Patent Application
20100081751
The present invention relates to the use of an organopolysiloxane composition, presented before use in a two-component form (RTV-2), vulcanizable from room temperature to give a self-adhesive elastomer on most varied supports, in particular on glass, metals, wood, polycarbonates and plastics, such as polyvinyl chloride (PVC), this being the case even in an enclosed atmosphere and after a heat treatment. More particularly, the present invention is targeted at compositions presented before use in the form of two components (RTV-2 compositions).
Organopolysiloxane compositions vulcanizable from room temperature are well known and are classified into two distinct groups: one-component (RTV-1) compositions and two-component (RTV-2) compositions.
Generally, one-component compositions crosslink when they are exposed to atmospheric moisture, that is to say that they cannot crosslink in an enclosed medium. One solution to this problem is described in French patent application FR-2 603 894, which describes an organopolysiloxane composition which cures to give an elastomer even in an enclosed atmosphere carrying acyloxy radicals bonded to silicon atoms and including a curing accelerator added before use chosen from the following hydroxides or oxides: CaO, SrO and BaO. However, these accelerated curing RTV-1 compositions which can crosslink under enclosed conditions exhibit the disadvantage of showing mediocre adhesion to the various substrates, such as metals, wood, plastics, concrete, and the like.
One solution which is currently used to overcome the problem of adhesion consists in employing a phase in which a primer is applied to the support before carrying out the deposition of the RTV-1 composition. Normal primers are, for example, a mixture of alkoxysilanes and of resin in organic solution. As the stage in which a primer is applied is rather expensive, a system which makes it possible to dispense with it is of great interest.
With regard to the two-component compositions, they are sold and stored in the form of two components, a first component comprising the base polymeric materials and the second component comprising the catalyst. The two components are mixed during use and the mixture crosslinks in the form of a relatively hard elastomer.
These two-component compositions are well known and are described in particular in the work by Walter Noll, “Chemistry and Technology of Silicones”, 1968, 2nd edition, on pages 395 to 398.
These compositions essentially comprise four different ingredients:
The mechanical properties of these compositions are then adjusted by the addition of fillers.
Two-component organopolysiloxane compositions which self-adhere by incorporation in a composition of silanes comprising an amine functional group are described in U.S. Pat. No. 3,801,572 and U.S. Pat. No. 3,888,815.
However, this patent does not set out the problem, nor provide a solution, of supplying self-adhesive seals and/or adhesives which retain, after a heat treatment, the following properties:
Moreover, the pot life, that is to say the time during which the composition can be used after mixing without curing, has to be sufficiently long, in order to allow it to be used, but sufficiently short, in order to obtain a molded item which can be handled at the latest a few minutes after it has been manufactured. It is therefore desirable that the catalyst makes it possible to obtain a good compromise between the pot life of the catalyzed mixture and the time at the end of which the molded item can be handled. In addition, the catalyst must confer, on the catalyzed mixture:
There has now been found, and it is this which constitutes the subject matter of the present invention, a novel polycondensation RTV-2 composition which makes it possible to obtain, after mixing of the two components and crosslinking, an excellent compromise with regard to setting kinetics and adhesive properties, even after a long-lasting heat treatment, or obtaining good resistance to “thermal reversion”.
More specifically, the present invention relates to the use of an organopolysiloxane composition vulcanizable to give a silicone elastomer from room temperature by polycondensation reactions in the preparation of self-adhesive seals and/or adhesives which retain good adhesion after a heat treatment at a temperature ≧100° C. for 3 days:
The said organopolysiloxane composition comprising:
R0aSi(OR1)4−a (I)
with at least one dialkyltin salt corresponding to the following general formula (II):
R2R3Sn(OCOR4)2 (II)
(R5)b(R6)cSi(OR7)4−(b+c) (III)
—Z—(X)n
According to one embodiment of the invention, the tin/silicon compound (D1) is prepared according to the following stages:
In the above, the term “aliphatic hydrocarbon group” is understood to mean a linear or branched group, preferably comprising from 1 to 25 carbon atoms, which is optionally substituted.
Advantageously, said aliphatic hydrocarbon group comprises from 1 to 18 carbon atoms, better still from 1 to 8 carbon atoms and even better still from 1 to 6 carbon atoms.
