubber component, and stickiness, oil bleeding and the like occur when formed into a molded body.

  (A) Content of (C) component with respect to 100 mass parts of components is 3-300 mass parts. If the addition amount of the component (B) is less than 3 parts by mass, the effect of the addition (improvement of fluidity) is not manifested, and if it exceeds 300 parts by mass, stickiness of the surface of the molded body and oil bleeding occur. The content of the component (C) with respect to 100 parts by mass of the component (A) is preferably 10 to 300 parts by mass, and more preferably 50 to 300 parts by mass.

(Description of radical generator)
The polyolefin-based elastomer composition of the present embodiment preferably further contains a radical generator. By adding the radical generator, the crosslinking reaction of the component (A) and the simultaneous progress of the decomposition of the component (B) can be performed more efficiently. Examples of the radical generator include peroxides and azo compounds. Examples of the peroxide include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1-bis (t-butylperoxy) octane, n-butyl-4,4-bis (t-butylperoxy) butane, n-butyl Peroxyketals such as -4,4-bis (t-butylperoxy) valerate, di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, t-butylcumyl peroxide, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2.5-bis (t-butylperoxy) diisopropyl Dialkyl peroxides such as benzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane; Oxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide , Diacyl peroxides such as m-trioyl peroxide, t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxyuralylate, t-butyl peroxybenzoate, di-t-butyl Peroxyisophthalate Peroxyesters such as 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, cumylperoxyoctate, t-butyl Hydroperoxides such as hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl peroxide Etc.

  Examples of the azo compound include α, α′-azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2 , 4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile) and other azonitriles.

  A radical generator may be used individually by 1 type mentioned above, and may use 2 or more types together. (B) It is preferable that the addition amount of the radical generator with respect to 100 mass parts of olefinic elastomers is 2-7 mass parts.

  In addition, as a method of cross-linking, a method of cross-linking by electron beam irradiation, a method of cross-linking by γ-ray irradiation, (A), a group derived from maleic anhydride or an epoxy group in advance is introduced into the component (B), A method of cross-linking with a dibasic compound such as diamine can also be adopted, but a method of cross-linking with a radical generator is preferred.

(Description of crosslinking aid)
The polyolefin-based elastomer composition of the present embodiment preferably further contains a crosslinking aid from the viewpoint of promoting the crosslinking of the component (A). The crosslinking aid can capture radicals generated by the decomposition of the radical generator and effectively complete the crosslinking reaction. Specific examples of the crosslinking aid include, for example, ethylbenzene, diethylbenzene, ethylvinylbenzene, divinylbenzene, triaryl isocyanurate, benzophenone, anthraquinone, 4,4-dinonyl-2,2′-dipyridyl and the like. These may be used alone or in combination of two or more. It is preferable that the addition amount of the crosslinking adjuvant with respect to 100 mass parts of components (A) is 0.5-6 mass parts from a viewpoint of promoting a crosslinking reaction.

(Description of stabilizer)
The polyolefin-based elastomer composition of the present embodiment may further contain a stabilizer as necessary. Examples of the stabilizer include a hindered amine (HALS) stabilizer, a phosphorus stabilizer, a sulfur stabilizer, and a phenol stabilizer.

  Examples of the hindered amine (HALS) stabilizer include dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol condensate, poly [{6- (1,1,3, 3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6 , 6-tetramethyl-4-piperidyl) imino} octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-tris {[3,5-bis (1 , 1-dimethylethyl) -4-hydroxyphenyl] methyl} -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, poly {[6- (1,1,3 , 3-Tetramethyl Butyl) amino-1,3,5-triazine-2,4-diyl] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl), and imino] and the like.

  Examples of phosphorus stabilizers include 3,6-bis (2,6-di-t-butyl-4-methylphenoxy) 2,4,8,10-tetrahexa-3,9-diphosphaspiro [ 5,5] undecane, tris (2,4-di-t-butylphenyl) phosphite, poly [(dipropylene glycol) phenyl phosphite], 3,9-dioctadecan-1-yl-2,4,8 , 10-tetraoxa-3,9-diphosphaspiro [5.5] undecane, 3,9-bis (2,4-di-t-butylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane, diphenylisodecyl phosphite, 2-ethylhexyl diphenyl phosphite, triisodecyl phosphite, triphenyl phosphite and the like. That.

  Examples of the sulfur stabilizer include 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 2,2-bis ({[ 3- (Dotesylthio) propionyl] oxy} methyl) -1,3-propanediyl-bis [3- (Dotesylthio) propionate] and the like.

