阅读说明：本技术 制品，特别是空气弹簧波纹管、金属-橡胶元件或减振器 (Article, in particular air spring bellows, metal-rubber element or damper ) 是由 托尔斯滕·立陶斯 迪特尔·博尔维茨 克劳斯·朔贝特 芭芭拉·帕松-韦塞洛 延斯·施托尔 于 2018-12-17 设计创作，主要内容包括：本发明涉及一种带有具有弹性特性的单层或多层主体的制品,特别是空气弹簧波纹管、金属-橡胶元件或减振器。为了提高阻燃特性,该制品的主体由至少一个由橡胶混合物构成的层D组成或包含该至少一个由橡胶混合物构成的层D,该橡胶混合物不含含有卤素的阻燃剂并且包含至少一种炭黑,该炭黑具有根据DIN-ISO 9277的在35与140m<Sup>2</Sup>/g之间的BET表面积和根据ISO 4656的在70与140ml/100g之间的吸油值(OAN)。(The invention relates to an article with a single-layer or multi-layer body having elastic properties, in particular an air spring bellows, a metal-rubber element or a damper. In order to improve the flame-retardant properties, the body of the article consists of or comprises at least one layer D of a rubber mixture which is free of halogen-containing flame retardants and comprises at least one carbon black havingAt 35 and 140m according to DIN-ISO 9277 2 BET surface area between/g and Oil Absorption Number (OAN) according to ISO 4656 between 70 and 140ml/100 g.)

1. Article with a single-or multi-layer body having elastic properties, characterized in that at least layer D of the body consists of a rubber mixture which is free of halogen-containing flame retardants and comprises at least one carbon black having a molecular weight between 35 and 140m according to DIN-ISO 9277²BET surface area between/g and Oil Absorption Number (OAN) according to ISO 4656 between 70 and 140ml/100 g.

2. The article of claim 1, wherein the amount of carbon black is from 5phr to 30 phr.

3. Article according to either of claims 1 and 2, characterized in that the rubber mixture of layer D additionally comprises zinc hydroxystannate or zinc stannate or a combination of zinc hydroxystannate and zinc stannate.

4. The article of any one of claims 1 to 3, wherein the layer D comprises 100phr of CR or a blend of CR and NR (CR/NR) as a rubber component.

5. The article of any one of claims 1 to 4, wherein the article is an air spring bellows, a metal-rubber element, a damper, a bearing, a bushing or a damping element of a multi-layer spring or a conical spring, a tubular object or a transmission belt.

Technical Field

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

Background

Articles with elastic properties for use in, for example, suspension and/or damping of motor vehicles or rail vehicles are made using elastomer mixtures (also referred to as rubber mixtures). These elastomer mixtures, which are typically used for the basic properties of such articles, are well known. Articles having outstanding elastic properties, such as metal-rubber elements or vibration dampers, preferably comprise vulcanized rubber mixtures based mainly on Natural Rubber (NR) and/or polyisoprene rubber (IR). Articles having very good resistance to weathering, mineral oils and heat, such as air spring bellows, preferably comprise vulcanized rubber mixtures based predominantly on neoprene (CR).

However, articles comprising these elastomeric mixtures exhibit significant disadvantages in terms of burning behaviour. The production of dense smoke is one of the results of combustion. The heat release rate is particularly high during the combustion of the above-mentioned elastomer mixtures, which are mainly based on NR and/or IR. The fumes produced during the combustion of elastomer mixtures, mainly based on CR, are toxic to humans and animals.

Due to the recent rise in fire safety requirements, which is reflected above all in the stricter fire safety standard EN45545, there is a growing demand for polymer articles which optimize the fire safety. The above-mentioned elastomer mixtures based mainly on NR and/or IR (above all because of the maximum heat release rate required) and also flame-retardant elastomer mixtures based mainly on CR (in particular because of the smoke toxicity required) no longer meet these fire safety requirements. Therefore, articles comprising these elastomer mixtures often no longer meet stringent requirements.

The customary way of improving the burning behavior of rubber mixtures is to sometimes incorporate directly relatively large amounts of flame-retardant substances. However, in the mixtures concerned, this measure often leads to impairment of the physical properties, in particular, for example, hardness, which is associated with use in dynamic applications. This is reflected in particular in a significant impairment of the damping, settling or vibration properties of the articles involved.

