HK1054562B - Filled elastomeric butyl compounds with improved scorch safety - Google Patents

Description

Filled elastomer butyl compounds with improved scorch safety

Technical Field

The present invention relates to a halogenated butyl elastomer with improved scorch safety (scorch safety), in particular a brominated butyl elastomer with improved scorch safety.

Background

Reinforcing fillers such as carbon black and silica are known to greatly improve the strength and fatigue properties of elastomeric compounds. It is also known that chemical interactions occur between the elastomer and the filler. For example, a good interaction between carbon black and highly unsaturated elastomers such as polybutadiene (BR) and styrene butadiene copolymers (SBR) occurs because a large number of carbon-carbon double bonds are present in such copolymers. Butyl elastomers may have only 1/10 or less carbon-carbon double bonds in BR or SBR, and therefore compounds made from butyl elastomers are known to interact poorly with carbon black. For example, the preparation of a mix by mixing carbon black with a BR-butyl elastomer results in BR domains containing a majority of the carbon black and butyl domains containing very little carbon black. It is also known that butyl compounds have poor abrasion resistance.

Canadian patent application 2,293,149 shows that it is possible to produce filled butyl elastomer compositions having greatly improved properties by mixing halobutyl elastomers with silica and specific silanes. Such silanes act as a dispersing and binding agent between the halobutyl elastomer and the filler. However, one disadvantage of using silanes is the release of alcohol during manufacture and the potential for alcohol release during use of the articles produced by the method. Additionally, silanes also add significantly to the cost of the resulting article.

Co-pending CA 2,339,080 discloses a process for preparing compositions comprising halobutyl elastomers and organic compounds containing at least one basic nitrogen-containing group and at least one hydroxyl group, wherein there is an enhanced interaction between the elastomer and the filler, in particular, the mineral filler. Of particular interest are primary amine and hydroxyl group containing compounds, such as ethanolamine. While addressing the problem of enhancing the interaction between the elastomer and the filler, the composition must be carefully processed to prevent any undesirable scorching of the composition. The skilled artisan understands that the term scorch (scorch) is the premature crosslinking of the composition during processing.

Disclosure of Invention

The present invention provides a process for preparing a composition comprising a halobutyl elastomer, an organic compound containing at least one basic nitrogen-containing group and at least one hydroxyl group, and a hydrated metal halide. In this process, there is an enhanced interaction between the elastomer and the filler, in particular with the mineral filler, and scorch safety is improved. The present invention also provides a filled halobutyl elastomer composition comprising a halobutyl elastomer, an organic compound containing at least one basic nitrogen-containing group and at least one hydroxyl group, and one or more hydrated metal halides. Such compositions have improved properties when compared to known carbon black-filled halobutyl elastomer compositions, and additionally have improved scorch safety. In particular, it provides a means of producing such fill compositions without the release of alcohol.

Organic compounds containing at least one basic nitrogen-containing group and at least one hydroxyl group of particular interest are those containing primary amines and hydroxyl groups, such as ethanolamine. Such organic compounds are believed to disperse and incorporate the silica into the halogenated elastomer.

Accordingly, in another aspect, the present invention provides a method comprising: halobutyl elastomers are mixed with fillers, in particular mineral fillers, in the presence of additives, an organic compound having at least one hydroxyl group and at least one basic nitrogen-containing group and one or more hydrated metal halides, and the filled halobutyl elastomer obtained is vulcanized (curing). The compositions produced have improved scorch safety and constitute another aspect of the invention.

The halobutyl elastomer, admixed with the filler and one or more organic compounds having at least one hydroxyl group and at least one basic nitrogen-containing group and one or more hydrated metal halides, may be a mixture with another elastomer or elastomeric compound. Halobutyl elastomers should constitute more than 5% of any such mixture. Preferably, the halobutyl elastomer comprises at least 10% of any such mixture. In some cases it is preferred not to use a mixture but to use the halobutyl elastomer as the sole elastomer. If mixtures are used, however, the other elastomers may be, for example, natural rubber, polybutadiene, styrene-butadiene or polychloroprene or elastomer mixtures comprising one or more of these elastomers.

