U.S. patent application number 14/257419 was filed with the patent office on 2014-08-14 for inhibitor combination, resin mixture containing same and use of same.
This patent application is currently assigned to Hilti Aktiengesellschaft. The applicant listed for this patent is Hilti Aktiengesellschaft. Invention is credited to Denis BERTIN, Johannes BRINKHORST, Didier GIGMES, Armin PFEIL, Derek PRATT, Luca VALGIMIGLI.
Application Number | 20140224424 14/257419 |
Document ID | / |
Family ID | 46275684 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140224424 |
Kind Code |
A1 |
PFEIL; Armin ; et
al. |
August 14, 2014 |
INHIBITOR COMBINATION, RESIN MIXTURE CONTAINING SAME AND USE OF
SAME
Abstract
The use of a mixture of 5-pyrimidinol derivatives with
sterically hindered phenol derivatives for adjusting the reactivity
and the gel time of resin mixtures and reactive resin mortars based
on radically polymerizable compounds is described. Furthermore, a
resin mixture containing the inhibitor combination, a reactive
resin mortar containing this resin mixture and two-component mortar
systems with the reactive resin mortar according to the invention
and a hardener with improved stability in storage and good
low-temperature hardening properties are also described. The resin
mixture according to the invention is suitable in particular for
chemical fastening of construction elements in boreholes in various
substrates.
Inventors: |
PFEIL; Armin; (Kaufering,
DE) ; BRINKHORST; Johannes; (Landsberg, DE) ;
GIGMES; Didier; (Allauch, FR) ; VALGIMIGLI; Luca;
(Bologna, IT) ; PRATT; Derek; (Ottawa, CA)
; BERTIN; Denis; (Marseille, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hilti Aktiengesellschaft |
Schaan |
|
LI |
|
|
Assignee: |
Hilti Aktiengesellschaft
Schaan
LI
|
Family ID: |
46275684 |
Appl. No.: |
14/257419 |
Filed: |
April 21, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13492149 |
Jun 8, 2012 |
8735475 |
|
|
14257419 |
|
|
|
|
Current U.S.
Class: |
156/332 ;
220/500; 524/5; 524/560; 526/328 |
Current CPC
Class: |
B65D 25/00 20130101;
C04B 40/0039 20130101; Y10T 428/13 20150115; C04B 28/06 20130101;
C04B 28/06 20130101; C04B 14/06 20130101; C04B 24/02 20130101; C04B
24/128 20130101; C04B 26/02 20130101; C04B 40/0039 20130101; C08L
33/10 20130101; C04B 14/066 20130101; C04B 40/0658 20130101; C04B
24/2641 20130101; C04B 24/02 20130101; C04B 40/0658 20130101; C04B
22/068 20130101; C04B 24/128 20130101; C04B 20/0076 20130101; C04B
24/02 20130101; C04B 24/128 20130101; C04B 40/065 20130101; C04B
2111/00715 20130101 |
Class at
Publication: |
156/332 ;
526/328; 524/560; 524/5; 220/500 |
International
Class: |
C04B 24/02 20060101
C04B024/02; C04B 40/06 20060101 C04B040/06; B65D 25/00 20060101
B65D025/00; C04B 24/12 20060101 C04B024/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 9, 2011 |
DE |
10 2011 077 254.5 |
Claims
1. A method of adjusting the reactivity and the gel time of resin
mixtures based on radically polymerizable compounds, comprising
adding a combination of a compound of general formula (I):
##STR00009## wherein R.sup.1 and R.sup.2 independently of one
another denote hydrogen or a branched or unbranched
C.sub.1-C.sub.20 alkyl group, X is --OR.sup.3 or --NR.sup.3.sub.2,
where R.sup.3 is a branched or unbranched C.sub.1-C.sub.20 alkyl
group or a C.sub.2-C.sub.4 polyalkylene oxide group, with a
compound of general formula (II) ##STR00010## wherein R denotes
hydrogen, a branched or unbranched C.sub.1-C.sub.18 alkyl group or
--OR.sup.3 or --NR.sup.3.sub.2, where R.sup.3 denotes a branched or
unbranched C.sub.1-C.sub.20 alkyl group, R' is hydrogen, a branched
or unbranched C.sub.1-C.sub.18 alkyl group and R'' is a branched or
unbranched C.sub.1-C.sub.18 alkyl group, for adjusting the
reactivity and the gel time of resin mixtures based on radically
polymerizable compounds.
2. The method according to claim 1, wherein R.sup.1 and R.sup.2 in
formula (I), independently of one another, are hydrogen or a
branched or unbranched C.sub.1-C.sub.8 alkyl group.
3. The method according to claim 2, wherein R.sup.1 and R.sup.2 in
formula (I), independently of one another are hydrogen or
methyl.
4. The method according to claim 3, wherein the compound of formula
(I) is 2-(dimethylamino)pyrimidin-5-ol,
2-(dimethylamino)-4,6-dimethylpyrimidin-5 -ol or
4,6-dimethyl-2-(octyloxy)pyrimidin-5-ol.
5. The method according to claim 1, wherein the compound of formula
(II) is 2,6-di-tert-butyl-4-methylphenol or
2,6-di-tert-butyl-4-hydroxyanisole.
6. (canceled)
7. The method according to claim 1, wherein the molar ratio of the
component of formula (I) to the compound of formula (II) is 1:1 to
1:10.
8. A resin mixture comprising at least one radically polymerizable
compound, optionally a reactive diluent and an agent for adjusting
the reactivity and the gel time, wherein the agent for adjusting
the reactivity and the gel time is a combination of a compound of
general formula (I) ##STR00011## wherein R.sup.1 and R.sup.2
independently of one another denote hydrogen or a branched or
unbranched C.sub.1-C.sub.20 alkyl group, and X is --OR.sup.3 or
--NR.sup.3.sub.2, where R.sup.3 is a branched or unbranched
C.sub.1-C.sub.20 alkyl group or a C.sub.2-C.sub.4 polyalkylene
oxide group, with a compound of general formula (II) ##STR00012##
wherein R denotes hydrogen, a branched or unbranched
C.sub.1-C.sub.18 alkyl group or --OR.sup.3 or --NR.sup.3.sub.2,
where R.sup.3 denotes a branched or unbranched C.sub.1-C.sub.20
alkyl group, R' is hydrogen, a branched or unbranched
C.sub.1-C.sub.18 alkyl group and R'' is a branched or unbranched
C.sub.1-C.sub.18 alkyl group.
