FR2487403A1 - THERMAL SCREENING CONSTRUCTION ASSEMBLIES AND METHODS OF THEIR MANUFACTURING - Google Patents

Abstract

THE INVENTION CONCERNS THERMAL SCREENING CONSTRUCTION ASSEMBLIES AND THEIR MANUFACTURING METHODS. THE CONSTRUCTIONS INCLUDE TWO METAL ELEMENTS 2, 3 JOINED BY A THERMAL INSULATION ELEMENT 4 IN THE FORM OF A SILICONE ELASTOMER WITH A TEAR RESISTANCE OF AT LEAST 7DANCM; THE PREFERRED SILICONE ELASTOMERS ARE TWO-COMPONENT SILICONE RUBBERS CURABLE AT ORDINARY TEMPERATURE BY ADDITION OF A CURING AGENT AND THE TWO-COMPONENT HEAT-HARDENABLE SILICONE RUBBERS. CONSTRUCTIONS ACCORDING TO THE INVENTION MAY BE USED IN THE CONSTRUCTION OF WINDOWS, DOORS AND THE LIKE.

Description

1. Construction sets making thermal screen

and methods of their manufacture.

  The present invention relates to heat shield construction assemblies and methods

of their manufacture.

  More particularly, the invention relates to

  single units of construction with heat shield, commonly referred to as extruded thermal insulation elements which can be used in construction

  mullions, windows, doors, their casings

sis and the like.

  Insulating materials are well known in the field of

  construction and they are used whenever a heat transfer through a building element has to be limited. In the construction of mullions, windows and doors, the use of such composite elements made of an insulating material

  interposed between metallic elements of

  tion, is well known. These composite elements of

  truction, whether mullions, or

  movable, are necessary to prevent heat escaping from the inside of buildings towards

  outside through these building elements.

  They are also needed to help maintain

  maintain sufficiently high surface temperatures on interior elements to

form no condensation.

  There is known in the prior art an element of

  truction comprising a heat shielding device

  that consists of an elongated nesting element of iso-

  plastic thermal insulation with protrusions

  in elongated grooves of two elongated metal members to form a rigid unitary member. Various thermoplastic compounds have been used to form the plastic interlocking element, for example polyvinyl chloride, polypropylene and polyurethanes. In a particular embodiment, the grooves of the two elongated elements and the two protruding portions of the plastic element have a Maltese cross section. Various processes have been developed to manufacture

  building elements making thermal screen.

  In one of the processes, a metal element having a generally U-shaped groove of a composition is filled

  fluid resin insulation. The composition is then hardened.

  resinous portion and eliminates a portion of the metal element forming the base of the groove by milling

  to obtain a unit building element of iso-

thermal lation.

  In another process of the prior art,

  in the usual way two metal elements, preferably aluminum, each having a groove C.

  A rigid plastic element is then shaped with

  both spaced protruding portions that fit into the grooves of the two metal elements. We

  then slide the protruding portions of the

  in the grooves of the two metal elements

  to form a rigid assembly comprising two spaced apart heat conductive metal elements and a rigid plastic element strongly fitted with the two elements to thereby obtain a

  mechanical connection and an intermediate heat shield.

  According to a modification of this type of process, the portions of the grooves (of the two metallic elements)

  overflowing metal elements and

  protruding portions of the thermoplastic element

  are shaped, crimped or deformed so that the mechanical connection between the thermoplastic element and the metal element is also

Hermetic as possible.

  Also known in the prior art another method of preparing a building element

  thermal insulation which uses a metallic element

  extruded having a removable inner sliding metal section. The inner section of the extruded metal member is removed to separate spaced metal members which are maintained.

  practically in the same relationship as before the separation

  tion. A plastic material is inserted between the

  spaced metallic elements when the metal inner section is removed to

  in the form of a thermally insulated unit

  nomic. Until now, plastics were used in the prior art as thermal insulation materials

  in building elements with heat shields

  nomic. However, these materials have certain disadvantages. Hard rigid plastics such as polyesters, polyurethanes and epoxides,

  although they are of great interest as

  thermal insulation elements in the heat shielding elements, are particularly fragile in

  the effect of shocks and under the conditions of low tempera-

  which they may be exposed before

  mounting. Organic elastomeric plastics pre-

  although they pose no problem of resistance

  shock-resistant when used as thermal insulation materials in heat shielding elements, do not have sufficient longevity, are difficult to set up at low temperature and, during their aging, which is faster than that of the building, they tend to harden or weaken. The invention relates to an improved building assembly having a heat shield (thermal insulation) comprising two metal elements which are rigidly joined to each other by a hardened silicone rubber fitting element. In the invention, various cured silicone rubbers are used as thermal insulation materials in the manufacture of

  building sets making thermal screen.

  Among the silicone rubbers are the two-component, heat-curable, two-component silicone rubbers by addition of a curing agent and the two-way silicone rubbers.

  components, heat-curable. The rubber

  two-component curable silicone burs that are used as thermal insulation materials

  in the invention have a tear resistance

at least 7 daN / cm.

  The silicone rubbers of the present invention

  a considerable advantage over elasto-

  mothers previously used as isolation materials

  in thermally insulated building assemblies. They can be applied and hardened

  fewer stages than, for example, urethanes

  in liquid form. The silicone rubbers of the invention can tolerate variations in temperature more easily than the products of the prior art while retaining their structural characteristics and their thermal insulation characteristics. Moreover, they do not show any variation in these characteristics as a result of the aging or distortions to which they are subjected by their contact with metals undergoing variations due to

  heat such as expansion and contraction

  tion. The silicone rubbers of the invention resist

  They are also exposed to extreme heat conditions and fire, and they form very little smoke under the effect of fire. These properties are an important factor in the choice of building materials to reduce

  minimum dangers due to flammability and the emission of

  flue gas from building elements.

