JP3847484B2 - Clay composite rubber material and method for producing the same - Google Patents

Description

【００８１】
【表２】

【００８２】
参考例１
本例は，不飽和基を有しない有機オニウムイオンを用いて調製した粘土複合ゴム材料である。
本例の粘土複合ゴム材料は，第１粘土複合材料とゴム材料とが混練され，かつ，上記第１粘土複合材料中の第２ゲスト分子が，ゴム材料の分子と架橋結合をしている。
【００８３】
上記粘土複合材料は，図１に示すごとく，炭素数６以上の有機オニウムイオン６で有機化された粘土鉱物７と，分子長が上記有機オニウムイオンと同じかそれよりも小さく，且つその分子内の極性基１０が粘土鉱物７と水素結合している第１ゲスト分子１と，分子長が上記有機オニウムイオンよりも大きく，且つその分子内に極性基を有しない第２ゲスト分子２とよりなる。第１ゲスト分子１及び第２ゲスト分子２は，少なくともその一部が粘土鉱物７の層間に入り込んでいる。
【００８４】
粘土鉱物は，ナトリウム型モンモリロナイト（山形県産，イオン交換容量１２０ｍｅｑ／１００ｇ）である。有機オニウムイオンは，ジステアリルジメチルアンモニウムイオン（ＤＳＤＭ）であり，その炭素数は３８である。第１ゲスト分子はステアリン酸であり，その炭素数は１８である。第２ゲスト分子は，液状ブチルゴム（ハードマン社製，商品名カレン８００）であり，その分子量は約５０００である。
【００８５】
次に，上記粘土複合ゴム材料の製造方法について説明する。
まず，モンモリロナイト２０．０ｇを８０℃の水２０００ｍｌに分散させた。次に，ジステアリルジメチルアンモニウムクロライド２１．０ｇを８０℃の水１５００ｍｌに溶解した。上記の分散液と溶解液とを一気に混合した。その沈澱物を８０℃の水で２回洗浄して，ＤＳＤＭで有機化されたモンモリロナイトを得た。これを，以下，ＤＳＤＭ−モンモリロナイトという。
【００８６】
灼残法により求めたＤＳＤＭ−モンモリロナイト中の無機含量は，５４．２重量％であった。Ｘ線回折法により，ＤＳＤＭ−モンモリロナイトの層間距離を測定して，膨潤挙動を観察した。ＤＳＤＭ−モンモリロナイトの層間距離は，３２．８Åであった。
【００８７】
次に，溶媒としてのトルエン２０ｇの中に，上記ＤＳＤＭ−モンモリロナイト１．０ｇ，ステアリン酸０．５ｇ，及び液状ブチルゴム（ハードマン社製，商品名カレン８００）１．０ｇを添加し，６時間混合した。次に，減圧下においてトルエンを蒸発させた。これにより，第１粘土複合材料を得た。
【００８８】
Ｘ線回折法により粘土複合材料におけるモンモリロナイトの層間距離を測定したところ，５４．８Åであった。
このことから，ステアリン酸と液状ブチルゴムとを添加することにより，無添加の場合に比べて，モンモリロナイトの層間距離が拡大し，膨潤することがわかる。
【００８９】
次に，上記第１粘土複合材料とゴム材料とを，ＡＳＴＭ Ｄ ３１８２に準拠し，ロールで混練した。上記ゴム材料は，ブチルゴム（日本合成ゴムＢｕｔｙｌ２６８）を用いた。
粘土複合ゴム材料の配合割合は，ゴム材料１００重量部に対し，第１粘土複合材料２０重量部（内，粘土鉱物５重量部），カーボン（旭カーボン＃７０）２０重量部，亜鉛華１重量部，イオウ１．７５重量部，加硫促進剤１重量部である。
【００９０】
次に，均一に混練した後，１５０℃，４０分間加硫で厚み２ｍｍのシートを成形した。シートからダンベル３号の試験片を切りだし，引っ張り試験を行った。その結果，１８．０ＭＰａの引っ張り強さであった。
また，厚み０．５ｍｍのシートも同様に成形し，窒素でのガス透過性を評価した。その結果，ガス透過率係数は１．９×１０^-11 ｃｍ³ ・ｃｍ・ｃｍ^-2・ｓｅｃ^-1・ｃｍＨｇ^-1であった。
【００９１】
【発明の効果】
以上のごとく，本発明によれば，極性の低いゴムポリマー中における粘土鉱物の分散性が高く，且つ力学的特性に優れた，粘土複合ゴム材料及びその製造方法を提供することができる。
【図面の簡単な説明】
【図１】本発明における，第１粘土複合材料の説明図。
【図２】本発明における，第２粘土複合材料の説明図。
【符号の説明】
１．．．第１ゲスト分子，
１０，３０．．．極性基，
１００．．．第１粘土複合材料，
２．．．第２ゲスト分子，
２００．．．第２粘土複合材料，
３．．．第３ゲスト分子，
６．．．有機オニウムイオン，
７．．．粘土鉱物，[0001]
【Technical field】
The present invention relates to a clay composite rubber material in which clay mineral is dispersed at a molecular level in a rubber polymer having low polarity, and a method for producing the same.
[0002]
[Prior art]
Conventionally, addition and mixing of clay minerals have been studied to improve the mechanical properties of rubber materials. For example, JP-A-1-198645 discloses a method in which an oligomer having an onium ion introduced into a terminal or a side chain is used to make an organic clay mineral, which is mixed into a rubber material. .
[0003]
[Problems to be solved]
However, in the conventional clay composite rubber material, it is not always easy to prepare an oligomer into which onium ions are introduced. In addition, since oligomers were immediately introduced between clay layers, swelling between clay layers was sometimes insufficient.
According to Giannelis et al., When polystyrene having no polar group is used, only one layer of polystyrene molecules can enter between layers, and there is a limit to interlayer swelling (EP Giannelis et al., Chem. Mater. 5, 1694-1696 (1993)).
[0004]
In addition, the inventors of the present application have introduced a technique in which an oligomer or polymer having a polar group in the molecule is sufficiently introduced between layers of clay minerals organized by onium ions, and polarity between layers of organized clay clay. The technology for introducing an oligomer or polymer having no polar group between clay layers after introducing a low-molecular substance having a group has been filed earlier ("Clay composite material and its production method" June 5, 1995). Application, “Clay composite material and method for producing the same, and blended material” filed on June 30, 1995). However, this technology is mainly for plastics and not for rubber materials.
