FR2479842A1 - Non-curing sealant compsn. - comprising di:organo:polysiloxane having silicon-bonded hydroxyl end gps., filler and organo:silicon nitrogen-contg. cpd. - Google Patents

Abstract

Sealant comprises (a) 100 pts. wt. of a di-organopolysiloxane having Si-bonded hydroxyl gp. at the terminal of a molecule chain having viscosity at 25 degrees C of 500,000 cs; (b) 1-500 pts. wt. of a filler; and (c) an oranic Si cpd, having 2 Si-bonded moisture hydrolysable -N gps. or -ONgps. in the molecule in an amt. enough to give same number of moles of -N or -ON gps. is total number of moles of Si-bonded hydroxyl gps. in (a). Viscosity of (a) is pref. 50-50,000 cs. (c) is pref. of formula R1R2Si(X)2 (I). In (I) R1 and R2 are opt. substd. monovalent hydrocarbon gp. and X is -N. or -ON. substd. monovalent hydrocarbon gp. and X is -N or -ON gp.; or of formula (II). In (II) R is opt. subst. monovalent hydrocarbon gp., n is 0-30. The -N gp. in (c) is pref. amino, amido or lactam gp. the -ON gp. in (c) is pref. aminoxy or oxime group. The amino gp. is pref. mono- or diorganoamino; the amido gp. is pref. N-organoamido; the aminoxy gp. is pref. diorganoaminoxy; and the oxime is pref. diorganooxime. Viscosity does not change when sealed from moisture for extended time. Discharge from container is easy. It is easily filled into spaces, dents etc. and is easily worked. The obtd. viscous putty-like material has excelelnt air tightness and water impermeability.

Description

The invention relates to non-curable sealing materials.

 The sealants can be roughly divided into non-hardenable and hardenable materials. Both types of material are used to seal joints to provide air and water tightness and are widely used in construction and civil engineering, vehicles, automobiles and aircraft. Especially in the case of construction, these sealing materials are widely used at the joints between different parts, to seal between the panes and window frames, and to seal the joints and interstices caused by cracks.

 As non-curable sealants, non-curable glazier sealants and oily caulking materials are known. The former are mainly formed from oils and fats and the latter are also mainly formed from oils and fats, polybutene and alkyd resins. These materials therefore have poor weather resistance. One drawback is that the durability of these non-curable sealing materials is reduced when used outdoors. Another disadvantage is that they cannot be used in places where high temperatures prevail due to their poor heat resistance. In addition, a defect in materials which include silicone oil sealants and sealants mainly formed from non-reactive silicone oil and a filler is that separation of the oil phase easily occurs. If a highly viscous silicone oil is used to reduce the separation of the oily phase, the viscosity of the sealant is increased and the disadvantage is that the workability during processing is reduced.

 The invention relates to a new material which does not have the drawbacks of the common non-curable sealing materials mentioned above.

The subject of the invention is a non-curable sealing material whose viscosity increases in contact with moisture, which does not harden and which practically retains its initial viscosity when stored in a container which does not allow the penetration of the moisture, characterized in that it consists essentially of the product obtained by mixing, under substantially anhydrous conditions, the following ingredients
-a- 100 parts by weight of a polydiorganosiloxane carrying hydroxyl groups attached to silicon atoms at the end of the molecular chains, the organic groups of the polydiorganosiloxane being monovalent hydrocarbon radicals substituted or not, this polydiorganosiloxane having a pitch viscosity more than 0.5 m2 / s at 250C,
-b- 1 to 500 parts by weight of a filler, and
-c- an organosilicon compound in an amount sufficient to provide nitrogen groups attached to silicon or groups comprising silicon-oxygen-nitrogen bonds, in a molar amount at least equal to the total molar amount of hydroxyl groups attached to atoms of silicon in (a), this organosilicon compound containing per molecule two hydrolyzable groups by humidity chosen from nitrogen groups attached to silicon and groups comprising silicon-oxygen-nitrogen bonds.