  The invention will be better understood on reading the

  following detailed description and examination of the

  annexed FIGURES in which: FIG. 1 represents a fragmentary section of a unitary construction unit with a heat shield consisting of two grooved metal elements mechanically joined by the interposition of a composition

  of two-component silicone rubber hardened

  holding a longitudinal reinforcing member; and FIG. 2 represents a fragmentary section of a metal element having three interconnected grooves

  whose hollow parts are filled with a composition

  two-component silicone rubber dur-

  cie and o a section of the metal element can

be removed by machining.

  The preferred embodiment of the invention will

now be described.

  Figure 1 illustrates a set form of

  improved unit truction comprising a thermal insulation element between two opposite metal elements. More particularly, as shown in this figure, the unitary construction unit comprises two spaced elongated metal elements, 2 and 3,

  united by a thermal insulation element 4 relative-

  rigidly formed of a cured silicone rubber composition. The heat insulating element 4 is a single elongated strip of unitary structure having two elongate elongate protruding portions 7 and 8. The two metal members 2 and 3 are formed to have elongate grooves 5 and 6 having a cross section. C with parallel openings

  opposites which are preferably images of one of the

  be. In addition, the grooves have recesses 9 and 10 whose size and shape correspond to the

  protrusions 7 and 8 of the element 4 of thermal insulation.

  The elongated C-shaped grooves each consist of an upper wall 11 and a lower wall 12 associated with the flanges 13 and 14 to form the elongated rectangular recesses 9 and 10 which in

  the finished set receive the projections 7 and 8 of the ele-

  4. Otherwise, the elongate grooves 5 and 6 may have a decreasing section, not shown, the narrowed portion of which comprises the openings receiving the thermal insulation element. The interior walls

  these grooves with decreasing cross-section may

  wedge-shaped wedge ribs. In this modification, the projections 7 and 8 of the thermal insulation element 4 of silicone rubber also have a decreasing section whose size and

  the shape correspond to the grooves with decreasing section

  health. In a modified structure that is not shown either, the upper and lower walls 11 and

  12 C-grooves can be folded towards the inside.

  laughter so that these grooves grip better the element

  thermal insulation made of silicone rubber.

  In a method of manufacturing a thermal barrier construction assembly in which the thermal insulation material is a silicone rubber, a metal element such as is used is extrusion formed in a manner known in the art. in the construction of mullions and moving frames and

  dormant. The extruded metal element is preferably

  aluminum or aluminum alloy. Each of these extruded elements, as illustrated in FIG. 2, has a structure similar to that of two extruded metal elements illustrated in FIG. 1, the only difference being that a metal element of union

  joins the flanges 14 to form a unitary unit.

  This type of extruded member has an additional elongated groove between the flanges 13 and 14 and a recess is located between the recesses 9 and 10 of the grooves

in C 5 and 6.

  After forming the extruded metal member, the uncured silicone rubber composition is poured, injected or otherwise inserted into recesses 9, 10 and mutually elongated grooves.

  met. The rubber composition is then cured.

  silicone rubber suitably according to whether it is curable at ordinary temperature or hardenable

  hot. As soon as the silicone rubber composition

  cone is cured, milling or otherwise removing the portion of the extruded metal member

  between the outer edges 14 and more particularly

  between the discontinuous lines of FIG. 2. In the assembly obtained, only the cured silicone rubber extends between the grooves 5 and 6 and constitutes

  a rigid thermal insulation element of the assembly.

  In another method of manufacturing a thermal barrier construction assembly whose heat shield is formed of a silicone rubber, two elements are extrusion formed in the usual way.

  of metal construction, one corresponding to the

  2 and the other to the element 3 of Figure 1. The extruded metal elements are preferably made of aluminum or an aluminum alloy. The extruded metal elements each comprise a groove in

  C, 5 or 6, the openings of these grooves being parallel

  between them and an extruded element being pre-

  image of the extruded element that corresponds to it.

  It is shaped and hardened by extrusion well

  known in the art the rubber composition of

  which is used as an insulation element

  to give it a form such that the element

  The silicone rubber thermal insulation element has two projections 7 and 8 whose size and shape correspond to the grooves of the two extruded metal elements. In one embodiment, the extruded hardened silicone rubber member may include an embedded reinforcing member

  16 of any suitable material

  sistante, which extends longitudinally in the element 4 of thermal insulation to increase its rigidity and strength. For example, the reinforcing member 16 may be made of an elongate aluminum strip disposed at the center of the insulation member

  thermal silicone rubber hardened and extended

  over its length. When the extruded silicone rubber element has been formed and hardened, it is joined to the two extruded cylindrical elements by

  slide or by gradually inserting the two doors

  7 and 8 of the extruded element 4 of silicone rubber cured in the grooves C, or 6, of the two extruded metal elements, to obtain a rigid construction assembly making

Thermal screen.

  The grooves of the extruded metal elements

  above and the corresponding thermal insulation element

  They may have any suitable section for interlocking these elements. we know

  in the prior art a large number of forms,

  appropriate configurations and configurations of the elements

  Such heat insulation assemblies are readily available to those skilled in the art and can easily be adapted to the grooves and projections of the extruded members of the assemblies of the invention. In addition, the interior surfaces of

  various grooves, which are in contact with the material

  Thermal insulation materials may be structured, for example, with points, perforated, ribbed, roughened and the like to promote and

  strengthen the union between the thermal insulation element

  that and the extruded metal elements.

