SU250774A1 - COMPOSITION FOR ADHESIVE SUBSTRATES - Google Patents

Description

This invention relates to a process for the preparation of new compositions used as primary adhesive adhesion layers for improving the adhesion of organopolysiloxane elastomers at a comlate temperature to solid substrates on which the elastomers are cured.

A known method of bonding silicone compounds with solid substrates, such as metals, concrete, fabrics, leather or paper, using a bonding sublayer, which improves the adhesion of the organopoli-siloxane to the substrate. In particular, French patent Ns 1207887 describes a process of increasing adhesion between polymers and metals due to the fact that metal surfaces are covered with a sublayer based on aminoalkylsilane or aminoalkylpolysiloxane or copolymers containing an organosiloxyl and aminoalkylsiloxyl component in various quantities. This process provides satisfactory bonding of, for example, silicone elastomers to steel, if the samples are not subjected to rigorous testing. If, however, the glued materials are subjected for a long period of time to boiling water or hot brine or to expansion and compression with high amplitude, then the durability of such materials is sharply reduced and cannot be used in the technique. French Patent No. 1208255 also describes a composition that can serve as an adhesive for bonding silicone rubbers to metals and other solid substrates. Such a composition includes an unlimited silane, e.g. monovinyltriethoxysilane, and aminoalkylsilane,

for example α-aminopropyltriethoxysilane. However, the compounds to be obtained do not withstand hard use for a long period of time.

The proposed compositions provide an opportunity to increase the adhesion of silicone elastomers, cured on solid substrates at room temperature, to these substrates. This opens up the prospect of obtaining assemblies with excellent performance.

under the action of boiling or salt water.

These compositions include the following constituents.