  Examples of the phenol-based stabilizer include 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,9-bis (2, 6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane, pentaerythritol = tetrakis [3- (3 ′, 5′- Di-tert-butyl-4′-hydroxyphenyl) propionate] and the like.

  As a stabilizer, you may use individually by 1 type and may use 2 or more types together. (A) It is preferable that the addition amount of the stabilizer with respect to 100 mass parts of components is 1-5 mass parts.

  The polyolefin-based elastomer composition that can be obtained as described above has a balance of fluidity, stickiness, oil bleeding, and the like, and thus can be used for a wide variety of injection-molded articles and the like. . Suitably, it can be set as the molded object obtained by injection-molding a polyolefin-type elastomer composition.

  The molded body of the present embodiment includes, for example, automotive interior parts such as door trims, headrests, seat belt covers, airbag covers, armrests, shift lever knobs, hand brake knobs and flips, horn pads, assist grips, glove boxes, console boxes, etc. And can be used for connectors for solar power generation modules, pen grips, packings, etc., and is particularly suitable as a skin material for automobile interior parts that are large-sized parts by thin molding. From this viewpoint, the polyolefin-based elastomer composition of the present embodiment can be suitably used as a polyolefin-based elastomer composition for the skin.

  The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to the following examples.

  The materials and measurement methods used in this example were as follows.

(1) (A) Olefin-based elastomer (A-1) Ethylene-octene random copolymer Ethylene / octene mass ratio (preparation ratio) = 60/40 (mass ratio)
Weight average molecular weight (Mw): 28 × 10 ⁴ , number average molecular weight (Mn): 1.1 × 10 ⁴ , Mw and Mn were both determined by gel permeation chromatography (GPC) measurement under the following conditions.

GPC apparatus: high performance liquid chromatograph HLC-8121 (manufactured by Tosoh Corporation)
Column used: TSKgel GMH-HR HT 30 × 2 + TSKgelGMH-HR-M (S) × 1 (Tosoh Corporation)
Detector: Refractive index measuring device Integrated with the above GPC device,
Mobile phase: o-dichlorobenzene Measurement temperature: 140 ° C
Calibration curve: Standard polystyrene kit (Varian)

Melt flow rate (MFR): 1 g / 10 min (2.16 kg load, 190 ° C., according to ASTM D1238)
Density: 0.857g / mL

(A-2) Ethylene-propylene-ethylidene norbornene (ENB) random copolymer Ethylene / propylene / ENB mass ratio: 70/25/5
Absolute average molecular weight (Mw): 19 × 10 ⁴ , number average molecular weight (Mn): 9 × 10 ⁴
GPC device: PL-GPC220 (manufactured by Polymer Laboratories)
Column used: TSK-gel GMH-HR-H (S) × 2 + TSKgel GMH-HR-M (S) × 1 Detector: Laser multi-scattering photometer PD2040 (manufactured by Polymer Laboratories),
Mobile phase: 1,2,4-trichlorobenzene Measurement temperature: 140 ° C.
Calibration curve: Linear standard polyethylene 1475a (American National Institute of Standards and Technology-made by NIST)
Ethylene / propylene dyad (doublet) fraction: 29.5 mol%
Density 0.870g / mL

(2) (B) Polypropylene resin Homopolypropylene Weight average molecular weight (Mw): 58 × 10 ⁴ , number average molecular weight (Mn) 6.5 × 10 ⁴
Mw and Mn were measured according to the method for measuring component (A-1).
MFR: 2 g / 10 min (2.13 kg load, at 230 ° C. measurement)
Density: 0.90 g / mL

(3) (C) Hydrocarbon oil The following hydrocarbon oils whose average molecular weight and molecular weight of 400 or less were measured by the following gas chromatograph FID method were used. Specific measurement conditions were as follows.
Column: HT-5 AISL 0.22 mmφ × 12 m
-Temperature condition: 50-440 degreeC Temperature rising rate 10 degree-C / min Initial 50 degreeC and final 440 degreeC hold for 10 minutes each-Sample melt | dissolved in 0.1 g / 10mL hexane solvent, and inject | poured 1 microliter into gas chromatography.
-Intensity detection method The FID method was used.
-Detection and measurement of molecular weight calibration curve, average molecular weight, and molecular weight of 400 or less C14, C16, C22, C24, C30, C40, C50 linear alkanes were measured under the above conditions, and the retention time (retention time) and The molecular weight relationship was determined.