The filled halobutyl elastomer can be cured to produce products having improved properties such as abrasion resistance, rolling resistance and traction. Vulcanization may be carried out using sulfur. The sulfur is preferably used in an amount of 0.3 to 2.0 parts by weight per 100 parts of rubber. Activators, such as zinc oxide, may also be used in amounts of 5 parts to 2 parts by weight. Other ingredients, such as stearic acid, antioxidants or accelerators may also be added to the elastomer prior to vulcanization. The vulcanization with sulfur is then carried out in a known manner. See, for example, the rubber technology, third edition, chapter ii, "mixing and vulcanization of rubber", Chapman & Hall publication, 1995, the disclosure of which is incorporated herein by reference.

Other curatives known to cure halobutyl elastomers may also be used. There are a large number of compounds known to cure BIIR, for example, bis dienophiles (e.g., HVA2 ═ m phenylene-bis-maleimide), phenolic resins, amines, amino acids, peroxides, zinc oxide, and the like. Combinations of the above vulcanizing agents may also be used.

The mineral-filled halobutyl elastomers of the invention can be blended with other elastomers or elastomeric compounds before vulcanization with sulfur. As will be discussed further below.

Drawings

FIG. 1 illustrates the stress-strain curves of the product of the invention and a comparative example.

FIG. 2 illustrates modulus and FeCl₃·xH₂Relation of O addition amount.

FIG. 3 illustrates the relationship between time to3 and the amount of hydrated metal halide added.

Detailed Description

The term "halobutyl elastomer" is used herein to refer to chlorinated or brominated butyl elastomers. Brominated butyl elastomers are preferred, and thus, the present invention will be described with reference to such brominated butyl elastomers as an example. It will be appreciated, however, that the present invention extends to the use of chlorinated butyl elastomers.

For example, halobutyl elastomers suitable for use in the practice of the present invention include, but are not limited to, bromobutyl elastomers. Such elastomers may be prepared by butyl rubber (which is isobutylene and usually C)₄～C₆Copolymers of conjugated dienes, preferably isoprene). However, comonomers other than conjugated dienes may also be used, examples being alkyl-substituted vinylaromatic comonomers, such as C₁～C₄-alkyl substituted styrenes. An example of such an elastomer that is commercially available is brominated isobutylene methylstyrene copolymer (BIMS) in which the comonomer is p-methylstyrene.

The brominated butyl elastomer typically comprises 1 to3 wt% isoprene and 97 to 99 wt% isobutylene based on the hydrocarbon content of the polymer, and 1 to 4 wt% bromine based on the brominated butyl polymer. The molecular weight of a typical bromobutyl polymer, expressed as the Mooney viscosity (ML 1+8 at 125 ℃), is between 28 and 55.

For use in the present invention, the brominated butyl elastomer preferably comprises 1 to 5 wt% isoprene and 95 to 99 wt% isobutylene (based on the hydrocarbon content of the polymer), and 0.5 to 2.5 wt%, preferably 0.75 to 2.3 wt% bromine (based on the brominated butyl polymer).

Stabilizers may be added to the brominated butyl elastomer. Suitable stabilizers include calcium stearate and epoxidized soybean oil, preferably in an amount of 0.5 to 5 parts by weight per 100 parts by weight of brominated butyl rubber.

Examples of suitable brominated butyl elastomers include Bayer Bromobutyl^*2030、Bayer Bromobutyl^*2040(BB2040) and Bayer Bromobutyl^*X2, commercially available from Bayer. Mooney viscosity (RPML) of Bayer BB20401+8, 125 ℃, according to ASTM D52-89) is 39 ± 4; bromine content, 2.0. + -. 0.3 wt%; approximate molecular weight Mw, 500,000 g/mol.