  Silicone rubber compositions with two

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  temperature-addition curable components

  (RTV) that can be used in the pre-

  This invention is well known in the art. The breeds

  US Pat. Nos. 3,436,366 and 3,847,848 describe

  detailed description of silicone rubber

  appropriate methods and methods of preparing them

  ration. In particular, US Patent No. 3,436,366 discloses

  written two-component silicone rubber compositions

  vulcanizable components cured by addition to the temperature

  ordinary temperatures which include by weight:

  (a) 100 parts of a liquid polysiloxane having

  vinyl chains having the formula: R2 Rp2 l 2

1 1 2 1

CH2 = CH-SiO SiO SiCH = CH2 n

  o R and R 'represent hydrocarbon radicals mo-

  novalents without aliphatic unsaturation, at least 50 mol% of the radicals R 'being methyl radicals and n is sufficient for the viscosity to be about 50 000 to 750 000 cSt at 25 C and preferably about 50 000 to 150,000 inclusive;

  (b) 20 to 50 parts of an organopolysilicon copolymer

  siloxanes comprising (R ") 3-SiO0,5 units and

  SiO2 units o R "is chosen from among the vinyl radicals

  and monovalent hydrocarbon radicals without aliphatic unsaturation, the ratio of (R ") 3-SiO 0.5 units to SiO 2 units being from about 0.5 / 1 to 1: 1 and about 2.5 to 10 mole% silicon atoms carry silicon-bonded vinyl radicals; (c) 0 to 200 parts of a finely mineral

  divided does not constitute a reinforcement of

  silicone mothers; (d) a platinum catalyst; (e) an amount of a liquid organohydrogenpolysiloxane of formula:

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  (R) (H) Sio4ab ab 4-ab sufficient to provide about 0.5 to 1.0 silicon-bonded silicon atom per silicon-bonded vinyl radical in the composition, where R has the same definition as above , a has a value of 1.00 to 2.10, ba a value of about 0.1 to 1.0 and the sum of a and ba a value of about 2.00 to 2.65, with at least two hydrogen atoms joined to silicon

per molecule.

  An example of a polysiloxane with

  of vinyl chains constituting the

  (a) silicone rubber compositions

  Addition-hardened RTVs, an organopolysilicon

  dimethylvinyl terminated loxane having a viscosity of about 550,000 cSt at 250C and

  a diphenylvinyl chain terminated copolymer

  It is composed of diphenylsiloxane units and dimethylsiloxane units and has a viscosity of about 150,000 cSt at 25 C. An example of the organopolysiloxane copolymer constituting

  the compound (b) rubber compositions of

  addition-hardened RTV resin, a copoly-

  of trimethylsiloxane units, SiO 2 units and methylvinylsiloxane units containing about 0.8 units of trimethylsiloxane per SiO 2 unit and about 7.0 mole% of the silicon atoms are present in the form of methylvinylsiloxane units, the of remaining silicon constituting a part

  a trimethylsiloxane unit or a SiO 2 unit.

  Finely divided mineral fillers constituting

  component (c) -silicon rubber compositions

  addition-hardened RTV cones can

  take virtually any type of finely divided mineral material, for example ground quartz, titanium dioxide, calcium silicate, ferric oxide, chromic oxide, glass fibers, calcium carbonate , carbon black,

lithopone and the like.

  The platinum catalyst constituting the component (d) used in the rubber compositions of

  addition-hardened RTV silicone, is

  by any of those that catalyze the reaction between silicon-bonded hydrogen radicals and silicon-bonded vinyl radicals. Among these

  materials are the platinum catalysts

  finely divided, chlo- acid catalysts

  platinum-hydrocarbon complexes and platinum alkoxide catalysts. These catalysts are well known in the art. The catalyst is used in an amount sufficient to provide about 10-3 to 10-6 gram atoms of platinum per mole

  vinyl radical united with silicon in the composition.

  Organohydrogenpolysiloxane, constituting the

  (e) adding additionally cured RTV silicone rubber compositions may be a

  1,3,5,7-tetramethylcyclotetrasiloxane, a dimethyl

  dimethyl chain-terminated lysiloxane

  hydrogen containing 2 to 3 silicon atoms per molecule

  or a copolymer consisting of dimethyl-

  siloxane, methylhydrogensiloxane units and trimethylsiloxane units and containing 2 to 5 or 10

  silicon atoms or more per molecule.

  To prepare RTV silicone rubber

  cis by addition above, the mixture is suitably

  all components (a), (b), (c), (d) and (e) previously described and the mixture is maintained at the temperature at which it cures. Although the silicone rubbers of the invention can be prepared

  by simply mixing the various components together

  property, it is often convenient to prepare

  these compositions into two separate

  it is combined extemporaneously to obtain the rubber

solid elastic rubber hardened.

  It is used as thermal insulation element

  in building sets with heat shields

  of the invention, those of these compositions of

  pre-added RTV silicone rubber

  previously described that have a tear-resistance

  at least 7 daN / cm. These components can be used

  hardened silicone rubber in one

  any of the previously described methods of manufacturing

  cation building sets making screen

  thermal. These compositions have characteristics

  desirable self-leveling features that ensure the production of void-free molded

  accurate reproduction of model details.

  General Electric Company manufactures dimeric forms

  of the previously added addition-cured RTV silicone rubber compositions which can be used in the building element

  making thermal screen of the invention and the traders

  under the following names: 2-Component RTV-630, 2-Component RTV-631, 2-Component RTV-632, 2-Component

  RTV-662, 2-Component RTV-664 and 2-Component RTV-668.

  U.S. Patent No. 3,847,848 describes another class of

  A class of two-component silicone rubber compositions which are cured by addition to the ordinary temperature, wherein the first component comprises: (a) a linear base fluid diorganopolysiloxane containing silicon-bonded hydroxyl end groups having a viscosity of 1000 to 000 000 cP at 25 ° C., the organic radicals of this diorganopolysiloxane being chosen from monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radicals, and

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  (b) from 5 X to 300% by weight, based on the weight of the linear basic diorganopolysiloxane, of

treated silica filler.