[0005]
In view of such conventional problems, the present invention intends to provide a clay composite rubber material having a high dispersibility of a clay mineral in a low polarity rubber polymer and a method for producing the same.
[0006]
[Means for solving problems]
  The invention of claim 1Has an unsaturated groupClay minerals organically formed by ion-bonding of organic onium ions having 6 or more carbon atoms, and the molecular length is the same as or shorter than that of the organic onium ions, and the polar group in the molecule is A first guest molecule that is bonded, the molecular length is larger than the organic onium ion, and in the moleculeHas an unsaturated group,The first and second guest molecules having no polar group, wherein at least a part of the first guest molecule and the second guest molecule are interposed between the clay mineral layers, and / or
  Has an unsaturated groupClay minerals organically formed by ionic bonding of organic onium ions with 6 or more carbon atoms and polar groups in the moleculeAnd an unsaturated groupAnd a third guest molecule having a molecular length equal to or longer than that of the organic onium ion, wherein at least a part of the third guest molecule enters between layers of the clay mineral. The polar group of the guest molecule is a second clay composite material that forms hydrogen bonds with the clay mineral,
  Rubber material is kneaded,
  And at least one of the second guest molecule or the third guest molecule is cross-linked with a molecule of the rubber material,
  The organic onium ion in at least one of the first clay composite material or the second clay composite material is cross-linked between at least one of the second guest molecule or the third guest molecule and the molecule of the rubber material. It is a clay composite rubber material characterized by forming.
[0007]
What is most remarkable in the present invention is that the rubber material is kneaded with the clay composite material in which the guest molecules are introduced between the clay mineral layers, and the guest molecules in the clay composite material and the molecules of the rubber material. Are crosslinked, and a crosslinked bond is formed between the organic onium ion, the second guest molecule or / and the third guest molecule, and the rubber material molecule.
[0008]
Next, the operation of the clay composite rubber material of the present invention will be described.
The clay composite rubber material is prepared by mixing one of various clay composite materials in which guest molecules are intercalated between the clay mineral layers organized as described above, and kneading the rubber material between the guest molecules and the rubber material molecules. A cross-linked bond is formed. Therefore, the clay mineral can be uniformly dispersed with a large interlayer distance even with respect to rubber molecules, which have conventionally been difficult to disperse. The reason is considered as follows.
[0009]
That is, as shown in FIG. 1, in the first clay composite material 100, since the clay mineral 7 organized by the organic onium ions 6 has a lot of space, it is an oligomer having a weak polarity between the layers. Alternatively, polymers could be incorporated, but were more likely to be eliminated immediately due to the polarity of the clay mineral silicate layer. However, as described above, when the polar group 10 is bonded to the first guest molecule 1, the polar group 10 forms a hydrogen bond with the silicate layer of the clay mineral 7 and remains between the layers. For this reason, the second guest molecule 2 that is hydrophobized between the clay minerals 7 and does not have a polar group can remain stably. Since the second guest molecule 2 has a longer molecular length than the organic onium ion, the second guest molecule 2 swells significantly between the layers.
[0010]
As shown in FIG. 2, in the second clay composite material 200, the third guest molecule 3 having a polar group 30 is introduced between the layers of the clay mineral 7 organized by the organic onium ions 6, so that the clay mineral 7 and silicate layers are formed with hydrogen bonds. Therefore, the third guest molecule 3 can remain between the clay mineral 7 layers. Since the third guest molecule 3 has a molecular length longer than that of the organic onium ion 6, the third guest molecule 3 swells significantly between the layers.
[0011]
As described above, at least one of the first and second clay composite materials in which the clay mineral layers are sufficiently swollen is kneaded with the rubber material. Then, the clay mineral is uniformly dispersed at the molecular level without agglomerating in the rubber material.
In addition, since the clay mineral is uniformly dispersed, the barrier property against gas and the like is improved. In addition, the movement of rubber molecules near the silicate layer is constrained. Therefore, it has a good effect on the mechanical properties of clay composite rubber materials.
[0012]
In the present invention, the organic onium ion in at least one of the first clay composite material or the second clay composite material may include at least one of the second guest molecule or the third guest molecule and the rubber material. A cross-linking bond is formed with the molecule. Therefore, the interface between the clay mineral silicate layer and the rubber is very tightly bonded.
Therefore, the movement of rubber molecules in the vicinity of the silicate layer is further restricted, and the mechanical properties, particularly the hardness and elastic modulus, are improved.
[0013]
Next, details of the present invention will be described.
In the clay composite rubber material of the present invention, at least one or both of the first and second clay composite materials are kneaded with the rubber material.
[0014]
First, the first clay composite material will be described.
The first clay composite material is composed of a clay mineral organized by organic onium ions, a first guest molecule, and a second guest molecule.
[0015]
  In the first clay composite material, the clay mineral is organically formed by ionic bonds with organic onium ions having 6 or more carbon atoms. When the number of carbon atoms is less than 6, the hydrophilicity of the organic onium ion increases, and the compatibility with the first and second guest molecules decreases..
[0016]
Further, as unsaturated organic onium ions, 1-hexenylammonium ion, 1-dodecenylammonium ion, 9-octadecenylammonium ion (oleylammonium ion), 9,12-octadecadienylammonium ion (linoleammonium ion) Ions), 9,12,15-octadecatrienylammonium ions (linoleylammonium ions).
[0017]
Among these organic onium ions, when producing a clay composite rubber material by the solvent dissolution method according to claim 12, a secondary onium ion is particularly preferable in terms of swelling property with respect to the solvent. In addition, although the organic onium ion to show in figure shows all as a bifurcated shape and has shown that it is a secondary onium ion, it is not the meaning limited to a secondary onium ion.
[0018]
As the clay mineral, it is preferable to use one having a large contact area with the first and second guest molecules. Thereby, the interlayer of the clay mineral can be greatly swollen. Specifically, the cation exchange capacity of the clay mineral is preferably 50 to 200 milliequivalents / 100 g. If it is less than 50 milliequivalents / 100 g, onium ions may not be sufficiently exchanged and it may be difficult to swell the clay mineral layers. On the other hand, if it exceeds 200 milliequivalents / 100 g, the bonding strength between the clay mineral layers becomes strong and it may be difficult to swell the clay mineral layers.
