JP2010111794A - Rubber composition capable of vulcanization-bonding to polyamide resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition capable of vulcanization-bonding to a polyamide resin without providing an adhesive layer and also capable of forming a composite product with a polyamide resin layer, such as a composite rubber hose. <P>SOLUTION: The rubber composition capable of vulcanization-bonding to the polyamide resin includes 10 to 100 pts.wt. talc and 0.1 to 30 pts.wt. resin crosslinking agent based on 100 pts.wt. blended rubber comprising 60 to 90 mass% acrylonitrile-butadiene rubber and 40 to 10 mass% halogenated butyl rubber. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rubber composition capable of vulcanization adhesion with a polyamide resin. More specifically, the present invention relates to a rubber composition capable of easily forming a composite hose with a polyamide resin and capable of being vulcanized and bonded to the polyamide resin.

Aromatic polyamide fibers with excellent strength, modulus, dimensional stability, etc. are used as reinforcing agents for rubber structures such as tires, belts and hoses. Adhesives are used as rubber and fiber adhesive compositions. It has been proposed to use a matrix component such as polyepoxide compound, rubber latex, blocked polyisocyanate compound, ethylene urea compound, etc. as a main active ingredient and silicic anhydride to be used for the production of rubber reinforcing cords. .
JP 2001-64620 A

For the flexible hose in which the innermost layer, the intermediate rubber layer, the fiber reinforcement layer, and the outer rubber layer are laminated sequentially from the inside, the innermost layer is a polyamide in order to bond the innermost layer and the intermediate rubber layer without an adhesive layer. A rubber made of a modified polyamide obtained by blending olefin and carboxyl group-containing modified polyolefin, with an intermediate rubber layer blended with silicic acid (salt) and brominated alkylphenol formaldehyde resin in a blended rubber of halogenated butyl rubber alone or butyl rubber There has been proposed a method of manufacturing a composite flexible hose comprising a composition and vulcanizing after laminating the respective layers. However, since the intermediate rubber layer is formed of halogenated butyl rubber alone or a blend rubber of this and butyl rubber, it cannot be used as a hydraulic hose.
Japanese Patent Laid-Open No. 7-117178

  In this proposal, a strong adhesive force can be obtained between the innermost layer and the intermediate rubber layer without providing an adhesive layer. The polyamide resin constituting the innermost layer is modified, and this modified functional group and the intermediate rubber are A complex reaction occurs between the halogen of the halogenated butyl rubber forming the layer, the reactive silanol group of the silicic acid (salt) contained therein, and the brominated alkylphenol formaldehyde resin, resulting in various bonds It is stated that it is presumed.

  Here, examples of the silicic acid (salt) include silicic anhydride, hydrous silicic acid, hydrous calcium silicate, hydrous aluminum silicate, etc., and many silanol groups are particularly preferable because of good adhesion to halogenated butyl rubber. Hydrous silicic acid is preferred.

  In addition, when NBR is used instead of brominated butyl rubber, chlorinated butyl rubber or a blend rubber of these with butyl rubber, the adhesive strength between the innermost layer and the intermediate rubber layer after normal and heat aging is reduced. What is remarkable is also shown in the examples (formulation examples 1-10).

Further, in the composite flexible hose having the above-mentioned configuration, an intermediate layer is also proposed which is composed of a composition in which a halogenated butyl rubber, silicic acid (salt), brominated alkylphenol formaldehyde resin, phenol resin and methylol melamine are blended. However, those as described above are used as silicic acid (salt).
JP 2000-220770 A

  An object of the present invention is to provide a rubber composition capable of being vulcanized and bonded to a polyamide resin without providing an adhesive layer, and capable of forming a composite such as a composite rubber hose with the polyamide resin layer. There is.