A. 100 weight. including organic cross-linked polymer with mol. weight. 400 having free isocyanite groups, which constitute 0.1-20% by weight of the total polymer. Jb. 10-100 weight. including organoalkoxysilane of the general formula RnRmSi (OR) 4-mn, (O, where R is a monovalent hydrocarbon radical with one or more double bonds of olefinic nature, possibly substituted by halogen atoms, aryloxyalkyl or methacryloxyalkyl radical; R is a monovalent saturated or saturated atoms or a methacryloxyalkyl radical; hydrocarbon radical; R is an alkyl or alkoxyalkyl radical; n is 1 or 2; m is O or 1; the sum m + n does not exceed 2. B. 50-1000 parts by weight of anhydrous organic solvent, miscible with the components of the composition, but not staying with them in rea G. O-100 parts by weight of alkoxysilane of the formula (OR) 3-x, (R) where R has the same meanings as above, R, is an alkylene radical with 3-6 carbon atoms, R is a monovalent hydrocarbon radical, mainly lower alkyl or cycloalkyl with 5 or 6 carbon atoms in the cycle, or phenyl; X is O or 1; Y is NHg or the aminoalkylamino group of the formula H.NCr H2rNH (g-integer 2-6), or the same aminoalkoxy group of the formula H2NCrH2gO (where g is as defined above). It is understood that in the above material, the expressions "lolimer," solvent, "organoalkoxysilane of formula I or" alkoxysilane formul II can be interpreted as a generalized term to mean a mixture with a content of groups corresponding to this expression. An organic polymer with free NCO- groups, which is one of the components of the proposed composition, should have a cross-linked structure. It is prepared by well-known technical methods, for example, by reacting an organic polybasic acid containing at least two carboxyl groups with a polyhydric alcohol containing more than two hydroxyl groups. Both reagents are used in ratios such that the number of hydroxyl groups exceeds the number of carboxyl. The polyester thus obtained is reacted with a calculated amount of polyisocyanate in order to obtain a polymer with a content of 0.1–20% of NCO groups –lol by weight. character with an excess of coli isocyanates. These polyurethane type polymers are specifically described in the book by J.M. Debell “German plastic Practice (J.M. Debell Workshop on German Plastics, pp. 300-316). As the polyhydric alcohols can be taken trimetilollropan, butanediols, propapdioly, glycerol, pentaerythritol, etc., and as polyisocyanates -.... Of toluene diisocyanate, toluoltriizotsianaty, hexane-1,6-diisocyanate, triizotsianattrifenilmetan etc. If substituting t diisocyanate, It is necessary to use a polyhydric alcohol as a different reagent (antagonist) containing at least three hydroxyl groups or a mixture of such polyhydric alcohols, of which at least one contains at least three hydroxyls. The molecular weights of these organic polymers fluctuate within wide ranges, namely, from 400 to as large as the resin-like or rubber-like material is obtained. However, the degree of polymerization of these compounds is limited by the requirement of solubility of the products obtained in conventional solvents, for example, esters, ketones and aromatic hydrocarbons. In the polymer of formula RnRmbi (OR). R is a hydrocarbon unsaturated radical, for example viil, allyl, butadienyl, cyclopentadienyl, cyclohexenyl, vinyl chloride, chloroallyl, chlorocylopeptidienyl or tetrachlorocyclocentadienyl, an acryloxyalkyl radical, for example an acryloxypropyl, or a methacryloxyalkyl radical, for example a methacryloxyadyl, the radical .R is a lower alkyl radical such as methyl, ethyl, pro. Peel or butyl, an aromatic radical, for example, phenyl-yl, or an aromatic radical substituted by halogen atoms or lower alkyl; R is lower alkyl, such as methyl, ethyl. propyl or butyl, or hydroxyalkyl radical, for example methoxyethyl, methoxypropyl or ethoxyethyl. Pz compounds of formula I include the following: n-viniltrietoksisila, vinylmethyldiethoxysilane, vinilfenildimetoksisilan, vinyltris (methoxyethoxy) silane, allyltriethoxysilane, allylmethyldiethoxysilane, butadieniltrietoksisilan, butadienmetildietoksisilan, tsiklopentadieniltrietoksisilan, .tsiklogekseniltrietoksisilan, 3- (trnmetoksisilil) -propilmetakr "lat and 3- (trimethoxysilyl ) -propyl methacrylate. Oti products are now readily available, especially vinylalkoxysilanes, allylalkoxysilanes and acryloxyalkylsilanes. The solvents used are ketones, esters or aromatic hydrocarbons, for example ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, ethyl should not contain such components that could react with isocyanates and silanes; therefore, it must be essentially free from water, amines, acids, and snares. The following alkoxysilanes of the formula II are included in the package: (y-aminonropyl) -trietho-thy; 4; apt; (Y-aminopronyl) -methyldiethoxysilane, (y-aminopronil) -phenylmethoxysilane, (A-aminobutyl) -triethoxysilane (A-aminobuty); -Amino-2-Metalliches-дд--д-дддд-,,-(,,,, ((,ддд (y-Aminonropoxy) - pronlalkoxysilanes can easily be obtained from the corresponding NC (CH,) nitrites. 