Mention may be made, as saturated aliphatic hydrocarbon group, of alkyl groups, such as the methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, 2-methylbutyl, 1-ethylpropyl, hexyl, isohexyl, neohexyl, 1-methylpentyl 3-methylpentyl, 1,1-dimethylbutyl, 1,3-dimethylbutyl, 2-ethylbutyl, 1-methyl-1-ethylpropyl, heptyl, 1-methylhexyl, 1-propylbutyl, 4,4-dimethylpentyl, octyl, 1-methylheptyl, 2-ethylhexyl, 5,5-dimethylhexyl, nonyl, decyl, 1-methylnonyl, 3,7-dimethyloctyl, 7,7-dimethyloctyl and hexadecyl radicals.
The unsaturated aliphatic hydrocarbon groups comprise one or more unsaturations, preferably one, two or three unsaturations of ethylenic type (double bond) and/or acetylenic type (triple bond).
Examples thereof are the alkenyl or alkynyl groups deriving from the alkyl groups defined above by elimination of two or more hydrogen atoms. Preferably, the unsaturated aliphatic hydrocarbon groups comprise a single unsaturation.
In the context of the invention, the term “carbocyclic group” is understood to mean an optionally substituted, preferably C3-C50, monocyclic or polycyclic radical. Advantageously, it is a C3-C18 radical which is preferably mono-, bi- or tricyclic. When the carbocyclic group comprises more than one cyclic nucleus (case of polycyclic carbocycles), the cyclic nuclei are fused in pairs. Two fused nuclei can be ortho-fused or peri-fused.
The carbocyclic group can comprise, unless otherwise indicated, a saturated part and/or an aromatic part and/or an unsaturated part.
Examples of saturated carbocyclic groups are cycloalkyl groups. Preferably, the cycloalkyl groups are C3-C18, better still C5-C10, cycloalkyl groups. Mention may in particular be made of the cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl or norbornyl radicals.
The unsaturated carbocycle or any unsaturated part of carbocyclic type exhibits one or more ethylenic unsaturations, preferably one, two or three. It advantageously exhibits from 6 to 50 carbon atoms, better still from 6 to 20 carbon atoms, for example from 6 to 18 carbon atoms. Examples of unsaturated carbocycles are C6-C10 cycloalkenyl groups.
Examples of aromatic carbocyclic radicals are (C6-C18) aryl groups, better still (C6-C12) aryl groups, and in particular phenyl, naphthyl, anthryl and phenanthryl.
A group exhibiting both an aliphatic hydrocarbon part as defined above and a carbocyclic part as defined above is, for example, an arylalkyl group, such as benzyl, or an alkylaryl group, such as tolyl.
The substituents of the aliphatic hydrocarbon groups or parts and of the carbocyclic groups or parts are, for example, alkoxy groups in which the alkyl part is preferably as defined above.
According to a particularly advantageous form, the substituents of the organoalkoxysilane of formula (I) and of the dialkyltin salt of formula (II) are defined in the following way:
The organoalkoxysilanes of formula (I) are well known compounds described in particular in French patents FR-1 330 625, FR-2 121 289, FR-2 121 631, FR-2 458 572 and FR-2 592 657 cited as reference.
Use may be made, for example, of the silanes of formula:
CH3Si(OCH3)3
CH3Si(OCH2CH3)3
CH3Si(OCH2CH2OCH3)3
Si(OCH2CH2OCH3)4
Si(OCH3)4
Si(OCH2CH3)4
CH2═CH—Si(OCH2CH2OCH3)3
C6H5Si(OCH3)3
C6H5Si(OCH2CH2OCH3)3
CH3Si[OCH2CH(CH3)(OCH3)]3
According to a particularly advantageous form, the organoalkoxysilane of formula (I) is tetraethoxysilane or tetramethoxysilane.
The dialkyltin salts of formula (II) are well known compounds described in particular in French patent FR-2 592 657 cited as reference.