9. The resin mixture according to claim 8, wherein R.sup.1 and
R.sup.2 in formula (I) independently of one another are hydrogen or
a branched or unbranched C.sub.1-C.sub.8 alkyl group.
10. The resin mixture according to claim 9, wherein R.sup.1 and
R.sup.2 in formula (I) independently of one another are hydrogen or
methyl.
11. The resin mixture according to claim 10, wherein an agent (c)
for adjusting the reactivity and the gel time is
2-(dimethylamino)pyrimidin-5-ol,
2-(dimethylamino)-4,6-dimethylpyrimidin-5-ol or
4,6-dimethyl-2-(octyloxy)pyrimidin-5-ol.
12. The resin mixture according to claim 8, wherein the compound of
formula (II) is 2,6-di-tert-butyl-4-methylphenol or
2,6-di-tert-butyl-4-hydroxyanisole.
13. (canceled)
14. The resin mixture according to claim 8, wherein the molar ratio
of the component of formula (I) to the compound of formula (II) is
1:1 to 1:10.
15. The resin mixture according to claim 8, wherein the resin
mixture also contains an accelerator for the curing agent.
16. A reactive resin mortar, comprising the resin mixture according
to claim 8 and inorganic additives.
17. A two-component mortar system, comprising the reactive resin
mortar according to claim 16 as component A and a hardener arranged
separately to inhibit reaction as component B.
18. The two-component mortar system according to claim 17, wherein
the hardener contains an organic or inorganic peroxide as the
curing agent.
19. The two-component mortar system according to claim 17, wherein
the hardener also contains inorganic additives.
20. The two-component mortar system according to claim 17, wherein
component A additionally contains a hydraulically setting or
polycondensable inorganic compound in addition to the reactor resin
mortar and component B additionally contains water in addition to
the curing agent.
21. A method of chemical fastening comprising applying the
two-component mortar system according to claim 17 for chemical
fastening.
22. A shell, cartridge or film bag containing a two-component
mortar system according to claim 17 comprising two or more separate
chambers in which the reactive resin mortar and/or hardener is/are
arranged.
23. The resin mixture of claim 8 wherein the resin mixture further
comprises a reactive diluents and an agent for adjusting the
reactivity and the gel time.
Description
[0001] This application is a divisional of U.S. application Ser.
No. 13/492,149 filed Jun. 8, 2012, which claims priority from
German Patent Document No. 10 2011 077 254.5, filed Jun. 9, 2011,
the disclosures of which are expressly incorporated by reference
herein.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The subject matter of the present invention is the use of an
inhibitor combination, in particular a 5-pyrimidinol derivative, in
combination with a sterically hindered phenol derivative to adjust
the reactivity and the gel time of mortar compositions based on
synthetic resin, in particular those based on radically
polymerizable compounds. The subject matter of the present
invention is also a resin mixture containing this inhibitor, as
well as a two-component mortar system with a reactive resin mortar
(component A) which contains the resin mixture, and a hardener
(component B), which contains a curing agent for the radically
polymerizable compound. Furthermore, the present invention relates
to the use of the resin mixture as an organic binder for use in the
construction field.
[0003] The use of resin mixtures based on radically polymerizable
compounds has long been known in a wide variety of fields,
including the construction field. In the field of fastening
technology, the use of resin mixtures as organic binders for
polymer concrete has proven successful. This involves in particular
their use as reactive resin mortar in two-component systems for
dowel applications in which the reactive resin mortar (component A)
contains the resin mixture based on radically polymerizable
compounds and the hardener (component B) contains the curing agent.
Other conventional ingredients such as inorganic additives or dyes
may be present in one component and/or the other. The reaction is
then initiated through the formation of free radicals when the two
components are mixed, and the organic binder is hardened to a
Duromer.
[0004] Resin mixtures containing a compound (a so-called
accelerator), capable of accelerating the polymerization reaction
and serving to accelerate the formation of the radical initiator,
require the addition of stabilizers for inhibiting compounds that
are capable of the polymerization reaction. These stabilizers serve
to prevent the polymerization reaction and therefore prevent
unwanted premature polymerization of the radically polymerizable
compound during storage by capturing the free radicals thereby
formed. Different compounds containing the radically hardenable
compounds in amounts of 20 ppm to 1000 ppm as additives are
generally used as stabilizers. Some of these stabilizers can also
be used to adjust the gel time, i.e., for a targeted delay in
initiation of the polymerization after mixing the resin mixture
containing the accelerator or the reactive resin mortar containing
the same with the hardener. However, the quantities of stabilizers
must be significantly increased here to 5000 ppm or even more,
depending on the desired gel time, and in particular when
accelerators are used. In this context, the compounds are referred
to as inhibitors to differentiate them functionally from
stabilizers Inhibitors of this type that are used are usually
phenolic compounds such as hydroquinone, p-methoxyphenol,
4-tert-butylpyrocatechol, 2,6-di-tert-butyl-4-methylphenol or
2,4-dimethyl-6-tert-butylphenol, or stable nitroxyl radicals such
as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol).
[0005] The phenolic compounds, however (in particular those that
are especially suitable because of their reactivity to function as
inhibitors for the premature polymerization of the aforementioned
reactive resins, e.g., hydroquinone, pyrocatechol and their
alkyl-substituted derivatives, e.g., 4-tert-butylpyrocatechol,
methylhydroquinone and the like) have the disadvantage that they
are deactivated by atmospheric oxygen, which leads to an insidious
loss of inhibiting effect during storage of a system inhibited in
this way. This deactivation is greater in the presence of alkaline
media, i.e., alkalizing fillers such as cement, which can be
problematic with mortar compounds having inorganic fillers or
organic-inorganic hybrid mortars. Deactivation of the inhibitor
results in the gel time dropping to unacceptably short times, so
the resins and/or mortar compositions exhibit a great gel time
drift during storage before use.
