Described are setting and hardening accelerators for hydraulic binders and said binder comprising compositions that are free of sulfates, alkali metals and chlorides. The setting and hardening accelerators comprise, as main component, water-soluble fluoride comprising aluminum salts and optionally complexing agents and/or amines.

This application claims the priority of European patent application no. 00 113 019.4, filed Jun. 21, 2000, the disclosure of which is incorporated herein by reference in its entirety.
The present invention relates to a sulfate-free and alkali-free or alkaline metal-free, respectively, and chloride-free accelerator as well as a method for setting and hardening of a hydraulic binder.
Examples for binders the setting and hardening of which occurs faster due to the addition of an accelerator of the present invention are for example cement or hydraulic lime, and examples for mixtures comprising such binders are mortar and concrete.
Applications for the inventive accelerator and the inventing method are the production of pre-fabricated elements and the acceleration of concrete produced at the construction site. In the first case, the usual acceleration of the hardening by heating (by means of electro ovens or oil ovens or steam) can be shortened or even entirely eliminated. In the second case, the time needed until the mold encasing the concrete can be removed, can be shortened, or the application of concrete can be continued also at lower temperatures. Further applications are in the production of fast setting cement and mortar mixtures, in particular for fixing pre-fabricated parts, casted parts etc.
A specific field of application is spraying mortar and spraying concrete. Such mortars and concretes serve the production of building constructions in underground and surface engineering as well as for the extension and lining of underground, natural or artificially constructed cavities, such as adits, tunnels or mines, for which the concrete must meet the static requirements as well as being water-tight. They also serve the consolidation of excavations, embankments, loose rock faces etc.
Already many substances are known that accelerate the setting and hardening of concrete. The most often used are i.a. strongly alkaline reacting substances such as alkali hydroxides, alkali carbonates, alkali silicates, alkali aluminates and alkaline earth chlorides.
Substances with strongly alkaline properties are undesired due to the health risks they can cause when persons are handling such substances. Burning of the skin of the worker, harmful effects on the respiratory system, especially the lungs, and irritation of the eyes and etching of the cornea can occur.
In view of concrete technology, strongly alkaline setting accelerators reduce the final strength, they cause larger shrinkage, what may result in crack formation and therefore strongly reduces the long time quality, in particular the resistance to sulfate of the concrete.
An important factor that affects the long time stability of concrete constructions is the later formation of Ettringit (furtheron referred to as Delayed Ettringit Formation (DEF)). By the formation of ettringit in the cured cement system, the structure of the building or construction, respectively, expands such that cracks or flakings occur.
In literature many documents concerning the DEF can be found that unambiguously show that an additional sulfate source significantly furthers the later formation of ettringit.
The commercially available accelerators comprise 15-25% sulfate and therefore are a not neglectable source for sulfate.
Further, in several standards, limitations for the sulfate content of concrete systems is prescribed (e.g. the Austrian standard [guideline Shotcrete] requires a maximal total sulfate content of 4.5% by mass SO3 [sum of accelerator and cements]).
The setting accelerator according to the present invention does not comprise any sulfate, thus hinders a supplementation of the concrete with sulfates and such does not add to the DEF.
Accelerators for the setting of hydraulic binders on the basis of amorphous aluminum hydroxide are already known from EP-A 0 026 262, in particular claims 1 and 11 to 13, as well as from chemical abstracts volume 86, number 18, May 1977, page 300, 126087c.
According to EP-A 0 026 262, page 2, last paragraph, the particle size of the amorphous aluminum hydroxide is in particular in the range of 4.8 and 5.4 xcexcm.
Also a swellable cellulose product and further additives can be comprised in such a hardening accelerator, see EP-A-0 026 262, in particular claims 8 to 10 and the examples.
From DE-A 2 548 687, in particular patent claim and page 15, the addition of aluminum sulfate and nitrates to setting accelerators on the basis of aluminates and aluminum oxide are known.
From FR-A 2 471 955, in particular claims 1 to 6, the use of formats and nitrates in accelerators are known.
EP 0 076 927 describes a method for the acceleration of the setting by addition of amorphous aluminum hydroxide and at least one water-soluble sulfate and/or nitrate and/or formiate.
EP 181 739 A1 describes the use of calcium sulfoaluminate and a mixture of calcium aluminates that together with alkali metals or alkaline earth metals and addition of 250% water result in a curable slurry.
JP 63 206 341 A2 discloses an accelerator comprising calcined alunite, calcium sulfoaluminate, sodium aluminate and sodium carbonate.
JP 58 190 849 A2 describes a mixture of calcium sulfoaluminate, calcium sulfate hemihydrate and calcium hydroxide for the preparation of fast setting, sprayable coatings.
SU 697 427 mentions a fast setting cement obtained by addition of calcium aluminate, calcium sulfoaluminate, calcium oxide, ferrite, silicate and gypsum.
JP 54 026 817 mentions the accelerated curing of gypsum by addition of calcium sulfoaluminate.
JP 53 099 228 describes an accelerator for grouting mortar based on calcium sulfoaluminate and calcium fluoroaluminate and water reducing agents.
In DE-OS 2 163 604 accelerators on the basis of calcium fluoroaluminate are mentioned.
From JP 01 290 543 A2 mixtures of calcium sulfoaluminate with calcium sulfate and lithium carbonate are known as accelerators for low temperature applications.
SU 1 350 136 A1 describes clinker with fast setting achieved by addition of barium sulfate, calcium aluminate and calcium sulfoaluminate.
WO 97/36839 describes the use of lithium silicate and/or lithium aluminate and/or aluminum salts.
WO 98/18740 comprises a method for the production of a setting and hardening accelerator for hydraulic binders. The product that according to claim 1 necessarily comprises of 5 components shows strong turbidity, high viscosity and a low storage stability. This can lead to plug up of the spray nozzles. At the construction site, upon dosing of the product, in particular at low temperatures, the high viscosity causes problems. A dilution of the product is not possible since thereby part of the basic salts are precipitated. The low pH-value leads to corrosion at dosing and spraying apparatuses.