  The object of the present invention is to provide 10 to 100 parts by weight of talc and 0.1 to 30 parts by weight of a resin crosslinking agent with respect to 100 parts by weight of a blend rubber comprising 60 to 90% by weight of acrylonitrile-butadiene rubber and 40 to 10% by weight of halogenated butyl rubber. It is achieved by a rubber composition that contains bismuth and can be vulcanized and bonded to a polyamide resin.

  In Patent Document 2, when NBR is used in place of the halogenated butyl rubber alone or a blend rubber of butyl rubber, the adhesive strength between the normal and heat-aged modified polyamide resin innermost layer and the intermediate rubber layer Contrary to the fact that the rubber composition of the present invention is significantly reduced, the rubber composition of the present invention uses an acrylonitrile-butadiene rubber (NBR) as a main component of a blend rubber with a halogenated butyl rubber, thereby lowering the viscosity of the rubber. It is possible to obtain a composite such as a composite rubber hose with a polyamide resin layer having excellent adhesion and oil resistance from the composition.

Although it is a well-known fact that NBR itself is excellent in oil resistance, in the present invention, silica (SiO ₂ ) can be obtained by containing NBR-halogenated butyl rubber blend rubber in combination with talc and a resin crosslinking agent. In addition, composites such as composite rubber hoses having excellent characteristics as described above have been obtained as compared with the case where a resin crosslinking agent is contained in combination.

  That is, in the rubber composition according to the present invention, the adhesive strength of the composite vulcanized and bonded to the polyamide resin layer is obtained by blending talc as a filler and further using it in combination with a resin crosslinking agent. It shows adhesive strength that can be said to be a synergistic effect. In addition, the adhesive strength is never inferior to that in the case where a conventional solvent-based adhesive is used, and a solvent-less operation is possible.

  The rubber composition of the present invention having such properties includes a fuel hose for automobiles required for various properties such as flexibility, bending resistance, and prevention of swelling due to hydraulic pressure, and a polyamide such as an elastomer tire in which rubber is dispersed in a polyamide resin. Effectively used as a rubber material to be vulcanized and bonded to resin.

  NBR used as the main component of blended rubber (60-90% by mass, preferably 65-85% by mass) is a commercially available very high nitrile content (AN content 43% or more), high nitrile content (36- 42%), medium-high nitrile content (31-35%), medium nitrile content (25-30%) and low nitrile content (24% or less) can be used as they are, but medium-high nitrile is preferred. The content is used. The NBR may be a hydrogenated NBR.

  As the halogenated butyl rubber, chlorinated butyl rubber or brominated butyl rubber is used, and brominated butyl rubber is preferably used from the viewpoint of reactivity. The halogen content is about 0.3 to 5% by weight for chlorinated butyl rubber and about 0.5 to 10% by weight for brominated butyl rubber.

  The halogenated butyl rubber is used in a ratio of about 40 to 10% by mass, preferably about 35 to 15% by mass in the blend rubber with NBR. If halogenated butyl rubber is used in a higher proportion, it will be inferior in oil resistance. On the other hand, if it is used in a proportion lower than this, it will reduce the rubber property during oil immersion test and peel test. Become.

  The NBR-halogenated butyl rubber blend rubber has about 10-100 parts by weight, preferably about 20-70% by weight talc and about 0.1-30 parts by weight, preferably about 2-15 parts by weight per 100 parts by weight thereof. Used with a resin cross-linking agent.

Talc has a composition formula of Mg ₃ [(OH) ₂ | Si ₄ O ₁₀ ], and the viscosity of the unvulcanized rubber composition is lower than that when silica is used. Excellent rubberity. When less than 10 parts by weight of talc per 100 parts by weight of blend rubber is used, not only the adhesiveness deteriorates, but also the liquid sealing property deteriorates, while when used in a proportion higher than 100 parts by weight, Since the hardness becomes too high, the flexibility and the buckling resistance of the hose are deteriorated.

  As the resin crosslinking agent, at least one of alkylphenol / formaldehyde resin, melamine / formaldehyde condensate and triazine / formaldehyde condensate is preferably used.