0 (CH, з) (OR) 3-x I by hydrogenating the nitrile group in the presence of nickel or cobalt. These nitriles are described more in detail in the Franzian patent LI 117942 and their recovery can be carried out using the technique of Vdovin and collaborators (Limit the USSR Academy of Sciences, Branch of Chemical Sciences, 1961, 11, 2007). The dissolution of compounds A and B or A, B and D can be done in any lorda; however, it is impractical to first dissolve A in C and add B or B + D to the solution. Concentration of A + B or A + + B + D in It fluctuates within a wide range, for example from 10 to 85 wt. % At low concentrations, the mixture can be stored for a long time in a hermetically sealed vessel for several months. The concentration of product used depends on the intended use. Pis-concentrated product is easier to smudge on poorly wetted or very porous surfaces, but such a product is necessary in the form of several successive layers. A highly concentrated solution dries slower than a weakly concentrated one, but it can be limited to one layer. Compound A contains free soil NCO, which accounts for 0.1–20 wt. % of the total polymer A, and these groups can react with the amino groups of compounds G with the formation of polyurea bonds - NnCONn. Therefore, if the composition must contain compounds G, it is necessary that the number of NCO groups exceed the number of amino groups and leave at least 0.42 g of free NCO groups per 100 g of A + B + G mixture. It is best to take such amounts of A, B and G , so that after mixing about 2.1 g of free NCO-groups per 100 g of A + B-f G mixture remain. However, higher concentrations are not excluded, especially if fast setting of the composition is desirable. If component D is not used, it is also recommended that the proportion of NCO groups be at least 2.1 g per 100 g of A + B mixture. Organonolysiloxane products that can be vulcanized at room temperature and which, when cured, have elastomers with high adhesion to the substrate, are well known mixtures. Basically, they consist of linear (a, co) hydroxyl linear dioorganopolysiloxane, one or more fillers, a vulcanizing agent, which most often represents a silicone compound containing at least three hydrolyzable soils, for example alkoxysilane or acetoxysilane, and possibly also a catalyst (metal - derivatives OR amines). Compositions of this type are o-nisans in French patents No. 1126411, 1179969, 1189216, in French patent N ° 1198749 and supplements thereto for N ° 74579 and 76483, as well as in French patents 1247170, 1248826 and 1370884. Proposed compositions are especially suitable to produce assemblies that are resistant to significant mechanical stresses and chemicals, such as boiling or salt water. In this way, very high quality assemblies with wooden or stone building elements can be obtained. The sealing elements obtained by this method are highly effective and superior to the known ones. If we compare the mechanical properties of adhesive joints ,. obtained with the use of organolysiloxane compounds capable of volcapacinic at three ordinary temperatures, using connective layers — in one case, a polymer with isocyanate groups and aminoalkylnlan; in the other, a mixture of unsaturated organoalkoxysilane and aminoalkylsilane; and compositions proposed in this invention, and the compositions proposed in this invention. In the latter case, they are better. Similarly, instead of using compound A instead of compound A, a conventional silicone resin of a single acid and a dihydric alcohol, or a mixed polymer formed of nylon ether and nylon chains with free hydroxyls, or an eoxichlorohydrin-2.2-bis enoxide resin ( 4-hydroxyphenyl) -1Noppaia combined with component B or components B and G, the results will be mediocre. Organic polymer A with free isocyanate groups is required to produce assemblies with high mechanical properties. Assemblies formed from a solid substrate, underlayer and silicone elastomer, which can be obtained using the compositions recommended, in this application, can be the most different. As a solid nodili any polymer. The proposed compositions are well suited for improving the sealing of floating bridges. During the construction of such bridges, it is possible to seal the grooves between wooden boards with the use of organopolysiloxane cold-vulcanizable composition, as described in French patent number 1359100 and 84044.

