DE102015217871A1 - Articles, in particular an air spring bellows, a metal-rubber element or a vibration damper - Google Patents

Abstract

The invention relates to an article having a base body with elastic properties, in particular an air spring bellows, a metal-rubber element or a vibration damper. The article is characterized by the following layer structure: a multi-layered elastic base body which contains at least one strength support layer B, a layer A based on at least one elastomer mixture and a layer C based on at least one elastomer mixture, and Knitted fabric, and - an outermost layer F which is based on at least one saturated backbone or at least 90% saturated backbone rubber.

Description

The invention relates to an article having a base body with elastic properties, in particular an air spring bellows, a metal-rubber element or a vibration damper.

Articles having elastic properties used for suspension of, for example, passenger cars and utility vehicles and / or for vibration damping are manufactured using elastomeric blends, also referred to as rubber blends. These mentioned articles belong to the group of rubber composite articles, since they are usually constructed of rubber compounds and reinforcements layers. These composite articles are subjected to particularly heavy dynamic loads in practical use. Due to their functionality, the rubber-textile composite is dynamically stressed. For this reason, particularly high demands are placed on the adhesion of the reinforcement layers to the rubber mixture. Even when specially prepared reinforcements are used, these high requirements can currently only be met if the rubber mixtures used for these articles are predominantly based on the classic unsaturated rubbers, such as natural rubber (NR), polyisoprene rubber (IR), styrene-butadiene rubber (SBR). , Polybutadiene rubber (BR) or chloroprene rubber (CR) are based, possibly with additionally contained direct adhesion systems. At required average use temperatures of -50 ° C to + 60 ° C, the articles preferably contain vulcanized rubber compounds predominantly based on NR, IR, SBR, BR or blends thereof. At required average service temperatures between -40 ° C to + 80 ° C, the articles preferably contain vulcanized rubber compounds that are predominantly CR based. Thus, article versions with differently optimized material properties are currently available. Both articles with advantages in low temperature properties and articles with advantages in weather, mineral oil and heat resistance are available. However, regardless of the above, the above articles show significant life-cycle weaknesses when exposed to extreme radiant heat. Extreme radiation heat is present when these articles are available in the overall system only a very small space and / or these items are placed in the vicinity of exhaust pipes or catalysts. Due to this occurring in practice meanwhile common circumstances costly replacement measures, such as the installation of heat shields must be implemented to comply with the required article life on the overall system. In the future too, the customer will be required to make permanent and cost-neutral improvements to the overall system. Among other things, various measures u.a. Sustainably demanded with the goal of weight reduction. This can i.a. by eliminating the replacement measures, i. especially by waiving the necessary heat shields done. However, the articles would then continue to be exposed to extreme radiant heat unprotected and thus have only a short lifespan.

The object of the invention is now to provide an article which is characterized by an optimized life under extreme radiant heat. At the same time, it is not necessary to fundamentally change the dynamic, particularly heavily loaded rubber-textile composite. Furthermore, the necessary physical properties of the article, in particular the weather resistance, should remain or be improved to a comparable level and the complexity in the production process should not be appreciably increased.

• – einen mehrschichtigen elastischen Grundkörper, welcher wenigstens eine Festigkeitsträgerschicht B, eine Schicht A auf der Basis wenigstens einer Elastomermischung und eine Schicht C auf der Basis wenigstens einer Elastomermischung enthält, und
• – eine Schicht D aus einem Gewebe oder Gewirke oder Gestrick, und
• – eine nach außen weisende Schicht F, welche auf Basis wenigstens eines Kautschuks mit gesättigter Hauptkette oder mindestens 90 % gesättigter Hauptkette ist.

This problem is solved by the fact that the article has at least the following layer structure:

• A multi-layered elastic base body which contains at least one strength support layer B, a layer A based on at least one elastomer mixture and a layer C based on at least one elastomer mixture, and
• A layer D of a woven or knitted or knitted fabric, and
• An outwardly facing layer F which is based on at least one saturated main chain rubber or at least 90% saturated main chain.

The following constructions of the article are possible according to the invention:

Version 1:

In a first preferred embodiment, the base body is formed in a multi-layered manner. The first layer A is the so-called "inner cap", which is composed of an elastomer mixture. This is followed by a second layer B, which is formed from at least one strength carrier. Subsequently follows the outer layer C, which is referred to as "outer cap" and which is formed from an elastomer mixture. This is followed by the layer D of a woven or knitted fabric, on which in turn the outwardly facing layer F, which is based on at least one rubber with a saturated or almost completely saturated main chain, is located. The result is the following layer structure: A, B, C, D, F. The individual layers are explained in more detail below.