[0006] To prevent such a gel time drift, German Patent Application
DE 195 31 649 A1 proposes replacing the stabilizer
4-tert-butylpyrocatechol, which is actually excellently suited for
this, with stable nitroxyl radicals such as piperidinyl-N-oxyl or
tetrahydropyrrole-N-oxyl, which are somewhat stable with regard to
gel time. However, it has been found that these inhibitors lead to
a disproportionately strong inhibition of the polymerization
reaction at low temperatures, and reactive resins containing these
inhibitors are subject to strong surface inhibition due to
atmospheric oxygen, which results in inadequate robustness of the
curing. Furthermore, it is presumed that traces of acid, which may
be present in the precursors of the radically curable,
ethylenically unsaturated compounds, such as polymeric methylene
diphenyl diisocyanate in urethane (meth)acrylate resins, for
example, lead to disproportionation of the nitroxyl radicals and
thus to their inactivation.
[0007] Sterically hindered phenols such as
2,6-di-tert-butyl-4-methylphenol and
2,4-dimethyl-6-tert-butylphenol have a much more stable behavior
with regard to gel time drift and also lead to suitable inhibition
of polymerization at room temperature. However, the quality of the
cured resin and thus the extraction strength of a dowel set with
the help of such an inhibited reactive resin are unsatisfactory at
low temperatures. In addition, most of the compounds used for
stabilizing the resins are not at all suitable as agents for
adjusting the gel time, i.e., as inhibitors, because when present
in larger quantities, such as those required to adjust the gel
time, they act as retarders, and have a deleterious effect on the
polymerization and thus on the final mechanical properties of the
polymer in a sensitive manner. They therefore act essentially to
stabilize the resin for storage.
[0008] To solve the problem of the inadequate hardening rate and
thorough hardening at low temperatures, European patent application
EP 1 935 860 A1 proposes that the highly activating tert-butyl
radical of 4-tert-butylpyrocatechol be replaced by radicals which
are not such strong activators, so that a sufficient inhibitor
quality can be achieved with a significantly lower gel time drift
along with a high performance level and great robustness of the two
component reactive resins even at low curing temperatures.
[0009] The pyrocatechol and its derivatives are very efficient
inhibitors for adjusting the gel time even at low temperatures but
they have a great tendency to autoxidation, which is exacerbated in
an alkaline medium and therefore there is in turn a great tendency
to gel time drift.
[0010] None of these previously known approaches lead to a
satisfactory gel time stability of the reactive resin, especially
in the presence of cement or other alkaline or acidic substances as
fillers, or in the case of elevated residual acid numbers of the
reactive resin mortar, to satisfactory low-temperature hardening at
the same time.
[0011] The present inventors have shown that the use of 3-pyridinol
and 5-pyrimidinol compounds as inhibitors has the same inhibiting
behavior with comparable load values of the cured mortar
composition in comparison with the inhibitors known from the prior
art, but do not have the disadvantages associated the prior art.
However, these compounds are relatively expensive to manufacture,
so their use in larger quantities, in particular as a bulk product,
would not be very economical. There is thus a demand for inhibitors
that have properties comparable to those of 3-pyridinol and
5-pyrimidinol but are less expensive to produce.
[0012] The object on which the present invention is based is thus
to provide inhibitors for free radical polymerization of the
reactive resin mortars based on synthetic resins as defined in the
introduction, in particular radically curable compounds, that are
filled with cement or other alkaline or acidic fillers, among
others, and/or contain compounds that have a high residual acid
value, are acid stable, ensure gel time stability during storage
and can achieve the reactivity, robustness and curing quality of a
mortar compound even at low temperatures, such as that achieved
with the inhibitors known from the DE 195 31 649 A1 and EP 1 935
860 A1.
[0013] It has been found that, when the previously known inhibitors
are replaced by pyrimidinol compounds substituted in para position
to the hydroxyl group, a satisfactory inhibitor quality can be
achieved with significantly less gel time drift. It has been
further found that, surprisingly, a high performance level and a
high robustness of the corresponding mortar compounds can also be
achieved even at low curing temperatures. The performance level at
low temperatures (-5.degree. C.) has been further increased by
adding sterically hindered phenols, such that the quantity of
expensive pyrimidinol compounds has been reduced significantly
without any loss of their positive properties.
[0014] The subject matter of the present invention is therefore the
use of an inhibitor mixture. Additional subject matters of the
invention include a resin mixture containing the inhibitor mixture,
a reactive resin mortar containing the resin mixture, a
two-component mortar system and use of same for chemical
fastening.
[0015] Without being bound by a certain theory, it is assumed that
the phenolic compound, which itself does not have a positive effect
on the gel time or the performance level (load values) regenerates
the pyrimidinol compound, so that the quantity of pyrimidinol
compounds can be reduced without reducing the positive effects,
such as low gel time drift, high load values and high robustness of
the system (attributed to the presence of the pyrimidinol
compound). The pyrimidinol compound is the main inhibitor, which
determines the reactivity. The phenolic compound determines the gel
time and may be referred to as a co-inhibitor.
[0016] The following definitions are used in the sense of the
present invention:
[0017] "Resin mixture" denotes a mixture of the reactive mixture of
resin production, containing the radically polymerizable compound,
optionally a catalyst for producing the compound and the reactive
diluents, accelerators and stabilizers plus optionally additional
reactive diluents; this term is used as synonymous with the term
"organic binder."
[0018] "Reactive resin mortar" denotes a mixture of a resin mixture
and inorganic additives; the term "component A" is used as
equivalent to this.
[0019] "Curing agent" denotes substances which induce the
polymerization (hardening) of the basic resin.
[0020] "Hardener" denotes a mixture of curing agent and inorganic
additives.
[0021] "Accelerator" denotes a compound capable of accelerating the
polymerization reaction (curing) which serves to accelerate the
formation of the radical initiator.
[0022] "Stabilizer" denotes a compound which is capable of
inhibiting the polymerization reaction (curing) and serves to
prevent the polymerization reaction and thus an unwanted premature
polymerization of the radically polymerizable compound during
storage; these compounds are usually used in such small amounts
that the gel time is not affected.
[0023] "Inhibitor" also denotes a compound capable of inhibiting
the polymerization reaction (hardening), which results in a delay
in the polymerization reaction immediately after adding the curing
agent; these compounds are usually used in amounts such that the
gel time is affected.
[0024] "Reactive diluent" denotes liquid or low-viscosity,
radically polymerizable compounds which dilute the resin mixture
and thereby impart the viscosity required for application thereof,
contain functional groups capable of reacting with the basic resin
and part of the cured compound (mortar) predominantly in
polymerization (hardening).