  The silica filler of these addition-cured RTV silicone rubber compositions is prepared by (a) contacting 100 parts of silica filler having a surface area of at least

  m2 / g and containing 0.2% to 2% by weight of

  selected from hydroxy, water and mixtures thereof, with: (1) 0.5 to 5 parts of a hydroxylamine of formula: R2

(A) R '- N - OH

  (2) 2 to 25 parts of a cyclic siloxane of

  (B) (R2SiO) n and (3) 1 to 20 parts of a silyl nitrogen compound of formula: (C) (R4Si) aX

  the above additives being simultaneously

  tact with this charge at a temperature included in

  range from 100 C to 180 C and (b) elimination of quantities

  Residualities of these additives in the feed. In

  this silica filler, R 'is selected from the radicals

  monovalent hydrocarbon clays and the hydro-radicals

* halogenated monovalent carbon; R2, R and R are all chosen from a hydrogen atom, radicals

  monovalent hydrocarbons and hydrocarbon radicals

  monovalent halogenated animals; n varies from 3 to 4; a is 1 or 2; X is selected from the radicals -NR Y, Y

I R5

  -ONR2 and -N- o R is selected from the hydro-radicals

  monovalent carbon and monovalent halogenated hydrocarbon radicals and Y is selected from an atom

248? 40

of hydrogen and the radicals R5.

  The second component of these rubber compositions

  two-part RVT silicone rubber

  % by weight, based on the weight of the diorganopolys-

  linear siloxane base of a silicate selected from the group consisting of (I) a monomeric organosilicate having the general formula: (D) (R50) 3SiR6

  or R5 is a radical selected from hydrogen radicals

  monovalent carbon, the monohydric hydrocarbon radicals

  halogenated valents and cyanoalkyl radicals and R6

  is chosen from alkyl radicals, halogenoalkyl

  coyles, aryls, haloaryls, alkenyls, cycloalkyl

  cysts, cycloalkenyls, cyanoalkyls, alkoxy and acyl-

  loxy and (II) a liquid product of partial hydrolysis of the aforementioned organosilicate. The second component of these addition-cured RTV silicone rubber compositions also contains 0.1 to 5% by weight, based on the weight of the linear diorganopolysiloxane, of a catalyst which is a carboxylic acid salt,

  an alcoholate, a hydroxide or an oxide of a metal

  taken in the range from lead to manganese in the series of electromotive forces of metals, such as lead, tin, zirconium, antimony, iron, cadmium, barium, calcium, titanium, bismuth and manganese, the catalytic metal that one

  particularly preferred being tin.

  In addition to the ingredients above, we also use

  in the first component of these addition-cured RTV silicone rubber compositions, a tert-alkoxypolysiloxane having a viscosity of 1000 to 10,000 cP at 25 C as described in US Pat. No. 3,438,930, and a first agent of lowering of viscosity and deepening of formula:

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R7 (E) H0 SiO H R7 P

  having a viscosity of 10 to 100 cSt at 25 C and a

  viscosity lowering fluid of formula:

R8 R8 R8

8 'I 8

(F) R -i Si Q-Si-R

18 18 18

  having a viscosity of 5 to 10,000 cP at 25 ° C, wherein R is a radical selected from monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radicals; p is an integer from 2 to 46; R8 is a chosen radical

  among the alkyl radicals, the alkyl radicals

  the aryl radicals, the halogenated aryl radicals,

  genes and cyanoalkyl radicals contain up to 8 carbon atoms; and S is an integer from 2 to 700. The tert-alkoxypolysiloxane fluid is present at a concentration of about 5% to 50% by weight based on the linear base diorganopolysiloxane. The first

  viscosity lowering agent (formula E

  above) is present at a concentration of approximately

  0.5% to 5% by weight relative to the basic linear diorganopolysiloxane. The second viscosity lowering agent

  (formula F above) is present at a concentration of 0% to 70% by weight relative to

  to the basic linear diorganopolysiloxane.

  The organopolysiloxanes (a) which are preferred in the first component of these rubber compositions

  RTV silicone compounds can be

  flavored by the average pattern formula: RmSiO4-m

  or R is selected from monohydrocarbon radicals

  and the value of m can vary between 1.99 and 2. The average formula of the unit covers organopolysiloxanes having terminal radicals other than radicals.

  hydroxyl radicals, such as single-functional terminal

  and trifunctional. It is preferred that the hydroxy, monofunctional and trifunctional terminal groups

be kept to a minimum.

  A typical example of these addition-cured RTV silicone rubber compositions is

  an organopolysiloxane consisting of 70 parts of

  silanol terminated thylpolysiloxane having a

  viscosity of 30,000 cP at 250C; 30 parts of polydi

  tert-butoxy-terminated methylsiloxane and silanols having an OH / tert-butoxy ratio of 2.7 and having

  a viscosity of 3000 cP; 27 parts of a polydimed

  trimethylsilyl-terminated thylsiloxane having

  a viscosity of 20 cP at 25 C and 1.8 parts of a poly-

  silanol-terminated dimethylsiloxane having a

  in silanol of 6.8% by weight and a viscosity of

15 cP at 25 C.

  With regard to the treated filler contained in this addition-cured RTV silicone rubber composition, the initial treated filler may be

  consisting of an ultrafine silica or a pre-silica

  or otherwise the treated feedstock may contain 5% to 95% by weight of ultrafine silica with the remainder being precipitated silica. The charges of

  silica which is used in the invention generally have

  a specific surface area that can vary between

  minimum of 50 m2 / g and a maximum of 300 to 500 m2 / g.