Variant 2:

In a second particularly preferred embodiment, the base body is formed in a multi-layered manner. The first layer A is the so-called "inner cap", which is composed of an elastomer mixture. This is followed by a second layer B, which is formed from at least one strength carrier. Subsequently follows the outer layer C, which is referred to as "outer cap" and which is formed from an elastomer mixture. This is followed by the layer D of a woven or knitted fabric, on which in turn the outwardly facing layer F, which is based on at least one elastomer having a saturated or almost completely saturated main chain, is located. Between layer D and layer F, in this variant there is additionally a layer E based on at least one thermoplastic, preferably in the form of a film. The result is the following layer structure: A, B, C, D, E, F. The individual layers are explained in more detail below.

The layers A, B and C thus form the basic body of the article in both variants.

Layer A

The first layer A is the so-called "inner cap", which is composed of an elastomer mixture and has particularly good elastic properties. The elastomer mixture is a vulcanizable, preferably thermoplastic-free, rubber mixture containing at least one rubber component as well as further mixing ingredients. The preferred rubber components for the layer A are preferably rubbers having an unsaturated main chain, ie rubbers having olefinic double bonds. These rubbers are also referred to as diene rubbers. According to Römpp, Chemistry Dictionary Online Version 4.0 Diene rubbers "are [...] all rubbers which are formed by polymerization or copolymerization of dienes and cycloalkenes. All diene rubbers thus have C = C double bonds either in the main chain or in the side groups. "The following rubbers are preferably used for layer A: chloroprene rubber (CR), natural rubber (NR), styrene-butadiene rubber ( SBR), isoprene rubber (IR), butadiene rubber (BR). The aforementioned types of rubber may be unblended. The use of a waste is possible. The usual compounding ingredients include at least one crosslinker, preferably sulfur or sulfur donors or peroxides, or a crosslinker system (sulfur-containing crosslinking agent and accelerator). Additional mixture ingredients are usually still a filler and / or a processing aid and / or a plasticizer and / or an aging inhibitor and optionally further additives (eg color pigments, reinforcing fibers). In this regard, reference is made to the general state of rubber mixing technology.

Layer B

The second layer B is formed from at least one strength carrier. This is preferably a cord fabric of one or more layers which have good adhesion to the layer A. Layer B forms the so-called scaffold As materials for layer B, all known synthetic and natural materials may be used alone or in combination, i. as a hybrid fabric. Synthetic materials are in particular synthetic polymers, such as polyacrylonitrile, polypropylene, polyester, polyamide, polyurethane, polyphenylene sulfide, polyoxadiazole, aramids, such as p-aramid, m-aramid or co-poly para aramid, polyimide, polyetherimide, polyetheretherketone, polyethylene 2,6-naphthalate, polyphenylene, polyphenylene oxide, polyphenylene sulfide, polyphenylene ethers, polybenzoxazoles, polyvinyl alcohol in question. The natural materials may be rock wool or asbestos, or cotton, flax or hemp, or wool or silk. Inorganic materials such as glass, ceramics, carbon (carbon), metal or rock, such as basalt, are also conceivable. Preferably it is polyamide, in particular PA6.6, or polyester alone or in combination. To obtain a sufficient Konfektionsklebrigkeit during the manufacturing process of the article, the cord fabric may be rubberized or frictional on one side or on both sides. For gumming, it may be preferable to use preferably either a composition which is quantitatively and / or qualitatively equal to the composition for the layer C or quantitatively and / or qualitatively equal to the composition for the layer A. This leads to a further reduction of the complexity in the manufacturing process and creates a dynamically suitable bond of adhesion.

Layer C

The layer C forms the so-called "outer cap" of the article.

The elastomeric mixture of the layer C is a vulcanizable, preferably thermoplastic-free, rubber mixture containing at least one rubber component as well as further mixing ingredients. The preferred rubber components for the layer A are preferably rubbers having an unsaturated main chain, ie rubbers having olefinic double bonds. These rubbers are also referred to as diene rubbers. According to Römpp, Chemistry Dictionary Online Version 4.0 Diene rubbers "are [...] all rubbers obtained by polymerization or copolymerization of dienes and [...] Cycloalkenes arise. All diene rubbers thus have C = C double bonds either in the main chain or in the side groups. "The following rubbers are preferably used for layer A: chloroprene rubber (CR), natural rubber (NR), styrene-butadiene rubber ( SBR), isoprene rubber (IR), butadiene rubber (BR). The aforementioned types of rubber may be unblended. The use of a waste is possible. To further improve the life under extreme radiant heat, the rubber composition for layer C may contain metal particles, for example aluminum in the form of aluminum flakes. Likewise, a coating based on at least one fluorine-containing elastomer, for. For example, FKM and / or PTFE, conceivable for the optimization of dynamic efficiency.