The brominated butyl elastomer used in the process of the present invention may also be a graft copolymer of a brominated butyl rubber and a polymer based on conjugated diene monomers. Our co-pending canadian patent application 2,279,085 relates to a process for preparing such graft copolymers comprising: mixing solid brominated butyl rubber with solid conjugated diene monomer as main component and some C-S- (S)_n-C-bonded polymers, where n is an integer from 1 to 7, at a temperature higher than 50 ℃ for a time sufficient to cause grafting. The disclosure of this application is incorporated herein by reference. The bromobutyl elastomer of the graft copolymer can be any of those described above. The conjugated dienes that may be incorporated into the graft copolymer are generally of the formula:

wherein R is a hydrogen atom or an alkyl group of 1 to 8 carbon atoms, wherein R is₁And R₁₁Can be the same or different and is selected from a hydrogen atom and an alkyl group of 1 to 4 carbon atoms. Some representative, non-limiting examples of suitable conjugated dienes include: 1, 3-butadiene, isoprene, 2-methyl-1, 3-pentadiene, 4-butyl-1, 3-pentadiene, 2, 3-dimethyl-1, 3-pentadiene, 1, 3-hexadiene, 1, 3-octadiene, 2, 3-dibutyl-1, 3-pentadiene, 2-ethyl-1, 3-butadiene and the like. Conjugated diene monomers of 4 to 8 carbon atoms are preferred; 1, 3-butadiene and isoprene are particularly preferred.

The polymer based on conjugated diene monomers may be a homopolymer, or a copolymer of two or more conjugated diene monomers, or a copolymer with a vinyl aromatic monomer.

The vinylaromatic monomers which can optionally be used are chosen so as to be copolymerizable with the conjugated diene monomer used. In general, any vinylaromatic monomer known to polymerize with organo-alkali metal initiators can be used. Such vinyl aromatic monomers generally contain from 8 to 20 carbon atoms, preferably from 8 to 14 carbon atoms. Some examples of vinyl aromatic monomers that can be so copolymerized include styrene, alpha-methylstyrene, a wide variety of alkylstyrenes including p-methylstyrene, p-methoxystyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 4-vinyltoluene, and the like. Styrene is preferably copolymerized with 1, 3-butadiene alone or with both 1, 3-butadiene and isoprene.

The filler is comprised of mineral particles, examples of which include silica, silicates, clays (e.g., bentonite), gypsum, bauxite, alumina, magnesia, calcium oxide, titanium dioxide, talc, and the like, and mixtures thereof. These mineral particles have hydroxyl groups on the surface, thus making them hydrophilic and oleophobic. This exacerbates the difficulty of achieving good interaction between the filler particles and the butyl elastomer. For many purposes, the preferred mineral is silica, especially silica obtained by carbon dioxide precipitation of sodium silicate.

The dry, amorphous silica particles suitable for use in the present invention have an average aggregate particle size of from 1 to 100 μm, preferably from 10 to 50 μm, most preferably from 10 to 25 μm. Preferably, less than 10% by volume of the aggregate particles are less than 5 μm, or more than 50 μm in size. Furthermore, suitable amorphous, dry silicas have BET surface areas, determined in accordance with DIN (German industry Standard) 66131, of from 50 to 450m²(ii)/g; and the DBP absorption, determined according to DIN 53601, is between 150 and 400g/100g of silica; the loss on drying, determined according to DIN ISO787/11, is between 0 and 10 wt.%. Suitable silica fillers may be available under the trade name HiSil^*210、HiSiL^*233、HiSiL^*234 were obtained from PPG industries. Also suitable are Vulkasil^*S and Vulkasil^*N, supplied by Bayer.

Carbon black is not generally used as a filler for halobutyl elastomer compositions, but in certain embodiments it may be present in an amount of up to 40 phr. If the mineral filler is silica and it is used in combination with carbon black, the silica should make up at least 55% by weight of the sum of silica and carbon black. If the halobutyl elastomer composition of the present invention is blended with another elastomer composition, the other composition may contain carbon black as a filler.

The amount of filler added to the halobutyl elastomer may vary over a wide range. Fillers are typically used in amounts of 20 to 120 parts by weight, preferably 30 to 100 parts, more preferably 40 to 80 parts per 100 parts of elastomer.