(C-1) Hydrocarbon oil having an average molecular weight of 357 and a molecular weight of 400% or less (manufactured by China Petrochemical Co., Ltd., trade name “industrial white oil # 70”)
(C-2) Hydrocarbon oil having an average molecular weight of 466 and molecular weight of 400% or less (product name “industrial white oil # 90” manufactured by China Petrochemical Co., Ltd.)
(C-3) Hydrocarbon oil having an average molecular weight of 487 and a molecular weight of 400% or less and 22% (trade name “Diana Process Oil PW90” manufactured by Idemitsu Kosan Co., Ltd.)
(C-4) Hydrocarbon oil having an average molecular weight of 674 and a molecular weight of 400 or less and 4.1% (trade name “Diana Process Oil PW380” manufactured by Idemitsu Kosan Co., Ltd.)

(6) Radical generator 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane Melting point: 3.9 ° C.
Decomposition temperature: 154 ° C (DSC measurement, heating rate 5 ° C / min)
Density 25 ° C .: 0.873 g / mL

(7) Crosslinking aid triaryl isocyanurate (TAIC)
-Purity 99% or more-Melting point: 23-27 degreeC
-Boiling point: 144 ° C
Specific gravity 30 ° C .: 1.16 [g / cc]
Divinylbenzene (DVB)
-Mixture of 57% by weight of divinylbenzene, 40% by weight of ethylvinylbenzene and 3% by weight of diethylbenzene-Melting point: -45 ° C
-Boiling point: 195 ° C
-Specific gravity 25 ° C: 0.90 [g / cc]

(8) Stabilizer-Tris (2,4-di-t-butylphenyl) phosphite-Purity 99% or more-Melting point: 183-186 ° C
-True specific gravity 25 ° C: 1.03 [g / cc]
-Bulk density: 0.32 [g / cc] powder

(9) Observation of polymer aggregates Using a hot press machine, a 0.1 mm thick stainless steel mold was placed as a spacer, a film having a resin thickness of 0.1 mm was formed at 200 ° C. and a press pressure of 10 MPa, and a light box was used. The polymer aggregate particles were visually observed by applying light from the back side. The size of the polymer agglomerate particles was determined by “standard spot gauge size table” issued by CES, the wireless communication machinery industry association, with the longest diameter of the aggregates observed. And the number of polymer aggregates (0.3 ≦ x <0.5) that is 0.3 mm or more and less than 0.5 mm, and polymer aggregates that are 0.5 mm or more and less than 1.0 mm (0.5 ≦ x <1) .0) were counted.

(10) Evaluation of stickiness An evaluation plate of 100 mm × 300 mm × 0.8 mm (thickness) was molded with an injection molding machine. At this time, the cylinder temperature of the injection molding machine was set to 210 ° C., and the shooting speed was set to 50 mm / s. The mold gate was one point on the upper part of the mold, and the gate diameter was 1.5 mm. The mold temperature was set to 50 ° C. The surface of the molded body cut out at 90 mm × 50 mm was conditioned for 1 hour at room temperature of 23 ° C., and the surface was touched with a finger to evaluate stickiness.

(11) Odor of molded body The odor of the molded body was evaluated based on whether or not there was an odor by bringing the nose close to the evaluation plate.

(12) Oil leaching A part of the evaluation plate was cut out, placed in a constant temperature box at 120 ° C., and the surface after being left for 48 hours was visually observed to confirm that no oil component oozed out.

(13) Appearance inspection of molded plate The surface of the evaluation plate was visually observed, and the surface appearance was evaluated depending on whether polymer aggregates were confirmed. Evaluation of the surface appearance is very good (the surface is smooth and shiny): ◎, good (the surface is smooth and shiny but has a little cloudiness): ○, bad (the surface is smooth, Evaluation was made in three stages: x.

<Preparation of polyolefin elastomer composition>
(A) Mixing and charging of raw materials First, all the resin component (A) component, (B) component, radical generator and crosslinking aid, and if necessary, 300 kg of stabilizers are all put into a 1000 m ³ tumbler. The mixture was kneaded at 10 rpm for 30 minutes. And these were discharged | paid out and it injected | thrown-in from the supply port of the extruder. A quantitative feeder was used to input the raw materials. During the kneading, the liquid radical generator was absorbed by the resin component.