Use may be made, for example, of the dialkyltin salts of formula:
(CH3COO)2Sn(CH3)2
(CH3COO)2Sn(n-butyl)2
(CH3COO)2Sn(n-octyl)2
[CH3(CH2)8COO]2Sn(CH3)2
[CH3(CH2)3CH(C2H5)COO]2Sn(CH3)2
(CH3COO)2Sn(CH2C6H5)2
[CH3(CH2)3CH(C2H5)COO]2Sn(CH3)2
[CH3(CH2)3CH(C2H5)COO]2Sn(n-butyl)2
[CH3(CH2)14COO]2Sn(n-butyl)2
[CH3(CH2)7—CH═CH—(CH2)7COO]2Sn(n-butyl)2
[CH3(CH2)12COO]2Sn(C2H5)2
[CH3(CH2)10COO]2Sn(n-butyl)2
[CH3(CH2)10COO]2Sn(n-octyl)2
According to a particularly advantageous embodiment, the dialkyltin salt of formula (II) is chosen from the group consisting of:
[CH3(CH2)3]2Sn[OCO(CH2)10CH3]2; and
[CH3(CH2)3]2Sn[OCOCH3]2
According to another preferred embodiment:
[CH3(CH2)3]2Sn[OCO(CH2)10CH3]2; or
[CH3(CH2)3]2Sn[OCOCH3)2
Mention may be made, as concrete examples of compounds of aminated polyalkoxysilane type (D3), of those with the following formulae:
The preparation of the aminated polyalkoxysilane compounds (D3) appears more specifically in U.S. Pat. No. 2,754,311, U.S. Pat. No. 2,832,754, U.S. Pat. No. 2,930,809 and U.S. Pat. No. 2,971,864.
It is particularly advantageous to use, as catalytic system (D), the following combination:
[CH3(CH2)3]2Sn[OCO(CH2)10CH3]2; or
[CH3(CH2)3]2Sn[OCOCH3]2
H2N(CH2)2NH(CH2)3Si(OCH3)3
In the above or the below, unless otherwise mentioned, the percentages are by weight.
The catalytic system which has thus been described is used to make possible or facilitate the curing to give silicone elastomers, from room temperature, of polyorganosiloxane bases crosslinkable by polycondensation reactions which are provided in the two-component form, the catalytic system being incorporated in one of the fractions with a crosslinking agent (B) while the other fraction comprises a reactive polyorganosiloxane (A) and water.
According to one embodiment of the invention, the organopolysiloxane composition according to the invention comprises:
The α,ω-dihydroxydiorganopolysiloxane reactive polymers (A) which can be used in the silicone bases according to the invention are more particularly those corresponding to the following formula (I):
in which formula:
It should be understood that, in the context of the present invention, use may be made, as reactive polyorganosiloxane (A), of a mixture composed of several hydroxylated polyorganosiloxanes which differ from one another in the value of the viscosity and/or the nature of the substituents bonded to the silicon atoms. Furthermore, it should be indicated that the hydroxylated polyorganosiloxanes of formula (1) can optionally comprise T units of formula R12SiO3/2 and/or Q units of formula SiO4/2 in a proportion of at most 1% (these % values expressing the number T and/or Q units per 100 silicon atoms).
Use is made of linear hydroxylated diorganopolysiloxane reactive polymers (A) having a dynamic viscosity at 25° C. ranging from 10 to 1 000 000 mPa·s and preferably ranging from 50 to 200 000 mPa·s.
A large majority of these base polyorganosiloxanes are sold by manufacturers of silicones. Moreover, their manufacturing techniques are well known; they are described, for example, in French patents FR-A-1 134 005, FR-A-1 198 749 and FR-A-1 226 745.
The R11 and R12 substituents mentioned above for the reactive polyorganosiloxanes (A) can be chosen from the following radicals:
Mention may be made, as examples of R11 and R12 radicals, of alkyl radicals having from 1 to 8 carbon atoms, such as methyl, ethyl, propyl, butyl, hexyl and octyl, vinyl radicals or phenyl radicals.
Mention may be made, as examples of substituted R11 and R12 radicals, of the 3,3,3-trifluoropropyl, chlorophenyl and β-cyanoethyl radicals.
In the products of formula (1) generally used industrially, at least 60% by number of the R11 and R12 radicals are methyl radicals, the other radicals generally being phenyl and/or vinyl radicals.
Mention may be made, as crosslinking agent (B), of:
R13kSi(OR14)(4−k) (2)
in which the R14 symbols, which are identical or different, represent alkyl radicals having from 1 to 8 carbon atoms, such as the methyl, ethyl, propyl, butyl, pentyl or 2-ethylhexyl radicals, or C3-C6 oxyalkylene radicals, the R13 symbol represents a saturated or unsaturated, linear or branched, aliphatic hydrocarbon group, a saturated or unsaturated and/or aromatic, monocyclic or polycyclic, carbocyclic group, and k is equal to 0 or 1; and
Mention may be made, as examples of C3-C6 alkoxyalkylene radicals, of the following radicals:
CH3OCH2CH2—
CH3OCH2CH(CH3)—
CH3OCH(CH3)CH2—
C2H5OCH2CH2CH2—
The R13 symbol represents a C1-C10 hydrocarbon radical encompassing:
The crosslinking agents (B) of formula (2) are products accessible in the silicones market; furthermore, their use in compositions curing from room temperature is known; it occurs in particular in French patents FR-A-1 126 411, FR-A-1 179 969, FR-A-1 189 216, FR-A-1 198 749, FR-A-1 248 826, FR-A-1 314 649, FR-A-1 423 477, FR-A-1 432 799 and FR-A-2 067 636.