[0019]
Examples of the clay mineral include smectite clay minerals such as montmorillonite, saponite, hectorite, beidellite, stevensite, nontronite, vermiculite, halloysite, or swelling mica. It may be natural or synthesized.
[0020]
The first guest molecule has one or more polar groups in the molecule. The polar group is bonded to at least one of the main chain, side chain, and terminal of the first guest molecule. Among these, the polar group is preferably bonded to the end of the first guest molecule. Thereby, the interlayer of the clay mineral can be swollen more greatly.
[0021]
In the present invention, the polar group means a group in which electrons are localized in a molecule and a charge is biased, and does not include completely polarized ions. Therefore, onium ions are not included in the polar group.
As in the invention of claim 2, the polar group of the first guest molecule and / or the third guest molecule is, for example, a hydroxyl group (OH), a halogen group (F, Cl, Br, I), a carboxyl group (COOH). ), A carboxylic anhydride group, a thiol group (SH), an epoxy group, and an amino group. The amino group is a primary, secondary, or tertiary amine (NH2, NH, N).
[0022]
Note that groups having a relatively strong degree of polarization, such as imino groups, phosphonyl groups, and sulfonyl groups, fall within the definition of the “polar group”, but these groups are not preferred in the present invention. This is because the first guest molecule containing these groups has low solubility in a solvent and lacks high-temperature stability for melting.
[0023]
The molecular length of the first guest molecule is the same as or shorter than the organic onium ion. When the molecular length of the organic onium ion is larger than the molecular length of the first guest molecule, it may be difficult to obtain the first guest molecule, and the type of the first guest molecule that is compatibilized in the low polarity polymer is limited. There is.
[0024]
As described in claim 8, the first guest molecule is, for example, an olefin or paraffin having a linear or branched structure, or a linear or branched structure and having a main chain and / or a side chain. Olefin or paraffin having an aromatic ring therein can be used. That is, the first guest molecule has, for example, one or more polar groups and a saturated or unsaturated linear or branched structure. Moreover, an aromatic ring may be included in the main chain and / or side chain.
[0025]
For example, lauryl alcohol (carbon number 12), stearyl alcohol (carbon number 18), stearic acid (carbon number 18), or stearyl chloride (carbon number 18) is used as the first guest molecule having the polar group. Can do. Further, polyethylene, polypropylene, polyisoprene, polybutadiene, or hydrogenated products or copolymers thereof having polar groups such as OH, COOH, Cl, and epoxy groups at both ends may be used. These first guest molecules are selected and used so as to be equal to or less than the molecular length of the organic onium ion. More preferably, the first guest molecule has 6 or more carbon atoms.
[0026]
The first guest molecules tend to expand widely between clay mineral layers as the mixing ratio increases. The mixing ratio of the first guest molecules is preferably 0.1 parts by weight or more with respect to 1 part by weight of the organized clay mineral. If the amount is less than 0.1 part by weight, the swelling between layers may be insufficient.
[0027]
The first guest molecule forms a hydrogen bond with the clay mineral due to its polar group. And at least a part of the first guest molecule penetrates between the layers of the clay mineral. It is not necessary for all of the first guest molecules to enter the interlayer. For example, as in the fifth aspect of the present invention, if 10% by weight or more of the total amount of the first guest molecules enters between the layers of the clay mineral in the first clay composite material, the layers sufficiently swell. On the other hand, if it is less than 10% by weight, the swelling between the layers may be insufficient.
[0028]
Next, the second guest molecule is a non-polar or low-polar oligomer or polymer having no polar group. This second guest molecule has a linear or branched structure, is saturated or unsaturated, and may or may not contain an aromatic ring. The molecular length of the second guest molecule is larger than that of the organic onium ion. When the molecular length is the same as or smaller than the molecular length of the organic onium ion, there is a problem that the swelling between the layers of the clay mineral becomes insufficient.
[0029]
As in the invention of claim 3, the second guest molecule is preferably a non-polar or low-polar oligomer or polymer having a molecular weight of 1000 to 500,000. If it is less than 1000, there is a risk that swelling between layers of clay minerals will be insufficient. On the other hand, when it exceeds 500,000, there is a possibility that it becomes hardly soluble in the solvent, and the softening point or melting point becomes higher than the decomposition point of the clay mineral. More preferably, the second guest molecule has a molecular length of about 3 to 4 times that of the organic onium ion.
For example, liquid polybutadiene, liquid polyisoprene, or liquid butyl rubber can be used as the second guest molecule.
[0030]
The second guest molecules tend to swell between the clay mineral layers as the mixing ratio increases. The mixing ratio of the second guest molecules is preferably 0.1 parts by weight or more with respect to 1 part by weight of the organized clay mineral. When the amount is less than 0.1 part by weight, there is a possibility that swelling between layers of the clay mineral is insufficient.
At least a part of the second guest molecule enters between the layers of the clay mineral. It is not necessary for all of the second guest molecules to enter.
[0031]
Next, the second clay composite material will be described.
The second clay composite material is composed of a clay mineral organized by organic onium ions and a third guest molecule.
[0032]
In the second clay composite material, the clay mineral and the organic onium ion are preferably any of those listed as the clay mineral and the organic onium ion. The third guest molecule has one or two or more polar groups in the main chain and / or side chain. As the polar group, any of the groups listed as polar groups of the first guest molecule is preferably used.
The polar group of the clay mineral, organic onium ion, and third guest molecule in the second clay composite material may be the same or different from the polar group of the clay mineral, organic onium ion, first guest molecule in the first clay composite material. Good.
[0033]
The molecular length of the third guest molecule is the same as or longer than the organic onium ion. When the molecular length of the organic onium ion is smaller, the third guest molecule does not protrude outward from the region where the organic onium ion is present at the clay interface, so that the clay mineral is difficult to disperse in the rubber material.
[0034]
As described in claim 9, the third guest molecule is, for example, an olefin or paraffin having a linear or branched structure, or a linear or branched structure and having a main chain and / or a side chain. Olefin or paraffin having an aromatic ring therein can be used.