An organic compound having at least one hydroxyl group and at least one basic nitrogen-containing group comprises: at least one hydroxyl group, which (without wishing to be bound by a particular theory) is reactive with the mineral filler; and at least one basic nitrogen atom-containing group that (without intending to be similarly limited) is reactive with the active halogen in the halobutyl elastomer (e.g., with the active bromine atom in the bromobutyl elastomer). The hydroxyl-containing functional group may be, for example, an alcohol or a carboxylic acid. Functional groups containing basic nitrogen atoms include, but are not limited to, amines (which can be primary, secondary, or tertiary amines) and amides. Preferred are primary alkylamine groups, e.g., aminoethyl, aminopropyl, and the like.

Examples of organic compounds having at least one hydroxyl group and at least one basic nitrogen-containing group that impart enhanced physical properties to mixtures of halobutyl elastomers and, in particular, silica include proteins, aspartic acid, 6-aminocaproic acid, diethanolamine and triethanolamine. Preferably, the additive should comprise a primary alcohol group and a primary amino group separated by a methylene bridge, which may be branched. Such compounds have the general formulA HO-A-NH₂(ii) a Wherein A represents C₁～C₂₀The alkylene group may be linear or branched.

More preferably, the number of alkylene groups between these two functional groups will be between 1 and 4. Examples of preferred additives include mono-ethanolamine and 3-amino-1-propanol.

The amount of organic compound having at least one hydroxyl group and at least one basic nitrogen-containing group used depends on the molecular weight per equivalent of the particular compound in each case. One important factor is the number of nitrogen atoms per unit weight of compound/weight of nitrogen. The nitrogen content may be between 0.1 and 5 parts per 100 parts (phr) of halogenated butyl rubber, preferably between 0.125 and 1phr, more preferably between 0.3 and 0.7 phr. Up to 40 parts of processing oil may be present, preferably 5 to 20 parts per 100 parts of elastomer, and additionally a lubricant, for example a fatty acid such as stearic acid, may be present in an amount of up to3 parts by weight, more preferably up to 2 parts by weight.

The hydrated metal halide has the formula MX_n(mH₂O), wherein M represents a metal selected from groups 1 to 16 of the periodic system of the elements according to IUPAC1985, X is selected from fluorine, chlorine, bromine and iodine and mixtures thereof, n is the number of halogen atoms required to counteract the positive charge of the metal ion, M is the average number of water molecules, typically water molecules will surround the positively charged metal ion. The value m is typically determined using X-ray structural analysis or by various gravimetric techniques commonly employed by those skilled in the art.

Preferred metals are selected from IUPAC groups 3-12, including chromium, nickel, cobalt, and iron.

Preferred halides are chloride and bromide.

The metal halide is generally added in an amount of 0.1 to 20phr, preferably 2 to 10 phr.

The metal halides are particularly useful for improving the scorch safety of primary amino alcohol-containing compounds.

The halobutyl elastomer, the filler and the additive are suitably mixed together at a temperature of from 25 to 200 ℃. Preferably, the temperature in one of the mixing stages is greater than 60 ℃, particularly preferably in the range of 90 to 150 ℃. Typically, the mixing time does not exceed 1 h; usually, a time of 2 to 30min is sufficient. Mixing is suitably carried out on a two-roll mill mixer, which will provide good dispersion of the filler in the elastomer. Mixing can also be carried out in a Banbury mixer or in a Haake or Brabender miniature internal mixer. Extruders can also provide good mixing with the added advantage of allowing shorter mixing times. Mixing may also be carried out in two or more stages. Furthermore, the mixing can be carried out in different apparatuses, for example, one stage can be carried out in an internal mixer and the other in an extruder.

The order of addition of the various constituents to the rubber is not critical, however, it may be advantageous to mix the metal halide, the filler and the organic compound having at least one hydroxyl group and at least one basic nitrogen-containing group prior to addition to the rubber.