U.S. Pat. No. 5,772,753 describes an accelerator on the basis of aluminum hydroxide with an organic anion. The production from an alkali aluminate solution comprises a very sumptuary washing procedure and mostly leads to insoluble aluminum compounds.
Hence, it is a general object of the invention to provide a sulfate-free and alkali-free or alkali metal-free, respectively, and chloride-free setting and hardening accelerator by which a very fast setting can be achieved.
Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the accelerator for the setting and hardening of a binder or a mixture comprising a binder is manifested by the features that said accelerator comprises at least one water-soluble fluoride comprising aluminum salt, and optionally a complexing agent (the term complexing agent as it is used in the scope of the present invention means substances that improve the setting procedure and the stabilization) and/or amines, whereby said amines act as stabilizers in order to prevent a precipitation of aluminum hydroxide. Preferably the pH-value of an accelerator of the present invention is in the range of about pH 2-8.
Further objects of the present invention are the use of an accelerator of the present invention for the acceleration of the setting and hardening of hydraulic binders, hydraulic binders admixed with latent hydraulic or inert fillers, mortar or concrete; a method for the accelerated setting and hardening of a mixture comprising a binder that is characterized in that usually 0.1 to 10 weight percent (this amount refers to an accelerator with 20-80 weight percent water content), referred to the weight of the binder, of an inventive sulfate-free, alkali-free or alkaline metal-free, respectively, and chloride-free setting and hardening accelerator are added to said mixture; as well as a hydraulic setting or hardened binder or binder comprising mixture containing an accelerator of the present invention.
A further object of the present invention is the production of a binder of the invention under generation of the water-soluble fluoride comprising aluminum salts from aluminum hydroxide and/or aluminum oxide and fluoric acid, optionally at enhanced temperatures, preferably prior to the admixture optionally further additives.
Furthermore, another object of the invention is a cured or uncured binder comprising mixture that also comprises an accelerator of the present invention.
The term alkali-free or alkaline metal-free, respectively, as it is used in the scope of the present invention corresponds to usual standards and means xe2x89xa61% Na2O-equivalents. For reasons of improved readability, furtheron only the term alkali-free will be used for designating the sulfate-free and alkali-free and alkaline metal-free accelerator according to the above definition.
The sulfate-free and alkali-free and chloride-free setting and hardening accelerator for hydraulic binders of the present invention comprises at least one water-soluble fluoride-comprising aluminum salt. It is especially suitable for inorganic hydraulic binders or hydraulic binder comprising mixtures. Examples for binders, the setting and hardening of which can be accelerated by the accelerator of the present invention are cement, hydraulic lime alone or in admixture with latent hydraulic binders and inert fillers, and examples for mixtures comprising such binders are e.g. mortar and concrete.
Preferred water-soluble fluoride comprising aluminum salts are in particular those that are producible from aluminum hydroxide and/or aluminum oxide and hydrofluoric acid. It has surprisingly been found that each aluminum hydroxide is usable for the generation of suitable fluorides, i.e. not only amorphous but also crystalline aluminum hydroxide. Dependent on the concentration and amount of hydrofluoric acid the exact composition of the fluoride comprising aluminum salts can slightly vary. The aluminum salts produced from e.g. aluminum hydroxide and/or aluminum oxide and hydrofluoric acid can either directly be used in the inventive accelerator or after drying, for example by means of spray drying, if an accelerator in powder form is desired.
The inventive accelerators can furthermore comprise at least one sulfate-free aluminum salt, and/or at least one complexing agent, and/or at least one amine, and/or at least one thickening agent. Preferably the at least one aluminum salt is selected from the group comprising oxalate, nitrate, glycolate, lactate, acetate, formiate or the respective basic salts or mixtures of the mentioned salts. The at least one complexing agent, preferably is a complexing agent selected from the group consisting of nitriloacetic acid, ethylene diamine tetraacetic acid, hydroxycarboxylic acids, polyhydroxycarbonic acids, phosphonic acids, salts of said acids, polyols or mixtures thereof, usually in an amount of 0.01-5 weight-% referred to the weight of a liquid accelerator with a water content of 20-80 weight-%. The at least one amine preferably is an amine selected from the group consisting of alcane amines and/or alcanol amines, whereby the alcane or alcanol preferably is selected from the C1-C6 alcanes or alcanols respectively, in an amount of 0.1-20 weight-% referred to the weight of a liquid accelerator with water content of 20-80 weight-%. The at least one thickening agent preferably is a thickening agent selected from the group consisting of bentonite, bentones, fermented organic biopolymers, alginates, polyglycol ethers, acrylate thickeners or urethane thickeners and mixtures thereof.
The inventive accelerators can be present as solutions, dispersions, or in powder form, whereby an inventive accelerator in powder form is preferably dissolved or dispersed in water prior to its use.
An inventive accelerator, preferably an accelerator in dissolved or dispersed form, is especially suitable for a method also being an object of the present invention. Said method for the acceleration of the setting and hardening of hydraulic binders as well as thereof produced mortars and concretes is characterized in that the inventive accelerator is added to the hydraulic binder in an amount of preferably 0.1 to 10 weight-% (water content of accelerator 0-80 weight-% water), referred to the weight of the hydraulic binder.
The inventive accelerator can be used for accelerating the setting and hardening of hydraulic binders, hydraulic binders in combination with latent hydraulic binders or inert fillers, mortar and concrete. A preferred use of the inventive setting and hardening accelerator is in spraying mortar or spraying concrete according to the dry spraying method or the wet spraying method. Said method is characterized in that the accelerator is added or addosed, respectively, to the dry binder, mortar or concrete, or to the binder, mortar or concrete mixed with water, in the conveyor pipe, the pre-wetting nozzle or the spraying nozzle in liquid or dispersed form with a liquid dosing apparatus directly into the mixture or into the mixing water. An accelerator in powder form is preferably addosed with a powder dosing apparatus directly at the above-mentioned places.
