The present invention relates to a process-for producing a fabric-elastomer composite that, when transfer or film coated, is preferable for use as an artificial leather substrate. The inventive procedure involves (a) producing an elastomer composition of at least four ingredients (an anionically-stabilized waterborne polymer dispersion, an acid-generating chemical, a cloud-point surfactant, and a foam-stabilizing surfactant); (b) incorporating sufficient gas into the liquid mixture to generate a spreadable foam; (c) applying the foam onto a porous textile substrate; (d) heating said foamed fabric until the elastomer coagulates over the fabric substrate; and (e) drying the resultant composite without destroying the coagulated structure. The resultant composite obtains a suppleness that is similar to that of leather and a surface that is suitable for transfer coating to produce artificial leather. The composite may be utilized as upholstery fabric in furniture or in automobiles, apparel, and the like. The particular composites produced are also contemplated within this invention.

The present invention relates to a process for producing a textile material that, when transfer or film coated, is preferable for use as an artificial leather substrate. The inventive procedure involves (a) producing an elastomer composition of at least four ingredients (a waterborne anionically-stabilized polymer dispersion, an acid-generating chemical, a cloud-point surfactant, and a foam-stabilizing surfactant); (b) incorporating sufficient gas into the liquid mixture to generate a foam; (c) applying the foamed elastomer composition onto a porous textile substrate; (d) heating the treated textile until the elastomer coagulates over the textile substrate; and (e) drying the resultant composite without destroying the coagulated structure. The resultant composite, herein disclosed, exhibits a suppleness that is similar to that of leather and a surface that is suitable for transfer or film-coating to produce artificial leather. The four-ingredient pre-mixture is a long-lasting, shelf-stable composition which will not react until it is exposed to sufficient amounts of heat, thus providing an improvement over the prior art. The particular compositions produced are also contemplated within this invention.
Polymer latexes (e.g., polyurethane and acrylate) have been utilized in a variety of ways, most notably as coatings or finishes on fabric surfaces. Such latexes may provide, for example, a barrier to potentially adverse environmental conditions. Furthermore, leather substitutes have also been produced through the use of waterborne polymer latexes. Such substitutes provide an alternative to more expensive, genuine leather articles. Such artificial leather substrates must exhibit the suppleness and appearance that are characteristic of genuine leather, and must withstand heavy and repeated use within automobile and furniture upholstery, for example.
Previous polyurethane-based leather substitute products include composites produced through the reaction of a polyurethane latex and an acid-generating chemical (specifically, hydrofluorosilicic salts). Such a composition is disclosed in U.S. Pat. No. 4,332,710, to McCartney, entirely incorporated herein by reference. McCartney teaches heat-activated coagulation of a polyurethane latex in conjunction with only an acid-generating chemical, such as salts of hydrofluorosilicic acid. Such a composition and method present some difficulties, primarily in the use of an acid-generating chemical alone to provide ionic coagulation. This two-component system often results in a non-uniform distribution in the textile substrate and can form stringy structures, which are unattractive as suede leather substitutes. Of particular concern are the environmental and safety issues associated with the use of hydrofluorosilicic acid salts, which are highly discouraged within the industry but which are patentee""s preferred acid-generating chemicals.
Other prior teachings involving polymer latex heat-activated coagulation include U.S. Pat. No. 4,886,702 to Spek et al. The ""702 patent discloses a method utilizing a composition comprising a waterborne polymer latex (including polyurethane and acrylate), a cloud-point surfactant coagulant, and a blowing agent, which evolves gas during heating. However, such a composition does not produce preferable leather-like textile products due to the stiff hand that results from the effect of the blowing agent. Second, the preferred blowing agent is freon, which is being phased out of production due to its deleterious environmental impact. Third, the coagulation process requires the addition of acid and/or salt compounds, which have the potential to coagulate the latex mixture prior to contact with a textile substrate, thus resulting in a non-uniform dispersion on the substrate surface. Last, the shelf-life of patentees"" composition is, at a maximum, only eight hours in duration, thereby placing certain limitations on manufacturing flexibility.
Furthermore, U.S. Pat. No. 4,171,391, to Parker, teaches polyurethane latex coagulation within an aqueous ionic or acid bath. Because the determining factors are the type and amount of ionic material (or acid) and the rate of diffusion of such a constituent from the bath to the substrate material, such a procedure is difficult to control. As a result, there is a lack of consistent uniform dispersion and coagulation from one textile substrate to another. Particularly with heavier fabric substrates, the necessary contact times may be as long as 30 minutes, translating into high costs for the manufacturer and, ultimately, the consumer.
These shortcomings indicate a need, then, within the industry, for improved leather-like textile-elastomer composites, which are relatively inexpensive to make, which have a more realistic appearance and improved aesthetic qualities when transfer or film coated, and which have an overall better performance over the prior art.
This invention concerns a leather-like textile-elastomer composite, and a method of producing this composite, the method comprising the sequential steps of:
(a) providing a textile fabric;
(b) producing a liquid elastomer composition comprising:
(i) a waterborne, anionically-stabilized polymer latex;
(ii) an acid-generating chemical;
(iii) a cloud-point surfactant; and
(iv) a foam-stabilizing surfactant,
xe2x80x83wherein sufficient gas is incorporated into the liquid elastomer composition to produce a foamed elastomer composition;
(c) applying the foamed elastomer composition of (b) to the textile fabric of (a);
(d) heating the coated textile to an initial temperature to effectuate a uniform dispersion and cause coagulation of said elastomer composition over the textile fabric; and
(e) subsequently heating the coagulated fabric to a temperature higher than the temperature utilized in step (d) in order to dry, but not destroy, the coagulated elastomer over the fabric.
Also, the invention concerns the elastomer composition of step (b) of the inventive method itself.
It is thus an object of the invention to provide an improved, more aesthetically pleasing leather-like fabric-elastomer composite. The term fabric-elastomer composite refers to an article comprised of a textile fabric, which has been coated on at least one side with an elastomer composition. An object of the invention is to provide a composite that has a more realistic, leather-like appearance and is more aesthetically pleasing when transfer or film-coated. A further object of the invention is to provide a relatively inexpensive method of making such a composite, by providing an elastomer latex with a shelf-life of at least two weeks and by providing an application method that allows greater manufacturing control. Another object of the invention is to provide a method of producing a leather-like article which includes environmentally safe, nontoxic, low odor, noncombustible chemicals. Yet another object of this invention is to provide leather-like composites, which when transfer or film-coated, are suitable for all intended uses in which a user requires or desires a faux-leather substrate.
Nowhere within the prior art has such a specific heat-activated coagulating method utilizing a foamed elastomer composition comprising a waterborne, anionically-stabilized latex, an acid-generating compound, a cloud-point surfactant, and a foam-stabilizing surfactant been disclosed, practiced, or fairly suggested. Such an elastomer composition provides a significant advantage over the two-component (latex and acid-generator) and different three component (latex, cloud-point surfactant, and blowing agent) compositions of the prior art. For instance, the inventive composition has a shelf-life measured in weeks (at least two weeks of stability and non-coagulation after initial admixing) instead of hours at a temperature as high as about 38xc2x0 C. (100xc2x0 F.). The coagulation occurs only after exposure to a heat source of sufficient temperature to effectuate such reactivity (such as temperatures greater than about 80xc2x0 C. or 176xc2x0 F.).