The increased interaction between the filler and the halobutyl elastomer results in improved filled elastomer properties. These improved properties include higher tensile strength, higher abrasion resistance, lower permeability and better dynamic properties. These would make the filled elastomers particularly suitable for many uses including, but not limited to, use in tire treads and tire sidewalls, tire innerliners, container liners, hoses, drums, conveyor belts, curing bladders, gas masks, vial stoppers and gaskets. These advantages are achieved together with an increase in the safety of scorching.

In a preferred embodiment of the invention, brominated butyl elastomer, silica particles, an organic compound having at least one hydroxyl group and at least one basic nitrogen-containing group, one or more metal halides, and, optionally, an extender oil are compounded on a two-roll mill mixer at a nominal mill temperature of 25 ℃. The mixed mix is then placed on a two roll mill mixer and mixed at a temperature above 60 ℃. It is preferred that the mixing temperature is not excessively high, more preferably not more than 150 ℃, because an excessively high temperature may cause vulcanization to excessively proceed to an undesirable extent and thus hinder subsequent processing. The product of mixing these ingredients at a temperature not exceeding 150 ℃ is a rubber compound with excellent stress/strain properties which will be easily further processed on a warm rubber mixer with the addition of vulcanizing agents.

The filled halobutyl rubber compositions of the present invention, and particularly the filled bromobutyl rubber compositions, have a wide range of uses, however, only specific examples of tire tread compositions are provided herein. Important characteristics of a tire tread composition are that it should have low rolling resistance, good traction, especially when wet, and good abrasion resistance to withstand wear. The compositions of the present invention exhibit improved abrasion resistance over rubber compounds that do not contain organic modifiers and also do not contain aqueous metal halides, while having improved scorch safety. As demonstrated in the examples below, the compositions of the present invention exhibit a combination of improved abrasion resistance and increased scorch safety.

The filled halobutyl elastomers of the present invention may be further compounded with other rubbers, for example, natural rubber, butadiene rubber, styrene-butadiene rubber and isoprene rubber, as well as compounds containing these elastomers.

The invention will be further illustrated by the following examples and figures.

Examples

Description of the experiments

Wear resistance: DIN 53-516 (No. 60 carborundum paper)

And (3) vulcanization rheological measurement: RPA analysis at 1 ° arc and 1.7Hz for ASTM D52-89 MDR2000E rheometer; 100 ℃, frequency 30cpm, strain: 0.5, 1, 2, 5, 10, 20, 50 and 90 °.

Mooney scorching of rubber compound: the measurements were carried out at 135 ℃ using a small rotor. The value of t03 obtained with this small rotor is equivalent to the value of t05 which is usually given for the (larger rotor).

Stress-strain: the samples were made by curing tc90+5min at 170 ℃ for large sheets, followed by coloring the appropriate samples. The test was carried out at 23 ℃.

Description of ingredients and general mixing procedure

Hi-Sil^*233-silica-PPG product

Sunpar^*2280 Paraffin Oil from Sun Oil

Maglite^*D-magnesium oxide, C.P.Hall

The bromobutyl elastomer, silica, oil, bonding compound and hydrated metal halide were compounded in a 1.57L Banbury (internal tangent) mixer with Mokon set at 40 ℃ and a rotor speed of 77 RPM. The vulcanizing agent was then added to the 6 inch x 12 inch cooled sample at 25 ℃.

Example 1

Investigating FeCl₃·xH₂O pairs containing brominated butyl rubber and HiSil^*233、Maglite^*The degree of reinforcement of the mixtures of D and ethanolamine (expressed as M300/M100 value), the degree of silica dispersion, the DIN abrasion resistance and the scorch safety are expressed as to3 values (min). Comprising brominated butyl rubber, HiSil only^*233 and Maglite^*The compound of D was used as a control. All of the mixes studied employed 0.5phr sulfur, 1.5phr zinc oxide, and 1.0phr stearic acid as the curative system.

The following FeCl was studied₃·xH₂The dosage level of O:

(i)0phr FeCl₃·xH₂O

(ii)2.4phr FeCl₃·xH₂O

(iii)4.8phr FeCl₃·xH₂O

(iv)9.7phr FeCl₃·xH₂O

all these mixes, except the control, all used 2.2phr of ethanolamine as organic additive containing at least one amino group and at least one hydroxyl group.

