AU9819498A - Glycerol-based fluidifying substance - Google Patents

Description

I

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE

SPECIFICATION

STANDARD PATENT Name of Applicant: Actual Inventor Address for service is: Exchem plc Robert Hardy Spensley WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: "Glycerol-Based Fluidifying Substance" The following statement is a full description of this invention, including the best method of performing it known to me:-

M

1/1 1 GLYCEROL-BASED FLUIDIFYING

SUBSTANCE

2 3 Inert substances are commonly employed to fluidify the 4 pre-set component of a load-bearing polymerisable composition, and can be used as liquid carriers for 6 polymerisation initiators therein. However, after 7 polymerisation the composition contains entrapped 8 molecules of the inert liquid substance, which 9 adversely affect mechanical properties of the set composition, by for example lowering its strength and 11 creep resistance, thereby reducing the capacity of the 12 composition to withstand sustained loading.

13 14 Water may be used as the inert liquid substance and has a relatively small effect on mechanical properties of 16 the set composition, for a similar level of 17 incorporation to other inert liquid substances.

18 However, the volatility of water at ambient 19 temperatures and humidities can lead to undesirable drying out or increased viscosity of the pre-set 21 components of the composition in which it is 22 incorporated.

23 24 Other than water, inert liquid substances, which have been used to fluidify the pre-set component of a 1 polymerisable composition, have been typically certain 2 esters of carboxylic acids such as di-alkyl phthalates, 3 long-chain alkyl benzoates, chlorinated hydrocarbons 4 such as the CERECLOR (TM) range (Imperial Chemical Industries), glycols such as propylene glycol, 6 polyglycols such as polyethylene glycol or 7 polypropylene glycol or silicone oils and blends 8 thereof.

9 In addition to their unfavourabl~e effect on the 11 mechanical properties of the set composition, these 12 substances compared with water are almost invariably 13 more toxic to health and the environment. They also 14 confer an inferior thermal stability to certain preferred free radical initiator(s) dispersed within 16 them. Furthermore, some of the inert substances are 17 immiscible with water so water cannot then serve as a 18 convenient flushing fluid in the preparation or use of 19 the composition.

21 Glycerol is known in the pharmaceutical field to be 22 used in certain pharmaceutical compositions as a 23 carrier for di-benzoyl peroxide, a known polymerisation 24 initiator. Glycerol is a fluid of low toxicity and is also a medium in which di-benzoyl peroxide has 26 stability against self-decomposition at elevated 27 ambient temperatures. With regard to these attributes 28 glycerol is a suitable inert liquid substance 29 conventionally employed in the pharmaceutical field.

31 Surprisingly it has now been found that glyc~rol may be 32 used as a very effective fluidifying element of a 33 substance to fluidify the pre-set component of a load- 34 bearing, and indeed any general non-pharmaceutical polyxnerisable composition such as a grout or adhesive.

36 Hence, it is an object of the present invention to 1 provide an improved substance to fluidify the pre-set 2 component of a non-pharmaceutical polymerisable 3 composition such as a grout or adhesive.

4 According to one aspect of the present invention there 6 is provided a fluidifying substance for a non- 7 pharmaceutical polymerisable composition wherein the 8 substance is or includes glycerol.

9 In one embodiment the substance wholly or substantially 11 comprises glycerol. The substance may comprise 12 glycerol along with 0-10, possibly 0-9.5, parts by 13 weight of water.

14 Where the composition includes a polymerisation 16 initiator the glycerol and water mixture is preferably 17 employed wholly or substantially as a liquid carrier 18 for the initiator.

19 Preferably the polymerisation initiator is a diacyl 21 peroxide such as di-benzoyl peroxide.

22 23 Optionally, to accelerate the initiating action of the 24 initiator, an accelerator is incorporated into one of the components that does not contain the initiator in a 26 multi-component polymerisable composition.

27 28 Preferably the accelerator for di-benzoyl peroxide 29 initiator is a tertiary amine, eg N,N-diethyl aniline or N,N-dimethyl para-toluidine.