  An example of such silica fillers is constituted

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  90 parts of ultrafine silica having a surface area of 200 m 2 / g and 10 parts of silica

  precipitate having a surface area of 300 m 2 / g.

  The compound of formula (A) which is particularly preferred

  specifically to treat the silica filler is hydroxyethylamine. The compound of formula (B) which is particularly preferred for treating the silica filler is hexamethyltrisiloxane and the compound of formula (C) which is particularly preferred.

is hexamethyldisilazane.

  In addition to the treated filler, in the above addition-cured RTV silicone rubber compositions, at a concentration of 5% to 100% based on the weight of the linear base linear diorganopolysiloxane, an untreated filler such as titanium dioxide, lithopone, zinc oxide, zirconium silicate, glass fibers, magnesium oxide, zirconium oxide, crushed quartz, asbestos, graphite, fibers

synthetic and similar.

  In the second component of the rubber compositions

  RTV silicone rubber in two parts hardened by ad-

  Examples of useful silicates include propyl silicate, ethyl silicate, and polypropyl silicate. Examples of useful catalysts present in the second component include zinc naphthenate, cobalt naphthenate, and lead naphthenate, zinc octanoate, cobalt octanoate, lead octanoate,

  chromium octanoate and tin octanoate, the car-

  bomethyloxyphenyltin, cycloalkyl triactotinate

  hexenyl-lead, dibutyltin dilaurate, di-

  dibutyltin octanoate, diphenyl diformate

  tin, diallyl-tin di-2-hexenoate, acrylate

  tricyclohexyl tin, tristearyl succinate

  tin, dibutyltin dimethoxide, tetramethyl

tin late and the like.

  In the preferred embodiment, the second component of RTV silicone compositions in two

  previous hardened parts, shall be

  of a mixture of a monomeric organosilicate, a metal catalyst and an aqueous solution of an alcohol, such as a 2% by weight aqueous solution of N, N-propyl alcohol, the amount of the aqueous solution of alcohol may vary from 0.1% to 10% by

  weight relative to the weight of the mono-organosilicate

mother.

  the silicone rubber compositions are prepared

  by addition of the above two components of the invention by simple mixing of the two aforementioned components of

  any appropriate way. These composites are used

  of RTV-cured silicone rubber

  With a tear strength of at least 7 daN / cm as thermal insulation elements in the thermal barrier construction assemblies of the invention. These cured silicone rubber compositions can be used in any of the previously described methods of making thermal barrier construction assemblies. These compositions have desirable characteristics

  self-leveling devices that ensure the

  free of voids and precise reproduction of details. General Electric Company manufactures a form of these silicone rubber compositions

  that can be used in building sets

  thermal shielding of the invention and

  commercialized under the name of 2-Component RTV-700.

  The hot-cured silicone rubbers useful in the invention are described in US Pat.

  No. 3,730,932. The compositions of the silicone rubber

  Two-component hot-cured cones of US Patent No. 3,730,932 include:

  (a) from 82% to 99.65% by weight of an organopolysiloxane

  polymeric siloxane of the formula: (1) RaSiO4 a

2

  R is chosen from monohydrocarbon radicals

  valents and halogenated monovalent hydrocarbon radicals

  and ranges from 1.95 to 2.01; having a molecular weight

  in the range of 100,000 to 2,000,000 and a viscosity of 100,000 to 100,000,000 cP at 250C; (b) from 20% to 60% by weight, based on the weight of the organopolysiloxane, of a finely divided filler

  having a strong reinforcing effect consisting of

  mineral deposits; (c) from 1% to 25% by weight relative to the weight of

  the organopolysiloxane of an implementation aid em-

  fishing that the mixture of polymer and filler

  coming before hardening, of formula:

R R O

I

SC (CH2) n - Sio SiO Si- (CH2) n CX

I I I

R R b R

  R represents a methyl or phenyl radical, X represents

  has a radical -OH, -NH2 o -OR ', where R' is methyl or ethyl, n is 2 to 4 inclusive and b is zero or a number

integer from 1 to 10 inclusive.

  Organopolysiloxanes of formula (1)

  of hot-cured silicone rubber can

  can be copolymers containing 2 dior

  ganosiloxane or more and copolymers of

  dimethylsiloxane units and methylphenol units

  nylsiloxane; or copolymers of methyl

  phenylsiloxane, diphenylsiloxane units,

  of dimethylsiloxane and methylvinyl-

  siloxane, as well as copolymers of

  methylsiloxane, methylvinylsiloxane units and

of diphenylsiloxane units.

  Generally, a small amount of

  monofunctional poses as chain terminators to adjust the length of the polymer chains. A preferred compound useful as a chain terminating agent has the formula:

CH3 CH3

I I

  (CH3) 3-SiO-SiO-SiO-Si- (CH3) 3

CH3 CH3

  An example of an organopolysiloxane constituting component (a) of heat-hardened silicone rubber has the formula: ## STR2 ##

  The charge constituting the component (b) of the compounds

  of silicone rubber hardened by the chain.

  is characterized by a particle diameter -8 less than 5 x 10-8 m and a specific surface area greater than 50 m 2 / g. Examples of suitable fillers are titanium dioxide, iron oxide, aluminum oxide, diatomaceous earth,

  calcium carbonate and quartz.

  The processing aid constituting the component (c) of the heat-curable silicone rubber compositions may also be selected from

  dihydrocarbon substituted oils and organo-

  hydroxylated polysiloxanes. We can cite as examples

  a completed chain dimethyldiphenylsiloxane

by alkoxy radicals.

  The aforementioned heat-cured silicone rubber compositions are cured with chemical curing agents and any of the conventional curing agents may be used. Preferred curing agents are organic peroxides conventionally used to cure silicone elastomers. Dimethyl peroxides corresponding to the formulas developed:

R R R

I I I

R -C -R R C- C - (CH2) n R

I I I

O O O

I! I

0 0

I I I

R-C-RR-C-R R-C-R

I II

R R R

  the symbols R represent the same alkyl radical or alkyl radicals of two or more different types and n is equal to zero or to an integer,

are particularly appropriate.

  Examples of hardening agents are

  peroxide type which is particularly preferred.

  for heat-curable silicone rubber compositions, di-tert-butyl peroxide, tert-butyl peroxide and triethylmethyl peroxide, tert-butyl peroxide and tert-butyltriphenyl peroxide and a di-tert peroxide alkyl such as dicumyl peroxide. Other appropriate agents that provoke

  hardening by means of hydrogen radicals

  saturated and unsaturated carbon of the silicon chain

  are aryl peroxides such as benzene peroxide

  zoyl, mixed peroxides of alkylaryl among

  which include tert-butyl perbenzoate, chloroalkyl peroxides such as

  1,4-dichlorobenzoyl, 2,4-dichlorobenzoyl peroxide

  zoyl, benzoyl peroxide and the like. generation

  In addition, the rubber composition is used to harden the rubber composition.

  silicone rubber, 0.1% to 8% of such peroxide

  relative to the weight of the polydiorganosiloxane polymer.

  The above heat-curable silicone rubbers can be converted to a solid elastomer at temperatures ranging from 80 to 6500C depending on the nature of the curing agent, the curing time, the amount and the nature of the curing agent. the charge and the like. We can harden the compositions

  with hot air, steam or heat

  oven fries. Although it is possible to prepare the

  cured silicone rubber compositions of the invention

  simply by mixing the various components together

  appropriate, and the provision of the necessary heat

  it is often practical to prepare these

  in the form of two separate components that are combined in the transformation under the effect of the

  heat into a hardened solid elastic form.

  We use as thermal insulation elements

  in building sets with heat shields

  of the invention those of these compositions of

  heat-cured silicone rubber

  having a tear strength of at least

  7 daN / cm. These rubber compositions can be used

  silicone bunch hardened by heat in one

  any of the previously described methods of manufacturing

  cation building sets making screen

  thermal. When using the rubber compositions

  With respect to the above-mentioned heat-hardened silicone rubber, it is preferable that the method of manufacture comprises forming an elongate cured silicone rubber strip which can be slid between the two elongated metal members to form

  the construction set making thermal screen.

  However, one can sink, inject, extrude

  otherwise, deposit the uncured silicone rubber compositions in the elongate channels of a metal member and cure in situ. Next, the bottom of the elongate central metal groove is removed by milling or the like to form an assembly.

  rigid construction making thermal screen.

  General Electric Company manufactures a form of these above heat-curable silicone rubber compositions that can be used in the thermal barrier construction elements of the invention and markets it as Blensil Silicone Rubber. made of

Blensil 44U and Blensil 88U.

  In addition to the particular silicone rubber compositions and the previously mentioned examples, a number of other compositions may be used as the thermal insulation material according to the invention.

  two-component silicone rubber which

  at room temperature by the addition of a curing agent and having a tear strength of at least 7 daN / cm and many other two-component curing rubber compositions which cure under the effect of heat and that have tear resistance

at least 7 daN / cm.

Claims (17)

  A heat shield construction assembly having a thermal insulation member with projecting portions which engage strongly with a pair of spaced elongate metal members, characterized by comprising an insulation member   made of a rubber composition of   hardened resin having a tear strength of at least minus 7 daN / cm.   2. Thermal insulation element according to the   cation 1, characterized in that the cured silicone rubber composition is selected from   two-component silicone rubber compositions   curable at room temperature by ad-   of a curing agent and the compositions   two-component silicone rubber hardened by heat.   3. Thermal insulation element according to the   cation 1, characterized in that the silicone rubber   hardened cone has an incor-   pored having high mechanical strength.   4. Thermal insulation element according to the   cation 2, characterized in that the compositions of   two-component silicone rubber which hardens   at the ordinary temperature are silicone rubbers comprising by weight:   (a) 100 parts of a liquid polysiloxane having   combinations of vinyl chains corresponding to the formula R2 R 'R2 12 1 1   CH 2 = CH-SiO SiO SiCH = CH 2 n o R and R 'are monovalent hydrocarbon radicals without aliphatic unsaturation, at least 50 mole%   radicals R 'being methyl radicals and n is   sufficient for the viscosity to be about 1000 to 750 000 cSt at 25 C;   (b) 20 to 50 parts of an organopolysilicon copolymer   siloxanes comprising units of formula (R ") 3-SiO0.5   and SiO2 units o R "is selected from among the   vinyl radicals and monovalent hydrocarbon radicals without aliphatic unsaturation, the ratio of   (R ") 3-SiOo0.5 units with the SiO2 units being   taken from about 0.5: 1 to 1: 1, and about 2.5 to about 1: 1 mole% of the silicon atoms are vinyl moieties bonded to silicon;   (c) from 0 to 200 parts of a fine mineral   split which has no reinforcing property of silicone elastomers; (d) a platinum catalyst; (e) an amount of a liquid organohydrogenpolysiloxane of formula: (R) a (H) bSiO4-a-b sufficient to provide about 0.5 to 1.0 silicon-bonded hydrogen atom per united vinyl radical   silicon in the composition, o R has the same   As previously, a has a value of 1.00 to 2.10, b has a value of about 0.1 to 1.0 and the sum of a and b varies from 2.00 to 2.67, with at least   two silicon-bonded hydrogen atoms per molecule.   5. Thermal insulation element according to the   cation 2, characterized in that the silicone rubber compositions which cure at ordinary temperature are silicone rubbers comprising: (a) a basic linear fluid diorganopolysiloxane   containing silicone-terminal hydroxyl radicals   and having a viscosity of 1000 to 10 000 000 cP   at 25 C, the organic radicals of this diorganopoly-   siloxane being selected from monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radicals; (b) from 5 X to 300% by weight, based on the weight of the linear base diorganopolysiloxane, of a treated silica filler prepared by (I) contacting portions of a silica filler having a specific surface area of at least 50 m 2 / g and containing 0.2% to 2% by weight of fragments selected from hydroxyl groups, water and mixtures thereof, with: (1) from 0.5 to 5 parts of a hydroxyamine of formula : R2 2 (A) R '- N - OH   (2) from 2 to 25 parts of a cyclic siloxane of   mule: (B) (R2SiO) and (3) from 1 to 20 parts of a silyl nitrogen compound of the formula: (C) (R3Si) aX the above additives being brought into simultaneous contact with said feedstock at a temperature of in the range of 100 to 1800C, and   (II) elimination of the residual quantities of the said   ditifs of the charge; o R 'is chosen from among the   monovalent hydrocarbon radicals, hydrogen radicals, R2 3 4   halogenated monovalent carbon; R2, R and R are all selected from hydrogen, monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals; n varies from 3 to 4; a is 1 or 2; X is selected from the radicals -NR Y, Y I 5   -ONR2 and -N- o R is selected from among the radicals   monovalent hydrocarbons, halogenated monovalent hydrocarbon radicals and Y is selected from hydrogen and R5; (c) from 1% to 15% by weight, based on the weight of the linear basic diorganopolysiloxane of a silicate,   selected from the group consisting of (I) an organosilicon   monomeric compound having the general formula: 6   (D) (R 50) 3 SiR o R 5 represents a radical chosen from monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radicals and   R6 is selected from alkyl, haloalkyl and   alkyl, aryl, haloaryl, alkenyl, cycloalkyl, cycloalkenyl, cyanoalkyl, alkoxy and acyloxy and (II)   a liquid product of partial hydrolysis of the organo-   silicate mentioned above; and (d) from 0.2% to 5% by weight of a catalyst of   hardening relative to the weight of the diorganopolysi- basic linear loxane.   6. Thermal insulation element according to the claim   2, characterized in that the curable two-component silicone rubber compositions   by heat are silicone rubbers taking:   (a) from 82% to 99.65% by weight of an organopolysilon   xane polymer of formula: (1) RaSio4_a   R is chosen from monohydrocarbon radicals   valents and monovalent hydrocarbon radicals   ranging from 1.95 to 2.01, having a molecular weight in the range of 100,000 to 2,000,000 and a viscosity of 100,000 to 100,000,000 cP. at 250C;   (b) from 20% to 60% by weight, based on the weight of the organopolysiloxane, of a finely divided filler with high reinforcing power consisting of inorganic compounds; (c) from 1% to 25% by weight relative to the weight of the organopolysiloxane of a processing aid chosen from dihydrocarbon substituted oils,   hydroxylated organopolysiloxanes and a compound of mule R R O   1 SCI (CH 2) n SiSiOSiO i (CH2) n CX R R R b   o R is a methyl or phenyl radical, X is a radical   dical -OH, -NH2 or -OR ', where R' is a methyl or ethyl radical, n is 2 to 4 inclusive and   b is zero or an integer from 1 to 10   sively; and (d) from 0.1% to 8% by weight based on weight   of the organopolysiloxane of a hardening catalyst is lying.   7. Improved construction element with heat shield characterized in that it comprises:   (a) a pair of elongated metallic elements   those having elongate grooves with opposite parallel apertures; and   (b) an elongated thermal insulation element   taking a cured silicone rubber strip having a tear strength of at least 7 daN / cm and having opposed protruding portions positioned in said grooves to interlock closely   with said pair of elongated metal members.   8. An improved heat shield construction assembly according to claim 7, characterized in that said cured silicone rubber strip is   composed of a composition selected from among   two-component silicone rubber compositions which are curable at room temperature by the addition of a curing agent and the curable two-component silicone rubber compositions by the heat.   9. An improved heat shield construction assembly according to claim 7, characterized in that   that the thermal insulation element has an element   incorporated reinforcement with resistance high mechanical   The heat shield construction assembly of claim 8, characterized in that said cured silicone rubber web is formed of a two-component high temperature curable silicone rubber composition comprising by weight:   (a) 100 parts of a liquid polysiloxane having   Vinyl chain sounds corresponding to the formula: R R 'R2 12 2 12   In which R and R 'are monovalent hydrocarbon radicals without aliphatic unsaturation, at least mole% of the radicals R' being methyl radicals and n is sufficient for the viscosity to be about 50,000 to 750,000 cSt at 250C;   (b) 20 to 50 parts of an organopolysilicon copolymer   siloxane comprising units of formula (R ") 3-SiO0,   and SiO2 units o R "is selected from the radicals   vinyl and monovalent hydrocarbon radicals without aliphatic unsaturation, the ratio of -R ") 3-SiO0 units to SiO2 units being between about 0.5 / 1 and 1/1, and about 2.5 to 10 mol% of the silicon atoms bear vinyl radicals bonded to silicon;   (c) from 0 to 200 parts of a fine mineral   split which has no reinforcing property of silicone elastomers; (d) a platinum catalyst; (e) an amount of a liquid organohydrogenpolysiloxane of formula: (R) a (H) bSiO4-ab sufficient to provide about 0.5 to 1.0 silicon-bonded hydrogen atom per silicon-bonded vinyl radical in the composition , o R has the same definition as above, has a value of 1.00 to 2.10, ba is a value of about 0.1 to 1.0 and the sum of a and b varies from 2.00 at 2, 67, with at least two   silicon-bonded hydrogen atoms per molecule.   11. Set of construction-making thermal screen   according to claim 8, characterized in that   said cured silicone rubber strip is formed   formed of a silicone rubber composition hardened   two-component ordinary temperature sand comprising: (a) a basic linear fluid diorganopolysiloxane   containing silicone-terminal hydroxyl radicals   and having a viscosity of 1000 to 10 000 000 cP   at 25 C, the organic radicals of this diorganopoly-   siloxane being selected from hydrocarbon radicals   monovalent, halogenated monovalent hydrocarbon radicals and cyanoalkyl radicals; (b) from 5% to 300% by weight, based on the weight of the linear base diorganopolysiloxane, of a treated silica filler prepared by (I) contacting 100   parts of a silica filler having a specific surface area   of at least 50 m 2 / g and containing 0.2% to 2% by weight of moieties selected from hydroxy, water and mixtures thereof, with: (1) from 0.5 to 5 parts of hydroxylamine of formula: R2 I (A) R '- N - OH   (2) from 2 to 25 parts of a cyclic siloxane of   mule: (B) (R3SiO) n and (3) from 1 to 20 parts of a silyl-nitrogen compound of formula: (C) R4Si) aX the above additives being brought into simultaneous contact with said feedstock at a temperature of in the range of 100 to 180 C, and   (II) elimination of the residual quantities of the said   ditifs of the charge; o R 'is chosen from the radicals   monovalent hydrocarbons, hydrocarbon radicals,   monovalent halogenated bones; R2, R3 and R4 are all   chosen from a hydrogen atom, the hydrophilic radicals   monovalent carbon and halogenated monovalent hydrocarbon radicals, n varies from 3 to 4; a is 1 or 2; X is selected from the radicals NR5Y, Y -.5   -ONR2 and -N- or R is selected from hydrogen radicals;   monovalent carbon, the monohydric hydrocarbon radicals   halogenated valents and Y is selected from a hydrogen atom   and the radicals R5; (c) from 1% to 15% by weight, based on the weight of the linear basic diorganopolysiloxane of a silicate,   selected from the group consisting of (I) an organosilicon   monomer cate corresponding to the general formula: - (D) (R 50) 3 SiR 6 o R 5 represents a radical chosen from monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyano radicals]. coyle and   R6 is selected from alkyl, haloalkyl and   coyl, aryl, haloaryl, alkenyl, cycloalkyl, cycloalkenyl, cyanoalkyl, alkoxy and acyloxy and (II) a liquid product of partial hydrolysis of the aforementioned organosilicate; and   (d) from 0.1% to 5% by weight of a hardness catalyst   the weight of the diorganopolysiloxane linear basis.   12. Construction set with heat shield   The method according to claim 8, characterized in that said cured silicone rubber strip is formed from a silicone rubber composition   two-component heat-curable ing:   (a) from 82% to 99.65% by weight of an organopolysilon   xane polymer of formula: (1) RaSiO4_a   R is chosen from monohydrocarbon radicals   valents and halogenated monovalent hydrocarbon radicals   and ranges from 1.95 to 2.01, having a molecular weight of   in the range of 100,000 to 2,000,000 and a viscosity of 100,000 to 1,000,000 cP at 25 C; (b) from 20% to 60% by weight, based on the weight of the organopolysiloxane, of a finely divided filler with high reinforcing power consisting of inorganic compounds; (c) from 1% to 25% by weight relative to the weight of   of an organopolysiloxane aid of implementation chosen   if, among the dihydrocarbon substituted oils, the hydroxylated organopolysiloxanes and a compound of formula: R R O I I!   SC (CH ..... SiO -SiO Si- (CH2) n- CXR R] b R   o R is a methyl or phenyl radical, X is a radical   dical -OH, -NH2 or -OR ', where R' is a methyl radical   or ethyl, n is two to four inclusive   and b is zero or an integer from 1 to 10 inclusive; and (d) from 0.1% to 8% by weight based on weight   of the organopolysiloxane of a hardening catalyst is lying.   13. Process for manufacturing a set of constructions   thermal shielding comprising the interlocking   of a pair of spaced grooves with an insulation element   thermal fraction, characterized by forming the element   thermal insulation with a composition of   silicone rubber having a tear resistance   after curing at least 7 daN / cm.   14. Process for manufacturing a set of constructions   thermal insulation made by extrusion of an element   metal section having two C-grooves in section   provided by a central groove, filling said grooves of said element with an insulation material   liquid thermal, hardening of this iso-   thermal and milling of the lower part of the elongate central groove, characterized in that said grooves are filled with a composition of   curable silicone rubber constituting the   of thermal insulation and after hardening   a tear strength of at least 7 daN / cm.   15. Improved process according to one of the claims   13 or 14, characterized in that the composition   curable silicone rubber among the   two-component silicone rubber compositions   curable at room temperature by ad-   of a curing agent and the compositions   two-component silicone rubber hardened by heat.   16. A method of manufacturing a set of con-   insulation-thermal truction by extrusion of two metal elements having in section two C-grooves, forming a thermal insulation element having   opposite projections whose size and shape cor-   correspond to those of said grooves and insertion of these protrusions of the thermal insulation member into said grooves, characterized in that the thermal insulation member is formed with a cured silicone rubber composition having a resistance   tearing of at least 7 daN / cm.   17. Improved process according to one of the claims   13 or 16, characterized in that the composition   of cured silicone rubber among the two-component room temperature curable silicone rubber compositions by adding a curing agent and the curable two-component silicone rubber compositions by the heat.