Isobutylene-based elastomer mixtures showing elevated strength and elasticity and reduced permeability
FIELD: polymer materials.
SUBSTANCE: invention, in particular, relates to isobutylene-based halogenated polymers showing elevated pre-treatment strength and elevated impermeability as well as to and a method for preparation thereof. Non-cured thin barrier layer for rubber products comprises 3-95% isobutylene-based polymer and 95-3% semicrystalline polymer having melting temperature from about 25 to about 105°C and melting heat from about 9 to about 50 J/g as measured by differential scanning calorimetry. This barrier layer is used for inside tire envelope and as inner tube. Rubber compound contains semi-crystalline propylene polymer with about 75 wt % propylene units and is prepared on common rubber manufacture equipment.
EFFECT: improved pre-treatment strength, pre-treatment elongation, and pre-treatment relaxation properties at elevated temperature and improved aging resistance and barrier properties.
35 cl, 8 tbl
The technical field to which the invention relates.
The present invention relates to polymers on isobutilene basis (UPS), in particular halogenated polymers on isobutilene basis, and more specifically to pomilovannomu the butyl rubber, with high resistance to treatment and increased impermeability, as well as to methods for their preparation.
Background of invention
To improve various properties, such as elasticity, strength, impermeability to air, etc., polymers on isobutilene basis mixed with a variety of compositions, such as natural rubber. It is known that tensile natural rubber (NC) crystallizes, and it is known that it includes a very large fraction of molecular weight, and both contribute to the manifestation of good properties to processing. The presence of such properties is important in the manufacture of rubber products crude rubber mixtures, in particular of such composites as bus, but may be important in extruded products, such as car camera, and molded products, such as sealing devices for pharmaceutical products. Thus, when it is necessary to improve the properties of polymers on isobutilene before processing, they are mixed with natural rubber. what, however, mechanical properties of polymers on isobutilene basis to oppose the processing properties of natural rubber in particular at elevated temperatures, up to about 50°C. the Addition of natural rubber significantly reduces the barrier properties of mixtures UPS/NC, which is not desirable for those applications requiring low permeability to gases, in particular in the manufacture of tires and automotive cameras. In blends with natural rubber is also reduced resistance to thermal aging.
Polymers on isobutilene basis, in particular halogenated polymers on isobutilene basis, and more specifically, commercially available brominated butyl rubber, are compositions which are of paramount importance for the manufacture of most sealing layers tubeless tires, resistant to thermal aging tubular products, car cameras and other known industrial products, such as products for the pharmaceutical industry. Used in the present description, the term "butyl rubber" is used to denote vulcanizing kauchukopodobnoe copolymer consisting by weight of from about 85 to 99.5% isoretinoin chains containing from 4 to 8 carbon atoms each. Such copolymers and their getting well known. Also well known halogenated butyl rubber, in particular the commercially available brominated butyl rubber. It can be obtained by treatment of a solution of butyl rubber in an organic dissolved the Le bromine and selection of the brominated butyl rubber by injection into contact with water vapor and drying the resulting aqueous suspension.
Commercially available brominated butyl rubber typically includes less than one bromine atom on the carbon-carbon double bond, originally contained in the polymer, or from about less than 3 wt.% bromine. The viscosity Mooney viscometer halobutyl rubbers, which can be used according to the present invention, measured at 125° (ML 1+8), is in the range from about 20 to about 80, more preferably from about 25 to about 55, and most preferably from about 30 to about 50. It is a relatively chemically resistant koutsokoumnis polymer which can be prepared mixture and vulcanizate to produce synthetic rubber, possessing exceptionally high impermeability to air, which can be used in the manufacture of the inner shells tire and automotive cameras.
Commercially available brominated butyl rubber has a higher reactivity than butyl rubber, so that it can be combined with other unsaturated polymers and with them devulcanizing, which prevents the lack of reactivity of the butyl rubber. However, the vulcanizates of the brominated butyl rubber are good impermeability to air, the characteristics of resistance to heat aging and General chemical resistance. One of the main purposes of it is applications is the fabrication of the inner shells for tubeless tires. In fact, such sealing layers are thin sheets of rubber, bonded to the tire carcass by covulcanization with rubbers that make up the tire carcass. Characteristics resistance to heat aging, impermeability to air and covulcanization the brominated butyl rubber determine its suitability for use in the manufacture of inner casings for car tires. Other known features of the application of halogenated butyl rubber include mixtures for the manufacture of white sidewall tires, resistant to thermal aging of tubular products and automotive cameras.
The disadvantage of butyl and halobutyl rubber is their lack of strength before treatment. The concept of "strength before treatment" is used to denote strength, cohesive ability and dimensional stability of rubber compounds before vulcanization or curing. In addition, to evaluate the strength to handle this application used the characteristics of the relative elongation of unvulcanized mixtures. Insufficient strength to handle complicates the processing and molding of rubber compounds based on butyl rubber. For example, in the manufacture of sealing layers tires need to prepare very thin sheets of butyl rubber mixture, to impose the and the raw tire carcass, and then vulcanizate. If the durability to handle butelli globaleconomy mixture is insufficient, there is a risk of rupture of thin sheets, if you don't treat them with great caution.