That is, the third guest molecule has, for example, one or more polar groups and a saturated or unsaturated linear or branched structure. The main chain and / or side chain may contain an aromatic ring.
[0035]
  Examples of the third guest molecule include,Polyethylene, polypropylene, polyisoprene, polybutadiene having a polar group such as OH, COOH, Cl, or an epoxy group at both ends, or a hydrogenated product or copolymer thereof may be used. These third guest molecules are selected and used so as to be equal to or larger than the molecular length of the organic onium ion.
[0036]
As the mixing ratio of the third guest molecule increases, the clay mineral layer tends to expand widely. The mixing ratio of the third guest molecule is preferably 0.5 parts by weight or more with respect to 1 part by weight of the organized clay mineral. If it is less than 0.5 part by weight, there is a risk that swelling between layers of clay minerals will be insufficient.
[0037]
Further, as in the invention of claim 4, the third guest molecule is preferably a nonpolar oligomer or polymer having a molecular weight of 500 to 100,000. If it is less than 500, there is a possibility that swelling between layers of clay minerals is insufficient. On the other hand, if it exceeds 100,000, it may become insoluble in the solvent, and the softening point or melting point may be higher than the decomposition point of the clay mineral. It is more preferable that the third guest molecule has a molecular length of about 3 to 4 times or more of the organic onium ion.
[0038]
At least a part of the third guest molecule penetrates between clay mineral layers. It is not necessary for all of the third guest molecules to enter between the clay mineral layers. For example, as in the sixth aspect of the present invention, if 10 wt% or more of the total amount of the third guest molecules enters the interlayer of the clay mineral in the second clay composite material, the interlayer expands sufficiently. If it is less than 10% by weight, swelling between the clay mineral layers may be insufficient. In particular, in the case where the third guest molecule is a polymer having a molecular weight of about 1000 to 10000, the expansion between the layers is sufficient if 10 wt% of the total amount of the third guest molecule is included.
[0039]
Next, as in the invention of claim 7, the rubber material is natural rubber, isoprene rubber, chloroprene rubber, styrene rubber, nitrile rubber, ethylene-propylene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, epichlorohydrin rubber, One type or two or more types selected from the group of acrylic rubber, urethane rubber, fluorine rubber, and silicone rubber can be used.
[0040]
The second guest molecule or the third guest molecule contained in the first and second clay composite materials is, for example, a sulfur crosslink called “vulcanization” or a molecule between the rubber molecules. A similar cross-linking bond is formed. An example of the cross-linking bond according to this is a peroxide cross-linking bond.
[0041]
The clay composite rubber material of the present invention is molded by, for example, a press molding method or an extrusion molding method.
The clay composite rubber material of the present invention can be used for various uses of ordinary rubber. In particular, the effect of the present invention can be exhibited most effectively when it is used when barrier properties against gas or the like and improvement of the mechanical properties of the rubber material are required.
[0042]
Next, as a first method for producing the clay composite rubber material, for example, as in the invention according to claim 10, the clay mineral is brought into contact with an organic onium ion having 6 or more carbon atoms to thereby form the clay mineral. An ionic bond between the organic onium ions and the clay minerals,
Next, a first guest molecule having a molecular length equal to or shorter than that of the organic onium ion and having a polar group in the molecule, a molecular length larger than that of the organic onium ion and not present in the molecule. By contacting a second guest molecule having a saturated group and not having a polar group with the clay mineral, the polar group of the first guest molecule is allowed to form a hydrogen bond with the clay mineral to form the clay. After obtaining the first clay composite material by hydrophobizing the surface of the mineral and allowing at least a part of the second guest molecule to enter between the layers of the clay mineral,
A method for producing a clay composite rubber material, wherein the first clay composite material is kneaded with a rubber material, and a cross-linking bond is formed between the unsaturated group of the second guest molecule and the molecule of the rubber material,
The organic onium ion has an unsaturated group, and in the step of kneading the first clay composite material with a rubber material, the unsaturated group of the organic onium ion, the unsaturated group of the second guest molecule, and the rubber There is a method for producing a clay composite rubber material characterized by forming a cross-linking bond with an unsaturated group in the material.
[0043]
What should be most noticeable in the first method is that the surface of the organized clay mineral is hydrophobized with a first guest molecule having a polar group, and the second guest molecule having an unsaturated group is made into an interlayer of the clay mineral. And the formation of crosslinks between the unsaturated groups and the rubber material molecules.
[0044]
Next, the operation of the first method will be described.
In the above manufacturing method, first, as shown in FIG. 1, the clay mineral 7 is made organic by bonding the organic onium ions 6 to the clay mineral 7. Thereby, a certain amount of space is generated between the layers of the clay mineral 7.
[0045]
Next, when the first and second guest molecules are brought into contact with the organized clay mineral, the first and second guest molecules 1 and 2 enter the space between the layers. The first guest molecule 1 has a polar group 10. Therefore, the clay mineral 7 is hydrogen-bonded and stays between the layers of the clay mineral 7 to make the layer of the clay mineral 7 hydrophobic. Therefore, the second guest molecule 2 having a low polarity that has entered the interlayer of the clay mineral 7 is not excluded by the polarity of the clay mineral, and can remain stably between the layers.
[0046]
The second guest molecule 2 has a molecular length larger than that of the organic onium ion 6 and is bulky. Therefore, when the second guest molecule 2 stays between the layers of the clay mineral 7, the layer is infinitely swollen with no limit.
Therefore, by kneading the first clay composite material 100 in the infinitely swollen state in the rubber material, the clay mineral, which is originally a polar substance, was uniformly dispersed at the molecular level in the low polarity rubber material. A clay composite rubber material can be obtained.
[0047]
The second guest molecule has an unsaturated group. Unsaturated groups crosslink with the rubber material molecules during kneading with the rubber material. Therefore, the movement of rubber molecules in the vicinity of the silicate layer is constrained, and the mechanical properties of the clay composite rubber material are favorably affected.