Disclosure of Invention

It is therefore an object of the present invention to provide an article having optimized fire safety behavior to meet the more stringent requirements described in particular in EN-45545. In particular, at least the hazard level 2 described in the standard should be reached. At the same time, the necessary physical properties of the article, such as in particular the hardness, should be kept at a comparable level.

This object is achieved by an article with a single-layer or multi-layer body having elastic properties, wherein at least layer D of the body consists of a rubber mixture which is free of halogen-containing flame retardants and comprises at least one carbon black having a molecular weight of 35 and 140m according to DIN-ISO 9277²BET surface area between/g and Oil Absorption Number (OAN) according to ISO 4656 between 70 and 140ml/100 g.

It has now surprisingly been found that the use of such finely divided carbon blacks has a positive effect on the combustion behavior. This enables a significant reduction in the amount of additional flame retardant. The lower amount of additional flame retardant required improves the dynamic adaptation of the rubber mixture, thereby extending the useful life of the article. Especially when blends of neoprene and natural rubber are used, the amount of additional flame retardant can be reduced without sacrificing the dynamic properties of the rubber mixture.

According to the invention, at least one carbon black is used, having a carbon number according to DIN-ISO 9277 between 35 and 140m²BET surface area between/g and Oil Absorption Number (OAN) according to ISO 4656 between 70 and 140ml/100 g. This means that preference is given to using carbon blacks which are designated N-1xy, N-2xy, N-3xy, N-4xy or N-5xy, where x and y may, independently of one another, be integers between 0 and 9. Carbon blacks are assigned according to the classification chart of ASTM D1765-06.

Particularly good properties are obtained with the carbon blacks N550 and N339.

The carbon blacks having the designations N-1xy, N-2xy, N-3xy, N-4xy or N-5xy may be used alone or in combination.

In a particularly preferred embodiment, N339 and N550 carbon blacks are each used alone or in combination. These two types are particularly suitable in terms of fire safety behavior (in this case especially N339), abrasion resistance (in this case especially N550) and dynamic behavior.

The total amount of carbon black used is preferably from 5phr to 30 phr. Amounts of 5phr to 30phr relate to the total amount of carbon black having the characteristics according to claim 1, if more than one carbon black having the characteristics according to claim 1 is used.

Detailed Description

In a preferred embodiment, the rubber mixture of layer D further comprises at least one additional flame retardant.

Here, particular consideration is given to: stannates (e.g., zinc stannate or hydroxide stannate), additional hydroxides (e.g., magnesium or calcium hydroxide), cyanurates (e.g., melamine cyanurate), borates (e.g., zinc or calcium borate), phosphorus-containing components (e.g., resorcinol diphosphate, melamine phosphate, or aromatic polyphosphates), nitrogen-containing components (e.g., ammonium phosphate), intumescent mixtures, carbonates (e.g., calcium or magnesium carbonate), or expanded graphite.

The expanding mixture expands to produce a foam. The intumescent mixture is used to protect combustible materials, such as plastic or wood, and also steel, which suffers from a loss of stiffness at elevated temperatures, from heat and fire.

Although antimony trioxide has health-hazardous properties, optionally small amounts of antimony trioxide in combination with at least one of the flame retardants can also be used.

However, it has proven to be particularly advantageous when the rubber mixture of layer D also comprises at least zinc hydroxystannate or zinc stannate, alone or in combination. The zinc hydroxystannate or zinc stannate is preferably used in a total amount of 0.5 to 5phr and exhibits particularly good advantages in terms of smoke density.

In an advantageous embodiment, the rubber mixture of layer D also comprises at least one acid scavenger, which further reduces the toxicity of the resulting fumes. The acid scavenger is preferably at least one oxide, of which calcium oxide and magnesium oxide are particularly suitable for use alone or in combination.

The rubber mixture of layer D comprises at least one rubber component, preferably selected from the group consisting of: ethylene-propylene copolymer (EPM) and/or ethylene-propylene-diene copolymer (EPDM) and/or nitrile rubber (NBR) and/or carboxylated nitrile rubber (XNBR) and/or (partially) hydrogenated nitrile rubber (HNBR) and/or fluoro rubber (FKM) and/or neoprene (CR) and/or Natural Rubber (NR) and/or Epoxidized Natural Rubber (ENR) and/or Isoprene Rubber (IR) and/or styrene-butadiene rubber (SBR) and/or carboxylated styrene-butadiene rubber (XSBR) and/or butyl rubber (IIR) and/or bromobutyl rubber (BIIR) and/or chlorobutyl rubber (CIIR) and/or Butadiene Rubber (BR) and/or chlorinated polyethylene (CM) and/or chlorosulfonated polyethylene (CSM) and/or alkylated chlorosulfonated polyethylene (ACSM) and/or polyepoxy Chloropropane rubber (CO; ECO; ETER) and/or ethylene-vinyl acetate rubber (EVA) and/or acrylate rubber (ACM) and/or ethylene-acrylate rubber (AEM) and/or silicone rubber (MQ, VMQ, PVMQ, FVMQ) and/or fluorinated methyl silicone rubber (MFQ) and/or perfluorinated propylene rubber (FFPM) and/or perfluorinated carbon rubber (FFKM) and/or Polyurethane (PU).

The rubbers mentioned may be used individually or in blends.

The rubber component of the rubber mixture of layer D preferably consists of a rubber or a rubber blend of at least two rubbers each providing a mixture with substantially low flammability and/or with good physical properties for use in dynamic high stress articles. These include in particular NR, ENR, IR, CR, CM, CSM, ACSM, BR, NBR, XNBR, HNBR. In a particularly preferred embodiment, the rubber component of the rubber mixture of layer D consists of 100phr of CR or of a rubber blend of CR and NR.

The body may consist of only layer D or may contain at least one further layer.

If additional layers are present, layer D is preferably the outermost, outwardly facing layer of the article.

However, layer D may also be embedded between further layers.

If the layer D is the outermost layer or if the layer D is embedded between further layers, the layer D may not completely surround the body but only partially exist, in the case of the preferred embodiment, especially in places which are particularly exposed to the risk of fire.

Thus, for example, a further layer a may be present which forms a so-called "inner cover" and is composed of an elastomer mixture and has particularly good elasticity. The elastomer mixture is a vulcanizable, preferably thermoplastic-free, rubber mixture comprising at least one rubber component and further compounding ingredients. The rubber components considered include, in particular: ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), carboxylated nitrile rubber (XNBR), (partially) hydrogenated nitrile rubber (HNBR), Fluororubber (FKM), Chloroprene Rubber (CR), Natural Rubber (NR), Epoxidized Natural Rubber (ENR), Isoprene Rubber (IR), styrene-butadiene rubber (SBR), carboxylated styrene-butadiene rubber (XSBR), butyl rubber (IIR), bromobutyl rubber (BIIR), chlorobutyl rubber (CIIR), brominated copolymer of isobutylene and p-methylstyrene (BIMS), Butadiene Rubber (BR), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), alkylated chlorosulfonated polyethylene (ACSM), polyepichlorohydrin rubber (CO; ECO; ETER), ethylene-vinyl acetate rubber (EVA), acrylate rubber (ACM), ethylene-acrylate rubber (AEM), silicone rubber (MQ, VMQ, PVMQ, FVMQ), fluorinated methyl silicone rubber (MFQ), perfluorinated propylene rubber (FFPM), perfluorinated carbon rubber (FFKM), Polyurethane (PU).

The above rubber types may be unblended. It is also possible to use blends.

The preferred rubber type depends on the type of article and the requirements for the individual article. The usual mixture constituents comprise at least one crosslinker or one crosslinker system (crosslinker and accelerator). The additional mixture constituents are usually at least one filler and/or at least one processing aid and/or at least one plasticizer, for example a phosphate ester plasticizer, and/or at least one aging stabilizer and optionally further additives, for example pigments, reinforcing fibers and the like.

Reference is made herein to the general technology of rubber mixing technology.

The composition of the rubber mixture of layer a may be qualitatively and/or quantitatively the same or different from the rubber mixture of layer D.

If the rubber mixture of layer a is qualitatively and quantitatively identical to the rubber mixture layer of layer D, i.e. is likewise flame-retardant, the fire-promoting gases and substances formed in the event of a fire can only pass out to the outside with delay, if at all, and thus enhance the article fire, if at all, only to a reduced extent. Furthermore, any strength member layer present which may melt rapidly (see layer B) is therefore better protected or does not pass out to the outside.

In particular embodiments, there may also be at least one layer B formed of at least one strength member. This layer is preferably a cord fabric consisting of one or more, preferably two, layers, which has good adhesion to layer a. In a very particularly preferred embodiment, this is a biststretch fabric as described, for example, in WO 2016045813 a 1.

The materials used for layer B may be any known synthetic and natural materials, alone or in combination (i.e., in the form of a hybrid fabric).

Synthetic materials contemplated include, inter alia, synthetic polymers such as acrylonitrile, polyacrylonitrile, polypropylene, polyesters, polyamides, polyurethanes, polyphenylene sulfide, polyoxadiazole, aromatic polyamides (such as meta-aramid, para-aramid, or co-para-aramid), polyimides, polyetherimides, polyetheretherketones, polyethylene 2, 6-naphthalate, polyphenylene oxide, polyphenylene sulfide, polyphenylene oxide, polybenzoxazole, polyvinyl alcohol.

The natural material may be rock wool or asbestos, cotton, flax or hemp, or wool or silk.

Inorganic materials such as glass, ceramics, carbon, metals (e.g., steel) or rocks (e.g., basalt) are likewise contemplated.

Preference is given to using polyamides (especially PA 6,6) or polyesters, alone or in combination.

To achieve sufficient processing tack during the production process of the article, one or both sides of the cord fabric may be rubberized or rubbed. The rubberizing can preferably be achieved using a composition quantitatively and/or qualitatively identical to that of layer C or to that of layer a. This simplifies the production process of the article and facilitates a dynamically suitable adhesive bond.

In another preferred embodiment, the article may further comprise at least one additional layer C.

This layer C then forms the so-called "outer cover" of the article. The layer C may be one layer or two layers. The elastomer mixture of the layer C is a vulcanizable, preferably thermoplastic-free, rubber mixture comprising at least one rubber component and further mixture constituents. The rubber components considered include, in particular: ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), carboxylated nitrile rubber (XNBR), (partially) hydrogenated nitrile rubber (HNBR), Fluororubber (FKM), Chloroprene Rubber (CR), Natural Rubber (NR), Epoxidized Natural Rubber (ENR), Isoprene Rubber (IR), styrene-butadiene rubber (SBR), carboxylated styrene-butadiene rubber (XSBR), butyl rubber (IIR), bromobutyl rubber (BIIR), chlorobutyl rubber (CIIR), brominated copolymer of isobutylene and p-methylstyrene (BIMS), Butadiene Rubber (BR), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), alkylated chlorosulfonated polyethylene (ACSM), polyepichlorohydrin rubber (CO; ECO; ETER), ethylene-vinyl acetate rubber (EVA), acrylate rubber (ACM), ethylene-acrylate rubber (AEM), silicone rubber (MQ, VMQ, PVMQ, FVMQ), fluorinated methyl silicone rubber (MFQ), perfluorinated propylene rubber (FFPM), perfluorinated carbon rubber (FFKM), Polyurethane (PU).

The above rubber types may be unblended. It is also possible to use blends.

The preferred type of rubber depends on the nature of the article. The usual mixture constituents comprise at least one crosslinker or one crosslinker system (crosslinker and accelerator). The additional compounding ingredients usually also comprise fillers and/or processing aids and/or plasticizers and/or aging stabilizers and also optionally further additives (e.g. pigments, adhesion promoters, flame retardants, reinforcing fibers).

Reference is made herein to the general technology of rubber mixing technology.

The article may also comprise at least one further layer E based on at least one thermoplastic. The thermoplastics used include, for example: polyolefins, in particular Polyethylene (PE) (e.g. LD-PE, LLD-PE, UHMW-PE) or polypropylene (PP), Polystyrene (PS); polyamides (PA), such as PA 6 or PA 6, 6); polyesters, for example PET, PEN or PBT. In a preferred embodiment, this layer E is in the form of a film. It has been found that the use of PE films is particularly suitable, since in the case of peroxidically crosslinking elastomer mixtures it forms a particularly good adhesive bond, so that in some cases further adhesion promoters can be dispensed with. Depending on the nature of the article and the nature of the further layers, layer E has a particularly good adhesion-enhancing effect. It can be applied to the article blank by means of radiant heaters and pressure.

The article is preferably an air spring bellows, a metal-rubber element, a damper, a bearing, a bushing or a damping element of a multi-layer spring or a conical spring. Alternatively, the article may be a tubular object. Tubular objects are, for example, any type of feed hose, air spring bellows (cross-ply bellows, axial bellows), and compensators (e.g., torque compensators, lateral compensators) in various embodiments. The article may also be a power transmission belt.

The article is preferably an air spring bellows, a metal-rubber element, a damper or a bearing, for example a box bearing or a tapered bearing, more particularly a moulding for a rubber spring railway vehicle wheel.