[0025] "Mortar compound" denotes the formulation obtained by mixing
the reactive resin mortar with the hardener, which contains the
curing agent, and can be used directly as such for chemical
fastening.
[0026] "Two-component mortar system" refers to a system comprising
a component A, the reactive resin mortar, and a component B, the
hardener, such that the two components are stored separately to
inhibit the reaction, so that hardening of the reactive resin
mortar occurs only after the components have been combined.
[0027] The subject matter of the invention is thus the use of a
combination of a compound of general formula (I)
##STR00001##
[0028] wherein R.sup.1 and R.sup.2 independently of one another
denote hydrogen, a branched or unbranched C.sub.1-C.sub.20 alkyl
group, and X is OR.sup.3 or NR.sup.3.sub.2 where R.sup.3 is a
branched or unbranched C.sub.1-C.sub.20 alkyl group or a
C.sub.2-C.sub.4 polyalkylene oxide group,
with a compound of general formula (II)
##STR00002##
[0029] wherein R denotes hydrogen, a branched or unbranched
C.sub.1-C.sub.18 alkyl group or --OR.sup.3 or --NR.sup.3.sub.2,
where R.sup.3 denotes a branched or unbranched C.sub.1-C.sub.20
alkyl group, R' is hydrogen, a branched or unbranched
C.sub.1-C.sub.18 alkyl group, and R'' is a branched or unbranched
C.sub.1-C.sub.18 alkyl group, for adjusting the reactivity and the
gel time of two-component reactive resin compounds based on
radically curable reactive resins.
[0030] Group X in formula (I) is an electron-shifting group which
can shift electron density into the aromatic ring either directly
or via conjugation or hyperconjugation and thus can activate the OH
group for hydrogen transfer to free radicals, preferably to alkyl
radicals such as those which occur in radical polymerization, and
at the same time contributes toward the solubility of the
5-pyrimidinol compounds because as a result of their high polarity,
these compounds cannot dissolve adequately in methacrylate resins
having a moderate to low polarity under some circumstances.
According to the invention, X denotes --OR.sup.3 or
--NR.sup.3.sub.2, where R.sup.3 is a branched or unbranched
C.sub.1-C.sub.20 alkyl group, preferably a branched or unbranched
C.sub.1-C.sub.8 alkyl group, especially preferably methyl or
n-octyl.
[0031] The radicals R.sup.1 and R.sup.2 in formula (I),
independently of one another, are preferably hydrogen or a branched
or unbranched C.sub.1-C.sub.8 alkyl group, especially preferably
hydrogen or methyl.
[0032] The compound of formula (I) is preferably a compound of
formula I-1 (2-(dimethylamino)pyrimidin-5-ol), formula I-2
(2-(dimethylamino)-4,6-dimethylpyrimidin-5-ol; Me2N-PymOH) or
formula I-3 (4,6-dimethyl-2-(octyloxy)pyrimidin-5-ol;
C8O-PymOH):
##STR00003##
[0033] The radical R in formula (II) is hydrogen, a branched or
unbranched C.sub.1-C.sub.18 alkyl group or --OR.sup.3 or
--NR.sup.3.sub.2, where R.sup.3 is a branched or unbranched
C.sub.1-C.sub.20 alkyl group, R' is hydrogen, a branched or
unbranched C.sub.1-C.sub.18 alkyl group, and R'' is a branched or
unbranched C.sub.1-C.sub.18 alkyl group. R is preferably a methyl
or methoxy group and R' and R'' denote a methyl, isopropyl or
tert-butyl group.
[0034] The compound of formula (II) is preferably a compound of
formulas II-1 (2,6-di-tert-butyl-4-methylphenol; BHT) or II-2
(2,6-di-tert-butyl-4-hydroxyanisole; TBA):
##STR00004##
[0035] The following three combinations (III-1), (III-2) and
(III-3) of compound (I-1) with compound (II-1), compound (I-2) with
compound (II-2) and compound (I-3) with compound (II-1), namely a
combination of (III-1) of 2-(dimethylamino)pyrimidin-5-ol with
2,6-di-tert-butyl-4-methylphenol, a combination (III-2) of
2-(dimethylamino)-4,6-dimethylpyrimidin-5-ol with
2,6-di-tert-butyl-4-hydroxyanisole or a combination (III-3) of
4,6-dimethyl-2-(octyloxy)pyrimidin-5-ol with
2,6-di-tert-butyl-4-methylphenol is most especially preferred, the
combination (III-3) being especially preferred:
##STR00005##
##STR00006##
[0036] The molar ratio of inhibitors I:II according to the
invention is between 1:1 and 1:10. The ratio may even be up to 1:50
in many cases. Those skilled in the art can easily discover to what
extent the main inhibitor I can be "diluted," i.e., replaced, by
the co-inhibitor II.
[0037] With these combinations, the gel time can be lengthened,
while at the same time the load values at low temperatures
(-5.degree. C.) are increased. One positive side effect is that
this makes it possible to significantly reduce the quantity of
expensive pyrimidinols.
[0038] Another subject matter of the invention is a resin mixture
comprising at least one radically polymerizable compound,
optionally at least one reactive diluent and an agent for adjusting
the reactivity and the gel time, such that the agent for adjusting
the reactivity and the gel time is a combination of a compound of
the general formula (I)
##STR00007##
with a compound of the general formula (II)
##STR00008##
as described above. Reference is made to the preceding discussions
with respect to the compounds of formulas (I) and (II).
[0039] The agent for adjusting the reactivity and the gel time is
preferably used in an amount of 100 ppm to 2.0 wt %, preferably
from 500 ppm to 1.5 wt % and more preferably from 1000 ppm to 1 wt
%, based on the radically polymerizable compound.
[0040] Ethylenically unsaturated compounds, cyclic monomers,
compounds with carbon-carbon triple bonds and thiol-yne/ene resins
are suitable as the radically polymerizable compounds according to
the invention, such as those with which those skilled in the art
are familiar.
[0041] Of these compounds, the group of ethylenically unsaturated
compounds is preferred, comprising styrene and derivatives thereof,
(meth)acrylates, vinyl esters, unsaturated polyesters, vinyl
ethers, allyl ethers, itaconates, dicyclopentadiene compounds and
unsaturated fats, of which unsaturated polyesters resins and vinyl
ester resins in particular are suitable, as described in EP 1 935
860 A1, DE 195 31 649 A1 and WO 10/108939 A1. Vinyl ester resins
are most preferred because of their hydrolytic stability and
excellent mechanical properties.