Additionally, the utilization of foaming to apply the inventive latex coating facilitates production through the ability to control more effectively the amount of coating applied, the depth of penetration of the coating into the fabric, and the rate and uniformity of the coagulation process. The prior art""s teachings do not permit such an extensive and beneficial ability to manipulate the amount of penetration and the location of the coating while controlling the coagulation reaction. In particular, the inventive method and composition provide a high level of coagulant uniformity within single composite substrates and also allow uniformity of appearance and performance between many different composites at the large-scale manufacturing level.
Yet another improvement available with the inventive method and composition is the use of a strictly aqueous system rather than an organic solvent-based system. Avoidance of organic materials provides less volatility, odor, combustibility, and toxicity as well as increasing the heat stability of the final product. Of particular benefit is the ability to utilize the inventive aqueous composition in conjunction with other compatible aqueous chemical systems used in other areas of textile manufacturing. Such adaptability and compatibility with other textile manufacturing procedures and materials is very important, for example, in reducing the chances of toxic emissions during textile processing.
Finally, and perhaps most importantly, the inventive method and composition impart a soft, fine-structured coagulum leather-like finish to fabrics which is comparable to, if not better than, leather-like finishes produced with organic solvent-borne systems (such as those described in U.S. Pat. No. 4,886,702, noted above). Thus, the inventive method and composition provide the means to produce, in a very safe manner, a fabric-elastomer composite having a desirable suppleness and appearance, which, when transfer or film-coated, effectively simulates a genuine leather article.
The term fabric-elastomer composite refers to an article comprised of a textile fabric, which has been coated on at least one side with an elastomer composition. As noted above, the inventive foamed elastomer composition comprises five materials: a waterborne polyurethane latex, an acid-generating chemical, a cloud-point surfactant, a foam-stabilizing surfactant, and sufficient gas that, when incorporated, produces the foamed product.
An anionically-stabilized polymer latex is an emulsion or dispersion formed from a polymer, an anionic surfactant, and water. Polyurethane, acrylic, or polyurethane-acrylic latex is preferable, but any waterborne anionically-stabilized polymer latex may be used. The preferred latexes are those having at least a 30% solids content, with greater than 50% solids being more preferred. One preferred example of an anionically-stabilized polyurethane latex is EX-62-655 (40% solids), available from Stahl. A suitable anionically-stabilized polyurethane-acrylic latex is Paranol T-6330 (50% solids), available from Parachem. Examples of suitable anionic surfactants for use in the polymer dispersion include, but are not limited to, poly-acrylic acid copolymers, sodium laurel sulfate, aryl and alkyl benzene sulfonate like, but not limited to, the proprietary Rhodacal DS-10 (from Rhodia). In addition to the anionic. surfactant and water, a nonionic surfactant may also be included in the polymer dispersion. Examples of a nonionic surfactant include polyvinyl alcohol and ethoxylated surfactants, such as Pluronic F-68 (from BASF). Also well known in the art is the incorporation of carboxyl or sulfate groups into the backbone of the polymer in order to help stabilize the latex. The waterborne criterion is of utmost importance within this invention primarily to insure that potentially environmentally harmful organic solvents are not present within the elastomer composition.
The term acid-generating compound denotes a chemical which is not an acid at room temperature, but which produces an acid upon exposure to a heat source. Examples include, but are not limited to, ammonium acid salts like ammonium sulfate, ammonium phosphate, and organic acid esters. One particularly suitable class of compounds that both meet this description and that provide superior results with little or no harmful environmental impact are organic acid esters. Some specific types of these compounds include ethylene glycol diacetate, ethylene glycol formate, diethylene glycol formate, triethyl citrate, monostearyl citrate,.a proprietary organic acid ester available from High Point Chemical Corporation under the tradename Hipochem AG45, and the like. The most preferred compound is ethylene glycol diacetate, available from Applied Textile Technologies under the tradename APTEX(trademark) Donor H-plus.
The term cloud-point surfactant is intended to encompass any surface-active agent that becomes less water soluble upon exposure to higher temperatures. This type of surfactant easily binds with the polymer latex upon gelling and facilitates the uniform coagulation of the latex over the entire contacted textile substrate. Specific surfactants that meet such requirements include poly(ethylene) oxides, poly(ethylene/propylene) oxides, polythio ethers, polyacetals, polyvinylalkyl ethers, organo-polysiloxanes, polyalkoxylated amines, or any derivatives of these listed compounds, with the preferred being polyalkoxylated amines, available from Clariant under the tradename Cartafix U(trademark).
The term foam-stabilizing surfactant includes any surface-active agent that improves the ability of the inventive composition to entrain, and retain, air. Particular examples include, but are not limited to, alkyl benzene sulfates and sulfonates (Rexoprene series from Emkay Chemical) like sodium laurel sulfate (also sold under the name Stephanol AM from Stepan Corporation), sodium dioctyl sulfosuccinate, dodecyl benzene sulfonate, alkyl amine oxides (Unifroth series from Unichem Corp.), alkyl phosphates (Synfac series from Milliken Chemical), ammonium stearate (Henkel), water-soluble cellulose derivatives (Hercules Inc.), and Alkasurf DAP-9 (Rhodia). In the absence of a foam-stabilizing surfactant, gas could be introduced into the elastomer composition, but the gas would not be incorporated or retained.
The proportions required within the inventive elastomer composition are based upon the ratio of weights between the latex and each of the remaining components. For instance, ratios between the latex and each of the other components (namely, the acid-generating compound, the cloud-point surfactant, and the foam-stabilizing surfactant) should be in the range of 5:1 to 200:1, with preferred ranges of from about 10:1 to about 50:1. The Examples below further illustrate the utilization of such ranges of weight ratios.
The gas associated with the foam production is selected from the group consisting of atmospheric air, mixtures of oxygen, nitrogen, and hydrogen, and the like. Atmospheric air is preferred as an inexpensive and readily available source. The gas is incorporated at a pressure in the range of 1 pound per square inch (gauge) to 100 pounds per square inch (gauge), with a preferred range of about 25 p.s.i.g. to about 50 p.s.i.g. The acceptable weight ratio of air to latex within the composition is in the range of 0.1:1 to 50:1, with a preferred range of 3:1 to 8:1.
The air, or other gas, is incorporated into the foam by mechanical agitation. The air-incorporation process, commonly called foaming, may be accomplished through any accepted procedure. Examples, not intended as limitations, include whipping with a Hobart mixer or a Gaston Systems mechanical foamer. The foamed elastomer composition can then be applied with screen coating, knife coating, parabolic foam coating, and the like, without any limitation intended.
It has been found that incorporating air into (or foaming) the inventive composition offers several benefits over conventional application methods. First, the amount of elastomer applied to the textile substrate is less than the amount that would be used in a dip application, thus resulting in cost savings to manufacture. Secondly, because the incorporated air reduces the density of the inventive composition, the substrates that are produced following coagulation have aesthetic properties that more closely resemble leather. In addition, the air incorporated into the foam increases the volume of the coating, improving application and creating an improved surface for transfer coating. Finally, the manufacturer has greater control over the application of the elastomer. As a result, the foam mixture does not have to be applied to both sides of the fabric, as it would be with a dip application. Further, the degree of penetration of the foam into the textile substrate can also be controlled.
Subsequently, the elastomer-coated textile fabric is heated. This heating step generates an acid and gels the cloud-point surfactant, which then uniformly coagulates the inventive latex over the entire substrate. The temperature required to initiate the reaction depends on the particular acid-generating compound utilized. However, in general, the requisite temperature should be at least 80xc2x0 C., with a high temperature being about 130xc2x0 C.