Some of the above disadvantages resolve known from the prior art solutions. In US no 4256857 described the increasing strength of unvulcanized rubber compound processing of the brominated butyl rubber relatively small amounts of certain organic amine compounds. Examples of acceptable amine compounds include N,N-dimethylhexylamine, N,N-dimethyldodecylamine, N,N-dimethylethanolamine, N,N-diethylcarbamyl and N,N-dimethylbenzylamine. It was found that these amine compounds give unvulcanized rubber mixture strength and allow you to keep a good capacity for processing. Although to increase the strength of the rubber is possible to conduct the reaction of the brominated butyl rubber and other aminovymi compounds, they usually degrade the ability of the rubber to the processing that is believed due to the formation of permanent cross-links. However, the implementation of this method requires extreme heat and time that would be inefficient or impractical for the processes of fast preparation of rubber mixtures in terms of the industrial production.
In US patent No. 5162409, issued in the name Morocskowski described rubber compound suitable for use in treads of automobile tires, including halogenated isobutilene rubber, which may be the only rubber in the rubber mixture or a component of combination of rubber. The preferred option includes a rubber component containing 20 to 60 wt.% styrene-butadiene rubber, 20 to 60 wt.% butadiene rubber and from 10 to 30 wt.% halogenated rubber, silica amplifier and selenological vulcanizing agent.
It is said that in the preferred embodiment, the rubber mixtures comprise from 10 to 30 ppm 100 frequent. rubber untreated precipitated silica used with an effective amount of selenological binders, for example from 1 to 8 ppm 100 frequent. the rubber. However, the strength properties isobutilene rubber or containing mixtures to improve processing irrelevant.
Known from the prior art solutions fail to achieve a satisfactory strength properties before treatment. The present invention proposes a new arrangement, which makes it possible to satisfy the need for high-strength before processing.
Summary of the invention
In accordance with one of the objects of this is th invention features a mixture, comprising a polymer on isobutilene basis and semi-crystalline polymer (PEP), which improves the strength properties of unvulcanized rubber mixture with a reduced deterioration of barrier properties and oxidation thermal aging. Semicrystalline polymers usually polyommatini with polymers on isobutilene basis and have a melting temperature of the crystalline phase below the temperature generated in the processes of mixing and molding. Another option offered thin barrier layer comprising a polymer on isobutilene basis and semi-crystalline polymer, where the semi-crystalline propylene polymer has a melting point of from about 25 to about 105°and a heat of fusion of from about 9 to about 50 j/g, as determined DSK.
In accordance with another alternative implementation of the present invention features a mixture comprising a polymer on isobutilene basis and semi-crystalline propylene polymer, the content of propylene units which is at least about 75 wt.%, as well as a version of the invention, related products, representing the mixture.
In accordance with another variant of the inner shell of the bus or the camera includes a commercially available brominated butyl rubber polymer and polycrest the symbolic polymer, where this semi-crystalline propylene polymer has a melting point of from about 25 to about 105°and a heat of fusion of from about 9 to about 50 j/g, as determined DSK.
Detailed description of the invention
In an advanced embodiment of the present invention, the mixture comprises an elastomer isobutilene basis and semi-crystalline polymer which exhibits improved properties of strength before treatment, relative elongation before treatment and relaxation before processing. Another alternative implementation of the present invention is a mixture comprising any elastomer isobutilene basis and semi-crystalline polymer which exhibits improved resistance to ageing and improved barrier properties. Increase strength before treatment in accordance with the invention achieve without significant damage to any other target properties or processing AIDS elastomers on isobutilene basis and without negative impact on subsequent processes of vulcanization, which is customarily elastomers isobutilene basis, or usefulness of thus obtained vulcanizate.
It was found that to improve the strength properties to the processing of polymers on isobutilene basis with a significant weakening of the negative impact on bar is Ernie properties and properties oxidizing thermal aging can add semi-crystalline polymers (PCP), preferably the class of saturated products (without unsaturated groups in the main chain). These polymers usually polyommatini with polymers on isobutilene basis and have a melting temperature of the crystalline phase below the temperature generated in the processes of mixing and molding. However, this allows us to improve the property before processing when performing manipulations with them and some of the subsequent processing operations, such as assembling of the bar, at temperatures below the melting temperature of the crystalline phase of semi-crystalline polymers.
Preferred semi-crystalline polymer is a thermoplastic copolymer, preferably statistical, ethylene and propylene having a melting point which, according to DSC analysis, ranges from about 25 to about 105°C, preferably in the range of from about 25 to about 90°s, and more preferably in the range of from about 35 to about 80°and the average weight percent propylene units which is at least about 75%, more preferably at least about 80%, and most preferably at least about 90%. Preferred for use according to the present invention semi-crystalline polymer (PEP) is described as the "First Polymer Component (FPC)" in co-pending application, U.S. filed may 13, 1999, serial number 60/133966 (case No. V the patent attorney), which is incorporated into this description by reference in accordance with existing US patent practice. The heat of fusion of the preferred semi-crystalline polymer is from about 9 to about 50 j/g, as determined by DSC, more preferably from about 11 to about 38 j/g, as determined by DSC, and most preferably from about 15 to about 25 j/g, as determined DSC (differential scanning calorimetry).