The usual compounding ingredients include at least one crosslinker, preferably sulfur or sulfur donors or peroxides, or a crosslinker system (sulfur-containing crosslinking agent and accelerator). Additional compounding ingredients are usually still a filler and / or a processing aid and / or a plasticizer and / or an aging inhibitor and optionally further additives (for example color pigments, reinforcing fibers). In this regard, reference is made to the general state of rubber mixing technology.

Layer D

The layer D consists of a woven or knitted or knitted fabric.

This is preferably a woven or knitted fabric in which the two sides can each be equipped with at least one adhesion promoter depending on the embodiment and application. The adhesion promoter may be resorcinol formaldehyde latex, a solution based on dinitrosobenzene, silane or a coupling agent based on at least one rubber. Both sides can be equipped with the same bonding agent or with different ones. In a particularly preferred embodiment, the fabric is a bi-stretch fabric which can be stretched horizontally and vertically, i. has a high elastic content in the warp and weft directions. The bi-stretch fabric has an extensibility of greater than 50%, preferably greater than 250%, in the warp direction and in the weft direction. In order to achieve the extensibility in the different directions, preferably in the warp direction and in the weft direction in each case a sufficient amount, preferably 5 to 50 wt .-% of elastane present. The stretching in both directions but can also by appropriate textile manufacturing technologies such. Ex. To apply as little tension as possible when winding the freshly woven textile web obtained.

By using a bi-stretch fabric with the advantageous property of all-direction compliance, it is avoided that in the vulcanization process, elastomer blend during the embossing phase, i. Forming phase, so to speak pushed away. As materials for the fabric, preferably the bi-stretch fabric, or knitted or knitted fabric, all natural and synthetic materials known to those skilled in the art may be used. Synthetic materials are in particular synthetic polymers, such as polyacrylonitrile, polypropylene, polyester, polyamide, polyurethane, polyphenylene sulfide, polyoxadiazole, aramids, such as p-aramid, m-aramid or co-poly para aramid, polyimide, polyetherimide, polyetheretherketone, polyethylene 2,6-naphthalate, polyphenylene, polyphenylene oxide, polyphenylene sulfide, polyphenylene ethers, polybenzoxazoles, polyvinyl alcohol in question. The natural materials may be rock wool or asbestos, or cotton, flax or hemp, or wool or silk. Inorganic materials such as glass, ceramics, carbon (carbon), metal or rock, such as basalt, are also conceivable. It is advantageous if a hybrid material of cotton, polyamide or polyester and elastane, with a cotton-dominating side and a polyamide or polyester-dominating side is used for the fabric, in particular the bi-stretch fabric, and / or the knitted fabric , In such a combination can be made of this fabric, knitted or knitted fabric prior to the manufacture of the article, a shell according to the required article diameter, the seams of this shell can be welded.

Layer E

The further layer E is based on at least one thermoplastic and is located between the layers D and F. As thermoplastics, for example, polyolefin, in particular polyethylene (PE), such as LD-PE, LLD-PE, UHMW-PE, or polypropylene ( PP), polystyrene (PS), polyamide (PA), for example PA6 or PA6.6, polyesters, for example PET, PEN or PBT. The layer E is formed in a preferred embodiment as a film. The use of a PE film has proven to be particularly suitable since it forms a particularly good adhesion bond and thus, if necessary, further adhesion promoters can be dispensed with. Depending on the nature of the article and the nature of the other layers, the layer E is particularly good adhesion. It can be applied to the article blank with the help of a heat radiator and pressure.

