FR2470149A2 - IMPROVEMENTS IN METHODS OF SEALING BOLTS OF MINES AND THE LIKE - Google Patents

Abstract

THE PRESENT INVENTION CONCERNS SEALING FILLERS OF THE "ONE-COMPONENT" TYPE IMPROVED BY THE ADDITION OF CARBON BLACK. THE CARBON BLACK IN THE PROPORTION OF 0.5 TO 5 BY WEIGHT IN RELATION TO THE INSATURE POLYESTER RESIN ALLOWS A BETTER COMPROMISE BETWEEN THE VISCOSITY OF THE LOAD AND ITS REACTIVITY. SEALING CHARGES FOR MINING GALLERY, ETC.

Description

Improvements to the sealing processes of the support bolts

mines and the like.

  The main patent describes a method for installing retaining bolts, characterized in that the rod to be sealed is inserted into the borehole containing the

  resin composition for sealing by hardening

  with a rotational speed which causes, in contact with the charges of the composition, the heating of said composition

  up to its hardening temperature.

  The main patent also describes compositions

  1-component resin suitable for this process.

  In the main patent, three nonlimiting formulations are each described, each consisting of a "matrix" (consisting of an unsaturated polyester resin, a silica

  colloidal, a catalyst, such as, for example, tertiary perbenzoate

  butyl, and an inhibitor, such as 2,6-ditertiobutyl-

  paracresol), chalk, and quartz sand. In these three

  formulations, the percentage by weight of the matrix is

  equal to 20.31%, 19.05%, and 17.74%, which respectively leads to

  at a viscosity at 200 ° C of 870, 1000 and 1300 poises. We see

  therefore the percentages of binder indicated in the main patent

  the main, ie the percentages of resin, lead to mastics having a relatively high viscosity. This results in two disadvantages and one advantage, the first disadvantage residing in the fact that one encounters certain difficulties in conveying this material, either in the conditioning of the sealing charges, or for the bulk injection in situ in the holes. the second disadvantage resides in the fact that, to introduce the bolt to be sealed with or without simultaneous rotation, it is necessary to implement relatively

  high, the advantage being that a relative viscosity

  High pressure exacerbates the thermal effect when the rod rotates, and therefore accelerates the setting of the sealant or the bolt lock. We therefore sought to achieve a better

  compromised on the basis of a lower viscosity for a reaction

  substantially equivalent sealant, without altering the stability

of the charge.

  It has now surprisingly been discovered that some incorporation of carbon black makes it possible to obtain

this result.

  The purpose of this addition is therefore to

  improved sealing compounds, containing carbon black. The incorporation of the carbon black according to the invention is carried out under the following conditions: either powdery carbon or pearls is used, powdered carbon being preferred; a carbon black of specific BET surface area is used

2 '2

  between 30 and 250 m 2 / g, preferably equal to 30 m 2 / g;

  the average size of the carbon particles is between approx.

  13 and 51 nanometers and is preferably 51 nanometers; - we. incorporates approx. 0.5 to 5% by weight of carbon black, based on the weight of the unsaturated polyester resin, the

  preferred content being 2.15%.

  The following examples illustrate the invention without

however, limit its scope.

EXAMPLE 1

  A mono-type sealant is prepared

  Component, Formulation below: Unsaturated polyester resin 500 g (25%) Ditertiobutyl-1,1 cyclohexane peroxide (catalyst) 10 g Inhibitor: 3,5-ditertiobutyl-4-hydroxyanisole 0.10 g Carbon black ( specific surface

m2 / g; average size of the

  particles 51 nm) 10.75 g Chalk (eg chalk GY 100) 1 183 g Quartz sand (eg quartz sand 16.14.2) 296 g Unsaturated polyester resins, eg resins marketed under the names brand: - Ukapon 77064, or - Ukapon T 120 S1 (Ugine-Kuhlmann), or

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  - Norsodyne 904, 905 or 907 (CDF-CHEMISTRY).

  As a catalyst (or hardener) it will also be possible

  use equivalent amounts of tertiary butyl peroctoate.

  With the aid of this composition, a bolting test is carried out, the characteristics of which are as follows: the diameter of the borehole is 22 mm; the length of the metal rod is 1 m; the diameter of the metal rod is 18 mm; and

  - The speed of rotation of the rod is 1600 rpm.

  In these conditions, the blocking time of the stem

is 38 s.

COMPARATIVE EXAMPLE 1

  In the main patent, under identical bolting test conditions, a blocking time of 30 seconds was obtained for formulation No. 1 (substantially 20.31% binder).

  If we compare example 1 with the results presented

  In this comparative example, we see that the presence of black

  carbon has resulted in a completely equivalent blocking time

  slow for a higher binder content (25% instead of 2c / o).

EXAMPLE 2

  A second batch of seals according to the invention of the following formulation is prepared: Unsaturated polyester resin 500 g (25%) Ditertiobutyl-1,1 cyclohexane peroxide (catalyst) 10 g Inhibitor: Toluhydroquinone (THQ) O, 10 g Black carbon (specific surface area 30 m2 / g, average particle size 51 nm) 10.75 g Chalk (eg GY 100) 1 183 g Quartz sand (eg quartz sand 16.14.2) 296 g bolting as in Example 1, and one reaches, under the same conditions, a time

blocking time of 120 s.