The field of application of the proposed compositions is wide: in industry, in construction (in particular, shipbuilding), in electronics and in aeronautics. Finally, these compositions produce new varnishes, adhesives and linings.

Considering the fast setting of these materials at room temperature, they can be glued together to solid surfaces, for example, wood, metals (iron, copper, cast iron and aluminum), glass, and textile materials (for example, cotton, wool, polyamide fibers, acetylcellulose,. polyester fibers), paper, concrete, gypsum, ceramics, synthetic and natural resins and rubbers. Of synthetic resins can be called melamine-formaldehyde, molovinoformaldehyde, alkyd, acrylic, phenolic and epoxy. The resulting adhesive compounds are characterized by long-term resistance to atmospheric agents and boiling water, regardless of whether the water is neutral, alkaline, or acidic, whether it contains mineral and organic salts or does not contain them.

Examples are given below to illustrate the invention and its use.

Example 1. 100 g of an adhesive sublayer solution are prepared by mixing the following components:

535 g of a solution of 428 g of ethyl acetate and 100 g of polyisocyanate (component A) with a content of 12.7 wt. % isocyanate group, and the polyisocyanate component itself is obtained from 143 g of trimethylolpropane, 107 g of butanediol-1,3, and 750 g of toluene-2,4-diisocyanate;

181 g of vinyl - tri- (methoxyethoxy) -silane (component B);

215 g of anhydrous ethyl acetate (component B),

69 g of (Y-amino iioyl) -triethoxysilane (component D).

In a two-liter jar, the solution of component A and 215 g of anhydrous ethyl acetate are heated, and then B and D are added with stirring, and a release of teilote is observed. The resulting mixture with 62.5 wt. % A + B + D are stored in a carefully sealed container for about a month.

The mixture is brushed onto oak planks with a (40X30) cm-g surface. Two layers with a slice for 2 hours are applied successively, after which two planks are assembled so that the spread layers are facing each other using adhesive tape. In this case, between the two sections, there should be a lumen in Julzh.

The selected volume, bounded by the tape and both sections, is filled with a self-curing in the cold composition containing the following components, wt. h .: Dihydroxylated dimethylpolysilo, xanic oil with a viscosity of 100,000 eats at 25 ° C100 Dimethylpolysiloxane oil blocked from each chain of a trimethylsilyl group with a viscosity of 20 eats at 25 ° C60 Methyltriacetoxysilane 5 Gas-phase beacon salsa, processed, tsit, tsaltsa, daste, tsit, tsit, tsitelnostelenesilane5

Acetylene black

Gidrofobizirovanny carbonate

calcium 25

The prepared assembly is processed by the following o6pia30M.

The assemblies are left for 7 days at room temperature (22-25 ° C) and a relative humidity of 50-70% (assembly I). Harvesting is left for 2 days at room temperature (22-25 ° C) and then for seven days in water, also at room temperature (assembly II).

The assemblies are left for 2 days at room temperature and then for 7 days in water with a content of 40 g of sodium chloride heated to 60 ° C (assemblies P1).

After that, all assemblies are subjected to dynamic tests. The results are shown in Table. one.

Table 1

For comparison, similar experiments were carried out, but with the replacement of composition A + B + C + D by one of the following products:

a) component A in the form of a 65% solution in ethyl acetate;

b) a mixture of B + G in the form of a 65% solution in ethyl acetate (with a weight ratio of B: D 181: 69);

c) a mixture of B-f G + methylpolysiloxane resin with an R / Si ratio of 1.3 (- with a weight ratio of () / resin 180: 70 and B: D 181: 69) as a 25% solution in a mixture of 5 weight. including toluene and 70 wt. including methanol;

g) a mixture of B + G + epoxy resin, commercially available iodine name "Epicote 828, in the form of a 65% solution in ethyl acetate, and the weight ratio of the components B-LH to the epicote is 250: 375, and the weight

e) a copolymer with the content of CH2-CHSiC3 / 2 and H2M (CH2) s51Oz ,, 2, obtained in accordance with part 7 of example 2 in the French patent no. 1207887;

e) with a solution based on (Y-amino-propyl) triethoxysilane, vinyltrietho-co-silane, methanol and water in accordance with example 10 of French Patent No. 1208225.

The results are shown in Table. 2

Example 2. Preparing the assemblies as indicated in example 1 with the use of the same cold vulcanizable orgapopolisiloxane, but using mixtures of type A + B + C as an adhesive sublayer:

a) a 70% solution in ethyl acetate of a mixture of component A, the same as in example 1, and vinyl-tri- (methoxyethoxy) -silane in a weight ratio of 535: 18);

b) a 70% solution in ethyl acetate of a mixture of component A and 3- (trimethoxnsilyl) -propylmethacrylate in a weight ratio of 535: 181.

As standards, sublayers are used from compositions a) and b), but with the replacement of component B by an organopolysiloxane that does not contain double bonds. Thus obtained the following mixtures:

c) a 70%, ethyl acetate solution of a mixture of component A and (y-aminopropnl) -triethoxysil a in a weight ratio of 535: 69;

: g) A 70% ethyl acetate solution of a mixture of component A and 2- (3,4-enoxocyclohexyl) ethyltrimethoxysilane in a weight ratio of 535: 170.