[0042] Examples of suitable unsaturated polyesters which may be
used in the resin mixture according to the invention are divided
into the following categories as classified by M. Malik et al. in
J.M.S.--Rev. Macromol. Chem. Phys. C40 (2 and 3), pp. 139-165
(2000):
[0043] (1) Ortho resins: These are based on phthalic anhydride,
maleic anhydride or fumaric acid and glycols such as 1,2-propylene
glycol, ethylene glycol, diethylene glycol, triethylene glycol,
1,3-propylene glycol, dipropylene glycol, tripropylene glycol,
neopentyl glycol or hydrogenated bisphenol A.
[0044] (2) Iso resins: These are synthesized from isophthalic acid,
maleic anhydride or fumaric acid and glycols. These resins may
contain larger amounts of reactive diluents than the ortho
resins;
[0045] (3) Bisphenol A fumarates: These are based on ethoxylated
bisphenol A and fumaric acid;
[0046] (4) HET acid resins (hexachloroendomethylene
tetrahydrophthalic acid resins): These are resins obtained from
anhydrides or phenols containing chlorine/bromine and the synthesis
of unsaturated polyester resins.
[0047] In addition to these resin classes, the so-called
dicyclopentadiene resins (DCPD resins) may also be differentiated
as unsaturated polyester resins. The class of DCPD resins is
obtained either by modification of one of the types of resins
mentioned above by Diels-Alder reaction with cyclopentadiene or
alternatively they are obtained by a first reaction of a diacid,
e.g., maleic acid with dicyclopentadienyl and then by a second
reaction, usually the synthesis of an unsaturated polyester resin,
wherein the latter is referred to as a DCPD maleate resin.
[0048] The unsaturated polyester resin preferably has a molecular
weight Mn in the range of 500 to 10,000 daltons, more preferably in
the range of 500 to 5000 daltons and even more preferably in the
range of 750 to 4000 daltons (according to ISO 13885-1). The
unsaturated polyester resin has an acid value in the range of 0 to
80 mg KOH/g, preferably in the range of 5 to 70 mg KOH/g resin
(according to ISO 2114-2000). If a DCPD resin is used as the
unsaturated polyester resin, the acid value is preferably 0 to 50
mg KOH/g resin.
[0049] Vinyl ester resins in the sense of the invention are
oligomers or polymers with at least one (meth)acrylate terminal
group, so-called methacrylate functionalized resins, which also
include urethane methacrylate resins and epoxy methacrylates.
[0050] Vinyl ester resins having unsaturated groups only in the
terminal position are obtained, for example, by reacting epoxy
oligomers or polymers (e.g., bisphenols A diglycidyl ether, epoxies
of the phenol-novolak type or the epoxy oligomers based on
tetrabromobisphenol A) with methacrylic acid or methacrylamide, for
example. Preferred vinyl ester resins include
methacrylate-functionalized resins and resins obtained by reacting
an epoxy oligomer or polymer with methacrylic acid or
methacrylamide, preferably with methacrylic acid. Examples of such
compounds are described in U.S. Pat. No. 3,297,745 A, U.S. Pat. No.
3,772,404 A, U.S. Pat. No. 4,618,658 A, GB 2217722 A1, DE 3744390
A1 and DE 4131457 A1.
[0051] In this context, reference is made to US Patent Publication
No. 2011/0071234, the contents of which are hereby incorporated by
reference in their entirety.
[0052] The vinyl ester resin preferably has a molecular weight Mn
in the range of 500 to 3000 daltons, more preferably 500 to 1500
daltons (according to ISO 13885-1). The vinyl ester resin has an
acid value in the range of 0 to 50 mg KOH/g resin, preferably in
the range of 0 to 30 mg KOH/g resin (according to ISO
2114-2000).
[0053] Ethoxylated bisphenol A dimethacrylate with a degree of
ethoxylation of 2 to 10, preferably 2 to 4, difunctional,
trifunctional or higher functional urethane methacrylate oligomers
or mixtures of these curable constituents are especially suitable
as the vinyl ester resin.
[0054] More suitable are the known reaction products of di- or
polyisocyanates and hydroxyalkyl methacrylates, such as those
described in DE 2 312 559 A1, adducts of (di)isocyanates and
2,2-propanebis-[3-(4-phenoxy)-1,2-hydroxypropane-1-methacrylate]
according to U.S. Pat. No. 3,629,187 and the adducts of isocyanates
and methacryloylalkyl ethers, alkoxybenzenes and/or
alkoxycycloalkanes, such as those described in EP 44352 A1. In this
context, reference is made to DE 2312559 A1, DE 19902685 A1, EP
0684906 A1, DE 4111828 A1 and DE 19961342 A1. Mixtures of suitable
monomers may of course also be used.
[0055] All these resins that may be used according to the invention
can be modified according to methods with which those skilled in
the art are familiar to achieve lower acid numbers, hydroxy numbers
or anhydride numbers, for example, or they may be made more
flexible by introducing flexible units into the basic structure and
the like.
[0056] In addition the resin may also contain other reactive groups
that can be polymerized with a radical initiator such as peroxides,
for example, reactive groups derived from itaconic acid, citraconic
acid and allylic groups and the like, such as those described in WO
2010/108939 A1 (itaconic acid ester), for example.
[0057] The resin mixture contains 10 to 90 wt %, preferably 30 to
70 wt %, based on the resin mixture, of at least one radically
polymerizable compound.
[0058] The resin mixture may contain solvents, if necessary. The
solvents may be inert with respect to the reaction system or they
may participate in the polymerization during hardening, so-called
reactive diluents.
[0059] In a preferred embodiment of the invention the resin mixture
contains additional low viscosity radically polymerizable compounds
as reactive diluents to adjust the viscosity of the radically
polymerizable compound which functions as a resin, if necessary.
The reactive diluents may be added in an amount of 90 to 10 wt %,
preferably 70 to 30 wt %, based on the resin mixture.
