Note: Descriptions are shown in the official language in which they were submitted.
--" 21g3426 ,., ,-'`_,~
-
WO 94/04588 PCT/EP93/02266
PROCESS FOR EMPLOYING A S~NTHETIC RESIN SYSTEM
The invention relates to a process for employing a
polyurethane-based synthetic resin system, wherein the system
comprises an isocyanate component a) and a polyol component
b), and auxiliary and additive agents c) can be added to
components a) and/or b), and the polyol component b) contains
a deficient proportion of primary or secondary di- or
polyamines. Synthetic resin systems of this kind are known,
for instance from Published, Non-Examined German Patent
Application DE-OS 36 10 729. They are used to prepare
coating and sealing means that harden under the influence of
moisture in the air.
To secure anchor bars in rock climbing, it is already
known to use so-called bonded anchors, in which the bonding
is done with two-component synthetic resin systems. One
possible way is to introduce the resin components into the
drilled hole in separate cartridges, into which the anchor
bar is then thrust, destroying the cartridges, and the
hardenable mixture is produced by rotation and after
hardening firmly holds the anchor by bonding it to the rock.
The hardenable mixture may, however, also be forced
into the drilled hole, using a pump, before or after the
introduction of the anchor bar.
Particularly with drilled holds made overhead, the
problem exists that some of the resin mixture sometimes flows
back into the drilled hole, so that the anchor is bonded only
inadequately in place.
The object of the invention is to overcome this
disadvantage in the mounting of bonded anchors.
According to the invention, this object is obtained by
. _ . . ' ~ _ _ . , ~ _, _ ~., . __. _ _ . _ =_ . __` ___ _ __ _ , _ _ _ ~ _= _ , _ ~ ~ _ -- -- _ _==, _ . ~ = ~ . _ . . _' .~,_
. _ _ ~ . . . _ . ~ _ _ _ , _ _ _ f _ _
_ ~ . ~_------~---- -- . ---- -- _ ~ _ _ _ ~ _ ~_ _ . . , ' . : _, ~ - ;' _ _ ~ - _ _; _ ~ _ ~_~ ' _ ~ ~ ', . _ _ ~' - . . _ I -. . '
' ., _ _ _ .--_ _ _ _ _ _ = _ _ ~ _ _ _ _ _ _ , _, _ _ =
21~3~2
:" `
WO 94/04588 PCT/EP93/02266
the characteristics of the body of claim 1. It has
surprisingly been demonstrated in experiments that the two-
component synthetic resin mixture according to the invention,
with gel-like consistency, is readily pumped and can also be
introduced easily into drilled holes oriented upward, so that
once it has arrived at the innermost point of the drilled
hole, it will not flow back out again by gravity before
hardening. It is also extremely surprising that the two-
component mixture has an adequate load-bearing force to
firmly hold the bonded anchor in the drilled hole until
hardening.
Further features are recited in the dependent claims.
The polyisocyanate component a) to be used in the
process of the invention preferably involves polyphenylene-
polymethylene-polyisocyanates, as prepared by
aniline/formaldehyde condensation and ensuing phosgenation
(~polymeric MDI " ), or derivatives, which are liquid at room
temperature and have carbodiimide, biurethane, urethane
and/or allophanate groups, of these polyisocyanates and their
prepolymers, that is, conversions products of polyisocyanates
with polyols in deficiency. Compounds generally known from
polyurethane chemistry, preferably long-chain polyols with
hydroxyl numbers below 150 mg KOH/g of substance, can be
considered as polyols for preparing prepolymers. The
polyisocyanate mixtures ("polymeric MDI") that are liquid at
room temperature and are obtained by phosgenation of
aniline/formaldehyde condensates, as well as their liquid
conversion products, having NCO groups, of the polyisocyanate
mixtures with deficient quantities (molar ratio of NCO/OH =
1:0.005 to 1:0.3) of multivalent alcohols with a molecular
--2--
~14~4~6
WO 94/04588 PCT/EP93/02266
weight range from 62 to 3000, in particular polyols having
ether groups and having a molecular weight range from 106 to
3000, are preferred. mixtures, which are liquid at room
temperature, of 2,4'- and 4,4'-diisocyanatediphenylmethane
are likewise suitable as polyisocyanate components a). In
principle, however, according to the invention other
polyisocyanates are also possible, such as those known from
German published, non-~m1ned patent application DE-OS 28 32
253, pages 10 and 11. Highly preferably, polyisocyanate
mixtures of the diphenylmethane series having a viscosity at
25C of from 50 to 5000 mPa s with an NCO content of
approximately 30 to 32 weight % are used.
The polyol component b) involves mixtures of organic
polyhydroxyl compounds with hydroxyl numbers between 30 and
2000, where the hydroxyl number of the mixture is between 200
and 500 mg KOH/g of substance.