The boiling point of water is the preferred temperature, particularly where a steam application (and most preferably a saturated steam application of 100xc2x0 C. to 110xc2x0 C.) is used. Such conditions are preferred because moist heat (steam) provides the most effective exposure for the elastomer composition. The presence of moisture permits a greater level of control over, the reaction since the addition of dry heat generally vaporizes the aqueous portion of the inventive latex, which promotes the undesirable formation of a continuous polymer film. The latex must remain moist in order for proper and uniform coagulation to ensue. Therefore, the elastomer composition preferably must contain water during the entire reaction. An exposure time of from about 1 minute to about 10 minutes, in a steam application, may be used. The preferred exposure time is about 2 minutes in a steam application. The utilization of a steam heating step again provides a distinct advantage over the prior art by retaining strictly aqueous solvent reaction conditions.
Alternatively, the coated fabric may also be exposed to rapid heating by a microwave or radio frequency heat source, which does not provide an appreciable loss of moisture to the overall elastomer composition. An exposure time of from about 1 second to about 1 minute in a microwave application may be used.
Yet another alternative is to expose the coated fabric to heating by a convection heat source. Preferably, the temperature should be raised slowly to allow the coating to coagulate prior to dry and prevent the coating from cracking. An exposure time of from about 10 seconds to about 10 minutes in a convection oven may be used.
After the first heating step, the composite is dried, preferably by high convection, low temperature heating (preferably, but not limited to, less than 130xc2x0 C.) or by microwave or radio frequency heating in order to prevent continuous film formation on the fabric surface. The second heating step is engineered to dry the composite without destroying the coagulation of the elastomer composition.
The textile fabric utilized within the inventive process may comprise any synthetic or natural fiber or blend of such fibers. As merely examples, and not intended as limitations, the textile fabric may be constructed from fibers of polyester, nylon (-6 or -6,6), cotton, polyester/cotton blends, wool, ramie, spandex, and the like. The fabric can have a knit, woven, or non-woven construction. The preferred knit substrate is made of polyester, and most preferably polyethylene terephthalate yarns. The preferred woven substrate is made of cotton.
The textile fabric may be treated with dyes, colorants, pigments, ultraviolet absorbers, softening agents, soil redisposition agents, lubricating agents, antioxidants, flame retardants, rheology agents, and the like, either before foaming or after, but with a preference for such additions before foaming. Within the elastomer composition, there may be incorporated any of the above-listed textile additives, as well as lubricating agents or cross-linking agents. One particularly desired agent is a softening/soil redisposition/lubricating additive Lubril QCX(trademark), available from Rhxc3x4ne-Poulenc. Desirable pigments include PP14-912 and PP14-905 available from Stahl.
It is believed that sanding or napping the fabric prior to the application of the elastomeric composition will improve the hand of the fabric-elastomer composite and will improve the adhesion between the fabric and the composition. The sanding or napping process has been found to impart, in the fabric-elastomer composite, a suede-like feel on the effective back of the composite. It is believed that sanding is preferable for knit fabrics and that napping is preferable for woven fabrics.
In addition, in some circumstances, it may be desirable to subject the finished fabric to a calendering process. Calendering improves the adhesion characteristics of the final product (that is, the fabric-elastomer composite that has also been transfer coated). In addition, the calendering process produces a feel similar to that of suede on the effective back of the transfer-coated fabric-elastomer composite. Calendering can be achieved on any equipment designed for such purpose, including, but not limited to, a Briem calender having a heated drum width of approximately 20 inches. Because the settings for temperatures, pressures, and speeds are all related to one another, a range of appropriate settings could be used to achieve the desired effect. For example, one such preferred setting involves a temperature of 150xc2x0 F., a pressure of 40 kg/cm2, and a speed of 2 yards/minute.
After calendering, the fabric-elastomer composite is subjected to either transfer or film coating to create a three-layer composite structure that resembles genuine leather in both appearance and tactile characteristics. In both transfer and film coating, the additional coating is applied in contact with the elastomer coating. The technical face of the textile becomes the effective back of the three-layer composite. The transfer coating process involves the application of a plurality of individual layers of polyurethane (typically, at least two, but up to five or more) to a paper backing. The coatings are then adhered to the fabric-elastomer composite, and the paper backing is removed, resulting in a three-layer leather-like product. The film coating process involves adhering a sheet-like film substrate to the fabric-elastomer composite, typically using adhesives and heat to laminate the film to the composite. The term xe2x80x9cfilmxe2x80x9d is used to mean any thin, flexible, sheet-like substrate, comprising a metallic substrate, a plastic or polymeric film, or a felt-like or flocked textile substrate.
The inventive composite may be utilized as upholstery fabric for furniture or in automobiles; within garments or apparel; or for any other purpose in which a textile leather substitute is desired.

Textile-lastomer composite preferable for transfer on film coating and method of making said composite


A method and system configures video calls and schedules the calls for a video call network based on a query from a user to establish a video call between end points of the video call network. A configuration engine accepts video call information from a query engine based on the video call request and applies device data and rules to determine one or more possible call configurations. The configuration engine or an associated optimization engine determines a preferred video call configuration and schedules devices of the video call network without requiring the user to have any in depth understanding of the device limitations and capabilities. Automatic configuration and scheduling of video calls simplifies the use of a video call network to reduce the expense and complexity of efficiently using network resources.

This invention relates generally to video call communications, and more specifically relates to a system and method for configuring and scheduling of video calls.
Video conference calls have developed from a novelty used rarely to grow into a commonly used business communication tool. Businesses often prefer the more personal communication available through video conferences compared with telephone conferences, and also enjoy savings in travel costs while still having a personal presence among the participants that is not possible with audio only communications. Further, video conferencing allows individuals at a number of disparate locations to share data, such as presentations and spreadsheets, while conducting a conference, thereby reducing the complexity of distributing written material before the conference occurs.
These advantages of video conferencing has resulted in a number of businesses installing video conferencing equipment for use by employees to communicate with other business locations across the business"" network. Additionally, businesses commonly communicate outside of their network, such as with video equipment located in a customer""s network, by establishing video calls through the public network.
The advantages and convenience of video calls are often offset by the difficulty of configuring and scheduling video calls in light of the limited video conferencing equipment available, the technical knowledge generally required to configure video calls, and demands on network bandwidths. For instance, a multi-point video conference call between three or more video end points typically requires the use of a multi-call unit (MCU) to coordinate the exchange of video data between the video end points. Thus, before establishing a multi-point video conference, the end point and MCU are configured to support the video conference. As another example, video end points sometime use different protocols so that a video conference between such end points typically requires a configuration with a gateway that insures a consistent communications pathway. In addition, for video conference calls that involve a large number of participants at distributed locations, the bandwidth generally used to support the multiple end points tends to exceed the capacity of individual MCU""s and gateways so that multiple MCU""s and gateways are needed to configure the video call.
To coordinate video conference equipment use, businesses typically dedicate staff that accepts requests for use of end points, schedules the video network devices to support the video call and coordinates and configures the video call. Maintaining staff for this purpose increases the expense of video conferencing and reduces its convenience. Further, for businesses with expensive video conferencing resources the task of coordinating use of those resources is complex and labor intensive. The complexity and labor associated with video conferencing grows as the number of participants outside the business"" network increases.
A significant problem that businesses encounter with video conferencing is the under utilization and non-optimized use of video conferencing equipment. For instance, conference calls can be difficult to configure, especially complex calls that are configured with MCU""s that are set up to accomplish the call. The use of a variety of different devices leads to scheduling difficulties for the resources that are available. In some instances, staff is simply overwhelmed and unable to keep up with video conferencing requests in a timely manner. This can lead to under utilization of the video conferencing equipment or an increase in staff size and corresponding increase in labor expense. Further, as the complexity of configuring and scheduling video conferences increases, business members are less likely to use video conferencing equipment because the time and hassle in arranging a video conference is not worthwhile. In addition, complexity leads to unreliability so that business members will avoid video conferences to reduce potential embarrassment when the conferences fail.