31 32 Optionally the glycerol and water mixture includes one 33 or more reagents to alter the reactivity of the 34 polymerisation initiator.

36 Preferably the further reagent is di-butyl phthalate 46 1 (preferably a 5% solution), which quickens the onset of 2 gelation of the polymerisable liquid after this has 3 been inter-mixed with the di-banzoyl peroxide based 4 component.

6 Other inert liquid substances which optionally may 7 constitute a minor part of the glycerol-based substance 8 may for example be any of those materials which 9 conventionally have been employed as a liquid carrier for such an initiator.

11 12 Preferably the other liquid materials should constitute 13 no more than 20% by weight of the total quantity of 14 inert liquid fluidifying substance.

16 when water is part of the composition, some or all of 17 it may be admixed with the glycerol part.

18 19 optionally when water is present in the glycerol-based substance, water compatible ingredients may be 21 incorporated into the glycerol mixture so as to modify 22 its properties. For example, incorporation of clay or 23 water-soluble polymer such as CARBOPOL (TM) (B F 24 Goodrich) can modify its rheology.

26 The fluidifying substance of the present invention can 27 be used to fluidify a one-component polymerisable 28 composition. It can also be used to fluidify one or 29 more components of a multi-component polymerisable composition.

31 32 A one-component form of such a composition may be 33 formulated, setting being effected by, for example, the 34 application to the composition of heat or radiation such as ultra-violet rays, gamma rays or electron beam, 36 optionally aided by the incorporation of a latent 1 initiator substance(s) in the composition.

2 3 According to a second aspect of the present invention, 4 there is provided a non-pharmaceutical polymerisable composition having at least one pre-set component, 6 wherein the component is fluidified by a substance 7 which is or includes glycerol.

8 9 In a preferred embodiment of the invention there is provided a composition, comprising a polymerisable 11 ethylenically unsaturated liquid substance, within 12 which prior to the onset of this polymerisation is 13 incorporated a mixture of glycerol and water within the 14 range of 0.1 to 50% by weight of the substance, wherein the mixture includes 0-10 parts by weight of water in 16 ratio to 1 part of glycerol.

17 18 The glycerol-based fluidifying substance mixture 19 constitutes the sole or major part by weight of inert liquid substance incorporated in the composition. The 21 composition after polymerisation is capable of enduring 22 at ambient temperatures an unconfined compressive 23 stress of at least 40 Newtons per square millimetre 24 without fracture.

26 Preferably the ethylenically unsaturated liquid 27 substance is either a liquid monomer, a mixture of 28 liquid monomers or a liquid polymer/oligomer ester of 29 acrylic acid or methacrylic acid, or a blend of these, optionally incorporating a dissolved ethylenically 31 unsaturated polymer/oligomer.

32 33 Examples of monomer are, non-exclusively, styrene, 34 substituted styrene such as tertiary-butyl styrene or para-bromo styrene or vinyl toluene or para-methyl 36 styrene or divinyl benzene or alpha-methyl styrene, 1 alkyl and hydroxyalkyl esters or acrylic acid or 2 methacrylic acid or crotonic acid or maleic acid or 3 fumaric acid or vinyl sulphonic acid, allyl esters of 4 carboxylic acids such as diallyl phthalate, etc or any blend of these. Examples of liquid or solid 6 polymer/oligomer are, non-exclusively, fumarate/maleate 7 based polyester, epoxy acrylate, epoxy methacrylate, 8 urethane acrylate, urethane methacrylate, novolac epoxy 9 acrylate, novolac epoxy methacrylate etc or any blend or hybrid of these.

11 12 Preferably any polymerisation initiator used in the 13 composition is di-benzoyl peroxide.

14 According to a third aspect of the present invention, 16 there is provided a method of fluidifying one or more 17 components of a non-pharmaceutical polymerisable 18 composition wherein the one or more components are 19 admixed with a substance which is or includes glycerol.