  Alkylphenol-formaldehyde resins are o-, m- or p-cresol, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-xylenol, p- It is obtained by condensation reaction of alkylphenol such as butylphenol and formaldehyde using a catalyst such as inorganic acid or organic acid such as hydrochloric acid or oxalic acid or zinc acetate, and excess unreacted alkylphenol is distilled off. For the implementation, commercially available products such as Taoka Chemical Industry Co., Ltd. tack roll 250-1, the company's Taco roll 201, etc. can be used as they are.

  Melamine / formaldehyde condensate is a so-called melamine resin obtained by heating reaction while adding an alkaline catalyst in a reaction kettle in the form of an addition polymerization reaction (methylolation, methyleneation) of melamine and formaldehyde. Commercially available products such as Crez 711 latex curing resin manufactured by American Cyanamide are used as they are.

  The triazine / formaldehyde condensate is a condensate obtained by reacting triazine and formaldehyde under alkaline reaction conditions. In practice, a commercial product such as Crez 915 latex curing resin manufactured by American Cyanamide Co., Ltd. is used as it is.

  These resin crosslinking agents are used in a proportion of about 0.1 to 30 parts by weight, preferably about 1 to 20 parts by weight, per 100 parts by weight of the blend rubber. If the proportion of the resin cross-linking agent used is less than these, the necessary cross-linking will not be performed sufficiently. On the other hand, if it is used in a proportion higher than this, the cross-linking reaction will progress during the molding, resulting in molding failure or molding. It becomes impossible.

  In the rubber composition containing the above components as essential components, other compounding agents generally added to NBR and halogenated butyl rubber, for example, fillers such as carbon black, oxides of divalent metals, or hydroxides An acid acceptor such as a product or hydrotalcide, an antiaging agent, and the like can be appropriately blended.

  Such a rubber composition can be vulcanized and bonded to a polyamide resin without using an adhesive. As the polyamide resin, for example, at least one of nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 46, and the like is used.

  Vulcanization adhesion can be performed on the laminated surface of a polyamide resin molded article such as a sheet or tube. For example, a sheet-like unvulcanized rubber composition is stacked on the laminated surface of a sheet-like polyamide resin, This is performed by heating and pressing at about 130 to 200 ° C. for about 10 to 120 minutes. In the case of a tubular polyamide resin, co-extrusion is carried out with the polyamide resin as the inner layer and the rubber composition as the outer layer, and then heated. The laminated composite can be formed by any vulcanization method such as vulcanization or steam vulcanization.

  Between the vulcanized rubber layer and the polyamide resin layer, there is a fiber reinforcement layer made of synthetic fibers such as polyvinyl alcohol, polyamide, polyester, and aramid, or synthetic fibers treated with resorcinol / formaldehyde latex. The fiber reinforcing layer is interposed prior to the vulcanization adhesion of the rubber composition layer.

  In the case of manufacturing the composite flexible hose as described above, the rubber composition is formed as an intermediate rubber layer, and the synthetic fiber fiber reinforcing layer and the outer rubber layer as described above are sequentially formed. The outer rubber layer is formed from a synthetic rubber excellent in ozone resistance such as EPDM, chloroprene rubber, isoprene rubber and the like.

  Next, the present invention will be described with reference to examples.

Example 1
Halogenated butyl rubber (ExxonMobil product 20 parts by weight)
EXXON Bromobutyl 2255; bromine content 1.8-2.2% by weight)
NBR (Lanxess Elastomer SAS product KRYNAC 3345F; CN content 33%) 80 〃
Talc (Mistron VAPOR, Japan Mythron product; average particle size 5μm) 30 〃
ISAF grade carbon black (Cabot Japan product 20 〃
(Show Black N220)
Anti-aging agent (SANYOFLEX 6PPD, product of Flexi) 1 〃
Resin cross-linking agent (Taoka Chemical Co., Ltd., Tactrol 250-1) 3 〃
Zinc oxide (Zondoh Chemical Industrial Products Zinc Oxide 3 types) 2 〃
The above components were kneaded using a Banbury mixer, and the unvulcanized rubber composition was molded into a sheet size of 6 inches × 6 inches × 2 mm (15.24 × 15.24 × 0.2 cm).