The polyhydroxyl compounds preferably involve the
polyether polyols, known per se from polyurethan chemistry,
or mixtures of various polyetherpolyols of this type.
Examples of readily usable polyether polyols are
propoxylation products of bivalent to octovalent starter
molecules, such as water, 1,2-dihydroxypropane,
trimethylolpropane, pentaerithritol, glycerine, sorbitol,
ethylene diamine and optionally cane sugar. In general,
component ti) has a mean hydroxyl functionality of 2.0 to
5.0, preferably 2.0 to 3. Suitable mixtures of this kind
may for instance be obtained in that corresponding mixtures
o~ starter molecules of the type given here as examples are
sub~ected to a propoxylation reaction. However, it is also
possible for separately prepared polyhydroxylpolyethers to be
21434~6
WO 94/04588 PCT/EP93/02266
mixed together after their preparation as the component (i)
to be used according to the invention.
As amines according to the invention, primary or
secondary di- or polyamines and mixtures thereof are used.
Examples of suitable aromatic amines are: 4,4'-
diaminodiphenylmethane, 3,3'-dimethyl-4,4'-
diaminodiphenylmethane, 3,3'-dichloro-4,4'-
diaminodiphenylmethane, 1,3,5-triisopropyl-2,4-
diaminobenzene, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-
methyl-3,5-diethyl-2,6-b, 1,3,5-triethyl-2,4-diaminobenzene
and technical mixtures with the last three compounds named,
3,5-di(methylthio)-2,4-toluenediamine, 3,5-di(methylthio)-
2,6-toluenediamine and technical mixtures of them, 1,2-
ethylene di-(4-amino)thiophenol ether, 1,3-propanediol di(p-
amino)benzoate, 3,5-diamino-4-chlorobenzoic acid isobutyl
ester, 1,3-propylene di-(4-amino)benzoate.
Examples of suitable cycloaliphatic amines are:
isophorondiamine, 4,4,-diaminodicyclohexylmethane, 3,3'-
dimethyl-4,4'-diaminocyclohexylmethane, N-cyclohexyl-1,3-
diaminopropane, N-($-aminoethyl)piperazine.
Examples of suitable aliphatic amines are:
diethylenetriamine, triethylenetetramine,
tetraethylenepentamine, diisopropyltriamine.
The following substances can be used as auxiliary and
additive agents c) conventional in polyurethane chemistry:
- Catalysts for accelerating the various isocyanate
addition reactions, in particular such as bismuth- or tin-
organic compounds, such as dibutyl tin dilaurate, organic
alkali salts such as potassium acetate, or tertiary amines,
such as triethylenediamine, dimethylethanolamine, or N-
., . . . :.
21~426
:'.
.
WO 94/04588 PCT/EP93/02266
ethylenemorphylene. These catalysts are generally jointlyused in a quantity of up to 2 weight ~, preferably in a
quantity of from 0.1 to 1 weight ~, referred to the total
mixture.
- Water traps for preparing non-foaming or low-foam
products, such as zeolite paste, which are used in a quantity
between 0.2 and 10 weight ~, preferably between 1 and 5
weight ~.
- Foam regulators, that is, foam stabilizers or
destabilizers, preferably on a polysiloxane base. They are
used in a quantity of up to 2~, preferably between 1 ppm and
1000 ppm, referred to the total mixture.
- Optionally water as a propellant, which can be used
in quantities of up to 5 weight ~, preferably 0.5 to 2 weight
.
- Optionally, physical propellants, such as partially
halogenated hydrocarbons or other volatile compounds, such as
dichlorofluoromethane or pentane, of which up to 20~ can be
added.
- optionally, organic or inorganic flame retardants,
such as phosphoric esters or aluminum-hydroxide derivatives,
in quantities of up to 20 weight ~ for liquid agents and 50
weight ~ for solid agents.
- Optionally, fillers, such as urea, ground quartz or
talcum, in quantities of up to 50~.
In the reaction mixtures to be used in the process
according to the invention, the various components are
present in a quantity that corresponds to an isocyanate
coefficient of from 90 to 150, preferably 120 to 140. The
term "isocyanate coefficient" is understood here to mean the
214342~
WO 94/04588 PCT/EP93/02266
quotient of the number of isocyanate groups present in the
reaction mixture, divided by the number of groups present in
the reaction mixture that are reactable with isocyanate
groups, multiplied by 100; the water enters into the
calculation as a difunctional compound.
Before the process according to the invention is
carried out, generally the auxiliary and additive agents c)
optionally to be jointly used are combined with the polyol
component b), whereupon the processing by the two-component
system ensues. This means that to produce the reaction
mixtures, the polyisocyanate component a) is intensively
mixed with the polyol component b), or with the mixture of
the polyol component b) and the auxiliary and additive agents
c). For this purpose, the mixing systems known per se in the
prior art may be employed.