Preferred for this application, the method of differential scanning calorimetry (DSC) described as the following. Using a punching stamp from a sheet of a preferred polymer pressed at approximately 200 to 230°With, in the preferred embodiment, taken from about 6 to about 10 mg of a sample and let at room temperature for 240 hours At the end of this period the sample is placed in a differential scanning calorimeter (Perkin Elmer 7 series thermal systems analysis) and cooled to a temperature of from about -50 to about -70°C. the Sample is heated at a rate of approximately 20°C/min to achieve a final temperature of from about 200 to approximately 220°C. Thermal performance record as the area under the peak melting of the sample, which is, as a rule, occurs at the maximum peak from about 30 to about 175°and the process proceeds in the temperature range from about 0 to about 200°C. Thermal performance as a measure of the heat of fusion is determined in joules. The melting temperature is fixed as the maximum temperature of the adsorption heat in the temperature range of melting of the sample.
Semi-crystalline polymer blended polymer compositions according to the present invention is able to crystallize a copolymer of propylene and another alpha-olefin containing less than 10 carbon atoms, preferably ethylene. The degree of crystallinity of the control panel increases due to able to crystallize stereoregular propylene sequences. The control panel has the following characteristics :
Preferred according to the present invention, the control panel is a statistical crystallizable copolymer having a narrow compositional distribution. Used in the present description, the term "crystallizable" with respect to the panel characterizes those polymers or sequences, which in the undeformed state are mostly amorphous, but when exposed to mechanical stress, annealing or in the presence of a crystalline polymer can crystallize. Crystal is izatio determine DSK, as set forth in the present description. Without intent to be limited to these frames, I believe that a narrow compositional distribution of the first polymer is important. Intermolecular composition distribution of the polymer determine thermal separation into fractions in the solvent. A typical solvent is a saturated hydrocarbon, such as hexane and heptane. This method of thermal separation into fractions described below. Typically, about 75 wt.%, and more preferably 85 wt. % polymer is isolated in the form of one or two adjacent, soluble fractions, and the rest of the polymer in immediately preceding or succeeding fractions. Each of these fractions (mass percentage content of ethylene units) differs by not more than 20 wt.% (relatively), and more preferably 10 wt.% (relative) of the average mass percentage content of ethylene units in just the first polymer component. If the first polymer component corresponds to the results of the above test on fractionation, it is characterized by a narrow compositional distribution.
All the panel length and the distribution of stereoregular propylene sequences corresponds almost random, statistical copolymerization with the formation of Kristallografiya. It is well known that the length of the sequence and distribution of related constants copolymerization. Under almost random copolymer, the inventors mean a copolymer for which the product of the copolymerization constants is usually 2 or less. In stereoblock structures average length polypropylene (PP) sequences greater than the length of sequences almost disordered copolymers of similar composition. Distribution PP sequences in the first known polymers with stereoblock structure rather consistent with the distribution in these block structures than disordered, almost statistical distribution. The copolymerization constants and the distribution of sequences of polymer can be determined by using the13C-NMR analysis, which indicates the location of the ethylene residues relative to neighboring propylene residues. To obtain a crystallizable copolymer with the required degree of disorder and a narrow compositional distribution, you must apply (1) the catalyst with a single active site and (2) a polymerization reactor with a stirrer with a continuous flow mix well Monomeric raw materials, which is possible only single polymerization environment for almost all polymer of the output circuits of the first polymer component.
The preferred control panel is characterized by a single broad transition during melting. It is defined DSK. Typically, the sample panel shows the secondary melting peaks near the main peak, and they are considered together as the corresponding single melting point. The highest of these peaks is considered corresponding to the melting point. These panel have a melting point less than 105°S, preferably less than 100°and a heat of fusion less than 45 j/g, preferably less than 35 j/g, more preferably less than 25 j/g, as determined DSK.
The panel composition according to the present invention includes a capable isotacticity to crystallize alpha-olefin sequences, i.e. preferably propylene sequences (according to NMR). Preferred crystallinity of the first polymeric component in accordance with one variant is from 1 to 65% gemostaticescoe polypropylene, preferably in the range from 3 to 20%, as determined by the melting heat annealed samples of the polymer.
Srednevekovaja molecular mass of the control panel may be in the range from 10000 to 5000000, preferably from about 80,000 to 500,000, with polydispersity (TTD) in the range from 1.5 to 40.0, more preferably in the range from 1.8 to 5 and most preferably in the range from 1,to 3. In a preferred embodiment, the value of ML (1+4) at 125°the control panel is less than 100, more preferably less than 75, and most preferably less than 60.