Therefore a need has arisen for a system and method which automatically configures video calls in a simplified and efficient manner.
A further need has arisen for a system and method which schedules video calls automatically in a more optimized manner so that video conferencing equipment is more efficiently used.
In accordance with the present invention, a system and method is provided that substantially eliminates disadvantages and problems associated with previously developed systems and methods for configuring video calls and scheduling those calls. A video network platform accepts queries with video call information for establishing a video call between plural video end points. A configuration engine associated with the video network platform applies rules and device data to determine one or more video call configurations available for scheduling a video call corresponding to the video call information.
More specifically, the video network platform analyzes queries for video calls, determines configurations to support the video calls and schedules video network devices accordingly. A rules based configuration engine accepts video call information from the queries and applies rules and device data to determine one or more video call configurations for a video call corresponding to the video call information. The device data is provided by a device database that stores information associated with devices available for the video call, such as video end points, MCU""s and gateways. The device data includes information for establishing and maintaining a video call including device address, bandwidth, port, protocol, and scheduling availability information. The rules are provided by a rules database and define parameters for configuring and scheduling video calls. In alternative embodiments, the configuration engine uses alternative scheduling engines to determine potential video call configurations and schedules.
The configuration engine determines one or more video call configurations based upon the number, location and type of devices available. For instance, if a query requests a video conference between three end points, a rule applied by the configuration engine determines that an MCU is needed. The configuration engine then determines the available MCU""s for configuring the video conference and presents the possible configurations for scheduling of the video call. In one embodiment, the configuration engine determines a preferred configuration and schedules the video call by saving the schedule information for the devices associated with the video conference in the device database.
An update engine interfaces with the device database to update the device data as device status changes on the video call network. For instance, if an end point, MCU or gateway device becomes inoperable, the update engine updates the scheduling data for the device in the device database so that the configuration engine will not schedule the device during down time. The update engine also tracks reliability information and stores the reliability information for devices in the device database. The configuration engine may then apply rules that use reliability information in determining video call configurations and scheduling devices for a video call.
An optimization engine interfaces with the configuration engine to aid in the selection of an efficient video call configuration based on desired optimization parameters. For instance, in one embodiment the optimization engine accepts possible video call configurations from the configuration engine and selects the most efficient of the possible video call configurations for scheduling of the devices associated with that video call configuration. In some instances, such as for complex video call networks with a relatively large number of devices, the number of possible video call configurations is quite large. In such instances, the optimization engine provides alternatives to the configuration engines so that the computations for determining possible configurations are reduced. For instance, the optimization engine may use estimation techniques that reduces the number of devices considered for a configuration. In yet another embodiment, the optimization engine considers existing schedules stored in the device database and computes a more optimal use of device resources, including rescheduling of devices to obtain better efficiency and utilization of the video call network as a whole.
The present invention provides a number of important technical advantages. One important technical advantage is that the configuration and scheduling of video calls is automated and simplified. The reduced complexity reduces the labor and cost associated with arranging video calls and increases the convenience so that individuals are encouraged to use video call devices. Further, establishing video calls between different video call networks is simplified by providing device data for the different networks in the device database. Thus, a central video network platform offers configuration and scheduling services for multiple companies in a straight forward and cost-effective manner.
Another important technical advantage of the present invention is that video call networks are used in a more efficient manner. By reducing complexity and simplifying call configuration and scheduling, device resources are less likely to go unused since coordination through scheduling staff is reduced. Further, optimization of schedules improves the utilization of devices so that the size and cost of a business"" video call network may be reduced.

System and method for video call configuration and scheduling


A table assembly structured for selective positioning between a conventional table orientation and a gaming orientation which facilitates the playing of the game of billiards thereon. A plurality of side rails are connected to an under portion of a table top of the table assembly and movable between a stored position and an operative position which respectively define the conventional and gaming orientations. When in the stored position, the plurality of side rails are disposed in a primarily hidden location in order to enhance the table""s appearance. A positioning assembly includes a plurality of linkage structures movably supporting the plurality of side rails along a complex path of travel as the plurality of side rails move between the stored and operative positions.

1. Field of the Invention
This invention relates to a table assembly which is capable of being selectively converted between a conventional orientation, for use in a conventional manner, and a gaming orientation, for use as a gaming table suitable for playing the game of billiards and possibly other games.
2. Description of the Related Art
The game of billiards as well as the related game of xe2x80x9cpoolxe2x80x9d or pocket billiards has enjoyed continued popularity for a number of years. A conventional billiard table generally includes an outer playing surface or face with a normally large area which may vary depending on whether the pool table is of a professional or regulation size or of a smaller size typically found in restaurants, lounges, etc. When structuring a professional or regulation table, the entire outer face is typically made from an extremely hard substance such as marble, slate, etc. Such material is generally recognized as being long lasting and relatively heavy. As such, the table includes a relatively extensive support structure made from solid wood or other materials. As a result, a conventional billiard table is typically quite heavy and includes a sufficiently large dimension and configuration to make such table assemblies either impractical or undesirable for use and installation in many locations.
In addition, the legacy of pool is such that many of the standard size tables are adorned with expensive wood working and/or inlay designs. As a result, the cost of a billiard and/or pool table can be quite high, thereby further rendering such tables undesirable for a vast majority of the consuming public. In spite of the disadvantages associated with the cost, weight, size, etc. of a pool or billiard table, the popularity of the sport has not significantly dwindled. Those interested in the playing of billiards universally recognize that a certain amount of inconvenience is involved since such tables and particularly standard size billiard tables are not practical for use in the average home.
In order to overcome the disadvantages and problems of the type set forth, there have been numerous attempts in the prior art to develop a modified table construction which is lighter, less expensive, smaller and as a result is more obtainable by the average consumer or billiards player. Conventional or known modifications in the prior art include the provision of collapsible or folding table which can be manipulated and/or otherwise oriented so as to facilitate the storage of the billiard table when not in use. In addition, even when such modified structures are left in their operative positions they are significantly lighter and usually smaller thereby enabling their positioning into and out of a stored location with relative ease. While operable and at least somewhat effective for their intended purpose foldable, collapsible or similarly structured billiard or like gaming tables may often suffer from a lack of stability. Accordingly, anyone familiar with the playing of billiards or pocket billiards is well aware that the stability of the table and playing surface is very important, especially to those who play the game on a more serious level.
As a result of the disadvantages associated with such foldable tables, further attempts in the prior art have resulted in a variety of differently structured conversion tables. This type of table assembly is capable of being selectively changed or converted from a table intended for conventional use into a gaming or other purpose table. In addition, numerous tables of this type are specifically designed and structured for the playing of billiards, pool, bumper pool, or other appropriate gaming activities.
In fact, such conversion tables do overcome at least some of the disadvantages and problems associated with collapsible gaming tables. In addition, such tables are generally less expensive, lighter and therefore more adaptable for use and/or positioning within a conventional household environment. However, such conversion tables have not gained wide spread popularity or use do at least in part to their being structured in a manner which does not truly represent the appearance of conventional table assembly when not being used as a gaming table. More specifically, the structural components or features which allow such table assemblies to be converted into a gaming table or the like, typically are obvious and/or unsightly when such table assemblies are in a conventional mode of operation.