Table 3

The results obtained after incubation of samples for 7 days at room temperature (22-25 ° C) and a relative humidity of 50-70% are given in table. 3

The table shows which beneficial results are obtained when using binary mixtures of organic isomeric with isocyanate groups and alkenylacetoxy or the same polymer and methacryloxyalkoxysilane.

Example 3. A 62.5% solution of A- | -B + D in ethyl acetate was used in this case as an adhesive sublayer on the walls of the cavities formed by the adjacent grooves of Iroko wood planks. On these walls, forming cavities of rectangular cross-section with a shrimp of 8 mm and a depth of iO mm, two layers are successively applied, each of which is allowed to dry for 2 hours. On the basis of each cavity, a cotton cord with a thickness of 1 mm, filled with organosilox, with an ovy composition of the following composition, is put, weight. including:

Dimethyl polysiloxane oil with a viscosity of 100,000 spois at 25 ° С90

Same as 20 seconds.

at 25 ° С10

Gas phase white soot10

Etiltriacetoxysilane3,6

The mixture is left for 5 days at room temperature (22-25 ° C) and a relative humidity of 50-70%, and then the assemblies are subjected to the following tests.

Compounds are stretched in the transverse direction by 50%, for which the slats are bold with 4 mm thick bricks by driving a wedge of appropriate thickness under the cavity with the elastomer. The compounds in this state are fixed in a suitable way and immerse the assemblies in boiling water for 7 days or in brine with 40 g / l of sodium chloride with a temperature of 60 ° C for such a l-: e period. Ne was observed neither peeling, nor rupture with similar tests, and using the products listed in Table II of Example 1 for the sublayers, adhesive joints were obtained, which were peeled off after a few hours in boiling water and in brines with temperature 60 ° C. Cut samples from the obtained assemblies with a width of 1.5 cm (using the compositions described). These samples are divided into 3 groups: samples I are assemblies subjected to exposure in the atmosphere at room temperature, the remaining samples are subjected in a state of stress to boiling water (II) or salt water (III). Measuring the mechanical properties of the Iroko assembly, the primary layer and the silicone elastomer gives the results shown in the table below. 4. Table 4 If the assemblies, after a five-day exposure at room temperature (22-25 ° C) and a relative moisture content of 50-70%, are subjected to accelerated aging, for which they are 50% under constant tension from stretching. salt water with a concentration of 40 g / l NaCl, L 25 ° C, for 24 hours, and then subjected to irradiation with a 1200 W ultraviolet lamp at 70 ° C for 24 hours and transferred to an ice-water mixture for 24 hours, and this cycle they are repeated 30 times, then no delamination or rupture is detected, despite such harsh testing conditions. Example 4. Three compositions are prepared for sublayers of the same components as indicated in example 1, but with varying ratio A / (B + D). Assemblies are made from iroko planks that are tested as before. The compositions of the new compositions 1, 2 and 3 are given in table. 5. Table 5 The ratio of the number of isocyanate groups to the number of amino groups in compositions 1 and 2 is greater than 1, while in com position 3 this ratio is 0.035: 0.09.