  Nylon 6-based compound (DuPont product Zytel ST811HSNC010) or nylon 11-based compound (Toray products BESN O YL-2) film (thickness 100 μm) cut into a size of 6 inches × 6 inches, the above It was placed on an unvulcanized sheet, and vulcanized and adhered for 60 minutes with a heating press at 150 ° C. for lamination.

The following items were measured for the unvulcanized rubber composition and the laminated composite.
Viscosity: Measured for viscosity of unvulcanized rubber composition at 125 ° C based on JIS K6300. Oil resistance test: Laminated composite in IRM903 (Test lubricant specified in JIS K6258)
Measure swelling after immersion for 70 hours at 120 ° C
Furthermore, a strip-shaped test piece having a width of 25 mm was prepared from the laminated composite,
Perform a peel test of the submerged laminate composite at a peel rate of 50 mm / min with N = 5 peel
Measure force average
In addition, the laminated composite after the peel test under the same conditions was peeled off at room temperature.
The condition with rubber is visually observed.
Evaluate with or without rubber and X with or without rubber Peeling test: A strip-shaped test piece with a width of 25 mm was prepared from the laminated composite and peeled at room temperature.
Perform film peel test at 50mm / min and measure average peel force of N = 5
Also, for the laminated composite after the peel test under the same conditions, visually check the state with rubber.
Observe with ○, with rubber, △ with some rubber, without rubber
X and rating

Example 2
In Example 1, the halogenated butyl rubber amount was changed to 30 parts by weight, and the NBR amount was changed to 70 parts by weight.

Comparative Example 1
In Example 1, instead of talc, the same amount of silica (Rhodia Silica Correa product ZEOSIL 165GR; wet process silica) was used.

Comparative Example 2
In Example 1, the halogenated butyl rubber amount was changed to 50 parts by weight, and the NBR amount was changed to 50 parts by weight.

Comparative Example 3
In Example 1, halogenated butyl rubber was not used and 100 parts by weight of NBR was used.

Comparative Example 4
In Example 1, NBR was not used, and 100 parts by weight of halogenated butyl rubber was used.

The results obtained in the above examples and comparative examples are shown in the following Table 1 (nylon 6-based compound film) and Table 2 (nylon 11-based compound film).

Claims (7)

  Polyamide resin in which 10 to 100 parts by weight of talc and 0.1 to 30 parts by weight of resin cross-linking agent are added to 100 parts by weight of blend rubber comprising 60 to 90% by weight of acrylonitrile-butadiene rubber and 40 to 10% by weight of halogenated butyl rubber A rubber composition that can be vulcanized and bonded.   The rubber composition according to claim 1, wherein the resin crosslinking agent is at least one of an alkylphenol / formaldehyde resin, a melamine / formaldehyde condensate, and a triazine / formaldehyde condensate.   A composite obtained by vulcanizing and bonding a rubber composition capable of being vulcanized and bonded to the polyamide resin according to claim 1 or 2 to the polyamide resin.   4. The composite according to claim 3, wherein a fiber reinforcing layer is interposed between the rubber layer and the polyamide resin layer which are vulcanized and bonded.   A composite in which a rubber layer vulcanized and bonded to a polyamide resin layer is used as an intermediate rubber layer, and a fiber reinforcing layer and an outer rubber layer are sequentially laminated thereon.   6. The composite according to claim 4, wherein the polyamide resin is at least one of nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, and nylon 46.   A composite rubber hose comprising the composite according to claim 4, 5 or 6.