There is a long existing need for a table assembly which can be easily and efficiently disposed between a conventional orientation and a gaming orientation. More over when in the gaming orientation such an improved table assembly should be structured to be strong, stable and include various structural features which enable the playing of at least one particular game, such as the game of billiards or pocket billiards. Also when in the conventional orientation the improved table assembly should be capable of being used in the intended manner such as a dinning room table or the like for which the table is normally used.
Importantly when in the conventional orientation, the appearance of the table assembly should be pleasing and in certain instances variable such that it is difficult or impossible to recognize that the table assembly may be converted into a gaming table. Also the versatility of such an improved table assembly should be such as to blend in with a variety of different interior designs. Finally such an improved table assembly should be formed from various materials and components which allow the playing of the intended game in a proficient manner while at the same time providing durability and a long operable life whether it is used primarily in the conventional orientation or the gaming orientation.
This invention relates to a table assembly capable of being used in the conventional manner, such as when disposed in a conventional orientation or alternatively as a gaming table, when disposed in a gaming orientation. When in the aforementioned gaming orientation the various structural and operative components of the table assembly are particularly adaptable for the playing of the game of billiards thereon. In addition, with little or no structural modification or variation, related games such as, but not limited to xe2x80x9cpoolxe2x80x9d or pocket billiards and/or xe2x80x9cbumper poolxe2x80x9d can also be played. Accordingly, when the table assembly is in the gaming orientation it is emphasized that it can be used to play games other than those indicated above and still be encompassed in the intended spirit and scope of the present invention.
Accordingly, the table assembly of the present invention comprises a table top including an outer surface. The outer surface is preferably disposed in a substantially horizontal orientation and in effect defines the playing surface on which the various games are performed when the table assembly is in the gaming orientation. It is also noted that the outer surface may include some type of felt or like material covering which may be fixedly or permanently attached to the outer surface. Alternatively, the surface covering may be disposed and structured to facilitate the temporary covering of the outer surface, and used when games are to be played thereon. As such, the outer surface will remain uncovered or include a different more practical covering when used in the conventional manner such as, but not limited to, a dining table.
The table assembly of the present invention also includes a support assembly comprising a plurality of legs or a variety of other types of support bases or structures. The support assembly is fixedly secured to an under portion, wherein the under portion is disposed beneath the table top. In certain structural embodiments of the present invention the under portion may be considered a part of the overall support in that it is generally disposed in interconnecting relation between the support assembly and the table top. As such the table top, effectively rests on a brace or frame which at least partially defines the under portion. In such an embodiment, both the under portion and the table top are supported by the plurality of legs or other support structure defining the support assembly. It is also emphasized that the under portion is structured to include certain openings or spaces for the removable containment and storage of a conversion assembly and an associated positioning assembly, to be described hereinafter.
It is to be understood that the table assembly may include a variety of different dimensions and configurations. However, the overall dimension and configuration of the table assembly and in particular the table top and outer surface may be structured so as to at least generally comply with or facilitate the playing of a particular game. By way of example, the games of billiards and pocket billiards generally require the use of a rectangular table top and outer surface surrounded by raised side rails extending along each of the four sides of the aforementioned configuration. Therefore, when it is intended to convert the table assembly of the present invention from a conventional orientation into a gaming table, wherein a game of billiards is to be played, the table top will assume a generally rectangular, multi-sided configuration.
Naturally, the overall configuration of the table top could vary based on the intent to design a table assembly which may be converted into a gaming table on which games, other than billiards, pool, etc. are to be played. Therefore, while the rectangular or multi-sided configuration may be utilized in at least one preferred embodiment of the present invention, the overall dimension and configuration of the table assembly may vary greatly and still be included within the intended spirit and scope of the present invention. However, for purposes of clarity, the various preferred embodiments of the present invention will be described with reference to a table top and outer surface having a multi-sided configuration which facilitates the playing of the game of billiards thereon.
The table assembly of the present invention further includes a conversion assembly movably mounted and selectively positionable between a stored position and an operative position. Further, the conversion assembly preferably includes a plurality of conversion members sufficient in number and cooperatively disposed such that each of the conversion members, when in the aforementioned operative position, are disposed above and in overlying relation to the peripheral portions of the each of the sides of the table top.
Variations in the structuring of the conversion members may be such that each of the sides of the table top are covered by a single, elongated conversion member. Alternatively, the plurality of conversion members may be dimensioned and structured such that at least one side of the table top requires a plurality of conversion members to extend along substantially its entire length, when they are in the operative position. In one preferred embodiment, the conversion members are more specifically structured to define a side rail, of the type used in playing the game of billiards. However, it is again noted that the side rails may assume a variety of different structures which more closely correspond or are required in the playing of games other than billiards.
Another feature of each of the preferred embodiments of the present invention is the inclusion of a positioning assembly. The positioning assembly is disposed and structured to movably position and support each of the plurality of conversion members as they are moved between the stored position and the operative position. Also, at least a portion of the positioning assembly moves with the conversion members in support thereof when the conversion members are moved between the operative position and the stored position.
As set forth above, one problem associated with known or conventional types of conversion tables is the inability to present an attractive appearance when the conversion table is in its conventional orientation. It is of course desirable to utilize a conversion table as a conventional piece of furniture including its ability to fit into the surrounding motif and design features of a dining room or other area where a table is normally utilized. Therefore, one feature of the various preferred embodiments of the present invention is the ability to present an aesthetically pleasing appearance of the table assembly, particularly when the table assembly is oriented for conventional use.


The present invention uses hydrophobically modified polyaminamide with standard wet strength agent to produce a softer and more absorbent paper material. The hydrophobically modified polyaminamide is substantive to cellulosic fibers, thus is able to carry polyethylene glycol esters or ethers, a non-substantive material to cellulosic fiber as stable complexes, into the paper product.

1. Field of the Invention
The present invention relates to an absorbent paper product with hydrophobically modified polyaminamides, preferably stable complexes of these with non-ionic fatty polyalkoxides, to increase the wet/dry tensile ratio and wettability of paper products, thereby, improving paper softness and absorbency. The present invention further relates to a process for producing the absorbent paper product of the present invention.
2. Background of the Invention
There are many characteristics of absorbent paper products, such as towel and tissue product, that must be considered in producing a final product having desirable attributes that make it suitable and preferred for the product""s intended purpose. Absorbency, strength (both wet and dry), and softness are among the most important and desirable characteristics of disposable paper towels. Absorbency is the ability of a product to absorb and retain liquid. Overall absorbency as perceived by the consumer is generally considered to be a combination of the total quantity of liquid a given mass of paper will absorb at saturation, as well as the rate at which the mass absorbs the liquid. Strength is the property of a paper product that causes the product to be held together while in use. Finally, softness is the product property accounting for the pleasing tactile sensations imparted to the human anatomy while the product is in use. In general, the major easily measured determinants of perceived softness include stiffness and bulk (density), with lower stiffness and higher bulk (lower density) generally improving perceived softness and/or tactile perception of the products.
These three product attributes often run counter to one another. For example, as strength is increased, softness and absorbency generally decrease.
Consumer product companies and vendors are constantly searching for methods/materials to either increase softness and absorbency while maintaining or increasing strength or to increase strength while maintaining or increasing absorbency and softness.