21 In formulating the preferred embodiment of the 22 invention any of the materials which are typically 23 employed in commercial compositions based on 24 polymerisable ethylenically unsaturated substances may be employed.

26 27 Such materials may be chemically reactive, for example 28 accelerators, inhibitors or chain transfer agents and 29 may be incorporated into a component of the composition that does not comprise the initiator, except in the 31 case of one component systems. Inhibitors retard the 32 rate of polymerisation and can also prolong the storage 33 life of the resin based component of the composition, 34 an example being hydroquinone. Chain transfer agents limit the length of the polymer chains formed during 36 setting of the composition, an example being dodecyl 1 mercaptan.

2 3 Such materials may also be chemically inert, for 4 example particulate solid fillers, rheology modifying agents, shrinkage or expansion additives, air release 6 agents, fibres or pigments.

7 8 In a further embodiment of the invention there is 9 provided a composition as herein described for use as a grout/adhesive for embedding, bonding or fixing a 11 reinforcement element, for example a high strength 12 tendon or plate, onto or into a construction material, 13 for example concrete or masonry or ground strata.

14 In a yet further embodiment of the invention there is 16 provided a composition as herein described for use as 17 an adhesive/patching mortar, an in situ flooring 18 material, a vehicle body repair compound, protective 19 coating or as a cast or moulded article.

21 The present invention is generally useful in load- 22 bearing compositions. The present invention is 23 certainly suited to uses where the set product is 24 required to withstand high/sustained stress in service.

In the use of a composition for "permanent" grouting of 26 a fixing or reinforcement tendon in the substrate, a 27 low tendency to creep is a particularly important 28 requirement. If the set composition is not resistant 29 to creep, the grouted fixing/tendon may undergo an undesirable relaxation in stress from its initial value 31 and/or undergo an undesirable irrevocable strain during 32 its service lifetime. Further, if the composition 33 continually experiences stress at values for which it 34 cannot resist creep, the composition will eventually fracture.

36 1 The use of glycerol as an inert liquid substance is 2 particularly beneficial with regard to limiting the 3 effects on mechanical properties whenever a high 4 proportion of inert liquid substance relative to polymerisable liquid substance is desired. For 6 instance, a relatively high level of inert liquid 7 substance may be desired in order to facilitate the 8 physical intermixing of two components of a capsule or 9 cartridge bonding composition at the point of use, or to assist the flow or proportioning of the components 11 of a pumpable or pourable form of the composition.

12 13 Several embodiments of fluidifying substances according 14 to the present invention exhibit improved qualities over previous fluidifying agents. The use of a 16 glycerol based fluidifying substance means that the 17 fluidifying substance is non-toxic, has a small effect 18 on the mechanical properties of the set composition 19 within which it is used, and water can be used as a flushing medium for the prepared. compositions. in 21 addition not only does the glycerol based fluidifying 22 substance provide both resistance to chemical attack 23 and a stable medium for radical polymerisation 24 initiators, but also, because of the low volatility of glycerol, the glycerol based fluidifying substance does 26 not have the problems of a water based fluidifying 27 agent, namely those of drying out and high viscosity of 28 the pre-set composition.

29 Whilst any known method may be employed for initiating 31 the setting of a polymerisation composition, a free 32 radical mechanism is often employed. A free radical 33 initiator is normally incorporated in the composition 34 for this purpose, and in the pre-set state of the composition it is incorporated, except in one component 36 compositions, in a separate component to that 1 comprising the polymerisable liquid substance.

2 Representative examples of free radical initiators are: 3 diacyl peroxides, such as dibenzoyl peroxide or bis 4 (2,4 dichlorobenzoyl) peroxide or di-lauroyl peroxide; tertiary butyl peroxy 2 ethyl hexoate; cumene 6 hydroperoxide; peresters, such as tertiary butyl 7 perbenzoate; azo compounds, such as 8 azodiisobutyronitrile; keto peroxides, such as methyl 9 ethyl ketone peroxide. In order to accelerate the generation of free radicals from such initiators, an 11 accelerator is commonly employed in one of the other 12 components, representative examples being tertiary 13 amine, such as N,N-dimethyl aniline and N,N-dimethyl 14 para-toluidine, aldehyde-amine condensation product, organic sulphonyl chlorides, organic salts of a 16 transition metal, such as cobalt naphthenate and copper 17 octoate or mixtures thereof. The free radical 18 initiator is typically incorporated at about 0.5% to 19 about 3% by weight of the polymerisable substance.