Brominated Isoprene Isobutylene Rubber (BIIR) with additives 60 parts per 100 parts rubber (phr) silica filler (HiSil)^*233) The mixing was carried out in the Banbury mixer under the mixing conditions described above. Then, on a cold rubber mixing mill, the same vulcanization is carried outThe formulation ingredients (1phr stearic acid, 0.5phr sulfur and 1.5phr zinc oxide) were added to each mix. The mixes were then vulcanized tc (90) +10min at 170 ℃ (for DIN abrasion test) or tc (90) +5min at 170 ℃ and finally tested. Table 1 gives the composition of the product and also FeCl₃·xH₂Physical property data for the compound of O and the compound without filler binder.

TABLE 1 masterbatch mixture

Examples of the invention	1a	1b	1c	1d	1e
						Coupling agent	9.7phrFeCl3	4.8phrFeCl3	2.4phrFeCl3	0phrFeCl3	Comparative example
Stress-strain (Bell)
						Vulcanization time (min) vulcanization temperature (. degree. C.) Subtlehr test temperature (. degree. C.) Shore (Shore) hardness A2(pts.) tensile at break (MPa) elongation at break (%) strain (% elongation) 2550100200300300/100	25170Die C237415.046469.7phrFeCl31.621.621.93.264.97 stress (MPa)2.62	23170Die C237614.456714.8phrFeCl31.721.651.82.744.15 stress (MPa)2.31	25170Die C237514.15152.4phrFeCl31.781.882.645.488.34 stress (MPa)3.16	19170Die C237217.533430phrFeCl31.832.313.678.2414.5 stress (MPa)3.95	34170Die C23764.9746 control 1.741.571.621.61.81 stress (MPa)1.02
DIN abrasion
						Abrasion volume loss (mm)3)	347	336	320	255	TSTM
Mooney scorching of rubber compound
						t value t03 (minutes)	5.32	2.55	7.47	1.36	＞30
MDRVulcanization characteristics
						MH(dN.m)ML(dN.m)δMH-ML(dN.m)ts1(min)ts2(min)t′10(min)t′25(min)t′50(min)t′90(min)t′95(min)	32.5216.8415.681.021.561.292.666.1420.3825.73	36.4318.0418.390.961.321.242.265.2918.3422.23	38.3216.7221.60.360.540.541.23.2220.9427.42	41.5814.0527.530.30.420.440.922.8213.5518.08	27.0519.627.431.531.132.737.232833.4

Examples of the invention	1a	1b	1c	1d	1e
						δt′50-t′10(min)	4.85	4.05	2.68	2.38	6.1
RPA Payne effect
						Strain 0.280.981.954.057.9516.0431.9564.03124.99249.98450.03	9.7phrFeCl32030.62212.92137.91816.31360.9877.94538.56320.77196.69117.0275.745	4.8phrFeCl32837.83319.83158.12465.51643.4990.26581.1336.77204.87124.1279.012	2.4phrFeCl31807.42024.62016.11736.61302859.99534.26317.42192.01116.1278.495	0phrFeCl3849.29937.58950.73881.04718.01526.43346.68220.23137.7399.171	Comparative example 2442.82518.62459.22110.81574.81029.5642.99387.5235.31135.7981.191

The data in Table 1 clearly show the addition of FeCl₃·xH₂O and monoethanolamineThe effect on promoting the dispersion and adhesion of the filler in the brominated butyl elastomer, compared to the control rubber compound. The ratio M300/M100 is generally used as a relative measure of the degree of reinforcement of the filler to the elastomeric compound (the higher the ratio, the stronger the reinforcement). M300/M100, 1.02 for the control (no silane or FeCl)₃·xH₂O), to FeCl-containing₃·xH₂The mixed rubber of O and monoethanolamine is 2.31-3.95. This is further emphasized by the stress-strain curve shown in figure 1.