To improve softness, standard paper making processes often add chemicals, e.g., softeners and debonders, to a fiber furnish or web to improve or change the properties of the web. Traditionally, softeners and debonders are used in the papermaking process to enhance softness or to adjust strength. Typically, these chemicals are added to the wet end of the paper making process, i.e., in the paper making slurry. When used in this manner, these chemicals can react with fines, pitch, sand and other materials associated with pulp fibers to form deposits. Deposits negatively impact productivity because they blind fabrics and plug felts. Significant expenses must be incurred to remove the deposits. In some instances, the presence of these chemicals requires adjustment of the system pH. Because of the fatty acid groups, hydrophobicity is imparted on the paper product and this renders it non absorbent. In some cases, additional expense must be incurred when hydrophilic surfactants are used to restore or impart absorbency. In some cases, it will be desirable to effect significant reductions in ultimate tensile strength. These are most easily obtained when debonders are added at the wet end.
These chemicals have occasionally been sprayed onto the wet web prior to drying. These processes can suffer from the disadvantages of contamination and materials loss while overspray and mist created during the spraying process can be irritating to the paper machine attendants. Unretained chemicals applied in this manner are usually recirculated back to the wet end where they may also react with fines, pitch, sand, and other materials associated with the pulp fibers to form deposits and may require pH adjustment. Deposits negatively impact performance and are expensive to I remove and clean up. Adding debonders by spraying is not usually as effective in reducing ultimate tensile strength as is wet end addition.
The use of wet strength agents to enhance the wet strength of a paper web is widely known. For example, Westfelt described a number wet strength agent materials and discussed their chemistry in Cellulose Chemistry and Technology, Volume 13, at pages 813-825 (1979). Freimark et al. in U.S. Pat. No. 3,755,220 issued Aug. 28, 1973 mention that certain chemical additives known as debonding agents interfere with the natural fiber-to-fiber bonding that occurs during sheet formation in I paper making processes. This reduction in bonding leads to a softer, or less harsh, I sheet of paper. Freimark et al. go on to teach the use of wet strength agents in conjunction with the use of debonding agents to off-set the undesirable effects of the debonding agents on the paper strength. These debonding agents reduce both dry tensile strength and wet tensile strength.
To impart greater softness to the paper product, styrene-butadiene latexes can be used as the binder system. However, these styrene-butadiene latexes are usually either nonionic in character or else are partially anionic due to inclusion of
anionic comonomers or surfactants. The nonionic styrene-butadiene latexes cannot be used as xe2x80x9cwet-end additivesxe2x80x9d in a conventional papermaking process. Instead, these nonionic latexes have to be impregnated or pattern-printed on the subsequently laid paper furnish, such as by the process described in European Patent application 33,988 to Graves et al, published Aug. 19, 1981.
An anionic styrene-butadiene latex can be used in a conventional wet-end additive papermaking process by adding a cationic polyelectrolyte. See, for example, U.S. Pat. No. 4,121,966 to Amano et al, issued Oct. 24, 1978; and U.S. Pat. No. 2,745,744 to Weidner et al, issued May. 15, 1956. The cationic polyelectrolyte used is typically a water-soluble cationic wet-strength agent. Basically, the cationic polyelectrolyte, when added, destabilizes the dispersed anionic latex particles which then flocculate and deposit on the paper fibers. Accordingly, the cationic polyelectrolyte and anionic styrene-butadiene latex cannot be combined together until the point at which they are used as the binder system in papermaking.
Polyethylene glycols (PEG) and PEG fatty esters and ethers are also used as wetting agents and plasticizers for paper products. Unfortunately these PEG derivatives are not substantive to the cellulose fibers. And the process involved to incorporate the PEG into the paper can be problematic and expensive.
U.S. Pat. No. 5,240, 562 to Phan et al. issued on Aug. 31, 1993 and discloses the use of preformed vesicles as a means of carrying these non-substantive I PEGs into the final paper substrate. However, these vesicles require preparing, maintaining and delivering complex formulations at high temperatures to the wet end of the paper machine.
U.S. Pat. No. 3,434,984 to James Hyland issued on Mar. 25, 1969 discloses thermosetting cationic resins which impart wet strength and water holdout properties to cellulosic materials. These resins are prepared by reacting epichlorohydrin and a polyamide. However, these materials can only be incorporated into the web at high temperatures of up to 200xc2x0 C.
There is a need in the paper industry to provide a paper product and a method for making the product where incorporation of wet strength agents can be done I efficiently and at room temperature while enhancing the softness and absorbency of the paper product.
The present invention provides an absorbent paper product that overcomes the disadvantages associated with the prior art technologies.
The present invention also overcomes the disadvantages associated with the prior art technologies by providing a method for making soft and absorbent wet strengthened paper products.
It has been discovered that a paper product with a hydrophobically modified polyaminamide, preferably stable complexes of these with nonionic polyalkoxides, and a standard wet strength agent improves the quality of the paper product, particularly making the wet strengthened product softer and more absorbent.
One embodiment of the present invention discloses a paper product comprising hydrophobically modified polyaminamides wherein the hydrophobic moieties are selected from mono-fatty esters, acids or epoxides and the polyaminamide is hydrophobically modified such that the hydrophobic group comprises 5 to 10 mole percent of the active amine sites on the polymer backbone.
Another embodiment of the present invention is a method for producing a paper product comprising adding a complex of the hydrophobically modified polyaminamides described above and a nonionic surfactant selected from mono-fatty esters or ethers of polyethylene glycol. Further, the amount of nonionic surfactant can be adjusted to accommodate all or a fraction of the hydrophobically modified polyaminamide sites on the polymer backbone. The complex is quite stable and accordingly is readily delivered and retained within the paper product under ambient conditions.
It has been found that complexes of hydrophobically modified polyaminamides and mono-fatty esters or ethers of polyethylene glycol provide similar increases in wet/dry tensile ratio in wet strengthened substrates as non-complexed hydrophobically modified polyaminamides. However, the complexed species once in the sheet of the paper product enhances the wettability of the substrate; thereby, improving both the absorbency rate and drape of the towel product. Particularly suitable nonionic surfactants include fatty sorbitols, fatty glucosides and the like.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
Reference will now be made in detail to the present embodiments of the invention. The present invention relates to an improved soft and absorbent paper product comprising a hydrophobically modified polyaminamide. It has been discovered that adding hydrophobically modified polyaminamides (HMCP) or, preferably a stable complex of HMCP with a nonionic surfactant and a wet strength resin achieves a softer and more absorbent wet strengthened paper product which has wet strength generally comparable to, or possibly even superior to, similar products made with wet strength resin alone.
The absorbent paper product of the present invention can be manufactured on any type papermaking machine. Traditionally, the production of absorbent paper toweling occurs by one of three basic technologies: (i) conventional wet press technology with wet creping and embossing, as described in U.S. Pat. No. 5,048,589 to Cook et al. which is incorporated herein by reference in its entirety; (ii) conventional wet press technology with dry creping and embossing, as described in U.S. Pat. No. 5,048,589 which is incorporated herein by reference in its entirety; and
most recently (iii) through-air-drying (TAD) with or without creping. Conventional TAD i processes are generally described in U.S. Pat. No. 3,301,746 to Sanford et al. and U.S. Pat. No. 3,905,863 to Ayers, which are incorporated herein by reference in their entirety.
Paper is generally manufactured by suspending cellulosic fiber of appropriate geometric dimensions in an aqueous medium and then removing most of the liquid. The paper derives some if its structural integrity from the mechanical arrangement of the cellulosic fibers in the web, but most, by far, of the paper strength is derived from hydrogen bonding which links the cellulosic fibers to one another. The degree of strength imparted by this inter-fiber bonding, while necessary to the utility of the product, can result in a lack of perceived softness that is inimical to consumer acceptance. One common method of increasing the perceived softness of a paper product is to crepe the paper. Creping is generally effected by fixing the cellulosic web to a Yankee drum thermal drying means with an adhesive/release agent combination and then scraping the web off the Yankee by means of creping blade. Creping, by breaking a significant number of inter-fiber bonds, adds to and increases the perceived softness of the resulting absorbent paper product.