According to the present invention, the accelerator is preferably produced in that the water soluble, fluoride comprising aluminum salt is produced from aluminum hydroxide and hydrofluoric acid, optionally at enhanced temperature, prior to the admixture of further components that possibly may be comprised in the accelerator. The aluminum hydroxide can be used in amorphous as well as crystalline form. As an alternative, also aluminum oxide can be used as starting material.
A further object of the present invention is also a hardenable or hardened, respectively, binder comprising mixture comprising the inventive accelerator.
By using an inventive setting and hardening accelerator, a very fast setting of the respective binder or mixture comprising such binder, is effected, and high initial and final strengths are achieved. The setting and hardening accelerator neither to the applying person nor to the environment are caustic or toxic.
At the same time, the costs at the construction site can be reduced due to a significantly enhanced effectivity and reduced maintenance of the apparatus as well as reduced down time compared with today""s alkali-free accelerators. Besides of the resulting technical also enormous economic advantages result.
Since the setting accelerators of the invention do not comprise any alkalis, neither the strength development nor the shrinkage are xe2x80x9cnegativelyxe2x80x9d affected.
The following examples further illustrate the invention. They, however, shall not limit it in any way.

Sulfate-free and alkali-free setting and hardening accelerator

Abstract: In comparison with alkaline accelerators, said accelerators result in an essential shortening of the setting time and a fast development of compressive strengths. In comparison with commercially available alkali-free accelerators based on aluminum sulfate and organic acids, by the accelerator of the present invention the later formation of ettringite is prevented.


A process for the manufacture of a water blocking tape for use in cable manufacture, which process comprises the steps of:

The present invention relates to a process for the preparation of water blocking tapes and to the use of such tapes in cable manufacture and, in particular, their use in the manufacture of communications cables using fiber optics.
Cables, in particular communication cables using fiber optics, can quickly be damaged by water ingress, particularly if the water travels along the inside of the cable to splices, junctions, signal boosters etc. In the case of underwater or buried cables this problem can be quite serious. The ingress of water into the cable may be simply by the diffusion of water through the outer polymeric jacket, or by rupture of the outer jacket. Rupturing of the outer jacket may be caused by rodent or insect attack, by impact or by abrasion.
A number of methods exist for combatting this problem. The most widely used approach is to fill the inner regions of the cable with a hydrophobic gel-like compound, such as that sold under the Trade Name Rheogel. This approach suffers from a number of disadvantages, including inefficiency of filling all of the voids within the cable, the process is messy and time consuming, and the adhesion of cable splices is difficult to achieve due to the gel interfering with welding operations or adhesives.
Superabsorbent polymers, e.g. partially crosslinked polymers which absorb many times their own weight in water, and swell considerably without dissolving, to form a gel have also been used. Such superabsorbent polymers have been provided in the form of wide sandwich tapes consisting of a layer of a superabsorbent polymer powder sandwiched between two layers of a non-woven fabric. Tapes of this type have been described, for example, in U.S. Pat. No. 4,837,077 and EP-A-0024631. However, these products are expensive and cause considerable unwanted increases in cable diameters due to their thickness.
Fibrous substrates with superabsorbent polymer incorporated therein, such as aramid substrates, have also been used, particularly as strengthening wraps for the inner portions of cables. Substrates of this type have been described in EP-A-0482703. However, the methods used to deposit the superabsorbent onto the fibers are not particularly effective and do not result in a high level of superabsorbent on the fibrous substrate. Furthermore, the fibers are not effectively bound together which leads to potential problems of loose fibers during cable assembly processes. Some methods of applying the superabsorbent to the fibers involve the use of organic solvents, with consequential environmental concerns.
In EP-A-0685855 we describe a water blocking composite for use in cables which comprises a strengthening member or buffer tube impregnated with or coated with a mixture of a thermoplastic resin and a water-swellable particulate material. Although these water blocking composites possess certain advantages, they are based on thermoplastic resins which limits their mode of application and the thickness of the coatings that can thereby be applied.
U.S. Pat. No. 5,188,883 discloses a composite tape structure for use in cables having a metal tape layer and a layer of a swellable water blocking material bonded thereto. The layer of water blocking material may be formed from tape impregnated with or provided with a particulate swelling material, or the particulate material may be applied directly to and bonded to the metal tape layer.
U.S. Pat. No. 5,204,175 discloses a water blocking tape made by impregnating a fabric substrate with a metal salt of acrylic acid in monomeric form, a covalent crosslinking agent and a water soluble resin, and then heating the impregnated fabric substrate to copolymerise the monomer and the crosslinking agent in the presence of the water soluble resin.
EP-A-0357474 discloses a fabric impregnated with a formulation which crosslinks in situ on heating to form an absorbent polymer.
U.S. Pat. No. 4,017,653 discloses water swellable absorbent articles which are coated with a dry water swellable polyelectrolyte formed by coating the article with a solution of a carboxylic synthetic polyelectrolyte and a covalent crosslinking agent, and heating the coated article to crosslink the polyelectrolyte. The absorbent articles are generally coated fibrous substrates which can be used in forming diapers, tampons, meat trays or bath mats. Also disclosed are free standing films of the water swellable polyelectrolyte. EP-A-0702031 discloses an aqueous composition of an absorbent polymer for use in preparing superabsorbent materials such as superabsorbent cellulosic fibers and superabsorbent nonwoven webs. The aqueous polymer composition comprises 20-90% of an xcex1,xcex2-ethylenically unsaturated carboxylic acid monomer and at least one softening monomer, the aqueous composition being adjusted to pH 4-6 with an alkali metal hydroxide or an alkaline earth metal hydroxide and containing a divalent or trivalent metal crosslinking compound.