[0060] Suitable reactive diluents are described in EP 1 935 860 A1
and DE 195 31 649 A1. The resin mixture preferably contains a
(meth)acrylic acid ester as the reactive diluent, where
(meth)acrylic acid esters are especially preferably selected from
the group consisting of hydroxypropyl(meth)acrylate, 1,2-butanediol
di(meth)acrylate, trimethylolpropane tri(meth)acrylate,
2-ethylhexyl (meth)acrylate, phenylethyl (meth)acrylate,
tetrahydrofurfuryl (meth)acrylate, ethyl triglycol (meth)acrylate,
N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminomethyl
(meth)acrylate, 1,4-butanediol di(meth)acrylate, acetoacetoxyethyl
(meth)acrylate, 1,2-ethanediol di(meth)acrylate, isobornyl
(meth)acrylate, diethylene glycol di(meth)acrylate,
methoxypolyethylene glycol mono(meth)acrylate, trimethylcyclohexyl
(meth)acrylate, 2-hydroxyethyl (meth)acrylate,
dicyclopentenyloxyethyl (meth)acrylate, and/or tricyclopentadienyl
di(meth)acrylate, bisphenol A (meth)acrylate, novolak epoxy
di(meth)acrylate,
di[(meth)acryloylmaleoyl]tricyclo5.2.1.0.sup.2.6decane,
dicyclopentenyloxyethyl crotonate,
3-(meth)acryloyloxymethyltricyclo5.2.1.0.sup.2.6decane,
3-(meth)cyclopentadienyl (meth)acrylate, isobornyl (meth)acrylate
and decalyl-2-(meth)acrylate.
[0061] Other conventional radically polymerizable compounds may
also be used alone or in mixture with the (meth)acrylic acid
esters, e.g., styrene, .alpha.-methylstyrene, alkylated styrenes
such as tert-butylstyrene, divinylbenzene and allyl compounds.
[0062] The nomenclature "(meth)acryl . . . / . . . (meth)acryl"
used to denote the radically polymerizable compounds means that
this terminology refers to both "methacryl . . . / . . . methacryl
. . . " compounds and "acryl . . . / . . . acryl" compounds.
[0063] According to a preferred embodiment of the invention, the
resin mixture is present in a pre-accelerated form; in other words,
it contains an accelerator for the curing agent. Preferred
accelerators for curing agents include aromatic amines and/or salts
of copper, cobalt, manganese, tin, vanadium or cerium. Especially
advantageous accelerators have proven to be N,N-dimethylaniline,
N,N-diethylaniline, N,N-diisopropanol-p-toluidine,
N,N-diisopropylidene-p-toluidine, N,N-dimethyl-p-toluidine,
N,N-diethylol-p-toluidine, N,N-diisopropylol-m-toluidine,
N,N-bis(2-hydroxyethyl)toluidine, N,N-bis(2-hydroxyethyl)xylidine,
N-methyl-N-hydroxyethyl-p-toluidine, cobalt octoate, cobalt
naphthenate, vanadium(IV) acetylacetonate and vanadium(V)
acetylacetonate.
[0064] The accelerator is present according to the invention in an
amount of 100 ppm to 5 wt %, preferably 1000 ppm to 2.5 wt %, based
on the resin mixture.
[0065] Another subject matter of the invention is a reactive resin
mortar which contains inorganic additives such as fillers and/or
other conventional additives in addition to the resin mixture
described above, the organic binder.
[0066] The amount of the resin mixture in the reactive resin mortar
is preferably 10 to 60 wt %, more preferably 20 to 30 wt %, based
on the reactive resin mortar.
[0067] The fillers used as conventional fillers, preferably mineral
or mineral-like fillers such as quartz, glass, sand, quartz sand,
quartz meal, porcelain, corundum, ceramics, talc, silica (e.g.,
pyrogenic silica), silicates, clay, titanium dioxide, chalk,
barite, feldspar, basalt, aluminum hydroxide, granite or sandstone,
polymeric fillers such as thermosetting plastics, hydraulically
curable fillers such as gypsum, slaked lime or cement (e.g.,
alumina cement or Portland cement), metals such as aluminum, carbon
black, also wood, mineral or organic fibers or the like or mixtures
of two or more thereof which may be added as a powder, in granular
form or in the form of molded bodies. The fillers may be present in
any forms, for example, as a powder or meal or as molded bodies,
e.g., in the form of cylinders, rings, spheres, flakes, rods,
saddle shapes or crystal shapes or also in fiber form (fibrillary
fillers) and the corresponding basic particles preferably have a
maximum diameter of 10 mm. Fillers are present in the respective
components preferably in an amount of up to 90, in particular 3 to
85 and especially 5 to 70, wt %. However, the globular inert
substances (spherical shape) are preferred and have a definite
reinforcing effect.
[0068] Other conceivable additives also include thixotropy agents
such as organically after-treated pyrogenic silica, bentonites,
alkyl and methyl celluloses, castor oil derivatives or the like,
plasticizers such as phthalic acid esters or sebacic acid esters,
stabilizers, antistatic agents, thickeners, flexibilizers,
hardening catalysts, rheology aids, wetting agents, coloring
additives such as dyes or pigments in particular, for example, for
differential dyeing of the components for better monitoring of
thorough mixing thereof or the like or mixtures of two or more
thereof are possible. Nonreactive diluents (solvents) may also be
present, preferably in an amount of up to 30 wt %, based on the
respective component (reactive resin mortar, hardener), for
example, from 1 to 20 wt % such as low alkyl ketones, e.g.,
acetone, di-low alkyl-low alkanolamides such as dimethylacetamide,
low alkylbenzenes such as xylenes or toluene, phthalic acid esters
or paraffins or water.
[0069] Further subject matter of the invention is a two-component
mortar system comprising the reactive resin mortar just described
as component A and a hardener which is stored in a separate
location spatially from the reactive resin mortar which thus
inhibits the reaction as component B. The hardener preferably
contains a peroxide as the curing agent. All the peroxides with
which those skilled in the art are familiar and which are used for
hardening unsaturated polyester resins and vinyl ester resins may
be used. Such peroxides comprise organic and inorganic peroxides,
either liquid or solid, wherein hydrogen peroxide may also be used.
Examples of suitable peroxides include peroxycarbonates of the
formula --OC(O)O--, peroxy esters of the formula --C(O)OO--, diacyl
peroxides of the formula --C(O)OOC(O)--, dialkyl peroxides of the
formula --OO-- and the like. These may be present as oligomers of
polymers. A series of examples of suitable peroxides is described
in US 2002/0091214 A1, paragraph [0018], WO 02051879 A1 and EP 1
221 449 A1.