21 The invention is illustrated by reference to the 22 following example.

23 24 Example 1 26 The composition of the invention may be based on two 27 components of the formulation described as an example 28 of a rock bolt capsule composition in Great Britain 29 Patent No. 2274894. The two components of the composition, in its pre-set state, are the Resin 31 component R, and the Catalyst component C. Both 32 components have the physical form of a liquid paste, so 33 enabling R and C to be pumped into the large and small 34 compartments respectively of an elongated twincomponent capsule. The ratio of R to C per unit length 36 of capsule may be varied within the range 10/1 to 35/1 by weight. The formulations of R and C are as follows-.

Ingredient Weight Weight Typej Resin component Rirag CRYSrIC 3601A (TM) styrene monomer part polyester part N,N-diethylanjjline (tertiary amnine) CABOSIL M5 (17M) (pyrogenic silica) 50:50 Blend of TRTJCARB 298 (TM) and TRUCARB 52 (TM) (powdered limestone mineral) Catalyst comonent, C.

LUCTDOL DAMPE D (TM) (di-benzoyi peroxide part) LUCIDOL DAMPED

(TM)

(water part) )liquid Water )plasticizer Glycerol TRUCARB 170 (TM) )powdered SNOWCAL 30 (TM) )mineral 9 0.2 0.3 79.5 8.0-12.0 8.0-12.0 0.05-0.40 0.1-0.4 65-83 Ethyleriically un-Satu rated liquid Substance (essential reactant) Ethylenically unsaturated polymer (essential reactant) Polyrnerisation aCCClCrjdtor reactant) Rheologycontrol agent (auxiliary) Particulate inert filler (auxiliary) Polymerisition initiator (essential reactant) Inert liquid substance, predominantly glycerol (water) (essential fluidifier for C) Particulate inert filler (auxiliary) 5-20 15-30 50-80 I I 1 The set composition, made by intermixing these 2 components in the ratio R/C within the range 10/1-35/1 3 by weight, has an unconfined compressive strength in 1 excess of 80 Newtons per square millimetre after 24 2 hours at 20 0 C, measured according to British Standard 3 test method 6319. This strength makes the composition 4 useful for the permanent fixing of a mechanically stressed rock bolt.

6 7 One use of the composition of the invention is as a 8 grout for anchoring/bonding a fixing element into or 9 onto concrete or masonry or ground strata. Settable compositions based on a polymerisable ethylenically 11 unsaturated liquid substance have been extensively used 12 world-wide for this purpose for over 30 years. For 13 this use it is common practice to formulate the 14 composition in the form of two components: component comprises the polymerisable liquid substance, a 16 polymerisation accelerator, particulate inert filler 17 and a rheology modifying agent; component comprises 18 a free radical polymerisation initiator, inert liquid 19 substance, particulate inert filler and a rheology modifying agent. For convenience, the components are 21 commonly packaged in the separate components of a 22 capsule or cartridge, and the composition is caused to 23 set after a short delay simply by intermixing 24 components and immediately prior to placement of the composition. The components of a capsule can be 26 intermi~xed by rotating the fixing element axially 27 through the capsule, whilst those of a cartridge can be 28 intermixed by co-extruding them through a static mixer 29 in a nozzle attached to the cartridge.

31 Use of a glycerol-based substance as the inert liquid 32 substance of the above composition upgrades the 33 mechanical properties of the set product so that the 34 product is more able to bear mechanical stress without structural impairment during its expected service 36 lifetime.