The magnitude of the complex modulus (G) at low strain levels is generally taken as a measure of the extent of silica dispersion (the lower the value of G at low stress, the better the silica dispersion). FIG. 2 shows the value pairs FeCl₃·xH₂Dependence of the amount of O added. Importantly, monoethanolamine and FeCl are included in the mix₃·xH₂In the case of O, a significant improvement in the silica dispersion compared to the control compound was observed.

A study of the DIN abrasion test data shows that monoethanolamine and FeCl₃·xH₂The addition of O to these mixes significantly improves abrasion resistance. The control compound was too soft to be measured (TSTM).

The t03 time obtained from the Mooney scorch measurement was taken as an indicator of the scorch safety possessed by a rubber precured. As t03 increases, the processability also improves. As is clear from the data presented in Table 1, monoethanolamine and FeCl₃·xH₂The addition of mixtures of O to these mixes improves the scorch safety (lower t03 values) compared to the control mix or to the mix containing monoethanolamine only. This particular phenomenon accounts for FeCl₃·xH₂The influence of O on the scorch safety of these mixes, and thus on their processability.

Example 2

Research into NiCl₂·xH₂O、CrCl₃·xH₂O and CoCl₂·xH₂O pair brominated butyl rubber, HiSil^*233、Maglite^*D and ethanolamine, the degree of reinforcement of the mix (expressed as M300/M100 value), the degree of silica dispersion, DIN abrasion resistance and scorch safety (expressed in minutes at t 03). Comprising brominated butyl rubber, HiSil only^*233、Maglite^*A rubber mixture of D and monoethanolamine was used as a control. All the mixes studied used a mixture of 0.5phr of sulfur, 1.5phr of zinc oxide and 1.0phr of stearic acid as the vulcanizing agent system.

The following levels of hydrated metal halides were studied:

(i)0phr (control)

(ii)8.5phr NiCl₂·xH₂O

(iii)9.6phr CrCl₃·xH₂O

(iv)8.6phr CoCl₂·xH₂O

All of these mixes, 2.2phr ethanolamine was used as organic additive containing at least one amino group and at least one hydroxyl group.

Brominated Isoprene Isobutylene Rubber (BIIR) with additives 60 parts per 100 parts rubber (phr) silica filler (HiSil)^*233) The mixing was carried out in the Banbury mixer under the mixing conditions described above. The same vulcanizing agent ingredients (1phr stearic acid, 0.5phr sulfur, and 1.5phr zinc oxide) were then added to each mix on a cold rubber mill. The mixes were then vulcanized tc (90) +10min at 170 ℃ (for DIN abrasion test) or tc (90) +5min at 170 ℃ and finally tested. Table 2 gives the product composition, as well as physical property data for the aqueous metal halide compound mill mixtures and the monoethanolamine-only mill mixtures.

The data in Table 2 clearly show the effect of adding the hydrated metal halide to the BIIR/HiSiL/monoethanolamine mix. Importantly, significant differences were observed in the change of metal centers. This indicates that, as expected, the degree of interaction between monoethanolamine and the metal center depends on the nucleophilicity of the metal center.

As shown by the data in table 2, the interaction of the hydrated metal halide with monoethanolamine inhibited the role of monoethanolamine as a silica dispersing and linking agent in BIIR. However, it is important to note the improvement in time t03 observed when the hydrated metal halide was added to the mix (FIG. 3).