A low degree of crystallinity of the control panel achieves the introduction of from 5 to 40 wt.% links of alpha-olefin, preferably from 6 to 30 wt.% links of alpha-olefin, and most preferably it comprises from 8 to 25 wt.% links of alpha-olefin, and even more preferably in the range from 8 to 20 wt.%, most preferably in the range from 10 to 15 wt.% links of alpha-olefin. These ranges of composition of the panel is dictated by the aim of the present invention. Alpha-olefins include one or more representatives of a number With2-With3-C20alpha-olefins. When the contents of the smaller component is below the above lower limits for the composition of the control panel the control panel is thermoplastic and has not separated morphology of the phases necessary for the manifestation of mixtures of recovery properties after stretching. When the contents of the smaller component higher than the above upper limits for the control panel, mixtures exhibit low tensile strength at break and the morphology of the separated phases with coarse dispersion. Not based on any theory, I believe that for crystallization with UPS for the manifestation of the advantages of the present invention for the control panel to the optimum content of isotactic p is DIPROPYLENE crystalline phase. As mentioned above, the preferred alpha-olefin is ethylene.
The share of semi-crystalline polymer in the mixture control panel/UPS according to the present invention can be varied in the range of from about 3 to about 95 wt.%, preferably in the range of from about 3 to about 60 wt.%, more preferably in the range of from about 4 to about 45 wt.%, and most preferably from about 5 to about 30 wt.%.
As a semicrystalline polymer component according to the invention it is possible to use more than one semi-crystalline polymer, as represented in this application. The preferred number of semi-crystalline polymers in this embodiment is three or less, and more preferably two. Different semi-crystalline polymers may be characterized by different crystallinity, if only the crystallinity was in the above ranges.
The crystallinity of a semicrystalline polymer, preferred for blending with isobutilene polymers, can also be expressed in percentage crystallinity. thermal energy of the highest order to the melting temperature of the crystalline fraction of the polypropylene is estimated at 189 j/g in Other words, 100%crystallinity corresponds 189 j/g Thus, in accordance with the above energy values of prepost is positive according to the invention polypropylene crystallinity is from about 5 to about 30%, more preferably from about 6 to about 20%, and most preferably from about 8 to about 15%. The preferred molecular weight of the polymer, expressed in units of viscosity by viscometer Mooney ML (1+4) at 125°S, is less than or equal to 30. The test referred to in the present description viscosity to Mooney viscometer is carried out in accordance with ASTM D-1646. Preferred semi-crystalline polymer is a statistical copolymer derived from propylene monomer, one or more other monomers selected from the series comprising ethylene, alpha-olefins containing from 4 to 8 carbon atoms each, styrene, and optionally one or more dienes. Semi-crystalline polymeric component may include a small number of links of at least one diene, and in a more preferred embodiment, at least one of the dienes is a non-conjugate diene, which contributes to vulcanization and other chemical modification. The content of diene units is limited to a level not exceeding about 10 wt.%, and preferably not exceeding about 5 wt.%. The diene can choose from a number that includes those compounds that are used for the vulcanization of ethylene propylene rubbers, preferably ethylidenenorbornene, vinylnorbornene, Dicyclopentadiene, and 1,4-hexadiene (available from the DuPont Chemicals).
The second component of the above mixtures is an elastomeric copolymer of at isobutilene basis. In a preferred embodiment of the invention uses polymers to isobutilene basis, more preferably halogenated polymers on isobutilene basis, and most preferably commercially available brominated butyl rubber, including star-shaped butyl rubber. Polymers on isobutilene basis, included in the above list, is available on the company ExxonMobil Chemical Co. and presented in US patents No. 2631984, 2964489, 3099644 and 5021509 included in this description as a reference in accordance with the present U.S. patent practice. The polymer isobutilene basis can be selected from the group comprising butyl rubber, polyisobutylene, random copolymers With4-C7samanaleya and para-alkylthiol, such as products EXXPRO™available on the company ExxonMobil Chemical Co. and presented in US patents№ 5162445, 5430118, 5426167, 5548023, 5548029 and 5654379 included in this description as a reference in accordance with the present U.S. patent practice, as well as mixtures thereof. However, the scope of the present invention is not limited to the above compositions and may include any elastomeric copolymer on isobutilene basis.
Improved property before processing with minor consequences for the barrier or in lonization properties of the proposed mixtures show the following information. Moreover, based on these data it can be assumed that the combination of low-molecular control panel from the UPS creates the opportunity for reducing the amount of plasticizer, such as oil and product STRUKTOL MS-40, available on the company Struktol Chemicals, Akron, PCs Ohio, which reduces the barrier disadvantages while maintaining good processing AIDS mixture. In the preferred embodiment, as a plasticizer use of low-molecular polyisobutylene polymer, i.e. polyisobutylene oil. Plasticizers are added to achieve acceptable processing characteristics, such as the ability to mixing, milling, calendering, molding and forming. When you add low-molecular control panel, they can also function as plasticizers, while the crystallinity control panel retains superior properties to handle even with a reduced molecular weight.