We have now developed a process for the preparation of water blocking tapes for use in the manufacture of cables which does not involve the of particulate water swellable materials, the use of thermoplastic binder resins or the use of covalent crosslinking agents which may be toxic and difficult to handle.
Accordingly, the present invention provides a process for the manufacture of a water blocking tape for use in cable manufacture, which process comprises the steps of:
(i) forming a coating of an aqueous solution of a water soluble polymer containing anionic groups and a multivalent ionic crosslinking agent on at least one surface of a substrate material selected from the group consisting of a metal foil, a plastic film, a plastic sheet, a multilayer film, and a laminate of at least two thereof; and
(ii) drying and/or curing the coating in order to form a partially crosslinked water swellable polymer coating on the at least one surface of the substrate material.
In another aspect the present invention provides a water blocking tape which comprises a substrate material as above defined having a coating on at least one surface thereof of a water soluble polymer containing anionic groups which is partially crosslinked with a multivalent ionic crosslinking agent.
The water soluble polymer used in the present invention contains anionic groups which are preferably selected from carboxyl, sulfonate, sulfate or phosphate groups, most preferably carboxylate groups. Examples of water soluble polymers for use in the invention are acrylic or methacrylic acid (co)polymers, itaconic acid (co)polymers, maleic anhydride copolymers, carboxymethylcellulose, 2-acrylamide-2-methylpropane sulfonic acid (co)polymers (such as AMPS from Lubrizol Corporation), polysaccharides and carboxymethyl starches. The most preferred polymers are acrylic and methacrylic acid homopolymers and the (co)polymers thereof.
The description of the process of the present invention will be made with reference to acrylic and methacrylic acid (co)polymers, but it will be understood that this is by way of example only, the process being applicable to the preparation of coatings based on other water soluble polymers as discussed above.
In carrying out the process of the present invention one or both sides of the substrate material which is selected from a metal foil, a plastic film, a plastic sheet or a multilayer film material, or a laminate of two or more thereof has a coating of an acrylic or methacrylic acid (co)polymer and a multivalent ionic crosslinking agent formed thereon. Generally, the coating will be formed as a continuous or discontinuous pattern on the substrate surface by coating the substrate with a coating solution comprising an aqueous solution of an acrylic or methacrylic acid (co)polymer containing the multivalent ionic crosslinking agent. The coating formulation is generally prepared by preparing an aqueous solution of the acrylic or methacrylic acid (co)polymer and then optionally partially neutralizing the acid, for example with an alkali metal hydroxide. The solution is then neutralized or maintained at a pH of above 7 and the required level of a multivalent ionic metal salt is added thereto. Alternatively, the coating formulation may be prepared by adding the multivalent ionic crosslinking agent to the solution of the partially neutralized or unneutralized acid (which will result in solids precipitation and/or gel formation) and then adding a base to redissolve the solids and provide the desired coating formulation. The pH of the solution is maintained at above 7 in order that the polymer and the multivalent metal ions remain in solution without crosslinking until the solution has been coated onto the substrate surface and the coating dried or cured in order to form a partially crosslinked water swellable polymer coating on the said surface. The pH of the solution may be adjusted, for example, with a combination of ammonium carbonate and ammonium hydroxide, or ammonium hydroxide alone. Once the solution has been coated onto the substrate, the loss of ammonia and water in step (ii) of the process of the invention results in activation of the crosslinking agent and the formation of the partially crosslinked water swellable polymeric material.
It will be understood by those skilled in the art that the coating on the substrate surface may be formed by first coating the substrate with a solution of an acrylic or methacrylic acid (co)polymer and thereafter applying a coating of a multivalent ionic crosslinking agent thereto. It is preferred, however, to apply both the polymeric material and the multivalent ionic crosslinking agent as a single solution.
The molecular weight of the starting polymeric material should be such that the final coating exhibits good film-forming properties and is preferably in the range of from 100,000 to 300,000. The polymer solution which is applied to the surface of the substrate will generally have a solids concentration in the range of from 1 to 50% by weight, preferably from 5 to 25% by weight, the actual value to be used depending upon the solution viscosity required in the particular coating method selected for coating the substrate surface. The amount of the multivalent ionic crosslinking agent which is incorporated into the coating will depend upon the required gel forming properties of the water swellable coating. Low levels of the ionic crosslinking agent will tend to give fast water uptake rates, but relatively weak gels, whilst higher levels will provide slower water uptake rates but stronger gels. Generally, the level of the ionic crosslinking agent will be in the range of from 0.001 to 0.1 molar equivalents, preferably 0.02 to 0.05 molar equivalents, of the multivalent ions based on the polymer.
The multivalent crosslinking agent preferably comprises an iron, aluminium or zirconium salt, or mixture thereof. Ammonium zirconium carbonate is the preferred salt for use in the present invention.
Other additives may be used in the coatings of the present invention, for example anti- blocking agents, colourants, heat stabilizers, surfactants, miscible co-solvents, such as lower alcohols, or any other additives known in the art.
The polymer solution may be incorporated onto or into the chosen substrate by any of a variety of well established methods, such as impregnation by dipping in a suitable bath, gravure printing, screen printing, spraying, doctor blade spreading or roller coating. The process of the present invention will generally be carried out using a wide film or sheet of material, which will then be cut to the predetermined required tape widths in a subsequent process.
It will be understood by those skilled in the art that the substrate which is treated in accordance with the process of the present invention may, if required, be pre-treated in order to increase its receptivity to the application of the coating compositions used in the present invention. Such pre-treatments may include plasma treatment, flame treatment, chemical etching, or the use of a primer coating.
The water blocking tapes of the present invention and the process for their production possess certain advantages over the prior art. The water blocking tapes of the present invention do not have any lower thickness limit which is dictated by the particle size of prior art particulate water swellable polymeric materials and no binder polymer is required. Accordingly, the coating is a completely water swellable, active polymer. The coated water blocking tape has a good flexibility and this lends to its use of application in the formation of the cables. The water blocking tapes of the present invention are prepared by a process which is aqueous based, and uses cheap polymeric starting materials. The ionic crosslinking agents which are used in the process are easier to disperse than covalent crosslinking agents and are less toxic and more easily handled than the covalent crosslinking agents used in the art.