12 Samples of 1.5 cm wide are taken from the prepared assemblies and these samples are subjected to five-day aging at room temperature (22-25 ° C) and relative humidity of 50-70%. The dynamometric tests of these samples gave the following results, shown in Table. 6. Table 6 Assemblies 1 and after exposure at room temperature for 5 days are subjected to stretching 50% to sample 3 and making them for 7 days in salt water (40 g / l NaCI) with a temperature of 60 ° C or boiling water. These samples are labeled respectively the series I and series II. No delamination of the compounds was detected in the I-series assemblies, regardless of the composition of the layer. On the contrary, from Assemblies -serion II, those that contain composition 3 in the form of a sublayer, are partially destroyed (the elastomer layer is peeled off and in a considerable part along the length). This proves the large value of the ratio of isocyanate and amino groups in terms of resistance to boiling water. Example 5. The rectangular sections (40X30) mm of a series of steel samples were brushed with a film for sublayers, using for each batch the composition of example 1, as well as composition a, b, c, and d of this example. Thereafter, 2 samples of the same batch are collected using an organosilicon silicon composition capable of vulcanization. At room temperature. One batch of samples is left for 7 days at room temperature (C) and a relative humidity of 50-70%, the other part is left for 2 days under the same conditions, then incubated for 7 days in saline water at a temperature of 60 ° C. Mechanical properties assemblies of steel are presented in Table. 7. Only the A + B-LB sublayer provides satisfactory results for bonding a silicone elastomer to steel. Example 6. 2 samples are again glued together (wood on one side and steel on the other). The cross section of different samples is 12 cm. As an intermediate sublayer, the composition of Example 1 is used, which is applied twice to wood and once to steel; The organopolysiloxane composition, vulcanizable at room temperature, has the following composition, wt. including:

13

250774

14

Table 7

White gas soot5 Diatom silica25 Titanium dioxide 0.5 Acetylene black 0.75 Methyl triacetoxysilane3 After gluing the assembly, it is left for 7 days At (room temperature (22-25 ° C) and relative humidity 50-70% then tested for mechanical strength. The results are in the table. 8. Table. Resistance. Tearing Substrate. Tearing, elongation, Example 7. The test is carried out as in Example 6, but the composition of the organopolysil sanate composition vulcanized at a natural temperature is as follows, in weight: Dimethyl polysiloxane dihydroxylated 10000 sg oil at 25 ° C100 Methylpolysiloxane liquid resin with R / Si l ratio, 77 16 Titanium dioxide2 Gas-phase white soot, octamethylcyclotetranloxane treated 22, 2 Methyl triacetoxysnane 7,6 Product with gross formulas, which is used in the sample, which is used in the sample, used for the sample, used for the sample, in the sample in the case, in the case for example, for example, in the case for example, for example, in the case for example, for example, in the case for example, in the case for example, in the case for example, it is used for example, in the case for example, in the case for example, in the case for example, in the case for example, the sample, the sample, the sample, the sample, the sample, has been applied. Table Samples of oak wood, aluminum and steel are collected in two.The dynamic properties of the new assemblies, determined for seven days at room temperature (22-25 ° C) and relative humidity of 50-70%, are given in Table. 9. Example 8. Blend wood samples similar to those shown in example 1 are prepared using this example, and the sublayer used is (COMPOSITION of example I, as an organopolysiloxane composition, vulcanizable in the cold, of the following composition, parts by weight : Dimethylpolysiloxane dihydroxylated oil with a viscosity of 5000 eats at 25 ° C100 Ferric oxide 65, Polyethyl silicate with 40% SiOa3 Product with the gross formula CisH3e04SnTi of example 1 of French patent N ° 1392648 1. After a seven-day vulcanization at room temperature 50-70% relative humidity, the tear resistance of the entire assembly is 5.6 kg / cm, tensile-elongation 90%. At higher stretch, the elastomer is discharged within the mass, but not peeled off from the oak samples. Example 9. Two strips of nylon fabric 2 wide cm covered with a layer of composition A-f + B + C -} - G (example 1) on a 4 si surface located at one end of the strip. After drying in air for 2 hours, the surface with the applied adhesive is coated with a vulcanizable composition of example 6 toli and: Noah 1 mm, then lay on this surface, p a covered adhesive layer, a second strip. Both strips are arranged in such a way that one is a continuation of the other. After seven days of vulcanization at room temperature (22-25 ° C) and 50-70% relative humidity, the resistance of the glued material to the shear is measured. It turned out to be equal to 8.2 kg / cm. The silicone elastomer is broken in bulk, but not peeled off from the nylon strip.