Layer F

The layer F faces outward and thus forms the outermost layer of the article. The layer F is based on at least one saturated main chain rubber or at least 90% saturated main chain. Particular examples of rubber components are: ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), (partially) hydrogenated nitrile rubber (HNBR), chlorosulfonated polyethylene (CSM), polychloroprene (CR ), in particular mercaptan-modified CR (CR-MD), xanthate-modified CR (CR-XT) or sulfur-modified CR (CR-S), alkylated chlorosulfonated polyethylene (ACSM), polyepichlorohydrin (ECO), terpolymers of ECO with ethylene oxide and unsaturated monomers (ETER ), Ethylene-vinyl acetate rubber (EVA) or silicone rubber (MQ, VMQ, PVMQ, FVMQ). The aforementioned types of rubber may be unblended. The use of a waste is possible. The rubber is part of a vulcanizable rubber composition containing at least one rubber component as well as other compounding ingredients. In addition, in the rubber mixture for the layer F, at least one thermoplastic, for. Ex. Polyethylene (PE), be included. The usual compounding ingredients include at least one crosslinker or crosslinker system (crosslinker and accelerator). The abovementioned rubbers of layer F are usually crosslinked peroxidically, but depending on the type of rubber, they can also be crosslinked by sulfur. Additional mixture ingredients are usually still a filler and / or a processing aid and / or a plasticizer and / or an aging inhibitor and optionally further additives, for example color pigments, reinforcing fibers. In particular, by the addition of fibers, the poor heat conduction of the rubber mixture of the layer F can be further reduced. Furthermore, it is preferred if the rubber mixture of the layer F additionally contains at least one blowing agent which gives the rubber mixture a pore structure after vulcanization. This leads to a further reduction of the thermal conductivity. Blowing agents. As blowing agents are usually pore-forming propellant gases such. As azo and diazo compounds, referred to, which split off gases (eg N ₂ or CO ₂ ) under the influence of heat or catalysts and therefore serve for the production of rubber mixtures with pore structure. The blowing agents decompose at a certain temperature during processing to form gas or with the addition of volatile solvents during vulcanization.

To further improve the life under extreme radiant heat, the layer F in the rubber mixture itself and / or on the surface metal particles, for example, aluminum in the form of aluminum flakes contain. Likewise, a coating based on at least one fluorine-containing elastomer, for. For example, FKM and / or PTFE, conceivable for optimizing the abrasion behavior.

The layer F may partially or completely cover the article. "Partially cover" means that only defined areas of the surface of the article are provided with the layer F.

The indicated layers are combined according to one of the abovementioned variants 1 or 2 before or during the blank production, ie before the actual vulcanization process. In the first phase of vulcanization, the so-called flow or Ausformphase, thus, the various layers can flow well together, which has a positive effect on the adhesion of the layers with each other. An additional and costly second vulcanization process is not required.

The article is preferably an air spring bellows, a metal-rubber element, a vibration damper or a damping element of a bearing, a bush or a laminated spring or cone spring. The article can also be a tubular body. Tubular bodies are, for example, conveying hoses of all types, air bellows (cross-layer bellows, axial bellows) and compensators in various designs (for example torsion compensator, lateral compensator). Likewise, the article may be a drive belt.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• Römpp, Chemistry Dictionary Online Version 4.0 [0009]
• Römpp, Chemistry Dictionary Online Version 4.0 [0012]

Claims (8)

 Article with a multilayer main body with elastic properties, characterized by the following layer structure: A multi-layered elastic base body which contains at least one strength support layer B, a layer A based on at least one elastomer mixture and a layer C based on at least one elastomer mixture, and A layer D of a woven or knitted or knitted fabric, and An outwardly facing layer F which is based on at least one saturated main chain rubber or at least 90% saturated main chain. Article according to claim 1, characterized in that the layer D consists of a bi-stretch fabric. Article according to one of claims 1 or 2, characterized in that the article still contains a further layer E. Article according to claim 3, characterized in that the further layer E is between the layer D and layer F. Article according to claim 3 or 4, characterized in that the further layer E is a film of polyethylene. Article according to one of claims 1 to 5, characterized in that the rubber for the elastomeric mixture of the layer A and / or the rubber for the elastomeric mixture of the layer C is selected from the group consisting of chloroprene rubber (CR), natural rubber (NR) , Styrene-butadiene rubber (SBR), isoprene rubber (IR) or butadiene rubber (BR). Article according to one of claims 1 to 6, characterized in that rubber for the layer F is selected from the group consisting of ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), (partially) hydrogenated nitrile rubber (HNBR), chloroprene rubber (CR), chlorosulfonated polyethylene (CSM), alkylated chlorosulfonated polyethylene (ACSM), polyepichlorohydrin (ECO), terpolymers of ECO with ethylene oxide and unsaturated monomers (ETER), ethylene-vinyl acetate Rubber (EVA), or silicone rubber (MQ, VMQ, PVMQ, FVMQ). Article according to one of claims 1 to 7, characterized in that it is an air spring bellows, a metal-rubber element, a vibration damper, a damping element of a bearing, a bush or a laminated spring or conical spring, a tubular body or a drive belt ,