Preference is more particularly given, among the crosslinking agents (B), to alkyltrialkoxysilanes, alkyl silicates and alkyl polysilicates, in which the organic radicals are alkyl radicals having from 1 to 4 carbon atoms.
The alkyl silicates can be chosen from methyl silicate, ethyl silicate, isopropyl silicate, n-propyl silicate and the polysilicates chosen from the partial hydrolysis products of these silicates; these are polymers composed of a significant proportion of units of formula:
(R14O)3SiO1/2, R14OSiO3/2, (R14O)2SiO2/2 and SiO4/2;
the R14 symbol representing the methyl, ethyl, isopropyl and/or n-propyl radicals. The basis for their characterization is usually their silica content, which is established by assaying the hydrolysis product of a sample.
Mention is more particularly made, as other examples of crosslinking agents (B) which can be used, of the following silanes:
CH3Si(OCH3)3; C2H5Si(OC2H5)3; C2H5Si(OCH3)3
CH2═CHSi(OCH3)3; CH2═CHSi(OCH2CH2OCH3)3
C6H5Si(OCH3)3; [CH3][OCH(CH3)CH2OCH3]Si[OCH3]2
Si(OCH3)4; Si(OC2H5)4; Si(OCH2CH2CH3)4; Si(OCH2CH2CH2CH3)4
Si(OC2H4OCH3)4; CH3Si(OC2H4OCH3)3; ClCH2Si(OC2H5)3;
Mention may be made, as other examples of crosslinking agent (B), of ethyl polysilicate or n-propyl silicate.
Use is generally made of 0.1 to 60 parts by weight of crosslinking agent of formula (2) per 100 parts by weight of reactive polymer of formula (1).
The compositions according to the invention can additionally comprise reinforcing or semireinforcing or bulking fillers (C) which are preferably chosen from siliceous fillers.
The reinforcing fillers are preferably chosen from pyrogenic silicas and precipitated silicas. They generally have a specific surface, measured according to the BET methods, of at least 50 m2/g, preferably of greater than 70 m2/g, a mean size of the primary particles of less than 0.1 μm (micrometer) and a bulk density of less than 200 g/liter.
These silicas can be incorporated as is or after having been treated with organosilicon compounds normally used for this use. These compounds include methylpolysiloxanes, such as hexamethyldisiloxane, octamethyltrisiloxane or octamethylcyclotetrasiloxane, methylpolysilazanes, such as hexamethyldisilazane or hexamethylcyclotrisilazane, chlorosilanes, such as dimethylchlorosilane, trimethylchlorosilane, methyl-vinyldichlorosilane or dimethylvinylchlorosilane, or alkoxysilanes, such as dimethyldimethoxysilane, dimethylvinylethoxysilane and trimethylmethoxysilane.
During this treatment, the silicas can increase their starting weight up to a level of 20%, preferably 18% approximately.
The semireinforcing or bulking fillers have a particle diameter of greater than 0.1 μm (micrometer) and are chosen from ground quartz, calcined clays and diatomaceous earths.
In addition to the main constituents (A), (B), (C) and (D), nonreactive linear polyorganosiloxane polymers (E) can be introduced with the intention of acting on the physical characteristics of the compositions in accordance with the invention and/or on the mechanical properties of the elastomers resulting from the curing of these compositions.
These nonreactive linear polyorganosiloxane polymers (E) are well known; they comprise more especially: α,ω-bis(triorganosiloxy)diorganopolysiloxane polymers with viscosities of at least 10 mPa·s at 25° C. formed essentially of diorganosiloxy units and of at least 1% of monoorganosiloxy and/or siloxy units, the organic radicals bonded to the silicon atoms being chosen from the methyl, vinyl and phenyl radicals, 60% at least of these organic radicals being methyl radicals and 10% at most being vinyl radicals. The viscosity of these polymers can reach several tens of millions of mPa·s at 25° C.; they thus comprise oils with a fluid to viscous appearance and soft to hard gums. They are prepared according to the usual techniques described more specifically in French patents FR-A-978 058, FR-A-1 025 150, FR-A-1 108 764 and FR-A-1 370 884. Use is preferably made of α,ω-bis(trimethylsiloxy)dimethylpolysiloxane oils with a viscosity ranging from 10 mPa·s to 1000 mPa·s at 25° C. These polymers, which act as plasticizers, can be introduced in a proportion of at most 70 parts, preferably of 5 to 20 parts, per 100 parts of the α,ω-dihydroxydiorganopolysiloxane reactive polymers (A).