[0048]
The organic onium ion has an unsaturated group, and in the step of kneading the first clay composite material with a rubber material, the organic onium ion unsaturated group, the second guest molecule unsaturated group, A cross-linking bond is formed with the unsaturated group in the rubber material. When the above organic onium ion is used, the second guest molecule and the rubber material are kneaded and cross-linked between the unsaturated group of the organic onium ion, the unsaturated group of the second guest molecule, and the molecule of the rubber material. Crosslinks are formed. For this reason, the clay mineral silicate layer and the rubber interface are very tightly coupled. Therefore, the movement of rubber molecules in the vicinity of the silicate layer is further restricted, and the elastic modulus of elasticity is improved when it is mechanical.
[0049]
An example of a method for bringing the clay mineral into contact with the organic onium ion is an ion exchange method. This ion exchange method is, for example, a method of immersing a clay mineral in an aqueous solution containing organic onium ions and then washing the clay mineral with water to remove excess organic onium ions.
[0050]
As the first guest molecule, those described above can be used. As the second guest molecule, liquid polybutadiene, liquid polyisoprene, liquid butyl rubber or the like having an unsaturated group can be used.
In bringing the first and second guest molecules into contact with the organized clay mineral, the order in which the two are brought into contact with each other is not limited. That is, both may be administered and contacted simultaneously, or one of them may be contacted and then the other may be contacted. In either case, the same effect can be obtained as a result.
[0051]
As a contact method of the first and second guest molecules, for example, as in the invention of claim 12, the first and second guest molecules are contacted with the organic clay mineral in a state in which the first and second guest molecules are dissolved in a solvent. There is a way to make it. Further, as in the invention of claim 13, there is a method in which the first and second guest molecules are brought into contact with the organized clay mineral while being softened or melted by heat.
[0052]
According to the former method of claim 12, the first and second guest molecules can enter the interlayer of the clay mineral at room temperature. Examples of the solvent that can be used in this method include solvents having low polarity such as toluene, benzene, xylene, hexane, and octane.
On the other hand, in the latter method of claim 13, in order to soften or melt the first and second guest molecules, the first and second guest molecules are set to a temperature equal to or higher than the softening temperature or the melting temperature. Heat. This heating is performed at a temperature at which the first and second guest molecules and the clay mineral do not decompose and exist stably. For example, the heating temperature is preferably 250 ° C. or lower. If it exceeds 250 ° C, the organized clay mineral may be decomposed.
[0053]
As a method for kneading the first clay composite material and the rubber material, a general method for kneading rubber can be used. In particular, a method of kneading with a rubber roll at 100 ° C. or lower is preferable. This is because if the temperature exceeds 100 ° C., the crosslinking reaction may proceed during kneading.
[0054]
When the first clay composite material and the rubber material are kneaded, it is necessary to form a sulfur cross-linking bond called “vulcanization” or a cross-linking bond equivalent thereto. For this purpose, in the case of the first clay composite material, the second guest molecule needs to contain an unsaturated group. An unsaturated group refers to a group in which a double bond or a triple bond is formed between carbons. Examples of the second guest molecule having an unsaturated group include liquid polybutadiene, liquid polyisoprene, and liquid butyl rubber.
In kneading, it is preferable to add a vulcanizing agent such as sulfur, a vulcanization accelerator, a crosslinking agent such as peroxide, and a filler such as carbon.
[0055]
Next, as a second method for producing the clay composite rubber material, for example, as in the invention of claim 11, the clay mineral is brought into contact with an organic onium ion having 6 or more carbon atoms to thereby form the clay mineral. An ionic bond between the organic onium ions and the clay minerals,
Next, the clay mineral is brought into contact with a third guest molecule having a polar group and an unsaturated group in the molecule and having a molecular length equal to or greater than that of the organic onium ion. After interposing at least a part of the third guest molecule between the layers, a hydrogen bond is formed with the clay mineral to obtain a second clay composite material,
A method for producing a clay composite rubber material, wherein the second clay composite material is kneaded with a rubber material, and a cross-linking bond is formed between the unsaturated group of the third guest molecule and the molecule of the rubber material,
The organic onium ion has an unsaturated group, and in the step of kneading the second clay composite material with a rubber material, the organic onium ion unsaturated group, the third guest molecule unsaturated group, and the rubber There is a method for producing a clay composite rubber material characterized by forming a cross-linking bond with an unsaturated group in the material.
[0056]
What is most notable in the second method is that a third guest molecule having a polar group and an unsaturated group enters between layers of an organized clay mineral, and the unsaturated group and the molecule of the rubber material. A cross-linking bond is formed between them.
[0057]
The second method is different from the above-described first method using the first and second guest molecules in that the third guest molecule is used.
The third guest molecule has a polar group and an unsaturated group, and its molecular length is the same as or longer than that of the organic onium ion. As the third guest molecule, for example, polybutadiene having —OH groups at both ends, polyisoprene having —OH groups at both ends, and the like can be used.
Others are the same as those in the first method.
[0058]
Next, the operation of the second method will be described.
In the above method, first, as shown in FIG. 2, a certain amount of space is generated between the layers of the clay mineral 7 by bonding the organic onium ions 6 to the clay mineral 7.
Next, the third guest molecule 3 having the polar group 30 is brought into contact with the organized clay mineral 7. Then, the third guest molecule 3 enters the space between the layers of the clay mineral 7 and is hydrogen bonded to the silicate layer of the clay mineral 7 by the polar group 30. As a result, the third guest molecules 3 remain between the layers without being excluded by the polarity of the surface of the clay mineral 7. For this reason, as in the first method described above, the interlayer of the clay mineral 7 is further swollen and becomes infinitely swollen. Therefore, by kneading the second clay composite material 200 in an infinitely swollen state in the rubber material, the clay mineral that is originally a polar substance can be uniformly dispersed in the rubber material at the molecular level.
[0059]
The third guest molecule has an unsaturated group. For this reason, this unsaturated group crosslinks with the molecule of the rubber material, and similarly affects the mechanical properties of the clay composite rubber material.
[0060]
The organic onium ion has an unsaturated group, and in the step of kneading the second clay composite material with a rubber material, the organic onium ion unsaturated group, the third guest molecule unsaturated group, A crosslink is formed between the rubber material and the unsaturated group. When an organic onium ion is used, a cross-linking bond is formed between the unsaturated group of the organic onium ion, the third guest molecule, and the molecule of the rubber material, and as described above, the mechanical properties of the clay composite rubber material are good. Influence.