Description o~ the Process
From anchor technology it is known that higher-
viscosity two-component synthetic resin compositions are
processed by means of metering pumps with a integrated
pressure tank. Because of the viscosity of the two-component
synthetic resin compositions, these pumps are not self-
aspirating, and a higher injection pressure is required for
the pressing operation. Because of the use of two-component
synthetic resin compositions, the metering pumps in PUR rock
fastening, which have already been introduced, can be
employed. The low-viscosity single components of the two-
component synthetic resin composition are aspirated by the
metering pump and after mixing, for instance using a static
` 2~3426
WO 94/04588 PCT/EP93/02266
mixture, react to make a higher-viscosity product, which can
then be pumped only by using pressure. This mixed two-
component synthetic resin composition, after hardening, bonds
the commercially available injection anchor in the drilled
hole, or bar anchors can be bonded in the drilled hole using
the mortar process.
The exemplary embodiments below in accordance with
tables 1-4 serve the purpose of further explanation of the
process. All the percentages given are referred to
composition percents.
EXAMPLES
In the examples of table 3 and 4, the starting
components listed in tables 1 and 2 are used for the system
components b) and c):
2~43426
Table 1
SyRtem Starting Hydroxyl number Viscosity
components b) components ~mg ~OH/g] at 25 C
(mPa 8)
Basic polyol I glycerine and380 450
propylene oxide
Basic polyol II saccharose, 1,2-380 580
propanediol,
propylene oxide
Basic polyol III trimethylol propane 380 600
propylene oxide
Flexibilizing 1l2-propanediol56 324
polyol I propylene oxide
Flexibilizing ditto 260 73
polyol II
Flexibilizing butanediol 176 277
polyol III tetrahydrofuran
Flexibilizing triethanolamine27 870
polyol IV propylene oxide
Ethylene glycol - 1808 16
Diethylene glycol - - 1057 26
Glycerine - 1827 750
Castor oil 160 680
Diamine I (N-(~-aminoethyl)piperazine)
Diamine II (N-cyclohexyl-1,2-diaminepropene)
Diamine III (3,3'-dimethyl-4,4'-diaminocyclohexylmethane)
Diamine IV technical mixture of
1,3,5-triethyl-2,4-diaminobenzene
--8 -
~ 2~43~2~
.
TablQ 2
Sy8 tem
components c) Starting cn~ron~nts
Catalyst I dimethylethanolamine
Catalyst II triethylenediamine, 33~ in ethylene glycol
Catalyst III dibutyl tin dilaurate
Catalyst IV potassium acetate
Catalyst v 2,4,6-tris(dimethylaminomethyl)phenol
Zeolite paste zeolite type .... 50~ in Castor oil
2~43426
:. .
WO 94/04588 PCT/EP93/02266
From Tables 1-4 it is clear that for the two-component
polyurethane system according to the invention, a wide range
of starting components [verb missing], particularly for
system component b) (Table 1), and also for system component
c) (Table 2).
It is understood that besides the starting components
listed others may also be suitable, because the components
listed in Tables 1 and 2 involve merely those that are listed
in changing compositions or formulations in Tables 3 and 4,
to the extent that in experiment series in combination with
the system components a) named in Tables 3 and 4 they have
lead to suitable two-component polyurethane mixtures, which
gel to a gel-like consistency in a fraction of a minute and
are capable, in this quasi-thixotropic state, of reliably
firmly holding an anchor in an upward-drilled hole until such
time as a fastening action by bonding, which makes the anchor
capable of holding a load, is attained within a setting time
on the order of some minutes.
--10 -
2143426
.
_2~
111
~ ~ o' ~ Q "o' 8 ~
>~ ~
CD O U~ ~ æ O ~ o ln O
-~221~i
c~
~ 0~ 0 ~ æ U~ O ~ ~
'. ~t ~ ~ ~ - O C~ ~ ~ ~ O
cy)
>~ ~
- - ==~
æ ~ 0 O~ ~
__ __~
~0 ~æ.
a ,~ r,~
~\ -
. . .
2i43~26
~ , 2 N
O ~æ ~ ~ 8 ~ ~
_z~2_~
o o u~ o ~ o
=--~ _--N
0 ~ æ
~ ~ ~ ~ U~ O ~ ~ ~ ~ ~ ~ ~ O ~ ~
,-5~ ~
~0
__ __~
o ~ ~ ~0
"
.. . .. . . .. . .....
` 214342G
.
WO 94/04588 PCT/EP93/02266
Tables 3 and 4 list 10 examples, which contain the
corresponding formulation instructions for assuring the
aforementioned reaction results.