11/1 Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims (6)

1. 3. A substance as claimed in Claim 1 which comprises 11 glycerol and 0 to 10 parts of water. 12 13 4. A substance as claimed in any of Claims 1 to 3 to 14 fluidify a polymerisation initiator in the composition. 16 17 5. A substance as claimed in Claim 4 wherein the 18 polymerisation initiator is a diacyl peroxide. 19
2. 6. A substance as claimed in Claim 5 wherein the 21 diacyl peroxide is di-benzyl peroxide. 22 23 7. A substance as claimed in any one of Claims 4-6 24 wherein the substance includes one or more reagents to alter the reactivity of the 26 polymerisation initiator. 27 28 8. A substance as claimed in Claim 7 wherein the 29 reagent is di-butyl phthalate. 31 9. A substance as claimed in any one of the preceding 32 Claims which includes one or more conventional 33 polymerisation initiator liquid carrier materials. 34
3. 10. A substance as claimed in Claim 9 wherein the or 36 all conventional carrier materials constitute no I 1 more than 20% by weight of the total quantity of 2 fluidifying substance. 3 4 11. A substance as claimed in any one of the preceding Claims to fluidify a one-component polymerisable 6 composition. 7 8 12. A substance as claimed in any one of Claims 1-10 9 to fluidify one or more components of a multi- component polymerisable composition. 11 12 13. A non-pharmaceutical polymerisable composition 13 having at least one pre-set component, wherein the 14 or a component is fluidified by a substance as defined in any one of Claims 1-10. 16 17 14. A composition as claimed in Claim 13 wherein the 18 composition includes a polymerisation accelerator. 19
4. 15. A composition as claimed in Claim 14 being a 21 multi-component composition, wherein the 22 accelerator is incorporated into the component or 23 one of the components that does not contain the 24 initiator. 26 16. A composition as claimed in Claim 14 or Claim 27 wherein the polymerisation initiator is di-benzyl 28 peroxide, and the accelerator is N,N-diethyl 29 aniline or N,N-dimethyl para-toluidine. 31 17. A composition as claimed in any one of Claims 13 32 to 16 comprising a polymerisable ethylenically 33 unsaturated liquid substance, within which prior 34 to the onset of polymerisation is incorporated a mixture of glycerol and water within the range of 36 0.1 to 50% by weight of the polymerisable 1 substance, wherein the mixture includes 0-10 parts 2 by weight of water in ratio to one part of 3 glycerol. 4
5. 18. A composition as claimed in any one of Claims 13 6 to 17 wherein the glycerol-based fluidifying 7 substance constitutes the sole or major part by 8 weight of inert liquid substance incorporated in 9 the composition. 11 19. A composition as claimed in Claim 17 or Claim 18 12 wherein the ethylenically unsaturated liquid 13 substance is either a liquid monomer, a mixture of 14 liquid monomers or a liquid polymer/oligomer ester of acrylic acid or methacrylic acid, or a blend of 16 these. 17 18 20. A composition as claimed in Claim 19 incorporating 19 a dissolved ethylenically unsaturated polymer/oligomer. 21 22 21. A composition as claimed in any one of Claims 13 23 to 20 for use as a grout/adhesive for embedding, 24 bonding or fixing a reinforcement element onto or into a construction material. 26 27 22. A composition as claimed in any one of Claims 13 28 to 20 for use as an adhesive/patching mortar, an 29 in situ flooring material, a vehicle body repair compound, protective coating or as a cast or 31 moulded article. 32 33 23. A method of fluidifying one or more components of 34 a non-pharmaceutical polymerisable composition wherein the or one or more components are admixed 36 with a substance which is or includes glycerol. 1 24. A method as claimed in Claim 23 wherein the or one 2 or more components are admixed with a substance 3 comprising glycerol and 0 to 10 parts of water. 4
6. 25. A fluidifying substance or polymerisable 6 composition substantially as herein described with 7 reference to the Example. Dated this twenty-ninth_ day of December 1998 EXCHEM plc Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant i