Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/16—Ethene-propene or ethene-propene-diene copolymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
  • C08K5/0016—Plasticisers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L21/00—Compositions of unspecified rubbers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L53/00—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L53/00—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L53/02—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers of vinyl-aromatic monomers and conjugated dienes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L91/00—Compositions of oils, fats or waxes; Compositions of derivatives thereof

Definitions

• the present invention relates to polyalphaolefin plastisizers for elastomers, and elastomer compositions containing polyalphaolefins.
• Polyalphaolefins may be used as plastisizing agents in elastomers and blends containing elastomers to plastisize the hardness of the product and to provide more flexible products with a lower residual compression suitable for lower working temperatures.
• Plastisizers are commonly used in elastomers to lower the raw material costs of the products and to improve the processibility thereof. Addition of a plastisizer is used to improve the collapse resistance of an article made of rubber or thermoplastic elastomer exposed to oil in the environment. Plastisizers present in the product reduce the ability thereof to absorb additional hydrocarbons. Most common plastisizers are compounds based on mineral oil.
• Patent application Fl 971338 discloses coatings of structures and profiled articles containing a mixture of thermoplastic elastomer with a non-elastomeric polyolefm, in general with homopolymers or random copolymers of propylen.
• An oligomer of poly- ⁇ -olefine type is used as polyolefm plastisizer in a matrix plastic (EPR, EBR, EPBR, PBR, SBR, EPM, EPDM).
• the monomers used comprise at least 3 carbon atoms, preferably 6 to 12 carbon atoms.
• Patent publication EP 300 689 discusses mixtures containing oligomeric polyalphaolefin, and an olefin elastomer.
• the object of the present invention is to provide polyalphaolefin plastisizers for elastomers, and elastomer compositions containing polyalphaolefins.
• the characteristic features of the polyalphaolefin plastisizers for elastomers, and elastomer compositions containing polyalphaolefins of the invention are disclosed in the appended claims.
• polyalphaolefins may be used as plastisizing agents in elastomers.
• Suitable polyalphaolefins include polyalphaolefin oils, h this connection, polyalphaolefin oil means an oil, preferably a food grade hydrogenated oil consisting of the polymerization product of a polyalphaolefin or a mixture of polyalphaolefins, having a molecular weight between 400 and 1000 g/mol.
• Suitable alphaolefins include butene, pentene, hexene, heptene, octene, nonene, decene, undodecene and dodecene, preferably decene.
• a particularly preferable polyalphaolefin is food grade polydecene.
• the content of polyalphaolefin oil or oils in the composition of the invention varies between 5 and 60 %.
• Suitable elastomers include the following rubber mixtures (a), thermoplastic elastomers (b) and vulcanizates thereof (c), and silicones (d):
• EPR ethylene-propylene rubber
• EPDM ethylene-propylene-diene rubber
• ACM/EAM polyacrylate rubber
• SBR styrene-butadiene rubber
• 1,2-sPB 1,2-syndio tactic polybutadiene rubber.
• SBC styrene-butadiene blockcopolymers, unl ydrogenated version hydrogenated version
• Vulcanization is accomplished while mixing either with a sulfur compound, organic peroxide or with a phenolic resin depending on the type of the elastomer.
• Unplastisized plastics typically include polycar- bonates, polyolefins (PE and PP), polyamides and polyuretanes. Compounding these plastics with elastomers provides in certain cases mixtures that may be plastisized.
• the elastomers may be imvulcanized or partly or totally vulcanized.
• Particularly preferable elastomers are the following polymers and mixtures thereof:
• composition of the invention contains from 20 to 95 % by weight of elastomer or mixture of elastomers.
• the ratio of polyalphaolefin oil to the elastomer is 0.05 to 1.5.
• compositions may comprise thermoplastics, inorganic fillers, other plastisizers based on mineral oil, antioxidants, pigments, agents protecting against ultraviolet light, agents deactivating metals, flame retardants, conductive fillers, and vulcanizing chemicals.
• polyalphaolefins have several advantages in plastisizing applications. For instance:
• polyalphaolefin is a pure product, thus facilitating the approval by the authorities.
• a low working temperature is an important characteristic of polyalphaolefins. They crystallize at very low temperatures, thus making possible to lower the brittle temperature of rubber or a thermoplastic elastomer. This is advantageous particularly for styrene elastomers. In applications of the automobile industry, the required lowest working temperature is commonly below -40 °C.
• polyalphaolefins have the following advantages in comparison with a mineral oil based plastisizer:
• a typical feature of polyalphaolefins is the chemical purity thereof, that is the lack of aromatic, naphtalenic, paraffmic (with the exception of isoparaffinic) components commonly present in mineral oils.
• mineral oil typically contains sulfur and other heteroatoms absent from synthetic polyalphaolefins.
• Elastomers plastisized with polyalphaolefin oil are more heat stable since heteroatoms causing autocatalytic decomposition are absent.
• the use of relatively expensive antioxidants may be reduced to provide the required thermal ageing properties, h
• the original colour of elastomers plastisized with polyalphaolefins is purer than that of products plastisized with mineral oils, thus allowing for the production of lighter products by means of pigments without using paints to provide a pure white colour.
• pigments are a preferable alternative.
• colour fastness in pigmented elastomers is clearly better when a polyalphaolefin plastisizer is used instead of mineral oil.
• an advantage is the better preservation of transparency for instance of the tubing of healt care apparatuses being sterilized.