[0061]
Further, both the first clay composite material and the second clay composite material can be kneaded with the rubber material to form a cross-linking bond between the second and third guest molecules and the rubber material molecules. In this case, the same effect as described above can be obtained.
[0062]
Further, as described above, as a method of bringing the third guest molecule into contact with the organized clay mineral, as in the invention of claim 12, the third guest molecule is organicized in a state in which the third guest molecule is dissolved in a solvent. There is a method of contact with clay minerals. Further, as in the invention of claim 13, there is a method of bringing the third guest molecule into contact with the organized clay mineral in a state of being softened or melted by heat.
[0063]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
In this example, the compounding ratio of the clay composite rubber material was changed, the sheet was molded, and the mechanical properties were evaluated.
First, methods for preparing various clay composite rubber materials will be described.
[0064]
(Samples 4 to 6 of the present invention)
As the clay mineral, sodium-type montmorillonite (produced in Yamagata Prefecture, ion exchange capacity 120 meq / 100 g) was used. As the organic onium ion, an oleyl ammonium ion having an unsaturated group in the molecule was used. As the third guest molecule, polyisoprene having a hydroxyl group (manufactured by Kuraray: LIR506) was used.
As the rubber material, butyl rubber (Nippon Synthetic Rubber Butyl 268) was used.
[0065]
Next, a method for producing the clay composite material will be described.
First, 20.0 g of montmorillonite was dispersed in 2000 ml of 80 ° C. water. Next, 8.8 g of oleylamine hydrochloride was dissolved in 1500 ml of water at 80 ° C. Both aqueous solutions were mixed at once. The precipitate was washed twice with water at 80 ° C. to obtain montmorillonite organized with oleylammonium ions. This is called OL-montmorillonite. The inorganic content in OL-montmorillonite determined by the residue method was 69.4% by weight. When the interlayer distance of montmorillonite was measured by the X-ray diffraction method, the interlayer distance of OL-montmorillonite was 22.5 mm.
[0066]
70 g, 140 g and 210 g of the above-mentioned OL-montmorillonite were mixed with 100 g of polyisoprene and mixed at 80 ° C. for 4 hours to obtain three types of second clay composite materials. When the interlayer distance of montmorillonite in the clay composite material was measured by X-ray diffraction, it was 70.0 mm.
To this, 3.0 g of sulfur, 5.0 g of zinc white, 3.0 g of stearic acid, and 1.5 g of a vulcanization accelerator (Noxeller MSA-G manufactured by Ouchi Shinsei Chemical Co., Ltd.) were added and kneaded.
[0067]
These kneaded materials were kneaded with butyl rubber and carbon in the composition shown in Table 1 to prepare clay composite rubber materials (Samples 4 to 6).
[0068]
(Comparative samples 1 to 3)
For comparison, a material composed of a rubber material and carbon was prepared without adding the second clay composite material, and these were designated as samples 1 to 3.
[0069]
(Comparative Samples 11-14, 18, 21-26, Reference Samples 15-17, 19, 20)
For comparison and reference, a clay composite rubber material was prepared using an organic onium ion having no unsaturated group in the molecule.
In this example, as shown in Table 2, the second clay composite material was used. The second clay composite material is composed of a clay mineral organized with an organic onium ion having no unsaturated group in the molecule and a third guest molecule. As the organic onium ion, a 38-carbon distearyldimethylammonium ion (hereinafter referred to as DSDM) was used. Montmorillonite was used as the clay mineral. DSDM-montmorillonite (denoted as DSDM-Mt) was used as the clay mineral thus organized. In DSDM-montmorillonite, the weight ratio of DSDM to montmorillonite was always the same. As the third guest molecule, liquid polybutadiene having a —OH group at both ends (Nippon Soda Co., Ltd., trade name G2000) (indicated as liquid rubber) was used. As the rubber material, butyl rubber (Nippon Synthetic Rubber Butyl 268) was used. Using these at various compounding ratios shown in Table 2, clay composite rubber materials were prepared in the same manner as Samples 4-6. These were designated as comparative samples 11 to 14, 18, 21 to 26, and reference samples 15 to 17, 19, and 20.
[0070]
Samples 18, 21, and 22 are examples in which untreated montmorillonite (indicated as Na-Mt) is used as an unorganized clay mineral. Samples 11 to 14, 18, and 21 to 26 are examples in which a sheet was formed without adding DSDM-Mt. Samples 15 to 17, 19, and 20 are examples in which montmorillonite and liquid rubber that are organized with DSDM that does not have an unsaturated group are added to a rubber material. Among these, samples 15 to 17 are cases where carbon is further added. Samples 19 and 20 are cases in which no carbon was added.
[0071]
(Measuring mechanical properties)
The storage elastic modulus, tensile strength, elongation, tensile stress and gas barrier performance of the clay composite rubber materials of Samples 1 to 6 and 11 to 26 were measured. The measurement method will be described below.
Storage elastic modulus; measured by a viscoelastic spectrometer.
Tensile strength: Clay composite rubber material is uniformly kneaded, vulcanized at 150 ° C for 40 minutes to form a sheet with a thickness of 2 mm, a test piece of dumbbell No. 3 is cut out, and tensile strength is measured by a tensile test. .
Tensile stress: measured by a tensile test in the same manner as the tensile strength.
Gas barrier performance: The clay composite rubber material was uniformly kneaded and vulcanized at 150 ° C. for 40 minutes to form a sheet having a thickness of 0.5 mm, and the gas permeability with nitrogen was measured.
[0072]
The measurement results are shown in Tables 1 and 2.
In the table, the numerical value in parentheses indicates the weight ratio of montmorillonite, and the numerical value on the left indicates the weight ratio of OL-montmorillonite in parts by weight. Is. In the numerical columns of Tables 1 and 2, “-” and “x” indicate that measurement is impossible.
[0073]
From the same table, it can be seen that when Samples 4 to 6 using OL-montmorillonite and Sample 2 not using OL-montmorillonite are compared, Samples 4 to 6 have better mechanical properties.
Further, Samples 4 to 6 of this example had higher storage elastic modulus, tensile strength, elongation, and tensile stress than Samples 15 to 17. The gas shutoff performance was also high.