dans laquelle R représente des radicaux hydrocarbonés monovalents substitués ou non qui peuvent entre des groupes méthyle, éthyle, propyle, octyle, phényle, vinyle ou 3,3,3-trifluoropropyle et m est un nombre tel que la viscosité à 250C soit au maximum de 0,5 m2/s.The components according to the invention will be described individually below. Component (a) is a polydiorganosiloxane carrying hydroxyl groups attached to silicon atoms at the end of the molecular chain and corresponding to the general formula:

in which R represents substituted or unsubstituted monovalent hydrocarbon radicals which can between methyl, ethyl, propyl, octyl, phenyl, vinyl or 3,3,3-trifluoropropyl groups and m is a number such that the viscosity at 250C is at most 0.5 m2 / s.

If the viscosity at 250C exceeds 0.5 m2 / S, very poor workability is obtained when the composition is prepared by adding a filler (component (b)) and a chain extender (component (c)), thus, very poor handling and workability when the composition is removed from containers such as cartridges, tubes and containers made of plastic sheet. In addition, if the viscosity is too low, the composition leaks out of the container clogged and the viscosity increase is insufficient after the filling of a gap or cavity, Preferably, the viscosity is 0.00005 to 0.05 put
Of hydroxyl group attached to a silicon atom at the end of the molecular chain is a functional group necessary for the condensation of component (a) with component (c) in the presence of moisture, to obtain a weight higher molecular and viscosity.

Component (a) can be a polymer of the same viscosity or a mixture of two or more polymers of different viscosities.

 The constituent (b) of the invention is a filler which serves to modify the viscosity of the constituent (a).

For example, the following fillers can be used: dry process silica (fumed silica), wet process silica (precipitated silica), diatomaceous earth, fine quartz powder, talc, mica powder, calcium carbonate, magnesium carbonate, carbon black, asbestos powder and glass powder.

 The amount of component (b) ranges from 1 to 500 parts by weight per 100 parts by weight of component (a). However, it is chosen arbitrarily from the above range, according to the types of fillers used and, in particular, according to the density and the ability to thicken, and according to the viscosity of the organopolysiloxane. In the case of fillers with a high thickening power, that is to say dry process silica, wet process silica, carbon black, asbestos powder, carbonate of light and fine calcium with untreated surface, the quantity used is relatively small whereas in the case of fillers having a relatively low thickening power, that is to say diatomaceous earth, fine quartz powder , mica powder, precipitated calcium carbonate with a treated surface and heavy calcium carbonate, the amount used is preferably greater.

Component (b) can be a single charge or a mixture of two or more charges.

 Component (c) is a component which helps increase molecular weight and viscosity by lengthening the chaste of the polydiorganosiloxane (component (a)) when the sealing material of the invention leaves a stoppered container and arrives in the 'air.

dans laquelle R, R1, R2 et X répondent aux définitions déjà données et n vaut de O à 30 inclusivement. En outre, le diorganosiloxane,mentionné peut contenir un groupe cyclique.Dans ces formules, R, R1 et R2 représentent des groupes alkyle, par exemple des groupes méthyle, éthyle ou propyle, des groupes alcényle, par exemple des groupes vinyle, allyle ou butadiényle, des groupes aryle, par exemple phényle, xylényle ou naphtyle, des groupes cycloalkyle, par exemple cyclo hexyle,desroupes cycloalcényle, par exemple cyclohexényle, des groupes aralkyle, par exemple benzyle, des groupes alcaryle, par exemple tolyle ou xylyle, ainsi que les groupes substitués correspondants. R, R1 et R2 peuvent être choisis dans la même classe ou dans des classes différentes.In other words, the constituent (c) is a bifunctional diorganosilane or a bifunctional diorganosiloxane hydrolysable by water. These compounds are generally represented either by the general formula
R1R2SiX2 in which R1 and R2 each represent a substituted or unsubstituted monovalent hydrocarbon radical and X a hydrolyzable group which may be a nitrogen group attached to silicon or a group comprising silicon oxygen-nitrogen bonds, or by the general formula

in which R, R1, R2 and X meet the definitions already given and n is from 0 to 30 inclusive. In addition, the mentioned diorganosiloxane may contain a cyclic group. In these formulas, R, R1 and R2 represent alkyl groups, for example methyl, ethyl or propyl groups, alkenyl groups, for example vinyl, allyl or butadienyl groups , aryl groups, for example phenyl, xylenyl or naphthyl, cycloalkyl groups, for example cyclo hexyl, cycloalkenyl groups, for example cyclohexenyl, aralkyl groups, for example benzyl, alkaryl groups, for example tolyl or xylyl, as well as corresponding substituted groups. R, R1 and R2 can be chosen from the same class or from different classes.