The compositions according to the invention can in addition advantageously comprise at least one silicone resin (G). These silicone resins are branched organopolysiloxane polymers which are well known and which are available commercially. They exhibit, per molecule, at least two different units chosen from those of formula R′″3SiO1/2 (M unit), R′″2SiO2/2 (D unit), R′″SiO3/2 (T unit) and SiO4/2 (Q unit). The R″′ radicals are identical or different and are chosen from linear or branched alkyl radicals or the vinyl, phenyl or 3,3,3-trifluoropropyl radicals. Preferably, the alkyl radicals exhibit from 1 to 6 carbon atoms inclusive. More particularly, mention may be made, as alkyl R radicals, of the methyl, ethyl, isopropyl, tert-butyl and n-hexyl radicals. These resins are preferably hydroxylated and have, in this case, a content by weight of hydroxyl group of between 5 and 500 meq/100 g.
Mention may be made, as examples of resins, of MQ resins, MDQ resins, TD resins and MDT resins.
The crosslinking to give an elastomer of the polyorganosiloxane bases (by a polycondensation reaction) which has just been described is carried out under the effect of the catalytic system (D) defined above. These compositions crosslink at room temperature in the presence of water present in the composition.
For use of the silicone compositions according to the invention, each composition is produced in the form of a two-component system formed of two parts P1 and P2 intended to be brought into contact with one another in order to produce the crosslinked elastomer by polycondensation.
According to another of its aspects, the present invention relates to a two-component system which is a precursor of the organopolysiloxane composition according to the invention, characterized:
According to a preferred embodiment, the two-component system which is precursor of the organopolysiloxane composition according to the invention is characterized in that:
The two-component compositions according to the invention can be shaped, extruded or in particular molded according to varied shapes and then be cured at room temperature to give an elastomer.
The compositions in accordance with the invention can be employed for multiple applications, such as the formation of seals and/or adhesive bonding in the construction industry or the transportation industry (examples: motor vehicle, aerospatial, railroad, maritime and aeronautical), the assembling of the most diverse materials (metals, plastics, natural and synthetic rubbers, wood, boards, polycarbonate, earthenware, brick, ceramic, glass, stone, concrete and masonry components), the insulation of electrical conductors, the coating of electronic circuits and the preparation of molds used in the manufacture of items made of synthetic resins or foams.
In addition, they are suitable for the formation of “in situ” seals used in the motor vehicle industry. These “in situ” seals encompass several types, namely “flattened” seals (known as “flowed gasket” seals), “shaped” seals (known as “profiled” seals) and “injection-molded” seals.
The “flattened” seals are formed following the application of a pasty strip of the compositions to the region of contact between 2 metal or plastic components to be assembled. The pasty strip is first deposited on one of the components and then the other component is immediately applied to the first; this results in flattening of the strip before it is converted into elastomer. Seals of this type are aimed at assemblages which do not have to be taken apart in common practice (oil sump seals, timing case seals, and the like).
The “shaped” seals are also obtained following the application of a pasty strip of the compositions to the region of contact between 2 components to be assembled. However, after the deposition of the pasty strip on one of the components, the strip is given time to completely cure to give an elastomer and only at this moment is the second component applied to the first.
Furthermore, the seals, due to their rubbery or fluid natures, match all the unevennesses of the surfaces to have seals formed on them; for this reason, it is pointless:
(1) to carefully machine the metal surfaces which have to be brought into contact with one another, and
(2) to forcibly tighten the assemblages obtained; these distinguishing features make it possible, to a certain extent, to dispense with fastening seals, spacers or ribs usually intended to stiffen and reinforce the components of the assemblages.