The viscosity of the coating formulations can be varied over a wide range in order to suit a variety of coating methods and coating weights. Furthermore, the general strength of the polymeric material on uptake of water can be controlled in order to suit individual cable design criteria. The process of the invention is applicable to the coating of a wide variety of substrates and thus can be used to coat components which are already used in a cable design and thus a cable can be rendered water blocking with virtually no increase in the complexity of assembly and the diameter of the cable with a minimum increase in weight. In the preferred embodiment of the invention the pH is used to control the activity of the ionic crosslinking agent and this provides the coating formulation with a good shelf life prior to application and use.
The present invention also includes within its scope a cable which incorporates therein a water blocking tape as hereinbefore described. The water blocking tape may comprise an intermediate strengthening member or an outer strengthening wrap of the cable.

Process for the preparation of water blocking tapes and their use in cable manufacture

Abstract: (ii) drying and/or curing the coating in order to form a partially crosslinked water swellable polymer coating on the at least one surface of the substrate material. Water blocking tapes are also provided which comprise a substrate material having a coating on at least one surface thereof of a water soluble polymer containing anionic groups which is partially crosslinked with a multivalent ionic crosslinking agent. The preferred water soluble polymer containing anionic groups is an acrylic or methacrylic acid (co)polymer.


A method (300) and system for controlling use of software programs on multiple workstations of a network. An agent running on each workstation detects (306) any new process (using a kernel hooking technique), which is started in response to the request of execution of a program (397). The process is suspended (308) and an authorization to run the program is requested (334) to an associated metering server. The metering server compares (380) the current usage of the product with the respective authorized conditions of use, and answers (382) the agent granting or denying the authorization to run. The process is accordingly resumed (312), in order to enable the program to start, or aborted (315), so as to prevent execution of the program. In any case, the program is not stopped (but it is prevented from starting); this avoids killing the program while it is performing potentially risky operations.

The present invention relates to a method and system for controlling use of digitally encoded products.
Digitally encoded products, such as software programs, can be perfectly reproduced in an infinite number of copies. However, unauthorized copying of programs generally involves infringement of intellectual property rights of their publishers. For this reason, it is of the utmost importance to verify compliance of the employed programs with corresponding authorized conditions of use. This problem is particularly acute in big organisations having a large number of computers, and it has been exacerbated in the last years by the widespread diffusion of the INTERNET, which further facilitates the uncontrolled distribution of this kind of products.
The above-mentioned verification is usually performed auditing all the computers manually. However, this procedure is time consuming (particularly in large sites), and prone to errors.
Some automatic tools have been also proposed for evaluating compliance of the programs with their authorized conditions of use. Typically, these tools exploit an agent installed on each computer. The agent periodically checks the programs running on the computer. The result of the verification is logged, in order to generate program usage reports. Moreover, if a program is running violating its authorized conditions of use the tool may kill the respective process (so as to stop execution of the program), and may make the program unable to start again.
However, the solution described above does not monitor usage of the programs in real-time, so that it is not possible to perform an actual licensing validation. In addition, when execution of a program is killed to enforce compliance with its authorized conditions of use, damage to the corresponding data may be suffered; this also forces an end-user to re-install the program on the computer for a next (authorized) usage.
A different solution proposed in the art, known as technical licensing, consists of modifying each program to include a call to a licensing management system. Every time the end-user starts the program a corresponding request is transferred to the licensing management system. The licensing management system verifies whether the running of the program falls within the limits set out by the authorized conditions of use embedded in a respective digital certificate, and provides a corresponding return code to the program. If the result of the verification is positive the program can continue its execution; otherwise, the program is forced to stop.
However, the solution described above requires each program to be modified by the publisher. In addition, it is quite rigid and cannot be readily adapted to different requirements. The technical licensing technology applies only to programs supporting the licensing management system, and it is completely ineffective to control usage of different products.
It is an object of the present invention to overcome the above-mentioned drawbacks. In order to achieve this object, a method as set out in the first claim is proposed.
Briefly, the present invention provides a computer-implemented method of controlling use of digitally encoded products including the steps of: requesting execution of a digitally encoded product on a computer, intercepting the execution request before starting of the product, verifying compliance of the execution request with authorized conditions of use of the product, and enabling or preventing starting of the product according to the result of the verification.
Moreover, the present invention also provides a computer program application for performing the method, a program product storing the application, and a corresponding data processing system for controlling use of digitally encoded products.
With reference in particular to FIG. 1, a data processing system 100 in which the method of the invention can be used is depicted. The system 100 includes multiple workstations 105w. The workstations 105w are grouped into a series of sub-sets; a metering server 105s is associated with the workstations 105w of each sub-set. The metering server 105s and the corresponding workstations 105w are connected to each other through a network 110 (for example an INTRANET). The different metering servers 105s communicate with an administrative server 115 (installed at a remote location) through a different network 120 (for example the INTERNET). Moreover, the administrative server 115 is connected to an assets management system 125 (through a further network 127), which stores information relating to the workstations and their users.
Each workstation 105w, for example consisting of a Personal Computer (PC), is formed by several units that are connected in parallel to a communication bus 130w. In detail, a microprocessor (μP) 135w controls operation of the workstation 105w, a RAM 140w is directly used as a working memory by the microprocessor 135w, and a ROM 145w stores basic programs for a bootstrap of the workstation 105w. Several peripheral units are further connected to the bus 130w (by means of respective interfaces). Particularly, a bulk memory consists of a magnetic hard-disk 150w and a driver 155w for reading CD-ROMs 160w. Moreover, the workstation 105w includes input devices 165w (for example consisting of a keyboard and a mouse), and output devices 170w (for example consisting of a monitor and a printer). A Network Interface Card (NIC) 175w is used to plug the workstation 105w into the network 110.