(A) Extrusion step, extrusion conditions, and addition of hydrocarbon oil For the resin kneading, using a twin-screw extruder “TEM58SS” (L / D = 54) manufactured by Toshiba Machine Co., Ltd., a temperature of 140 to 160 ° C., Extrusion was performed at a die temperature of 200 ° C. FIG. 1 is a conceptual diagram showing an outline of the configuration of the resin composition production apparatus used in this example. The twin screw extruder 1 is the first type of the twin screw extruder 1 for the purpose of aligning the particle diameter of the crosslinked polymer aggregates by the crosslinking reaction of the component (A) and the purpose of efficiently and simultaneously decomposing the component (B). A feed kneading disk (not shown) was provided at a position of L / D = 14.5 from one supply port 2, and then a three-thread screw rotor was installed.
As the overall screw configuration, the kneading disk configuration was provided at two locations before the hydrocarbon oil addition and at two locations after the hydrocarbon oil addition. The resin discharge amount was 350 kg, and Q / Ns (discharge amount / rotation number) = 1.0.
Hydrocarbon oil was liquid-added from the liquid addition part 3 provided in the position of L / D = 27 from the 1st supply port 2. FIG. The screw configuration was a two-thread configuration including a kneading section (not shown) including a kneading disk before and after the liquid addition section 3. The injection pressure at the time of liquid addition was controlled to be within the range of 1 to 5 MPa. The screw configuration at the location where the liquid was added was such that the neutral of the kneading disk was installed at the injection port of the liquid addition portion 3 so that the injection pressure was between 1 and 5 MPa.

(C) Filtration of molten resin The molten resin kneaded by the twin screw extruder 1 was filtered by installing a wire mesh 4 between the twin screw extruder 1 and the die 5. During filtration, a filtration pressure was stabilized by installing a gear pump (not shown). In each example and each comparative example, as the wire mesh 4, a wire mesh shown below was superposed under the conditions shown in each table. Here, the value indicated by “filtering mesh (mesh)” in each table indicates the number of meshes of the wire mesh arranged downstream from the number of meshes of the wire mesh arranged upstream from the left side to the right side. Yes. For example, in Example 1 (Table 1), it is described as 40/100/40. This is because the number of meshes of the wire mesh arranged on the upstream side and the number of meshes of the wire mesh arranged on the downstream side are Is 40, which means that the number of meshes of the metal mesh placed between them is 100. That is, in the first embodiment, from the upstream side, a superposition of a wire mesh with 40 meshes → a wire mesh with 100 meshes → a wire mesh with 40 meshes is arranged.
Further, in Example 14 (Table 4), 40/100/40/40 is described. From the upstream side, this is a mesh with a mesh number of 40 → a mesh with a mesh number of 100 → a mesh with a mesh number of 40 → mesh A superposition of several 40 wire meshes is arranged. In addition, the metal mesh of the mesh numbers 20, 40, 100, 300, and 350 used by each Example and each comparative example is shown below.

Number of meshes 20: Aperture 0.874mm, plain weave, opening ratio 47%
Number of meshes 40: Opening 0.405mm, plain weave, opening rate 41%
Number of meshes 100: Aperture 0.154 mm, plain weave, open area 37%
Number of meshes 300: Aperture 0.050mm, plain weave, opening ratio 34%
Number of meshes 350: Opening 0.038mm, plain weave, opening rate 27%

(D) Collection of sample The sample was evaluated by collecting 25 kg from the granulator 8 after 1 hour from the start of extrusion.

  The production conditions of each Example and each Comparative Example and the results of physical property evaluation of the obtained resin composition are shown in the following table.

As is clear from each table, it was at least confirmed that in each example, all of stickiness, odor, oil bleeding, and surface appearance of the molded product were excellent.
According to Comparative Examples 1 and 2 and the like, it was confirmed that if the number of polymer aggregates in the molded product was too small, stickiness and oil bleeding occurred, and if it was too large, the surface appearance deteriorated.
According to Comparative Examples 3, 4 and the like, the resin does not flow without injection of hydrocarbon oil and injection molding cannot be performed, and when the addition amount is large, even if polymer aggregates are present in the resin composition, they can be retained. It was confirmed that stickiness and oil oozing were observed, and the surface appearance of the molded article was poor.
According to Comparative Examples 5 to 8 and the like, it was confirmed that the hydrocarbon oil having a low molecular weight and a molecular weight of 400 or less was sticky, the odor of the molded body, the oil bleeding, and the surface appearance of the molded body were not good.
According to Comparative Examples 9 to 10 and the like, it was confirmed that the number of polymer aggregates was excessive and the surface appearance of the molded article was poor. Further, according to Comparative Example 11 and the like, polymer aggregates were not observed, and it was confirmed that hydrocarbon oil could not be retained in the molded body and oil bleeding occurred.