• Polyalphaolefins are particularly advantageous as plastisizers for elastomeric insulating materials of cables and conductors. Polar impurities present in mineral oil lower the loss factor causing increasing power losses in power transmission for medium and high voltage insulating materials. With respect to electrical properties, polyalphaolefin is comparable to commonly used insulating materials, polyethylene and EP(D)M rubber.
• Aromatic components present in mineral oil dissolve styrene blocks present in polystyrene containing elastomers, thus lowering the tensile strenght.
• Polyalphaolefin has no influence on polystyrene blocks since it is free of aromatic components.
• polyalphaolefins The molecular weight distribution of polyalphaolefins is very narrow compared to that of mineral oils that are originally distillates. This narrow molecular weight distribution brings about several advantages. Of these, the most important for elastomers is the low weight loss at increased temperatures. A polyalphaolefin oil and mineral oil having identical viscosities differ considerably from each other with respect to weight loss in favour of polyalphaolefin. Volatile oils cause following problems in practical applications of elastomers:
• polyalphaolefin oils include the lack of odour and the lower flash point at a constant viscosity, thus contributing to process safety.
• isoparaffins and paraffins have lower dissolving powers in elastomers, which directly influences the compatibility of the oils with elastomers.
• the absence of relatively heavy molecules from polyalphaolefin oils makes a polyalphaolefin oil more preferable than mineral oils, the final result with respect to compatibility being equally good.
• polyalphaolefins have a very low solidification point, about -60 °C, whereas the solidification point of paraffin oils is about -15 °C, that of naphtalene oil being about -30 °C.
• polyalphaolefin plastisizers are best preserved at extremely low temperatures. This is important for instance for buffering rubber strips of automobiles and protective rubbers of joints.
• Polyalphaolefins have a very high viscosity index compared to mineral oils. This is important in processing of elastomers. Particularly when elastomers are mixed at high temperatures, the viscosity of the mixture will not decrease as much as that of mixtures containing mineral oils, and thus higher shear forces are provided for mixing, thus improving the dispersion of components. This has a direct effect on almost all performance values of elastomers. Depending on the composition, the following factors are improved:
• compositions of the invention containing polyalphaolefins may be used as interior elastomers of automobiles such as seals in passages to the engine room, rubbers in the engine room such as tubes and seals, buffering rubber strips, protective rubbers of joints, in medical apparatuses and devices such as the tubings and seals of medical instruments, seals of food packages, isolating materials of cables, cable jackets, and further, in elastomeric articles that are generally white, and in applications being demanding with respect to transparency.
• Elastomers and plastics used in medical applications and having a very high compatibility with polyalphaolefins include:
• the combination PP/SEBS is generally used in those applications of styrene elastomers that are demanding with respect to working temperature and environmental pollution.
• Typical medical uses of elastomers are syringes and needles, intravenous urinary catheters, dosage tubings and devices, clinical cardiac valves and vessel implants, disposable packages and trays.
• the composition of the invention has several advantages.
• the glass transition temperature of the elastomer and plastic is lowered, thus making the products very suitable to applications requiring good low temperature resistance properties (cables, exterior parts of automobiles).
• the evaporated amounts of organic compounds are lowered, being advantageous for medical applications and for interior elastomers of automobiles.
• the products are colourless and transparent. The products resist sterilization and exposure to high temperatures for extended periods of time without losing their properties.
• Polyalphaolefin may be mixed with elastomers and plastics during the production thereof. In this manner, elastomer and plastic products particularly suitable for medical and medicinal apparatus applications are obtained. Medical applications have high special requirements on materials, such as resistance to sterilization. These require- ments are restricted in no way by the composition of the invention.
• Elastomer for medical, automobile industry, and cable applications PP/EPDM or PP/EPR blend
• composition of the example good processing characteristics and a Shore A hardness of 85 are attained. Thermal ageing properties of the mixture are also especially good.
• the example is directed to a basic SEBS blend.
• the combination PP/SEBS is gener- ally used in those applications of styrene elastomers that are demanding with respect to working temperature and environmental pollution.
• the ability to plastisize SEBS elastomers greatly depends on the styrene content thereof.
• An elastomer with a low styrene content accepts a plastisizer in an amount that is more than 1.5 times its own weight.
• polyalphaolefin plastisizers The effect of polyalphaolefin plastisizers on low temperature resistance was studied by means of the glass transition temperature T g .
• a common plastisizer i.e. paraffin oil was used.
• the samples to be studied were the formulations of Examples 1 and 2.
• Example 5 The use of a polyalphaolefin oil as the plastisizer is particularly preferable for the production of clear white elastomer products.
• the translucency of translucent elastomers suitable for instance for health care applications is better preseved by using a polyalphaolefin oil instead of mineral oil.
• Thermoplastic elastomers were sterilized in an autoclave for 15 minutes at 121 °C. Elastomers may be hardened by autoclaving as the plastisizing oils are evaporated. This was not the case for polyalphaolefin oils due to the low volatile matter thereof.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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Cited By (27)

Citations (8)

• 2000
  • 2000-12-29 FI FI20002884A patent/FI20002884A7/fi unknown
• 2001
  • 2001-10-12 WO PCT/FI2001/000888 patent/WO2002031044A1/en not_active Ceased
  • 2001-10-12 AU AU2002210589A patent/AU2002210589A1/en not_active Abandoned

Patent Citations (8)

Non-Patent Citations (2)

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