Another method of increasing a web softness is through the addition of chemical softening and debonding agents. Compounds such as quaternary amines that function as debonding agents are often incorporated into the paper web. These cationic quaternary amines can be added to the initial fibrous slurry from which the paper web is subsequently made. Alternatively, the chemical debonding agent may be sprayed onto the cellulosic web after it is formed but before it is dried, however as mentioned. the degree of reduction in ultimate tensile strength is generally somewhat less by spraying than that attained with wet end addition.
Papermaking fibers used to form the soft absorbent products of the present invention include cellulosic fibers commonly referred to as wood pulp fibers, liberated in the pulping process from softwood (gymnosperms or coniferous trees) and hardwoods (angiosperms or deciduous trees). The particular tree and pulping process used to liberate the tracheid are not critical to the success of the present invention. Cellulosic fibers from diverse material origins may be used to form the web of the present invention, including non-woody fibers liberated from sabai grass, rice straw, banana leaves, paper mulberry (i.e. bast fiber), abaca leaves, pineapple leaves, esparto grass leaves, and fibers from the genus hesperalae in the family agavaceae. Also recycled fibers which may contain any of the above fibers sources in different percentages can be used in the present invention.
Papermaking fibers can be liberated from their source material by any one |of the number of chemical pulping processes familiar to the skilled artisan including sulfate, sulfite, polysulfite, soda pulping, etc. The pulp can be bleached if desired by chemical means including the use of chlorine, chlorine dioxide, oxygen, etc.
Furthermore, papermaking fibers can be liberated from source material by any one of a number of mechanical/chemical pulping processes familiar to anyone experienced in the art including mechanical pulping, thermomechanical pulping, and chemithermomechanical pulping. These mechanical pulps can be bleached, if one wishes, by a number of familiar bleaching schemes including alkaline peroxide and ozone bleaching.
The suspension of the fibers or furnish may contain chemical additives to alter the physical properties of the paper produced. These chemistries are well understood by the skilled artisan and may be used in any known combination.
The hydrophobically modified polyaminamides of the present invention are compatible with conventional permanent wet strength agents. The hydrophobically modified polyaminamides form a stable complex with nonionic surfactant such as mono fatty esters and ethers of polyethylene glycol. This complex carries the usually non substantive nonionic surfactant into the sheet of paper.
As used herein, the term xe2x80x9cpolyaminamidexe2x80x9d represents a polymer of an amine moiety with an amide substituent or a polymer of an amide moiety with an amine substituent. That is, it is a polymer having both amine and amide groups along the backbone.
The hydrophobically modified polyaminamide may be produced by any known means to those known in the arts. For example HMCP maybe produced by reacting a polyaminamide with (i) an epoxide of a long hydrocarbon, or (ii) an ester of a E fatty acid, or (iii) an acylchloride of a fatty acid, or (iv) a fatty acid.
As used herein, the term xe2x80x9cepoxidexe2x80x9d represents a three-membered cyclic ether which can be optionally substituted with any functionality known to those of ordinary skill in the art.
As used herein, the term xe2x80x9cfatty acidxe2x80x9d represents long-chains of aliphatic acids.
The molecular weight of the HMCP is adjusted by any means known to those skilled in the art, a preferred example is by cross-linking the HMCP, at 12% solids, with epichlorohydrin. Low solids are required for the cross-linking reactions because of the tendency of the HMCP""s to associate are higher solids. The preferred solids content is typically below about 20% by weight depending on the molecular weight with lower solids contents being preferred for higher molecular weight formulations to safeguard against gelation.
Any suitable wet strength agents, typically used to impart wet strength to toweling, can be selected by those of ordinary skilled in the art, a non-limiting example is polyaminamide-epichlorohydrin (PAE). Gloxylated polyacrylamides are also usable.
The level of hydrophobic groups in the polyaminamide required to achieve the desired paper performance effects of the present invention is preferably between 5 and 10 mol % of the active amine sited on the polymer backbone.
Stable complexes of the HMCP""s and mono-fatty esters of polyethylene glycols are easily formed by mixing the two components and heating to the cloud point temperature of the PEG ester. The resultant clear solutions can be stored at any temperature that does not alter the desired chemical or physical nature of the composition. The solution is preferably stored at room temperature but is stable over the range of temperatures typically encountered in mills and warehouse facilities. We prefer to effect the complexing at neutral pH but, depending on the nature of the nonionic surfactant, the complexing can be accomplished at other pH values if the nonionic surfactant is stable at that pH. For a whole host of practical reasons, the most preferred solvent for effecting the complexing is water but other polar solvents can be used if the other components are soluble therein and do not react therewith.
The amount of HMCP necessary depends upon the molecular weight of the HMCP as can be determined by those skilled in the art. The amount of nonionic surfactant complexed with the HMCP can range from 0 to 1 equivalent of the hydrophobe content of the HMCP.
In use, the HMCP is complexed with a mono-fatty ester of polyethylene glycol. Preferably the latter has an elevated hydrophile-lipophile balance (HLB), in water. Because this complex is stable, it can be easily used and stored over a wide range of commonly encountered ambient temperatures and transported then mixed if desired with a wet strength agent for the paper prior to its incorporation in the wet end of the paper machine. Alternatively, it can be added to the paper making process alone or in a line separate from any wet strength agent.
Further, since the cationic nature of the HMCP makes it highly substantive to cellulosic fibers, the complex with the mono-fatty esters or ethers of polyethylene glycols carries these mono-fatty esters or ethers of polyethylene glycols into the sheet and retains them there. This is a very significant advantage as the polyethylene glycol is not normally substantive to the sheet which severely limits the ease with which it may be incorporated into the sheet. The complexes of HMCP""s and PEG esters or ethers provide similar increases in wet/dry tensile ratio as the non-complexed HMCP""s while carrying the non-substantive PEG ester or ether into the substrate. The PEG ester or ether once in the sheet enhances the wettability of the substrate; thus, improving both absorbency rate and drape of the paper product. The amount of HMCP retained in the sheet may be between about 0.5 and about 2 pounds per ton of dry fiber.

Use of hydrophobically modified polyaminamides with polyethylene glycol esters in paper products


Large-format composite relief printing plates are produced by applying individual photopolymerizable relief printing plates to a large-format substrate, by a process in which the image information is transmitted to the individual relief printing plates by means of a laser. The individual photopolymerizable relief printing plates are positioned on the substrate with the aid of a laser. A composite of relief printing plates comprises a substrate, a laser-structurable layer applied thereon and insoluble in printing inks and printing plate developers, and relief printing plates applied thereon and having an IR-ablatable layer.

The present invention relates to a process for the production of large-format composite relief printing plates by applying individual photopolymerizable relief printing plates to a large-format substrate, the image information being transmitted to the individual relief printing plates by means of a laser. The present invention furthermore relates to a process in which the individual photopolymerizable relief printing plates are positioned on the substrate with the aid of a laser. The present invention also relates to a composite of relief printing plates comprising a substrate, a laser-structurable layer applied thereon and insoluble in printing inks and printing plate developers, and relief printing plates applied thereon and having an IR-ablatable layer.