Suitable mixtures for thin barrier layers, such as inner sheath for bus and car cameras, can be prepared using conventional mixing equipment, including, for example, mixing, plastical on rollers, the preparation of the rubber mixture in the syringe machine, mixing in a closed mixer (such as with the use of a Banbury mixer®) etc. Specialist for the preparation of rubber mixtures well svestka sequence of operations when mixed and created temperature, with the goal dispersion of polymers, fillers, activators and vulcanizing agents in the polymer matrix without the accumulation of excessive amounts of heat. For an effective process of mixing applied Bunbury mixer, in which load the polymer components, filler and plasticizer, and the composition is stirred for the time required to achieve a specific temperature to ensure adequate dispersion of the components. In another embodiment, the polymers and part of the fillers (for example, from one to two thirds) are mixed in a short period of time (in particular, from about 1 to 3 min), then mix the rest of the fillers and oil. Stirring is continued for from about 5 to 10 minutes at high rotor speed, and during this period the temperature of the blend components is approximately 150°C. After cooling, the components are mixed in the second stage using rollers for rubber mixtures or in Bunbury mixer, and at this stage at a relatively low temperature, in particular from about 80 to about 105°C, thoroughly and evenly dispersed vulcanizing agent and an optional accelerator of vulcanization. For specialists in this field of technology is quite obvious possibility of different options in% the SSE mixing, therefore, the scope of the present invention to any particular methods of mixing is not limited. The mixing is carried out with the aim carefully and evenly dispersing all of the components of the composition.
Proposed by the present invention a mixture with increased strength before treatment can be used alone or combined with other rubbers and process with the same components and the same methods as applied in the case of conventional brominated butyl rubber, i.e. with fillers such as carbon black, silica and clay, plasticizers, oils for filling rubber, such as isobutilene oil, substances for improving the adhesiveness with vulcanizing agents, such as zinc oxide and/or sulfur, and with additional vulcanization accelerators or without them. To such other rubbers which can be combined commercially available brominated butyl rubber with the strength to handle according to the present invention, include those with whom it is possible to combine commercially available brominated butyl rubber, such as unsaturated rubbers, including natural rubber, polyisobutylene rubber, ethylene copolymers, in particular ethylene-cycloolefin and ethylene-isobutilene copolymers, styrene-butadiene rubber, polybutadiene, polyisoprene and styrene-butadiene polymers, and less unsaturated rubbers, in particular e is ilen-propylene-diene polymers (EPDM). EPDM is a designation under ASTM ternary copolymer of ethylene with propylene and a non-paired with diolefines. The preferred EPDM is a ternary copolymer grade VISTALON 2300®available on the company Exxon Chemical Company. Other acceptable polymers are presented in US patents No. 5763556 and 5866665, which are included in the present description as a reference in accordance with the present U.S. patent practice.
Proposed by the present invention a mixture with increased strength up processing alone or in combination with other rubbers to vulcanizate reaction with vulcanizing groups are well known in the art, and such curing group used in the usual quantities. Polymer mixtures, such as those used in the manufacture of tires, usually vulcanized. It is known that the physical properties, performance characteristics and durability of vulcanized rubber compounds directly related to the number (density) of cross-links and the type of cross-links formed during the vulcanization reaction (see, for example, the work of The Post Vulcanization Stabilisation for NR. W.F.Helt, B.H.To & W.W.Paris, Rubber World, August 1991, p.18-23, which is incorporated into this description by reference). Typically, the polymer mixture can be made by adding molecules curing substances, such as sulfur, zinc is, other metals, the initiators of radical polymerization, etc. with subsequent heating. The process according to this method can be accelerated, and when the rubber elastomer mixtures acceleration is often used. The mechanism of accelerated vulcanization of natural rubber involves the complex interaction between the vulcanizing agent, a vulcanization accelerator, an activator, and polymers. Ideally, the formation of effective cross-links, which connect between the two polymer chains and increase the overall strength of the polymer matrix, consumes all available vulcanizing agent. In the art known for a variety of curing agents, which include, though not limited to, the following products: zinc oxide, stearic acid, tetramethylthiuramdisulphide (TMTD), 4,4'-dithiodimorpholine (DTDM), terabyteunlimited (TBTD), benzothiadiazole (MBTS), dehydrate hexamethylen-1,6-beastialityfree salt (product ERP 390), 2-(morpholinothio)benzothiazole (MBS or MOR), a mixture of 90% MOR and 10% MBTS (product MOR 90), N-oxydiethylene-N-oxydiethylene (HSSE), 2-ethylhexanoate zinc (AGC) and MS-sulfur. Additionally, this technology is known for a variety of vulcanizing group (see, for example, Formulation Design and Curing Characteristics of NBR Mixes for Seals. Rubber World, September 1993, s-30,which is incorporated into this description by reference). A number of other components of the mixture is in the range, which in the art is known.
Given the purpose of the present description, the properties were determined as follows.
I. Strength before treatment/relaxation voltage
Strength tests before the treatment is carried out in accordance with the standards listed in ASTM D-41287.