As the compositions in accordance with the invention rapidly cure at room temperature and even in an enclosed environment, the result of this is that the “shaped” seals (and also the other “in situ” seals) resulting from the curing of these compositions are self-adhesive and can be manufactured under highly constricting industrial manufacturing conditions. For example, they can be manufactured on the normal assembly lines of the motor vehicle industry equipped with an automatic device for the deposition of the compositions. This automatic device very often has a mixing head and a depositing nozzle, the latter moving along according to the outline of the seals to be manufactured.
The compositions manufactured and distributed by means of this device have to have a curing time which is properly adjusted in order, on the one hand, to avoid the compositions from setting solid in the mixing head and, on the other hand, to obtain complete crosslinking after the end of the deposition of the pasty strip on the components on which seals are to be formed. These “shaped” seals are more especially suitable for cylinder head cover seals, gearbox case cover seals, timing spacer seals and even oil sump seals.
The injection-molded seals are formed in an enclosed environment, in cavities which are often completely closed; the compositions placed in these cavities are rapidly converted to elastomers. These seals can, for example, ensure the leaktightness of crankshaft bearings.
The compositions in accordance with the invention are also suitable for the formation of rapidly curing and self-adhesive seals and/or adhesives in other fields than the motor vehicle industry. Thus, they can be used to adhesively bond and to form seals with regard to plastic switch cabinets, to produce seals and/or adhesives:
The compositions in accordance with the invention are very particularly suitable for the formation of seals in an enclosed environment liable to be subjected to a heat treatment because of the type of application, for example for seals used to adhesively bond the components in domestic electrical appliances, such as baking ovens. This is because, in some applications, the seal has to withstand temperatures of greater than or equal to 100° C. while maintaining an adhesion in accordance with the requirements of the application.
Another subject matter of the invention relates to the use of a composition according to the invention or of a two-component system according to the invention in the manufacture of self-adhesive seals and/or of adhesives, in particular in the motor vehicle industry or in the field of domestic electrical appliances.
The final subject matter of the invention relates to a self-adhesive seal and/or an adhesive prepared by room temperature curing:
The invention also relates to the use of a composition according to the invention or of a two-component system according to the invention in the manufacture of self-adhesive seals and/or of adhesives, in particular in the motor vehicle industry or in the field of domestic electrical appliances.
The self-adhesive seal and/or the adhesive retain good adhesion after a heat treatment.
According to a specific form of the invention, the self-adhesive seal and/or the adhesive retain good adhesion after a heat treatment ≧100° C. for 3 days, that is to say:
According to a specific form of the invention, the self-adhesive seal and/or the adhesive retain good mechanical properties after a heat treatment; in particular, after a heat treatment ≧100° C. for 3 days, the mechanical properties are as follows:
The invention also relates to the use of a composition according to the invention or of a two-component system according to the invention in the manufacture of self-adhesive seals and/or of adhesives exhibiting properties of resistance to power unit fluids of use in particular in the motor vehicle industry.
According to a specific form of the invention, the self-adhesive seal and/or the adhesive according to the invention retain good mechanical properties after aging at 150° C. in a 0w30 oil for 3 days:
Other advantages and characteristics of the present invention will become apparent on reading the following examples, given by way of illustration and without implied limitation.
A two-component composition comprising the following parts P1 and P2 is prepared:
The compositions are given in table 1 below.
10 parts by volume of the component P2 are added to 100 parts by volume of the component P1. Self-adhesive seals are obtained which, even after a heat treatment at 220° C. for 3 days, exhibit a noteworthy adhesion to a glass/stainless steel support, as is shown by the results in table 2.
In order to evaluate the adhesive properties of the compositions (after mixing the two components P1 and P2) before and after a heat treatment at 220° C. for 3 days, mixed adhesive bondings (standard MNRPS-748, seal with a thickness of 1 mm) were carried out between glass/stainless steel.
10 parts by volume of the component P2 are added to 100 parts by volume of the component P1. Self-adhesive seals are obtained which, even after a maximum heat treatment (3 days at 220° C. or at 250° C. or at 300° C.) or a continuous heat treatment (1000 h at 250° C.), exhibit outstanding mechanical properties, as is shown by the results in table 3.
In order to evaluate the mechanical properties of the compositions (after mixing the two components P1 and P2) before and after a heat treatment, measurements of Shore A hardness (SAH) were carried out according to the instructions of standard ASTM-D2240 and measurements of elongation at break (E/B, %) and of tensile strength (T/S, MPa) were carried out according to the instructions of standard ASTM-D412. The results are recorded in table 3.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0506435 | Jun 2005 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR06/01342 | 6/14/2006 | WO | 00 | 8/3/2009 |