des groupes amide

des groupes imide

des groupes lactame

des groupes aminoxy

des groupes oxime

X is a group which is hydrolyzable by water and attached to a silicon atom. Examples of hydrolyzable groups are amine groups

amide groups

imide groups

lactam groups

aminoxy groups

oxime groups

6
In these formulas, R3 to R12 each represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon radical. Examples are the groups shown as examples for R, R1 and R2.

For reasons of ease of preparation of the silanes and siloxanes containing these functional groups, R3 to R12 are preferably chosen from substituted or unsubstituted monovalent hydrocarbon radicals. R13 and
R14 represent alkylene groups.

des aminoxysilanes et des aminoxysiloxanes tels que
(CH3)2Si[ON(CH3)2]2,
(CH3)(C6H5)Si[ON(CH3)2]2 ,
(CH3)(CH2=CH)Si[ON(CH3)2]2 ,
(CH3)2Si[ON(CH3)(C2H5)]2 ,
(CH3)(CH2=CH)Si[ON(C2H5)2]2 ,

des oximinosilanes et des oximinosiloxanes tels que (CH3)2Si[ON=C(CH3)2]2, (CH3)(CH2=CH)Si[ON=C(CH3)2]2,
(CH3)2Si[ON=C(CH3)(C2H5)]2 ,
(CH3)(C6H5)Si[ON=C(CH3)(C2H5)]2 ,

des amidosilanes et des amidosiloxanes tels que ::

Examples of component (c) are the following: aminosilanes and aminosiloxanes such as (CH3) 2SitNH (C4) J2,
(CH3) 2Si [NH (C6H5)] 2, (CH3) 2Si [N (CH3) 2] 2, (CH3) (C6H5) Si [N (CH3) 2] 2
(CH3) (CH2 = CH) If [N (CH3) 2] 2,
(CH3) 2Si [N (C2H5) 2] 2,
(CH3) (C6H5) If [N (CH3) (C2H5)] 2,

aminoxysilanes and aminoxysiloxanes such as
(CH3) 2 If [ON (CH3) 2] 2,
(CH3) (C6H5) If [ON (CH3) 2] 2,
(CH3) (CH2 = CH) If [ON (CH3) 2] 2,
(CH3) 2 If [ON (CH3) (C2H5)] 2,
(CH3) (CH2 = CH) If [ON (C2H5) 2] 2,

oximinosilanes and oximinosiloxanes such as (CH3) 2 If [ON = C (CH3) 2] 2, (CH3) (CH2 = CH) If [ON = C (CH3) 2] 2,
(CH3) 2 If [ON = C (CH3) (C2H5)] 2,
(CH3) (C6H5) If [ON = C (CH3) (C2H5)] 2,

amidosilanes and amidosiloxanes such as:

des imidosilanes et des imidosiloxanes tels que

ou des silanelactames et des siloxanelactames tels que

imidosilanes and imidosiloxanes such as

or silanelactams and siloxanelactams such as

Component (c) can be formed from a single compound or from two or more compounds. However, when two or more types of compounds are used in the mixed state, a hydrolyzable group X is preferably chosen from the same type of group. The amount of organosilicon compound used is sufficient to provide nitrogen groups attached to the silicon or groups comprising silicon-oxygen-nitrogen linkages in a molar amount at least equal to the total molar amount (mole%) hydroxyl groups attached to silicon atoms at the end of the molecular chain of component (a).

 By doing so, the composition of the invention can be stored for a long time when it is prepared and stored under substantially anhydrous conditions. When put in contact with air, a very viscous product is obtained and an extremely viscous form of putty can be obtained.