[0070] The peroxides are preferably selected from the group of
organic peroxides. Suitable organic peroxides include tertiary
alkyl hydroperoxides such as tert-butyl hydroperoxide and other
hydroperoxides such as cumene hydroperoxide, peroxy esters or
peracids such as tert-butyl peresters, benzoyl peroxide,
peracetates and perbenzoates, lauryl peroxide including (di)peroxy
esters, perethers such as peroxydiethyl ether, perketones such as
methyl ethyl ketone peroxide. The organic peroxides used as
hardeners are often tertiary peresters or tertiary hydroperoxides,
i.e., peroxide compounds with tertiary carbon atoms bound directly
to an --O--O-acyl group or an --OOH group. However, mixtures of
these peroxides with other peroxides may also be used according to
the invention. The peroxides may also be mixed peroxides, i.e.,
peroxides having two different peroxide-carrying units in one
molecule. Benzoyl peroxide (BPO) is preferably used for
hardening.
[0071] The curing agents are expediently inertized by water,
nonreactive diluents having a liquefying effect, for example,
phthalates (WO 0205187 A1) or inert fillers, quartz sands and
aluminas being preferred.
[0072] The peroxides are used according to the invention in amounts
of 0.1 to 10 wt %, preferably from 1 to 6 wt %, based on the resin
mixture.
[0073] Component B of the two-component mortar system preferably
also contains inorganic additives, these additives being the same
as those that may be added to component A.
[0074] In a preferred embodiment of the two-component mortar
system, component A additionally contains a hydraulically setting
or polycondensable inorganic compound in addition to the reactive
resin mortar, and component B also contains water in addition to
the curing agent. Such mortar compositions are described in detail
in DE 42 31 161 A1. Component A preferably contains cement, for
example, Portland cement or aluminate cement as the hydraulically
setting or polycondensable inorganic compound, wherein cements
having little or no iron oxide content are especially preferred.
Gypsum may also be used as such or in mixture with the cement as
the hydraulically setting inorganic compound. Silicatic
polycondensable compounds, in particular soluble, dissolved and/or
amorphous silicon dioxide-containing substances may also be used as
the polycondensable inorganic compound.
[0075] The two-component mortar system preferably comprises
component A and component B, which are accommodated separately in
different containers to inhibit the reaction, for example, in a
multichamber device such as a multichamber cartridge, from which
containers the two components are dispensed and mixed by the action
of mechanical pressing forces or under the influence of a gas
pressure. Another possibility is that the two-component mortar
system may be fabricated as two-component capsules, which are
introduced into the borehole and are destroyed by impact rotational
setting of the fastening element with simultaneous thorough mixing
of the two components of the mortar composition. A cartridge system
or an injection system, in which the two components are expressed
from the separate containers and are passed through a static mixer,
in which they are mixed homogeneously and then discharged through a
nozzle, preferably directly into the borehole, is preferably
used.
[0076] The resin mixture according to the invention, the reactive
resin mortar and the two-component mortar system are used
especially in the construction field, for example, for maintaining
concrete, as polymer concrete, as a coating composition based on
synthetic resin or as a cold-curing road marking. They are
especially suitable for chemical fastening of anchoring elements
such as anchors, rebar, screws and bolts and the like in boreholes,
in particular in boreholes in different substrates, in particular
mineral substrates such as those based on concrete, porous
concrete, brickwork, lime sandstone, sandstone, natural rock and
the like.
[0077] In contrast with resin mixtures and reactive resin mortars
which are inhibited with phenolic inhibitors, the systems according
to the invention also have a stable gel time, even after prolonged
storage, i.e., the gel time does not drift toward inacceptable
short values even in subsequent use. In comparison with heart [sic]
mixtures and reactive resin mortars, which are inhibited with
stable nitroxyl radicals, the systems according to the invention
have good and thorough hardening, even at low temperatures.
[0078] The following examples serve to further illustrate the
invention.
EXAMPLES OF EMBODIMENTS
[0079] The gel times and the load values of the mortar compounds
produced according to the examples and the comparative examples are
compared below:
[0080] a) Determination of Gel Time
EXAMPLE 1
Component A
[0081] To prepare the reactive resin mortar, 4.06 g
2,6-di-tert-butyl-4-hydroxyanisole (TBA) and 2.89 g
2-(dimethylamino)-4,6-dimethylpyrimidin-5-ol (Me2N-PymOH) are added
to 976.1 g methacrylate resin and stirred until obtaining a
homogeneous solution. This corresponds to an inhibitor ratio of
approx. 1:1. Then, 72.4 g pyrogenic silica (Aerosil.RTM. R202;
Evonik Degussa GmbH), 482.68 g aluminate cement and 868.82 g quartz
sand F32 are dispersed in the resin solution in a dissolver in
vacuo until a homogeneous paste was obtained.
Component B
[0082] As the hardener for the methacrylate resin, 10 wt % of a 40%
dispersion of benzoyl peroxide in water and 14 wt % demineralized
water are used as the starting materials and then 53 wt % of a
quartz sand with an average particle size of 40 .mu.m and 22 wt %
of an alumina with an average particle size of 0.8 .mu.m are
dispersed therein and thickened with 1 wt % pyrogenic silica.
COMPARATIVE EXAMPLE 1
[0083] A reactive resin mortar and a hardener according to the
above example are prepared for comparison, with the difference
being that 4.06 g 2,6-di-tert-butyl-4-hydroxyanisole (TBA) was used
as the inhibitor in the reactive resin mortar.
COMPARATIVE EXAMPLE 2
[0084] A reactive resin mortar and a hardener according to the
above example were prepared for comparison, with the difference
being that 0.33 g 2-(dimethylamino)-4,6-dimethylpyrimidin-5-ol
(Me2N-PymOH) is used as the inhibitor in the reactive resin
mortar.
[0085] The gel time was determined for the compositions from
example 1 and the comparative examples 1 and 2, with the amounts
being set so that the amounts of inhibitors shown in Table 1 were
obtained. The results together with the quantities of inhibitor
used are shown in Table 1.
[0086] The gel time of a mixture of components A and B of the
two-component resin composition is determined using a commercial
device (GELNORM.RTM. gel timer) at a temperature of 25.degree. C.