The metering server 105s (for example consisting of a mid-range computer) is likewise formed by a bus 130s, multiple microprocessors 135s, a RAM 140s, and a ROM 145s; the metering server 105s further includes a hard-disk 150s, a driver 155s for CD-ROMs 160s, input devices 165s, output devices 170s, and a NIC 175s (for accessing the networks 110 and 120).
Similar considerations apply if the system has a different architecture, if the workstations, the metering servers and the administrative server are connected to each other in a different manner, if other networks are employed, if each workstation or metering server has a different structure or includes different components, if no assets management system is provided, and the like.
Considering now FIG. 2, a partial content of the working memories 140w and 140s of the workstation and of the metering server, respectively, is shown. The information (programs and data) is typically stored on the respective hard-disks and loaded (at least partially) into the working memories when the programs are running; the programs are initially installed onto the hard disks from CD-ROMs.
An operating system 205w and an operating system 205s provide a software platform for the workstation and the metering server, respectively. A stack 210w (on the workstation) and a stack 210s (on the metering server) process a set of protocol layers working together for defining network communications. In order to ensure effective transmission of information across the INTERNET, the information is encrypted (so as to ensure security), and it is transmitted using protocols (such as the HTTP) able to cross firewalls.
Considering in particular the workstation, the operating system 205w includes a main module 215 (known as kernel), which provides all the essential services required by other parts of the operating system. A kernel extension module 220 adds functionality to the operating system, using publicly available, standard interfaces.
A runtime agent 225 is running in the background, for controlling execution of application programs 230 on the workstation. The runtime agent 225 interfaces with the stack 210w, in order to exchange information with the metering servers. The runtime agent is silently installed on the workstation during a registration process, in which an end-user of the workstation registers himself/herself by connecting to a web page hosted on the associated metering server.
The runtime agent 225 controls several memory structures. Particularly, a server table 235 includes the IP addresses of possible alternative metering servers associated with the workstation (in addition to the main one directly connected to the workstation, and identified in a configuration table of the runtime agent). A control catalogue 240 lists the programs whose execution on the workstation must be controlled; on the other hand, an internal log 245 lists the programs not included in the control catalogue 240, but which have been nevertheless executed on the workstation. Moreover, the runtime agent 225 controls entering of information into a running table 250; the running table 250 lists the programs currently in execution on the workstation and for which a corresponding authorization to run has been granted (together with an identifier of the metering server that has granted the authorization). The runtime agent 225 also generates a program inventory 255 (for transmission to the metering server), which includes information about the programs installed on the workstation.
Moving now to the metering server, a licensing agent 260 running in the background controls the associated workstations. The licensing agent 260 interfaces with the stack 210s, in order to exchange information with the workstations and the administrative server.
The licensing agent 260 manages an authorization catalogue 265, which contains information about the authorized conditions of use of each program; for example, the authorization catalogue 265 specifies the maximum processing power or the maximum capacity of the working memory of the workstations on which the program can run, the number of licenses for the program (defining the maximum number of instances of the program allowed to run concurrently), and the like. In addition, the licensing agent controls entering of information into a metering table 270, which lists the programs currently in execution on the workstations, and whose authorization to run has been granted by the metering server. The licensing agent 260 also manages a global catalogue 273 including known programs that could be generally allowed to run on the associated workstations.
Moreover, the licensing agent 260 manages a repository 275 that contains different information to be distributed to the associated workstations (such as the up-to-date version of the runtime agent code, or the list of the alternative metering servers and of the programs to be controlled) or collected from the workstations (such as real-time reporting of software usage and inventory information of programs installed on the workstations).
Similar considerations apply if the programs and data are structured in a different manner, if other modules or functions are provided, if the data are stored in equivalent memory structures, if different conditions of use are envisaged, if the information is transmitted using different protocols, if the licensing agent is embedded in a web server, and so on. Alternatively, the runtime agent is installed by a logon script stored on the workstation, or it is deployed by means of a software distribution system.
As shown in FIG. 3a-3c, a series of routines, which together make up a method 300, are performed on the workstation and the metering server for controlling use of programs installed on the workstation.
Particularly, the kernel extension module is loaded during the bootstrap of the workstation. The routine implemented by the kernel extension module starts at block 302, and then cycles in an idle loop at block 304 waiting for an event to occur. If a request of execution of a program is detected the blocks 306-308 are executed, if a corresponding response message is returned by the runtime agent the blocks 310-315 are executed, whereas if the termination of a program is detected the block 318 is executed; in every case, the routine then returns to block 304 waiting for a new event to occur. Conversely, if the workstation has been shut down, the routine ends at the final block 322.
The bootstrap of the workstation also involves the loading of the runtime agent, which implements a routine starting at block 324. The routine cycles in an idle loop at block 326 waiting for an event to occur. If an execution request is notified the blocks 328-334 are executed, if a corresponding response message is received from the metering server the blocks 336-346 are executed, if a program termination is notified the blocks 348-350 are executed, whereas if a time-out has expired the blocks 364-374 are executed; in every case, the routine then returns to block 326 waiting for a new event to occur. Conversely, if the workstation has been shut down, the routine ends at the final block 375.
At the same time, the licensing agent is loaded during the bootstrap of the metering server. The licensing agent implements a routine that starts at block 376, and then cycles in an idle loop at block 378 waiting for an event to occur. If an execution request message is received the blocks 380-386 are executed, if a termination message is received the block 387 is executed, if information is received from a workstation the blocks 388-390 are executed, if a checking message is not received from each associated workstation for a pre-set period of time the blocks 392-393 are executed, whereas if a management message is received from the administrative server the block 394 is executed; in every case, the routine then returns to block 378 waiting for a new event to occur. Conversely, if the metering server has been shut down, the routine ends at the final block 396.