A. sample Preparation. Samples of sheet material to be tested is prepared from plastinirovannogo on rollers sample size 102×102×6.0 mm and a weight of approximately 85±5, Unvulcanized sample at room temperature within a form placed between Mylar sheets, noting the direction of the roller "grain". The form is loaded into the vulcanizing press in which a temperature is set to approximately 100°and pressed in total for about five minutes: within two minutes under low pressure (approximately 7800 pounds) and within three minutes under high pressure (30000 pounds). Next, the molded sheet material is removed and before the test leave for conditioning at room temperature for at least about 24 hours
B. The Test. Preferred standard test temperature is 23±2° (in the open atmosphere of the laboratory) or 40°C. the Samples experience with test Masha is s Instron, in which set the following operating parameters:
a torque element: 1000 H
pneumatic clamps: for a given air pressure 30 psi
speed slider: 127 mm/min
the speed of the tape recorder: 50 mm/min
full scale: 25 N
the distance between clamps: 25 mm
On each side of the sample substrate of Mylar material is removed, preferably with acetone. Measure the thickness of the sample and note 25 mm control label. To prevent adhesion of the ends of the sample to clamp them on each side covered with a Mylar material. The sample is placed in the clamps of the testing machine, aligning the reference mark on the top and bottom edges of the clamps. Sample stretch 100% (increasing the distance between the clamps from 25 to 50 mm) or 200% (increasing the distance between the clamps from 25 to 75 mm). After the cessation of deformation for a tension watch up until its value will not pass the level, after which the power is reduced by 75% (up to 25% of the value, which stops the slider).
C. Calculations. Using the data sample sizes (width and thickness) and the value of the tension force, expect:
(I) strength before treatment: stress at 100%elongation (at the point of stopping the slider)
in N/mm2=force (N)/the width of the sample×thickness (mm);
(II) time, d is axali (t75): records on the tape recorder counting time, during which the force (force) tension is reduced by 75% from its value when the relaxation begins to shift to the point where the force is reduced to 25% of its initial value); time should be considered after stopping the slider (it is necessary to exclude a 12-second time deformation);
(III) the average test results of three (3) good samples for each mixture; the resulting average values taken for the strength to processing time and up to 75%reduction efforts.
By The Normalization. Obtained for different materials strength before treatment and stress relaxation may be normalized with respect to the given material. This is implemented by dividing each received reference efforts on the reference force standard material. For measurement normalization should be carried out using identical parameters. However, after normalization of the materials, the parameters of which were determined with one or more changes in tests to determine these parameters, it is possible to compare, if the standard material is the same as when the test determines both the number of parameters. For example, if testing a single number the degree of reduction was 75% and 50% in trials of another series, the results of both series can be normalized to the same hundred is standard material, the parameters which were determined in both conditions. As the reduction proceeds in exponential form, the normalized relaxation time is not strictly depends on the degree of reduction.
A further portion of the test methods presented in the patent US 5071913, which fully included in the present description by reference.
The example below includes data that illustrate the set experienced by improving the relative elongation before treatment, the strength before treatment and relaxation of the integrity of the material of the barrier thin layers and mixes in General, in particular the model mixtures for the inner lining of the tire. Barrier thin layers and cooked the mixture of the above composition can be used in the manufacture of products, preferably such vulcanizing products and/or vulcanizates, as the inner shell for tires, tubes for automobile tires, tubes, and sealing means for pharmaceuticals, decking for roofs, belts, tubes, hoses, etc. thin barrier layer can also be used to prevent the penetration or leakage of gas or other fluid.
The understanding of the essence of the present invention can be simplified, if we refer to the following example and tables, which its volume is not limited.
Closed is Musicale using model composition was stirred some rubber compounds. These rubber mixtures were prepared on the basis of any one of the four bromobutyl rubbers (No. 1 through 4) or mixtures of two of these bromobutyl rubber with a semi-crystalline polymer in accordance with the present invention (No. 5 through 18) or with an amorphous polymer [EPDM rubber, VISTALON 2200®, molecular weight, expressed in units of viscosity by viscometer Mooney ML (1+4) at 125°S, is less than or equal to 33. The test referred to in the present description viscosity to Mooney viscometer is carried out in accordance with ASTM D-1646; the product is technically available on the company Exxon Chemical Company, Budget, pieces of Texas, which is usually used in the composition of the rubber compounds for automotive cameras, No. 19 and 20] or with natural rubber (No. 21). The panel was introduced in quantities or 15, or 20 ppm 100 frequent., the amorphous polymer was added in an amount of 20 ppm 100 frequent., and NC used in the amount of 25 ppm 100 frequent., as shown in table 1. Oil was injected in amounts of 0, 5 or 10 ppm 100 frequent., and black carbon were added in quantities of 60, 70 or 80 ppm 100 frequent.
Vulcanizing the group, are presented in table 1, was introduced in the mill.
Properties of rubber compounds without components vulcanizing group was determined at room temperature and at 50°C. it Was found that in order to achieve relevant results of the tests before the molding of the specimens for testing with the defining properties before treatment should be carefully calendering. Samples of the molded sheet material cut in the form of strips with a length of 2.5 inches, a width of 0.5 inches and a thickness of about 0.1 inches to the length of the samples corresponded to the direction of the calendered sheet emerging from the calender. During all test strips held in a tensile testing machine so that the distance between the grips was 1 inch. The test, which was carried out at room temperature, was a test of the relaxation voltage, in which the strip was stretched by 100% relative to its initial length between the grips at a speed of 5 inches/min, and then recorded the relaxation voltage over time. The test, which was carried out at 50°With included test relaxation voltage similarly to the above, in which the sample is stretched between the grips 200% relative to its initial length. Test properties to processing was carried out at 50°C. test tensile applied the same model and configuration, testing, and the sample was stretched to rupture at a speed of 10 inches/min All tests were performed three times and recorded the average value.