To do so, components A and B were mixed in a volume ratio of 3:1
and then were thermally regulated at 25.degree. C. in a silicone
bath after being mixed, and the temperature of the sample is
measured. The sample itself is in a test tube, which is placed in
an air jacket countersunk in the silicone bath for thermal
regulation.
[0087] The heat evolved by the sample is plotted as a function of
time. The analysis is performed according to DIN16945, Sheet 1 and
DIN 16916. The gel time was the time at which a 10K increase in
temperature is reached, namely from 25.degree. C. to 35.degree. C.
here.
TABLE-US-00001 TABLE 1 Determination of the gel time of
two-component resin compositions Targeted filling Inhibitor
(25.degree. C. .fwdarw. 35.degree. C.) (min) Quantity (mol/g).sup.a
Me2N-PymOH* 4.6 .+-. 0.4 1.32*10.sup.-4 TBA** 4.8 .+-. 0.3
1.32*10.sup.-4 Me2N-PymOH + TBA 4.2 .+-. 0.4 1.32*10.sup.-4 (1:1)
Me2N-PymOH 9.7 .+-. 0.5 2.64*10.sup.-4 TBA 8.9 .+-. 0.4
2.64*10.sup.-4 Me2N-PymOH + TBA 15.7 .+-. 1.9 2.64*10.sup.-4 (1:1)
.sup.aBased on component (A)
*2-(dimethylamino)-4,6-dimethylpyrimidin-5-ol
**2,6-di-tert-butyl-4-hydroxyanisole
[0088] It is clear from this that the gel time of the resin
compositions according to the invention, adjusted using the
inhibitor combination at room temperature, is in the range of that
of the resin compositions adjusted using the individual inhibitors.
The gel time was increased by a factor of 4 when the amount of the
1:1 inhibitor combination was doubled, whereas the gel time was
only reduced by one-half when the amount of the individual
inhibitors was doubled. This shows clearly that there is a
synergistic relationship between the two inhibitors for adjusting
the gel time.
[0089] b) Determining the Load Values
EXAMPLE 2
[0090] As in example 1, a reactive resin mortar and a hardener were
prepared, except that 2.1 g 2,6-di-tert-butyl-4-methylphenol (BHT)
(9.76 mol/g) and 2.41 g 4,6-dimethyl-2-(octyloxy)pyrimidin-5-ol
(C8O-PymOH) (9.74 mol/g) are added as inhibitors to the reactive
resin mortar. This corresponds to a molar ratio of the inhibitor
combination BHT:C8O-PymOH of approx. 1:1.
EXAMPLE 3
[0091] As in example 1, a reactive resin mortar and a hardener are
prepared, except that 2.38 g 2,6-di-tert-butyl-4-methylphenol (BHT)
and 0.27 g 4,6-dimethyl-2-(octyloxy)-pyrimidin-5-ol (C8O-PymOH) are
added as inhibitors to the reactive resin mortar. This corresponds
to a molar ratio of the inhibitor combination BHT:C8O-PymOH of
approx. 10:1.
COMPARATIVE EXAMPLE 3
[0092] A reactive resin mortar and a hardener according to the
above examples are prepared for comparison, except that 3.07 g
2,6-di-tert-butyl-4-methylphenol (BHT) was used as the inhibitor in
the reactive resin mortar.
COMPARATIVE EXAMPLE 4
[0093] A reactive resin mortar and a hardener according to the
above examples were prepared for comparison, except that 9.84 g
4,6-dimethyl-2-(octyloxy)pyrimidin-5-ol (C8O-PymOH) is used as the
inhibitor in the reactive resin mortar.
[0094] To determine the load values of the cured composition, an
anchor threaded rod M12 which is doweled into a borehole in
concrete with a diameter of 14 mm and a borehole depth of 72 mm
using the two-component reactive resin according to the invention.
The average failure load is determined by centrally extracting the
anchor threaded rod with tight support using high-strength anchor
threaded rods. Three anchor threaded rods are doweled in place in
each case and their load values are determined after curing for 24
hours. The load values thereby determined are also listed as
averages in Table 1 below.
TABLE-US-00002 TABLE 2 Results of determination of load values
Reference.sup.1 -5.degree. C..sup.2 +40.degree. C..sup.3 In service
+80.degree. C..sup.4 Inhibitor [N/mm.sup.2] [N/mm.sup.2]
[N/mm.sup.2] [N/mm.sup.2] BHT* 60.9 48.2 55.7 54.2 C8O** 53.3 42.8
49.7 39.1 BHT + C8O 54.9 56.5 54.9 52.2 (1:1) BHT + C8O 62.1 53.0
55.1 47.3 (10:1) .sup.1Dry, cleaned borehole, setting and curing at
room temperature .sup.2As 1, but setting and curing at -50.degree.
C. [sic] .sup.3As 1, but setting and curing at +40.degree. C.
.sup.4As 1, but setting and curing for 24 hours at room
temperature, then heating to +80.degree. C. within 24 hours and
performing the extraction test at +80.degree. C.
*2,6-di-tert-butyl-4-methylphenol
**4,6-dimethyl-2-(octyloxy)pyrimidin-5-ol
[0095] As shown by Table 2 above, the two-component resin
compositions, adjusted according to the invention with the
inhibitor combination 1:1 and 10:1, have load values at +40.degree.
C. and +80.degree. C. that are within the range of those obtained
with the resin compositions adjusted using the individual
inhibitors. At temperatures of -5.degree. C., the load values of
the two-component resin compositions, adjusted with the inhibitor
combinations are higher than the values obtained with the
individual inhibitors. It is also clear that a reduction in the
concentration of C8O-PymOH with a simultaneous increase in the
concentration of BHT (molar ratio 1:10) yields a load value only
slightly greater than that with the molar ratio of 1:1.
[0096] These examples prove the surprising fact that, depending on
the desired effect, a lengthening of the gel time or an increase in
the load values can be achieved through appropriate choice of
inhibitor combination. Furthermore, it has been shown that the
quantity of expensive inhibitors can be greatly reduced in favor of
the less expensive co-inhibitor without sacrificing the positive
effects of the inhibitor combination.
[0097] The foregoing disclosure has been set forth merely to
illustrate the invention and is not intended to be limiting. Since
modifications of the disclosed embodiments incorporating the spirit
and substance of the invention may occur to persons skilled in the
art, the invention should be construed to include everything within
the scope of the appended claims and equivalents thereof.
* * * * *