In addition to components (a), (b) and (c), a catalyst can be added which accelerates the reaction between components (a) and (c), for example a diorgano-tin dicarboxylate. In addition, various additives can be added which are generally incorporated into conventional sealants based on silicone oil, for example mineral pigments, organic pigments, heat-resistant agents, adhesiveness, anti-sagging agents and flame retardants.

 The composition of the invention can be prepared as follows. For example, component (b) is added to component (a) and mixed in one of the various types of mixers until a homogeneous mixture is obtained. After degassing, component (c) is added and the whole is mixed again until a homogeneous mixture is obtained. In this case, it is necessary to remove as much as possible the humidity from the mixture of these constituents (a) and (b) and it is necessary to add the constituent (c) and to incorporate it under anhydrous conditions. The sealing material obtained can be sucked in by a caulking gun and then used for sealing. Alternatively, the material can be packaged in a container that is impermeable to the ingress of moisture in a significant quantity, for example in cartridges. , aluminum foil tubes and plastic sheet containers, and close the container for preservation. Then the sealant can be used when needed.

 The sealing material of the invention has the following characteristics and effects: (1) if it is stored in a container which does not allow the infiltration of moisture in a significant amount, the viscosity is unchanged after a long storage; (2) the fact that a low viscosity polydiorganosiloxane is used, the product can easily be removed from the container; (3) one can easily fill a gap or a caté; (4) the job of finishing the blocked place is very easy; (5) the viscosity increases sharply within one or more days after filling and an extremely viscous substance similar to a putty can be obtained; (6) the sealant-like substance thus obtained has an excellent air and water tightness and no separation of the oily phase occurs after long storage. This non-hardening waterproofing material is especially useful for construction and civil engineering.

The following nonlimiting examples are presented to illustrate the invention.

 The "parts" indicated in the following examples are by weight. The viscosity is measured at 25 C.

The atmosphere used for the sealing work has a temperature of 23 to 250C and a relative humidity of 60 to 65%.

EX PLUE 1
100 parts of a polydimethylsiloxane carrying terminal hydroxyl groups and having a viscosity of 0.015 mus and 45 parts of fine and light calcium carbonate with an untreated surface are mixed thoroughly (average particle size e 0.1 / m, surface specific BET: 7.5 m2 / g). After degassing, 8 parts of dimethyl-bis- (N-methylacetamido) -silane are added and the whole is mixed in a closed system to protect from moisture. The mixture obtained is conditioned in an aluminum tube. The material of the aluminum tube is manually expressed and a vertical joint 5 mm deep and 8 mm wide is plugged with the content, along a concrete slab. prefabricated. After 3 days, an extremely viscous putty was formed to a depth of 5 mm. After 6 months, there was no sagging and no oil phase separation was observed. When this sealant is stored in the aluminum tube at room temperature for 6 months, there is no change in viscosity and the product can still be expressed manually very easily.

EXAMPLE 2
100 parts of a polydimethylsiloxane bearing hydroxyl end groups and having a viscosity of 0.002 m2 / s are mixed with 20 parts of a dry process silica, the surface of which has been treated with trimethylchlorosilane to make it hydrophobic and which has a BET specific surface of 130 m2 / g. After degassing, 10 parts of methylvinyl-bis- (N, N-diethylaminoxy) -silane are added. The whole is mixed in a closed system protected from humidity and the mixture obtained is conditioned in a paper cartridge whose inner surface is lined with aluminum foil.

This cartridge is introduced into a hand gun.

The contents are expressed manually and used to plug a horizontal groove between a glass slab and an aluminum flush (7 mm deep, 4 mm wide). After 5 days, an extremely viscous mastic formed to a depth of 7 mm. After 6 months, no oil phase separation is observed. When this sealant is stored for 6 months in the paper cartridge, there is no change in viscosity and the material can still be easily expressed using a hand gun.