EXAMPLE 3

  A sealing compound according to the invention is prepared with the following composition: Unsaturated polyester resin 500 g (25%) Ditertiobutyl-l, 1 cyclohexane peroxide (catalyst) 10 g Inhibitor: 2,6-ditertiobutylparacresol (for example, "Bisoxol" product ) 0.25 g Carbon black (specific surface 30 m 2 / g, average particle size 51 nm) 10.75 g Chalk (eg chalk GY 100) 1 183 g Quartz sand (eg quartz sand 16.14. 2) 296 g A bolting test is carried out as in Examples 1 and 2, and under the same conditions a time is obtained.

blocking time of 63 s.

  If we compare the three

  above, between them and with the comparative example, it is found that, on the one hand, the incorporation of carbon black makes it possible to obtain a better viscosity / reactivity compromise, and, on the other hand, that this carbon black does not alter the scale of intrinsic activity of the inhibitor with respect to temperature: it is seen, in fact, when we replace the 3,5-di-tert-butyl-4-hydroxyanisole (which may for example be the product " Topanol 354 "), of Example 1, with the toluhydroquinone of Example 2, keeping the same amount of inhibitor, the blocking time is passed from 38 to 120s, which fully reflects the difference in reactivity existing between the two products, and known to those skilled in the art. Similarly, with regard to the third inhibitor used, that is to say 2,6-ditertiobutylparacresol (which may for example be the product

  Eisoxol "), we see that its weaker activity leads to

  a larger quantity, which reduces the time to

blocking at 63 s.

  Naturally, we can use other products

than those exemplified above.

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COMPARATIVE EXAMPLE 2

  In the main patent, formulation No. 2 contains substantially 19% binder, and under the conditions indicated for

  the bolting test in Comparative Example 1, the blast time

cage is 30s.

COMPARATIVE EXAMPLE 3

  A comparative composition of formulas

  following matrix Unsaturated polyester resin 17.29% of the final composition

Ditertiobutyl peroxide

l, 1-cyclohexane 2% of the resin

  2,6-ditertiobutylparacresol 0.1% of the resin.

   Final setting Matrix 18% Chalk (GY 100) 65.6%

Quartz sand 16.14.2 16.4%.

  For a blocking test of a rod 18 mm in diameter and 1 m in length, driven into a hole 22 mm in diameter at the rotation speed of 1618 rpm, we obtain a

blocking time of 39.5 s.

  The examples and comparative examples above show that the incorporation of carbon black makes it possible to reach the desired compromise without altering the stability of the load, which is surprising. Carbon black also has advantages.

  annexes: the quality of the seal is improved by its incorporation

  Thanks to the resulting increase in thermal conductivity, sealing becomes very homogeneous very quickly; the carbon black has a high affinity for the compounds which have chromophoric groups and, therefore, absorbs the excess of quinone or other stabilizer contained in the unsaturated polyester resin: this allows the organic peroxide to react more quickly on the mixture unsaturated polyesters / styrene; carbon black acts finally as a reducing agent; and this role of antioxidant enables it to improve the life of the mastic

  of "monocomponent" type in storage.

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  The carbon black furthermore has a high specific surface which favors the absorption phenomena, and produces an additional effect of improving the viscosity,

  when the mass is in motion.

  Naturally, depending on the batches of resin, and the viscosity, we can modulate the setting time, beyond the

  non-limiting examples described above.

  It will also be possible to incorporate in the matrix a small amount of colloidal silica (for example at 2% of the resin) with a BET specific surface area of 100 m 2 / g

  approximately, whose role is to prevent the settling of products.

  This incorporation of silica is however not essential. It was finally noticed that the absence of inhibitor, in the above charges containing carbon black, resulted in a bad stability of the system the presence

inhibitor is therefore necessary.

  Of course, those skilled in the art can make modifications to the examples and embodiments which have just been described in a non-limiting manner, without departing from the scope of the invention.

Claims (5)

R E V E N D I C A T I 0 N S   1 - Sealing charge as described in claim 1 of the main patent, consisting of an unsaturated polyester resin, a catalyst, an inhibitor, and fillers, characterized in that it contains carbon black . 2 - charge according to claim 1, characterized in that it contains a quantity of carbon black representing approx. of   0.5 to 5% by weight of the resin of the filler, preferably 2.15%.   3 - Filler according to claim 1 or 2, characterized in that the carbon black incorporated is in the form of beads or, preferably, in a powder form, having a specific surface area of between 30 and 250 m / g (BET ),   preferably equal to 30 m2 / g, approximately.   4 - Filler according to any one of the claims   1 to 3, characterized in that the average particle size   carbon black is between 13 and 51 nm, and is preferably 51 nm, approx.   - Filler according to any one of the claims   1 to 4, characterized in that it has the following formulation: Unsaturated polyester resin 500 g (25% by weight) Catalyst 10 g Inhibitor 0.10-0.25 g Carbon black 10> 75 g Chalk 1,183 g Quartz sand 296 g.   6 - Load according to any one of the claims   1 to 5; characterized in that the catalyst is selected from ditertiobutyl-1,1-cyclohexane peroxide, and the peroctoate of   tert-butyl, in that the inhibitor consists of 3,5-di-   tert-butyl-4-hydroxyanisole, or toluhydroquinone or 2,6-ditertiobutylparacresol, and that   carbon has a BET specific surface area of 30 m / g, and a average meter of particles of 51 nm.   7 - Load according to any one of the claims   1 to 6, characterized in that it contains colloidal silica.