Example 11 lists a comparison example, in which system
component b) was prepared without a diamine, with the
composition otherwise similar to examples 1-10. When such a
mixture was employed, the special effect of a rapidly ensuing
gelation to a gel-like consistency or a quasi-thixotropic
state, which enables an anchor to be firmly held in an
upwardly inclined drilled hole, was not attained.
It can be seen from Fig. 1 that a rapid rise in
viscosity within fractions of a minute is attained only with
mixtures in which a diamine cross-linking agent, as
illustrated in the mixture of example 4, is used, and that by
comparison without diamine cross-linking agents, as
demonstrated in example 11, only a gradual increase in
viscosity occurs, so that this mixture is not capable of
firmly holding an anchor in an upwardly inclined drilled
hole.
In injection resins based on two-component polyurethane
resins that do not form a gel-like consistency after the
components are mixed together, seepage from the effect of
gravity occurs when they are employed in markedly fissured
rock. In the polyurethane system according to the invention,
based on a two-component polyurethane, the system, after the
low-viscosity individual components are mixed in a volumetric
ratio of 1:1, after from 2 to 12 seconds becomes a
lubricating greaselike product, which hardens after 4 to 5
minutes.
2~L~13~26
WO 94/04588 PCT/EP93/02266
The system should be processed by the known injection
technique for two-component polyurethane mixtures, so that no
special metering pumps are needed.
Usaqe exam~le 12 (injection test)
An injection anchor was inserted into a drilled hole in
a moist synthetic rock (anhydride). The resin mixture with a
gel-like consistency, with the upwardly oriented drill hole
to be filled, emerged from the injection anchor at the
innermost part of the drilled hole and had to be forced back
again uniformly from the innermost point to the mouth of the
hole, because on account of its gel-like (quasi-thixotropic)
consistency it did not automatically flow downward under the
influence of gravity. Fig. 2 shows the strain diagram of
the anchor test. It shows the increase in force of the
injection anchor. At a bonded-in length of 50 cm, the anchor
was put under strain after a hardening time of 1 h. It was
not possible to pull the anchor out of the drilled hole;
instead, it was broken off with a force of 250 kN.
Usaqe example 13
Strength tests were carried out on low-foam sample
bodies. The following values were ascertained:
- compressive strength 20.4 N/mm2
- bending strain strength 5.2 N/mm2
- modulus of elasticity 1.1 kN/mm2
- density 695 kg/m3
-14-
.. . .
~1~3~26
WO 94/04588 PCT/EP93/02266
Since in an annular gap, because of the greater flow
pressure, the two-component polyurethane system does no~ foam
up so markedly, it can be assumed that the strengths are even
higher than the values given above.
Usaqe comparison example 14 with cable anchor
In anchor work in in tight spaces, flexible cable or
rope anchors are often used. The adhesive bond between these
anchors in the rock is attained in that anchor mortar based
on cement paste is injected into the drilled hole in the
prior art, and the anchor is then thrust in by hand.
In the comparison example, a cable anchor 4 m in length
was used, which has a squeeze binding that can hold an anchor
plate, in order to anchor the rock face end on an edge of the
rock face. ~ cement-based anchor mortar was used, which was
stirred with water in a simple mixing and pumping device and
introduced into the drilled hole via a feed hose. The
consistency of the mortar was so viscous that it did not flow
out of the steeply upwardly inclined holes. The cable
anchors could be inserted by hand into the drilled hole
filled with mortar.
The disadvantage of this anchor mortar is the
comparatively complicated preparation of a suitable mortar
consistency, the careful cleaning of the line paths of mortar
residues that is needed thereafter by flushing with water,
and the relatively late load-bearing action of the cement
mortar, compared with the faster-binding resin-based bonding
mixtures.
~ 214342~
WO 94/04588 PCT/EP93/02266
Usaqe exam~le 15 with cable anchor
The anchor setting test was done with the two-component
polyurethane system in a 4 m long transparent plexiglas tube
closed on both end. The tube was set up vertically and
secured to a block of stone. In the test, a 4 m long cable
anchor was thrust into the tube to its innermost point. A
plastic hose with an inside diameter of 6 mm was secured to
the cable anchor. During the injection, a pressure loss of
35 bar occurred in the injection hose. After 30 seconds, the
annular space between the anchor and the tube wall was
entirely filled with polyurethane resin mixture. The resin
mixture was so pasty that only a very slight portion of the
gel-like (quasi-thixotropic) resin mixture flowed out of the
tube opening, as can be seen from Fig. 3. This test entirely
confirmed the excellent firm-holding property of the newly
developed two-component polyurethane system during the
initial gel-like (quasi-thixotropic) consistency state. In
contrast to a cement mortar, the hardening process was ended
incomparably faster, however, so that the load-bearing action
of the anchor bonded with synthetic resin becomes effective
very much earlier.
-16-