TABLE 2

Examples of the invention	2a	2b	2c	2d
					Coupling agent	Is free of	8.5NiCl2(xH2O)	9.6CrCl3(xH2O)	8.6CoCl2(xH2O)
Stress-strain (Bell)
					Vulcanization time (min) vulcanization temperature (. degree. C.) Subtlehr test temperature (. degree. C.) Shore hardness A2(pts.) tensile at break (MPa) elongation at break (%) strain (elongation) 2550100200300300/100	19170Die C237217.53343 No 1.832.313.678.2414.5 stress (MPa)3.95	21170Die C237113.928638.5NiCl2(xH2O)1.511.451.532.23.39 stress (MPa)2.22	28170Die C236212.1510129.6CrCl3(xH2O)1.211.141.151.512.26 stress (MPa)1.97	21170Die C237213.488978.6CoCl2(xH2O)1.591.541.521.92.74 stress (MPa)1.80
DIN abrasion
					Abrasion volume loss (mm)3)	255	345	399	374
Mooney scorching of rubber compound
					t value t03 (minutes)	1.36	2.91	26.03	3.15
MDR vulcanization characteristics
					MH(dN.m)ML(dN.m)δMH-ML(dN.m)ts1(min)ts2(min)t′10(min)t′25(min)t′50(min)t′90(min)t＇95(min)δt′50-t′10(min)	41.5814.0527.530.30.420.440.922.8213.5518.082.38	29.2713.6715.61.622.42.033.787.1316.2418.685.1	22.5813.199.392.584.142.54.8211.2532.939.248.75	30.6514.3416.311.21.741.512.926.1416.218.994.63

Examples of the invention	2a	2b	2c	2d
					RPA Payne effect
Strain 0.981.954.057.9516.0431.9564.03124.99249.98450.03	None 849.29937.58950.73881.04718.01526.43346.68220.23137.7399.171	8.5NiCl2(xH2O)1721.41840.31554.11132.8734.77457.16279.81180.07116.0977.572	9.6CrCl3(xH2O)1518.81770.91561.11148.8726.52431.18243.56139.6478.8549.298	8.6CoCl2(xH2O)1967.42080.316921189752.33461.02279.01178.54115.176.902

Claims (15)

1. A process for preparing a filled halobutyl elastomer comprising blending a halobutyl elastomer, filler particles, an organic compound having at least one hydroxyl group and one basic nitrogen group, and one or more hydrated metal halides, and curing the filled halobutyl elastomer obtained, wherein the filler particles are blended in an amount of 20 to 120 parts by weight based on 100 parts of the elastomer, the organic compound having at least one hydroxyl group and one basic nitrogen group is blended in an amount such that the nitrogen content per 100 parts of the elastomer is 0.1 to 5 parts, and the metal halide is blended in an amount of 0.1 to 20 parts per 100 parts of the elastomer.

2. The method of claim 1, wherein the basic nitrogen-containing group is an amino group.

3. The method of claim 2, wherein the amino group is a primary amino group.

4. The method of claim 1, wherein the organic compound having at least one hydroxyl group and one basic nitrogen-containing group has an amine group and a carboxylic acid group.

5. The method of claim 4, wherein the organic compound having at least one hydroxyl group and one basic nitrogen-containing group is an amino acid.

6. The process of claim 1 wherein the organic compound having at least one hydroxyl group and one basic nitrogen-containing group is an amino alcohol.

7. The method of claim 1, wherein the metal halide is a metal bromide or chloride.

8. The method of claim 1, wherein the metal halide is present in an amount of 0.1 to 10 phr.

9. The method of claim 1, wherein the filler is silica or carbon black.

10. The process of claim 1, wherein the filled halobutyl elastomer is blended with another elastomer or elastomeric compound before it is vulcanized.

11. The process of claim 1, wherein the filled halobutyl elastomer is cured with 0.3 to 2.0 parts by weight of sulfur.

12. A filled halobutyl elastomer composition comprising at least one halobutyl elastomer, filler particles, at least one organic compound having at least one hydroxyl group and one basic nitrogen group, and one or more hydrated metal halides, wherein the filler particles are blended in an amount of 20 to 120 parts by weight based on 100 parts of the elastomer, the organic compound having at least one hydroxyl group and one basic nitrogen group is blended in an amount such that the nitrogen content is 0.1 to 5 parts per 100 parts of the elastomer, and the metal halide is blended in an amount of 0.1 to 20 parts per 100 parts of the elastomer.

13. A filled, vulcanized elastomeric composition prepared according to the process of claim 1.

14. A filled, vulcanized elastomeric composition according to claim 13 in the form of a motor vehicle tire tread.

15. A filled, vulcanized elastomeric composition according to claim 14 in the form of an automotive tire innerliner.