The test results before treatment on the relaxation voltage at room temperature in tables 2 and 3 expressed as "strength before treatment (OMT). rocheste before processing can be defined as the force at the end of the stretch (100%strain) and time to reduce effort by 75%, or from efforts at the end of the stretch, either from peak voltage, which is achieved at a lower tension. Time was measured from the date of termination stretching. During the strength tests before treatment with 50°To apply the same settings during the test at room temperature, but the relaxation time to reduce effort by 75% was determined based on the peak voltage. Recorded residual stress (OS) after 2 min after the start of the stretching module (after 2 min). As parameters of tensile tests at 50°C of the material before treatment was detected voltage when the elongation of 100%, the maximum stress and elongation in percent before breaking. Similar parameters were registered also for the average of the sample and the most durable of the sample. The results of the characterization to treatment are summarized in table 1 (amounts stated in part./100 miscast. rubber), and for samples of the present invention and graphs the voltage - time and stress - strain at 50°presented in tables 2 and 3.
As for strength before treatment (OMT) at room temperature, as can be seen, all samples from the control panel exhibit higher values of the SAR. Samples # 1 and # 4, is made of bromobutyl the lowest molecular weight of the star bromobutyl without a second polymer, showed the smallest relaxation time. Relative assessment of PDO at 50°similar, but the relaxation time of the rubber compounds containing the second polymer, and rubber composition not containing the second polymer is much more intimate. A large increase in the relative elongation at break at 50°show all rubber mixtures containing 20 ppm 100 frequent. PKP. Increased elongation is important to maintain material integrity, when calendered sheet materials are processed at elevated temperatures. The higher strength to handle also facilitates implementation of manipulation, thereby reducing deformation during processing.
Mixture of semi-crystalline polymer showed improved processability during mixing, the softening in the mill and calendering (or other high-temperature processes molding the mixture to the processing, such as injection molding), as demonstrated experience in the preparation of the sample for this example. Some of these characteristics can be demonstrated by the flow in the capillary, as shown in tables 4 and 5. The molding of the capillary was performed using an instrument Monsanto Processability Tester (MPT), are technically accessible for Alpha Technologies of Akro, PCs Ohio, at 100°C. Reduced swelling spriteimage at high shear rate flow mixes with the control panel in contrast to 100%-s bromoethylene compositions indicates a reduced elasticity in the processing, which can facilitate forming processes, even when the values of viscosity at high shifts similar. Viscosity can also be reduced by using a semi-crystalline polymer with a molecular weight, in a preferred embodiment, the appropriate viscosity to Mooney viscometer in the range of from 5 to 40, which is able to perform the functions of the plasticizer at a temperature in excess of above the melting point of the crystalline phase, but still discover improved properties due to the crystalline phase at such low molecular weight semi-crystalline polymer.
Presented in tables 1, 6, 7 and 8 physical properties after vulcanization show improved hardness, semi-crystalline polymer blends with reduced relative changes in the properties of the vulcanized materials after aging, in particular the hardness and module.
An important property of polymers on isobutilene basis in the manufacture of products containing gases, is impermeability to air. The data given in the following tables indicate improved impermeability to air, when the polymers on isobutilene basis combined with semi-crystalline polymer, provided in this application, compared with the same data for natural rubber or amorphous polymers and mixtures thereof. As shown by the data in tables 7 and 8, the decrease in oil content can significantly reduce the permeability, whereas the increase in the content of carbon black gives only a negligible advantage. Because some low molecular weight semi-crystalline polymers can act as plasticizers to improve the barrier properties can reduce the oil content without compromising processing.
As shown in experiment No. 8 tests on the material, which contains about 20 wt.% semi-crystalline polymer, the strength to handle increases.
Var denotes a vibrating disk plastomer for vulcanization firm Monsanto, described in detail in the standard American society for testing and materials, ASTM D-2084.,
Although the invention is described with reference to specific options for the second run obviously, these options are simply illustrative of the principles and possible applications of the present invention. Therefore, it is also clear that in these illustrative ways you can make a variety of changes and that may provide other options, without exceeding the essence and scope of the invention defined by the following claims.
1. Barrier thin layer of rubber products, including polymer isobutilene basis and semi-crystalline polymer, where the thin barrier layer includes from about 3 to about 95 wt.% semi-crystalline polymer and the semi-crystalline polymer has a melting point of from about 25 to about 105°and a heat of fusion of from about 9 to about 50 j/g, as determined differential scanning calorimetry, and this thin layer of uncured.
2. Barrier thin layer according to claim 1, the heat of melting semi-crystalline polymer which comprises from about 11 to about 38 j/g, as determined differential scanning calorimetry.