Whenever the end-user requests execution of a program on the workstation (block 397), for example by double clicking with the mouse on a respective icon, the kernel starts a new process. The starting of the process is notified to the kernel extension module (using a so-called kernel hooking technique), which reports the information to the runtime agent at block 306. The kernel extension module then suspends the process at block 308.
In response to the notification, the runtime agent verifies whether the program is included in the control catalogue at block 328. If not, the method passes to block 330, wherein the runtime agent notifies the kernel extension module that the program may be started; the program is then added to the internal log at block 332. In response thereto, the kernel extension module resumes the process associated with the program at block 312, in order to enable the program to start its execution. Conversely, if the program is included in the control catalogue the runtime agent sends a corresponding execution request message to the metering server at block 334 (including configuration information defining the
When the licensing agent running on the metering server receives the execution request message, it verifies at block 380 whether execution of the program would comply with the authorized conditions of use stored in the authorization catalogue (for example whether the execution environment meets the authorized one and the number of instances of the program already running does not reach the maximum value allowed). The licensing agent returns a corresponding response message to the workstation at block 382. A test is then performed at block 384 to determine whether the authorization to run has been granted. If so, the licensing agent adds the program to the metering table at block 385, and then passes to block 386; conversely, the method descends into block 386 directly. Considering now block 386, the metering server sends an e-mail of notification to a system administrator when a pre-set percentage (such as 80%) of the available licenses for the product have been granted, and a further e-mail of notification when the metering server has run out of licenses for the product.
As soon as the runtime agent receives the response message, a test is made at block 336 to determine whether the authorization to run has been granted. If so, the method descends into block 338 (described in the following). On the contrary, the runtime agent verifies at block 340 whether alternative metering servers are listed in the server table. If one or more alternative metering servers are available, the runtime agent sends the execution request message to each alternative metering server in turn, so as to perform the same verification described above; the method then descends into block 338. Conversely, if no alternative metering server is available the method proceeds to block 338 directly.
Considering now block 338, the runtime agent forwards the response message to the kernel extension module and then passes to decision block 344. If the authorization to run has been granted, the program is added to the running table at block 346 (conversely, the method returns to block 326 directly).
As soon as the kernel extension module receives the response message, a test is carried out at block 310 to determine whether the authorization to run has been granted. If so, the kernel extension module resumes the process associated with the program at block 312, in order to enable the program to start its execution; conversely, if the authorization to run has been denied the kernel extension module aborts the process at block 315, so as to prevent starting of the program.
When execution of the program is terminated (block 398), the event is notified to the kernel extension module, which reports the information to the runtime agent at block 318. In response to this notification, the runtime agent checks at block 348 whether the program is included in the running table. If so, the runtime agent sends a corresponding termination message to the metering server at block 349; passing to block 350, the program is deleted from the running table (conversely, the method returns to block 326 directly). When the licensing agent (on the metering server) receives the termination message, the program is deleted from the metering table at block 387, in order to release the respective license.
Whenever the time-out, for example of a few minutes, has expired (block 364), the runtime agent sends a checking message to each metering server that has granted an authorization to run a program on the workstation (as indicated in the running table). The method then passes to block 366, wherein the runtime agent sends the whole internal log to the associated metering server.
A test is made in decision block 368 to determine whether a longer time-out (for example of some tens of minutes) has expired. If so, the runtime agent scans the hard-disk of the workstation at block 370, in order to collect information about the programs installed thereon. Continuing to block 372, the installation information so collected (stored in the program inventory) is sent to the metering server. The runtime agent then downloads (from the metering server) any upgrade to the server table, to the control catalogue and/or to the code of the runtime agent at block 374, without requiring any user intervention.
Moving now to the licensing agent running on the metering server, any information (such as the internal log or the program inventory) received from an associated workstation is stored at block 388. When the metering server receives an internal log, the method checks at block 389 whether each program listed in the internal log is included in the global catalogue. If so, the method passes to block 390, wherein the program is added to the control catalogue to be distributed to the workstation and to the authorization catalogue (with no limit on the corresponding authorized conditions of use); in this way, any next request of execution of the program will be always enabled, so as to allow the usage of the program to be tracked for analysis by the system administrator. Conversely, the method returns to block 378 directly.
Considering now block 392, if a checking message is not received from a generic associated workstation for a pre-set period of time (for example ten minutes), all the programs running on this workstation are deleted from the metering table at block 392 (in order to release the respective licenses); a corresponding e-mail of notification is sent to the system administrator at block 393.
Moreover, whenever a management message is received from the administrative server, the corresponding actions are performed at block 394. For example, the authorization catalogue for each metering server may be extracted from a master catalogue stored on the administrative server; each authorization catalogue is then deployed to the corresponding metering server (thereby reducing the amount of information to be transferred on the network). Moreover, the administrative server may collect information from the metering server (such as about the programs installed and/or running on the corresponding workstations). The administrative server may then create different reports. In detail, the system administrator may request reports on usage of products (filtered by start and end time), on detailed usage of a specific product, on comparative views of installed, used and licensed products. Security profiles are also defined on the administrative server, so that each end-user of the workstations can only access information relating to programs he/she is using. In this way, the administrative server implements a single repository where usage, procurement and inventory data are collected and managed.
Similar considerations apply if an equivalent method is performed (for example with several concurrent processes that execute the above described operations in parallel), if other functions are provided, if the execution of the program is requested by another program, if the execution request message includes different information, if the time-out values are different or may be customised by the system administrator, if equivalent checking messages are sent to the metering servers periodically (for example including the corresponding records of the running table), if no e-mail of notification is sent to the system administrator, and so on. Alternatively, the proposed method is employed to control use of equivalent digitally encoded products, such as audio and video recordings, electronic books, or multimedia works.