EXAMPLE 3:
100 parts of a dimethylsiloxane / methylphenylsiloxane copolymer carrying hydroxyl groups at the ends of the molecular chain and having a viscosity of 0.008 m2 / s (phenyl group content: 5 mol%) and 10 parts of dry process silica are carefully mixed. having a BET specific surface of 200 m2 / g. After degassing, II parts of methylphenyl-bis- (N-cyclohexylamino) -silane are added and the whole is mixed in a closed system protected from humidity.

The mixture is packaged in a cylindrical container formed from a sheet of polyvinylidene chloride and the container is wrapped with a sheet of polyvinylidene chloride aluminized by evaporation. After 6 months, the envelope is removed and the cylindrical container made of polyvinylidene chloride sheet is introduced into a hand gun. The material is expressed manually and a horizontal groove is plugged with the content between clad aluminum panels (depth 10 mm, width 12 mm). After 7 days, an extremely viscous mastic formed to a depth of 10 mm. After 6 months, no separation of the oily phase is observed.

EXAMPLE 4: 4
Sealants are prepared using as component (c) the compounds indicated in
Table I below, under the same conditions as in Example 1. The characteristics which are indicated in Table I are determined.

EXAMPLE 5:
In a sealing material such as that of Example 1, instead of fine and light calcium carbonate, 120 parts of colloldal calcium carbonate with treated surface are used (average particle size 0.04 μm, BET specific surface area 31 m2 / g), under the same conditions as in Example 1. The prepared sealing material is conditioned in an aluminum tube. The material of the aluminum tube is expressed and with this sealing material a horizontal groove is plugged between a glass plate and an aluminum channel (depth 7 mm, width 4 mm). After 5 days, an extremely viscous putty was formed up to a depth of 7 mm. After 6 months, there was no separation of the oily phase. There is no change in viscosity when this material is left in the aluminum tube at room temperature and the contents can still be easily expressed manually.

TABLE I
Constituent (c) Amount Aptitude Time before Separation added, during phase formation parts jection of an oily putty at the very end of viscosity 6 months to a depth of 5 mm α , # - bis- [dimethyl- good 3 days none (N, N-diethylaminoxy)] dimethylsiloxane (degree of polymerization: 10) methylvinyl-bis- (bad 10 days no thethylethylketoximino) silane

Claims (5)

1. Non-hardening sealant whose viscosity increases on contact with moisture, which does not harden and which practically retains its initial viscosity when stored in a container which does not allow moisture to penetrate practically, characterized in that that it consists essentially of the product obtained by mixing, under substantially anhydrous conditions, the following ingredients  (a) 100 parts by weight of a polydiorganosiloxane carrying hydroxyl groups attached to silicon atoms at the end of the molecular chains, the organic groups of the polydiorganosiloxane being monovalent hydrocarbon radicals substituted or not, this polydiorganosiloxane having a pitch viscosity more than 0.5 m2 / s at 25 C, (b) 1 to 5QO parts by weight of a charge, and (c) an organosilicon compound in an amount sufficient to provide nitrogen groups attached to silicon or groups having silicon-oxygen-nitrogen bonds, in a molar amount at least equal to the total molar amount of hydroxyl groups attached to atoms silicon in (a), this organosilicon compound containing per molecule two hydrolysable groups by humidity chosen from nitrogen groups attached to silicon and groups comprising silicon oxygen-nitrogen bonds. 2. Material according to claim 1, characterized in that the viscosity of the polydiorganosiloxane (a), at 250C, is 0.00005 to 0.05 m2 / s. 3. Material according to claim 1 or 2, characterized in that the organosilicon compound (c) is a diorganosilane corresponding to the general formula RR Sil2 in which R1 and R2 each represent a monovalent hydrocarbon radical substituted or not and X is the hydrolysable group . 4. Material according to 1 or 2, characterized in that the organosilicon compound (c) is a siloxane corresponding to the general general formula

wherein R, R1 and R2 each represent a substituted or unsubstituted monovalent hydrocarbon radical, n is from 0 to 30 inclusive, and X represents the hydrolyzable group.  5. Material according to any one of claims 1 to 4, characterized in that the hydrolyzable group is an amine, amide, imide, lactam, aminoxy or oxime group.