3. Barrier thin layer according to claim 1, the heat of melting semi-crystalline polymer which comprises from about 15 to about 28 j/g, as determined differential scanning calorimetry.
4. Barrier thin layer according to claim 1, comprising from about to about 30 wt.% semi-crystalline polymer.
5. Barrier thin layer according to claim 1, semi-crystalline polymer which is a statistical copolymer.
6. Barrier thin layer according to claim 1, the polymer isobutilene the basis of which is chosen from the group comprising butyl rubber, statistical copolymers With4-C7samanaleya and para-alkylthiol and mixtures thereof.
7. Barrier thin layer according to claim 6, the polymer isobutilene the basis of which is halogenated.
8. Barrier thin layer according to claim 7, halogenated polymer isobutilene the basis of which is the brominated butyl rubber.
9. Barrier thin layer according to claim 1, the permeability to air is at about 30°With less than about 3.5 [(ml under standard conditions)(mm)]/[(m2)(760 mm Hg)(h)].
10. Barrier thin layer according to claim 1, the permeability to air is at about 30°With less than approximately 2.2 [(ml under standard conditions)(mm)]/[(m2) (760 mm Hg)(h)].
11. Barrier thin layer according to claim 1, strength to processing which corresponds to the stress at 100%elongation at about 50°With from about 0.1 to about 1 MPa.
12. Barrier thin layer according to claim 1, additionally comprising one or more of the following components: amorphous polymer, an oil, a plasticizer, a lubricant, isobutilene oil, an antioxidant, a stabilizer is, fillers, pigments and carbon black.
13. Barrier thin layer according to claim 1, semi-crystalline polymer which is obtained from the
a) propylene monomer,
b) one or more other monomers selected from the series comprising ethylene, alpha-olefins containing from 4 to 8 carbon atoms each, and sterols, and
C) optionally one or more dienes.
14. The inner shell of the tyre barrier thin layer according to claim 1.
15. Camera for tyre barrier thin layer according to claim 1.
16. Mixture for rubber articles comprising the polymer isobutilene basis and semi-crystalline propylene polymer, the content of propylene units which is at least about 75 wt.%, where this mixture is unvulcanized.
17. The mixture according to item 16, in which the semicrystalline propylene polymer has a melting point of from about 25 to about 105°and a heat of fusion of from about 9 to about 50 j/g, as determined differential scanning calorimetry.
18. The mixture according to item 16, in which the heat of melting semi-crystalline propylene polymer is from about 11 to about 38 j/g, as determined differential scanning calorimetry.
19. The mixture according to item 16, in which the heat of melting semi-crystalline sawn through the second polymer is from about 15 to about 28 j/g, as determined differential scanning calorimetry.
20. The mixture according to item 16, in which the semi-crystalline polymer additionally contains units of one or more dienes.
21. The mixture according to claim 20, in which the links of at least one of the one or more dienes are parts of a non-conjugate diene.
22. The mixture according to item 21, non-conjugate diene which is chosen from the group consisting of ethylidenenorbornene, vinylnorbornene, Dicyclopentadiene and 1,4-hexadiene.
23. The mixture according to item 16, the polymer isobutilene the basis of which is chosen from the group comprising butyl rubber, polyisobutylene, random copolymers With4-C7samanaleya and para-alkylthiol and mixtures thereof.
24. The mixture according to claim 19, the polymer isobutilene the basis of which is halogenated.
25. The mixture according to paragraph 24, the polymer isobutilene the basis of which is the brominated butyl rubber.
26. The mixture according to item 16, the polymer isobutilene the basis of which is haloesters statistical copolymer With4-C7samanaleya and para-alkylthiol.
27. The mixture according to item 16, the semi-crystalline polymer which is a statistical copolymer.
28. The mixture according to item 16, air permeability which is at about 30°With less than about 3.5 [(ml under standard conditions) (mm)]/[(m2)(760 mm Hg)h)].
29. The mixture according to item 16, air permeability which is at about 30°With less than approximately 2.2 [(ml under standard conditions) (mm)]/[(m2)(760 mm Hg)(h)].
30. The mixture according to item 16, the strength to processing which corresponds to the stress at 100%elongation at about 50°With from about 0.1 to about 1 MPa.
31. The mixture according to item 16, further comprising one or more of the following components: amorphous polymer, lubricant, isobutilene oil, antioxidants, stabilizers, fillers, pigments and carbon black.
32. The mixture according to claim 19, semi-crystalline polymer which is a statistical copolymer derived from
a) propylene monomer,
b) one or more other monomers selected from the series comprising ethylene, alpha-olefins containing from 4 to 8 carbon atoms each, and sterols, and
C) optionally one or more dienes.
33. The product of the material constituting the mixture according to item 16.
34. The method of preparation of the polymer mixture according to item 16, comprising a mixture of polymer isobutilene basis and a semicrystalline polymer, the content of propylene units which is at least about 75 wt.%.
35. The method according to clause 34, further comprising adding one or more of the following components: nortryptaline, lubricant, isobutilene oil, antioxidants, stabilizers, fillers, pigments and carbon black.