More generally, the present invention provides a computer-implemented method of controlling use of digitally encoded products. The method starts with the step of requesting execution of a digitally encoded product on a computer; the execution request is intercepted before starting of the product. Compliance of the execution request with authorized conditions of use of the product is verified, and starting of the product is enabled or prevented according to the result of the verification.
The solution of the invention allows programs running on the computer to be controlled in real-time. In this way, a very effective licensing validation is carried out at low cost.
Operation of the proposed method is completely safe, because the program is prevented from starting and it is not killed while already processing data and performing potentially risky operations. Moreover, the integrity of the program is not affected by the denying of the authorization, so that execution of the program may be readily enabled later on (without having to re-install its code).
The solution of the present invention provides an integrated solution for controlling use of any type of programs, either technically licensed ones and non-technically licensed ones. Therefore, even programs that do not contain any special logic for enforcing authorized conditions of use may be controlled; at the same time, the proposed method also supports existing solutions exploiting licensing management systems.
The preferred embodiment of the invention described above offers further advantages.
Particularly, the execution request is intercepted by detecting the starting of the respective process; the process is suspended, and it is then resumed or aborted later on according to the result of the verification.
This procedure is very simple, but at the same time quite effective.
Advantageously, the operating system notifies the starting of the process to the kernel extension module, which in turn reports the execution request to the runtime agent running on the workstation; at the same time, the kernel extension module suspends the process (waiting for a response to the execution request).
The provision of the kernel extension module and the runtime agent makes the implementation of the solution of the invention platform-independent, and readily portable to any kind of operating system.
In a preferred embodiment of the invention, the execution request is processed by a metering server, which controls multiple workstations associated therewith.
The proposed architecture allows a very flexible management of the licenses. For example, concurrent use of a maximum number of instances of each program on the workstations may be controlled from a single point in a very simple manner.
Advantageously, if the associated server has already granted all the available licenses, the workstation is allowed to contact alternative metering servers.
Therefore, the total number of licenses available for each product may be shared among all the workstations of the organisation (even if they are controlled by different metering servers).
However, the solution of the invention leads itself to be carried out also intercepting the execution request in a different manner (for example monitoring any end-user action), employing only the kernel extension module or the runtime agent, processing the execution request by the workstation directly (without any metering server), and even not allowing the workstations to contact any alternative metering server.
Preferably, the control catalogue lists the programs to be metered (execution of the other programs is not affected by the envisaged method).
This feature makes it possible to implement customised licensing policies by the system administrator.
The programs not included in the control catalogue are always allowed to run; however, they are added to the internal log, which is periodically sent to the metering server (for updating the authorization catalogue and the control catalogue for the workstation).
The internal logs provided by the different workstations allow usage of any new product to be readily tracked (with unlicensed programs that are reported to the metering server as soon as they are used).
Alternatively, no control catalogue is provided (with all the programs that are always controlled), the running of programs not included in the control catalogue is notified to the metering server immediately, the authorization and control catalogues are updated in a different manner according to the internal log (even without using any global catalogue), or only the programs listed in the control catalogue may be executed on the workstation (provided that they are authorized to).
In addition, when the program ends its execution a termination message is sent from the workstation to the metering server that has granted the respective authorization to run; the program is then deleted from the running table (on the workstation) and the metering table (on the metering server).
This procedure ensures direct release of the corresponding license, as soon as the program ends its execution; the license is then immediately available for use by other workstations.
Advantageously, each workstation periodically sends a checking message to the respective metering servers that have granted the authorizations to run; if the checking message from a workstation is not received for a pre-set period of time, the metering server automatically releases the licenses used by the workstation.
In this way, if a workstation cannot release a license, for example because of a network problem, the license is released automatically on the metering server.
However, the solution of the invention is also suitable to be implemented detecting the termination of each program in a different manner (for example with a polling procedure under the control of each metering server), and even without any periodic transmission of the checking message (with the licenses that are automatically released after a pre-set period of time, such as every night).
Advantageously, each workstation periodically collects installation information, which is then sent to the associated metering server.
The envisaged feature makes it possible to track and keep watch of products installed on each workstation (even if they are not used).
In a preferred embodiment of the invention, a single administrative server centrally controls multiple metering servers.
The proposed three-tier architecture (workstations, metering servers and administrative server) enables a very flexible management of the licenses from a centralised point.
For example, the administrative server collects information from all the metering servers, in order to provide historical reporting concerning program usage and inventory information for all the workstations. In addition, it provides an administrative interface to maintain licensing information from a centralised point.
Therefore, it is possible to save money by detecting over compliance conditions (wherein too many licenses are available for unused products), or it is possible to detect potential infringement conditions in advance (in order to take corrective actions before running out of licenses).
The proposed architecture features a high scalability. For example, in a small company only one metering server and one administrative server are needed (even installed on the same computer). Conversely, in a large company, multiple metering servers (controlled by a single administrative server) may be provided in one or more networks. On the other hand, the administrative server may be installed in a remote location and may control metering servers at different facilities (for example in an organisation that offers software management services to other companies).
Alternatively, the installation information is collected on request, the proposed method only controls execution of the programs (and not their installation), or the system has a different architecture (even without any administrative server).
Advantageously, the solution according to the present invention is implemented with a computer program application, which is provided on CD-ROM. The application consists of programs installed on each workstation and on the associated metering sever.
Alternatively, the programs are provided on floppy-disks, are pre-loaded onto the hard-disks, or are stored on any other computer readable medium, are sent to the workstation and the metering server through a network (typically the INTERNET), are broadcast, or more generally are provided in any other form directly loadable into their working memories. However, the method according to the present invention leads itself to be carried out even with a hardware structure, for example integrated in chips of semiconductor material.
Naturally, in order to satisfy local and specific requirements, a person skilled in the art may apply to the solution described above many modifications and alterations all of which, however, are included within the scope of protection of the invention as defined by the following claims.

This patent is subject to a terminal disclaimer.

System for controlling use of digitally encoded products

International Business Machines Corporation