[0074]
The reason for this is estimated as follows. That is, the polyisoprene as the third guest molecule and the oleylammonium ion as the organic onium ion both have an unsaturated group in the molecule. Therefore, when both are kneaded and vulcanized, a cross-linking bond is simultaneously formed in the organic onium ion. Therefore, the interface between the montmorillonite silicate layer and the butyl rubber is very firmly bonded. Therefore, the movement of rubber molecules in the vicinity of the silicate layer is constrained, and the mechanical properties, especially the hardness and elastic modulus, are thought to improve.
[0075]
Next, based on the results shown in Table 2, the presence or absence of organication of montmorillonite will be discussed.
Comparing sample 19 using organic montmorillonite (DSDM-Mt) with sample 22 using non-organic montmorillonite (Na-Mt), sample 19 has a storage modulus and gas barrier. It was excellent in nature.
From this, it can be seen that excellent mechanical properties can be obtained by organicizing montmorillonite.
[0076]
The reason is that when montmorillonite is made organic, liquid butyl rubber enters between the layers of montmorillonite, the layers swell, and montmorillonite is uniformly dispersed at the molecular level in the rubber material. As a result, it is considered that montmorillonite restrained the molecular motion of the rubber material and had a good influence on the mechanical properties such as storage elastic modulus and gas barrier property of the clay composite rubber material.
[0077]
On the other hand, when montmorillonite is not organicized, liquid butyl rubber cannot enter between the layers, and the layers do not swell. For this reason, montmorillonite is not uniformly dispersed in the rubber material. For this reason, the molecular motion of the rubber material is not easily restrained. For this reason, it is considered that the mechanical properties of the clay composite rubber material were not improved.
[0078]
Next, the storage elastic modulus of the clay composite rubber material is considered.
Samples 15, 16, and 17 show that the storage modulus is remarkably improved when the montmorillonite content is increased to 5, 10, and 15 parts by weight. The reason is that the more liquid butyl rubber enters between the layers of organic montmorillonite, the more the layers swell and the more easily montmorillonite is uniformly dispersed in the rubber material. And, it is considered that the storage elastic modulus was increased by the uniform dispersion of montmorillonite.
Samples 19 and 20 both have zero carbon, but in this case as well, sample 20 with a higher content of montmorillonite improved the storage modulus.
[0079]
Next, the gas barrier property of the molded sheet is considered. Sample 11 has a large amount of carbon and zero montmorillonite. On the other hand, Samples 19 and 20 have a small amount of carbon and a large amount of montmorillonite. When these were compared, the gas permeability of the samples 19 and 20 with a large amount of montmorillonite was reduced by 60 to 70%. This indicates that the greater the content of montmorillonite, the higher the gas barrier properties.
[0080]
[Table 1]

[0081]
[Table 2]

[0082]
Reference example 1
This example is a clay composite rubber material prepared using an organic onium ion having no unsaturated group.
In the clay composite rubber material of this example, the first clay composite material and the rubber material are kneaded, and the second guest molecules in the first clay composite material are cross-linked with the molecules of the rubber material.
[0083]
As shown in FIG. 1, the clay composite material is composed of a clay mineral 7 that is organized with an organic onium ion 6 having 6 or more carbon atoms, a molecular length equal to or smaller than that of the organic onium ion, The first guest molecule 1 in which the polar group 10 is hydrogen-bonded to the clay mineral 7 and the second guest molecule 2 having a molecular length larger than that of the organic onium ion and having no polar group in the molecule. . At least a part of the first guest molecule 1 and the second guest molecule 2 penetrates between the layers of the clay mineral 7.
[0084]
The clay mineral is sodium montmorillonite (produced in Yamagata Prefecture, ion exchange capacity 120 meq / 100 g). The organic onium ion is distearyldimethylammonium ion (DSDM), and its carbon number is 38. The first guest molecule is stearic acid and has 18 carbon atoms. The second guest molecule is liquid butyl rubber (manufactured by Hardman, trade name Karen 800), and its molecular weight is about 5000.
[0085]
Next, a method for producing the clay composite rubber material will be described.
First, 20.0 g of montmorillonite was dispersed in 2000 ml of 80 ° C. water. Next, 21.0 g of distearyldimethylammonium chloride was dissolved in 1500 ml of 80 ° C. water. The above dispersion and solution were mixed at once. The precipitate was washed twice with water at 80 ° C. to obtain montmorillonite organized with DSDM. This is hereinafter referred to as DSDM-montmorillonite.
[0086]
The inorganic content in DSDM-montmorillonite determined by the residue method was 54.2% by weight. The interlayer distance of DSDM-montmorillonite was measured by X-ray diffraction method, and the swelling behavior was observed. The interlayer distance of DSDM-montmorillonite was 32.8 mm.
[0087]
Next, 1.0 g of the above-mentioned DSDM-montmorillonite, 0.5 g of stearic acid, and 1.0 g of liquid butyl rubber (trade name Karen 800, manufactured by Hardman) are added to 20 g of toluene as a solvent, and mixed for 6 hours. did. Next, toluene was evaporated under reduced pressure. As a result, a first clay composite material was obtained.
[0088]
When the interlayer distance of montmorillonite in the clay composite material was measured by X-ray diffraction method, it was 54.8 mm.
From this, it can be seen that the addition of stearic acid and liquid butyl rubber increases the interlayer distance of montmorillonite and swells compared to the case of no addition.
[0089]
Next, the first clay composite material and the rubber material were kneaded with a roll in accordance with ASTM D 3182. Butyl rubber (Nippon Synthetic Rubber Butyl 268) was used as the rubber material.
The blending ratio of the clay composite rubber material is 20 parts by weight of the first clay composite material (including 5 parts by weight of clay mineral), 20 parts by weight of carbon (Asahi Carbon # 70), and 1 part by weight of zinc white relative to 100 parts by weight of the rubber material. Part, sulfur 1.75 parts by weight, vulcanization accelerator 1 part by weight.
[0090]
Next, after uniformly kneading, a sheet having a thickness of 2 mm was formed by vulcanization at 150 ° C. for 40 minutes. A dumbbell No. 3 specimen was cut from the sheet and a tensile test was conducted. As a result, the tensile strength was 18.0 MPa.
Further, a 0.5 mm thick sheet was formed in the same manner, and the gas permeability with nitrogen was evaluated. As a result, the gas permeability coefficient is 1.9 × 10^-11 cm^Three・ Cm ・ cm^-2・ Sec^-1・ CmHg^-1Met.