[Example 16]
Using the composition of Example 14, a box-shaped molded body (skin) having a size of 200 mm × 200 mm × 100 mm (depth) and a thickness of 1 mm was formed. The injection molding gate is the center of the bottom surface. The injection molding machine used was “SG220” manufactured by Sumitomo Heavy Industries, Ltd. The molding conditions were: resin temperature: 230 ° C., mold temperature: 60 ° C., injection time: 15 seconds, back pressure: 10%, injection speed: 86%, injection pressure 12 MPa. The surface state of the molded body was very good (◎), and there was no stickiness or oil bleeding.

  According to the present invention, it can be a polyolefin-based elastomer composition free from stickiness and oil bleeding, and as a raw material for various uses such as automobile interior parts, OA machine members, solar power generation module members, daily goods, etc. Can be used in a wide range of fields.

DESCRIPTION OF SYMBOLS 1 ... Twin screw extruder, 2 ... 1st supply port, 3 ... Liquid addition part, 4 ... Wire mesh, 5 ... Die, 6 ... Strand, 7 ... Strand cooling tank, 8 ... Granulator

Claims (11)

(A) 100 parts by mass of an olefin elastomer,
(B) 70 to 210 parts by mass of a polypropylene resin;
(C) 3 to 300 parts by mass of a hydrocarbon oil having an average molecular weight of 400 to 1000 and a content of a component having a molecular weight of 400 or less, of 30% by mass or less;
Is a polyolefin-based elastomer composition obtained by melt-kneading at least,
When the polyolefin elastomer composition is compression-molded into a film having a thickness of 0.1 mm, light is applied from one surface of the film, and an area of 5 cm × 5 cm on the surface opposite to the surface is observed, A polyolefin-based elastomer composition that satisfies the following conditions (1) and (2);
(1) There are 1 or more and 150 or less polymer aggregates of 0.3 mm or more and less than 0.5 mm.
(2) There are 1 or more and 150 or less polymer aggregates of 0.5 mm or more and less than 1.0 mm.   The melt-kneading has a step of at least simultaneously crosslinking the component (A) and decomposing the component (B), and during and / or after the step, The polyolefin elastomer composition according to claim 1, wherein component C) is added to the reaction system.   In the melt-kneading, the component (A), the component (B), and the component (C) are composed of one or more first metal meshes having an opening of 0.2 to 1 mm and an opening of 0.05. The polyolefin elastomer composition according to claim 1 or 2, comprising at least a step of passing through a second wire mesh of ~ 0.17 mm in two or more in random order. The condition (1) is that there are 1 or more and 100 or less polymer aggregates of 0.3 mm or more and less than 0.5 mm;
The polyolefin system according to any one of claims 1 to 3, wherein the condition (2) is that 1 or more and 100 or less polymer aggregates of 0.5 mm or more and less than 1.0 mm exist. Elastomer composition. The condition (1) is that there are 1 or more and 50 or less polymer aggregates of 0.3 mm or more and less than 0.5 mm;
The polyolefin system according to any one of claims 1 to 3, wherein the condition (2) is that there are 1 or more and 50 or less polymer aggregates of 0.5 mm or more and less than 1.0 mm. Elastomer composition.   The component (A) is an ethylene- (α-olefin having 3 to 12 carbon atoms) copolymer and / or an ethylene- (α-olefin having 3 to 12 carbon atoms) -nonconjugated diene copolymer. The polyolefin-type elastomer composition as described in any one of Claims 1-5.   The polyolefin elastomer composition according to any one of claims 1 to 6, wherein the component (B) is homopolypropylene.   The polyolefin elastomer composition according to any one of claims 1 to 7, wherein the resin composition is a polyolefin elastomer composition for skin. A step of melt-kneading the component (A), the component (B), and the component (C);
The melt-kneading has a step of performing at least simultaneously the crosslinking of the component (A) and the decomposition of the component (B), and
During the process and / or after the process, the component (C) is added to the reaction system, and then one or more first wire meshes having a mesh opening of 0.2 to 1 mm and a mesh opening of 0.05. Having a step of passing through a second wire mesh of ~ 0.17 mm in two or more, in random order;
The manufacturing method of the polyolefin-type elastomer composition as described in any one of Claims 1-8.   The method for producing a polyolefin-based elastomer composition according to claim 9, wherein both the first wire mesh and the second wire mesh are plain weave wire meshes.   The molded object obtained by injection-molding the polyolefin-type elastomer composition as described in any one of Claims 1-8.