[0091]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a clay composite rubber material having high dispersibility of clay minerals in a rubber polymer having low polarity and excellent mechanical properties, and a method for producing the same.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a first clay composite material in the present invention.
FIG. 2 is an explanatory diagram of a second clay composite material in the present invention.
[Explanation of symbols]
1. . . First guest molecule,
10, 30. . . Polar group,
100. . . First clay composite,
2. . . Second guest molecule,
200. . . Second clay composite,
3. . . Third guest molecule,
6). . . Organic onium ions,
7). . . Clay minerals,

Claims (13)

Clay minerals organically formed by ionic bonding of organic onium ions with 6 or more carbon atoms having an unsaturated group , the molecular length is the same as or shorter than the above organic onium ions, and the polar group in the molecule is A first guest molecule hydrogen-bonded to the clay mineral, and a second guest molecule having a molecular length larger than that of the organic onium ion and having an unsaturated group in the molecule and having no polar group. , The first guest molecule and the second guest molecule are at least a part of the first clay composite material and / or
An organic onium ion having 6 or more carbon atoms having an unsaturated group is ion-bonded to form a clay mineral, a polar group and an unsaturated group in the molecule, and a molecular length of the organic onium ion It consists of third guest molecules that are the same or larger, and at least a part of the third guest molecules penetrates between the layers of the clay mineral, and the polar groups of the third guest molecules form hydrogen bonds with the clay mineral. A second clay composite material,
Rubber material is kneaded,
And at least one of the second guest molecule or the third guest molecule is cross-linked with a molecule of the rubber material,
The organic onium ion in at least one of the first clay composite material or the second clay composite material is cross-linked between at least one of the second guest molecule or the third guest molecule and the molecule of the rubber material. A clay composite rubber material characterized by forming.   2. The polar group of the first guest molecule and / or the third guest molecule according to claim 1, wherein the polar group is selected from the group consisting of a hydroxyl group, a halogen group, a carboxyl group, a carboxylic anhydride group, a thiol group, an epoxy group, and an amino group. A clay composite rubber material characterized by being a seed or two or more kinds.   3. The clay composite rubber material according to claim 1, wherein the second guest molecule is a nonpolar oligomer or polymer having a molecular weight of 1000 to 500,000.   4. The clay composite rubber material according to claim 1, wherein the third guest molecule is a nonpolar oligomer or polymer having a molecular weight of 500 to 100,000.   5. The clay composite according to claim 1, wherein 10% by weight or more of the total amount of the first guest molecules enters between layers of the clay mineral in the first clay composite material. Rubber material.   The clay composite according to any one of claims 1 to 5, wherein 10% by weight or more of the total amount of the third guest molecules enters between layers of the clay mineral in the second clay composite material. Rubber material.   The rubber material according to any one of claims 1 to 6, wherein the rubber material is natural rubber, isoprene rubber, chloroprene rubber, styrene rubber, nitrile rubber, ethylene-propylene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, epichlorohydrin rubber, A clay composite rubber material characterized by being one or more selected from the group of acrylic rubber, urethane rubber, fluoro rubber, and silicone rubber.   The first guest molecule according to any one of claims 1 to 7, wherein the first guest molecule is an olefin or paraffin having a linear or branched structure, or a linear or branched structure and having a main chain and / or a side. A clay composite rubber material characterized by being an olefin or paraffin having an aromatic ring in the chain.   The third guest molecule according to any one of claims 1 to 8, wherein the third guest molecule is an olefin or paraffin having a linear or branched structure, or a linear or branched structure and having a main chain and / or a side. A clay composite rubber material characterized by being an olefin or paraffin having an aromatic ring in the chain. By bringing the clay mineral into contact with an organic onium ion having 6 or more carbon atoms, an ionic bond is formed between the clay mineral and the organic onium ion to organicize the clay mineral,
Next, a first guest molecule having a molecular length equal to or shorter than that of the organic onium ion and having a polar group in the molecule, a molecular length larger than that of the organic onium ion and not present in the molecule. By contacting a second guest molecule having a saturated group and not having a polar group with the clay mineral, the polar group of the first guest molecule is allowed to form a hydrogen bond with the clay mineral to form the clay. After obtaining the first clay composite material by hydrophobizing the surface of the mineral and allowing at least a part of the second guest molecule to enter between the layers of the clay mineral,
A method for producing a clay composite rubber material, wherein the first clay composite material is kneaded with a rubber material, and a cross-linking bond is formed between the unsaturated group of the second guest molecule and the molecule of the rubber material,
The organic onium ion has an unsaturated group, and in the step of kneading the first clay composite material with a rubber material, the unsaturated group of the organic onium ion, the unsaturated group of the second guest molecule, and the rubber A method for producing a clay composite rubber material, wherein a cross-linking bond is formed with an unsaturated group in the material. By bringing the clay mineral into contact with an organic onium ion having 6 or more carbon atoms, an ionic bond is formed between the clay mineral and the organic onium ion to organicize the clay mineral,
Next, the clay mineral is brought into contact with a third guest molecule having a polar group and an unsaturated group in the molecule and having a molecular length equal to or greater than that of the organic onium ion. After interposing at least a part of the third guest molecule between the layers, a hydrogen bond is formed with the clay mineral to obtain a second clay composite material,
A method for producing a clay composite rubber material, wherein the second clay composite material is kneaded with a rubber material, and a cross-linking bond is formed between the unsaturated group of the third guest molecule and the molecule of the rubber material,
The organic onium ion has an unsaturated group, and in the step of kneading the second clay composite material with a rubber material, the organic onium ion unsaturated group, the third guest molecule unsaturated group, and the rubber A method for producing a clay composite rubber material, wherein a cross-linking bond is formed with an unsaturated group in the material.   12. The clay according to claim 10, wherein the first guest molecule and / or the second guest molecule, or the third guest molecule is brought into contact with the organized clay mineral in a state dissolved in a solvent. A method for producing a composite rubber material.   The first guest molecule and / or the second guest molecule, or the third guest molecule according to any one of claims 10 to 12, in contact with the organic clay clay in a state of being softened or melted by heat. A method for producing a clay composite rubber material.

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