For printing on very large surfaces with relief printing plates, for example on corrugated board for cardboard packaging with flexographic printing plates, correspondingly large printing plates are required. These are difficult to handle and are expensive. Frequently, printing is to be effected on only one or more small portions of a large total area. The following procedure is customary for this purpose: the printing plates required for the portions to be printed on are produced from individual, small photopolymer printing plates and adhesively bonded to a mounting sheet in the position where the printed image is to appear within the total area. The mounting sheet with the individual plates bonded thereon is hooked into the printing cylinder by means of an angle bar fastened to it and is fastened to said printing cylinder in a defined position. In the case of multicolor printing, such a mounting sheet with corresponding plates is produced for each color.
However, the mounting of the printing plates is extremely time-consuming and labor-intensive. In the case of multicolor compositions, mounting must be carried out with very exact positioning so that the various color dots precisely match one another in the print. Mounting exactly to the dot has to date required mounting apparatuses with video cameras for detection of the register marks. Mounting exactly in register must be tested in a complicated procedure by superposed printing in a proof press. If a color is not printed exactly in register, then the corresponding printing plate must be removed from the mounting sheet and stuck on again in an improved position. After such a correction, proof printing of all colors for a further check is necessary again.
WO 98/01792 has therefore proposed carrying out the production of large-area printing plates by means of an inkjet process. Here, an inkjet printer applies marks for positioning the individual plates on a mounting sheet. After individual photopolymer plates, i.e. plates not yet exposed and developed, have been stuck on, a photomask is applied to the individual photopolymer plates by means of an inkjet printer. The plate composite as a whole is then exposed and developed. The recording of images on photopolymer relief printing plates by means of an inkjet process has been disclosed, for example, also by EP-A 465 949, WO 97/25206 or JP-A 63-109 052.
However, the disadvantage of image recording by means of an inkjet process is the low resolution, which is limited to about 600 dpi in the case of the inkjet printer. The print quality is therefore subject to limits.
It is known that higher resolutions can be achieved by image recording on printing plates by means of IR ablation, for example disclosed by EP-A 767 407 or U.S. Pat. No. 5,262,275. However, these advantages could not be utilized to date in the production of large-format printing plates on a mounting sheet since they were cancelled out by the mounting problems described above and poor registration.
It is an object of the present invention to provide a process which permits the production of large-format composite relief printing plates by direct image recording from a digital data stock with substantially higher resolution than that known in the prior art.
We have found that this object is achieved by the process described at the outset and the composites described at the outset and comprising photopolymerizable relief printing plates.
In the novel process, a dimensionally stable substrate is first provided with marks for positioning the photopolymer printing plates. The term dimensionally stable is to be understood as meaning that the substrate should not distort under the influence of environmental conditions, for example temperature variations or variations in the atmospheric humidity. In particular, those materials which are also advantageously used as substrates for flexographic or letterpress printing plates are employed as dimensionally stable substrates. Examples of such materials are foils of metals such as steel, aluminum, copper or nickel or sheets of plastics such as polyethylene terephthalate (PET), polybutylene terephthalate, polyamide or polycarbonate. Particularly suitable dimensionally stable substrates are polyethylene terephthalate sheets. These substrate sheets are in general from 100 to 500 xcexcm, preferably from 200 to 500 xcexcm, for example 250 xcexcm, thick.
The choice of a suitable method by means of which the dimensionally stable substrate can be provided with positioning marks is not limited. In principle, any method which leaves marks on the substrate which are so clearly visible that these marks are detectable with the naked eye without technical aids can be used. For example, the positioning marks can be applied manually, if necessary assisted by suitable drawing or marking tools. The position of the mark is advantageously calculated by means of a computer with the aid of the layout data stocks. Furthermore, marks can be applied, for example, by means of suitable drawing apparatuses or plotters.
In a preferred embodiment, the positioning marks are written with the aid of an IR laser. This embodiment also comprises the use of a dimensionally stable substrate which is itself laser-structurable. Such a substrate contains components which can interact with the IR laser. The preferred embodiment of the invention furthermore comprises the coating of a dimensionally stable substrate with a laser-structurable layer.
The laser-structurable layer on the substrate is insoluble and preferably also non-swellable in the printing inks used, for example flexographic printing inks based on water, alcohols and esters, and in the developers usually used for developing the relief printing plates, for example those based on chlorinated hydrocarbons or high-boiling hydrocarbon solvents.
The laser-structurable layer on the substrate can be written on by means of an IR laser. Suitable laser-structurable layers are, for example, thermochromic layers which undergo an irreversible color change on exposure to an IR laser, or are IR-ablative layers which are removed or evaporated on exposure to an IR laser, with the result that the substrate underneath becomes visible again.
The thermochromic layers contain thermochromic systems. In general, such thermochromic systems consist of organic layers which, under the influence of activators, for example of free radicals, acids, bases or oxidizing agents, undergo irreversible rearrangement or conversion into a form which has different absorption behavior with respect to light. In this way, an irreversible color change is achieved. Under the influence of heat, the activators result in the conversion of the absorbing substances. Suitable thermochromic systems are disclosed, for example, in DE-A 33 42 579. An example of such a system is Michler""s ketone with benzyl tosylate as activator.
Suitable IR-ablative layers on the substrate sheet contain IR-absorbing materials and have high absorption in the wavelength range from 750 to 20000 nm. Furthermore, in the visible range of the spectrum, i.e. in the wavelength range from 400 to 750 nm, the layer has an optical density of at least 0.5, preferably at least 1.0. Examples of suitable IR-absorbing materials are dyes which absorb in the IR range, such as phthalocyanine compounds, and furthermore strongly colored inorganic pigments, such as carbon black, graphite or chromium oxides. The IR-ablative layer on the substrate sheet preferably contains at least one finely divided substance having a high absorption in the wavelength range from 750 to 20000 nm. Suitable substances are in particular finely divided carbon black grades, for example Printex(copyright) U (from Degussa), having a mean primary particle size of from 13 to 30 nm.
The laser-structurable layer which is insoluble in printing inks and printing plate developers and is present on the substrate sheet is crosslinked. One or more monomeric or oligomeric compounds may be used as crosslinking components of the layer. The crosslinking can be effected at room temperature, at elevated temperatures or by exposure to actinic light. In the case of radiation-curing, suitable photoinitiators are expediently added. Suitable components for the crosslinking are, for example, monomeric or oligomeric polyfunctional isocyanates mixed with polyfunctional alcohols, for example phenoxy resins. Also suitable are, for example, ethylenically unsaturated compounds, preferably polyethylenically unsaturated compounds, which are capable of free radical polymerization, in combination with photoinitiators. For example, mono- and polyfunctional acrylates and methacrylates, such as butyl acrylate, 2-ethylhexyl acrylate, hexanediol diacrylate, hexanediol dimethacrylate, butanediol dimethacrylate, glycidyl dimethacrylate or mixtures thereof, are particularly suitable.
The laser-structurable layer may contain, for example, polycarbonates, poly(meth)acrylates or poly(meth)acrylic esters as additional binders. Mixtures of different binders may also be used. Said layer may furthermore contain binders and additional assistants, for example plasticizers, dispersants, fillers or surfactants. The layer can advantageously be applied by casting, by dissolving the components of the layer in a suitable solvent, if necessary distributing solids contained therein, for example carbon black, uniformly by dispersing, applying the solvent uniformly to the substrate sheet and evaporating the solvent. If required, the cast layer is then crosslinked at elevated temperatures or by exposure to actinic light. Alternatively, the layer can also be cast on a sheet, dried and crosslinked and this layer then laminated with the substrate sheet, the sheet on which the layer was cast being removed again. Expediently, the coating is applied to an entire web which serves as stock for the production of large-format composite relief printing plates.
With the use of a substrate which is itself laser-structurable, coating with an additional laser-structurable layer can be dispensed with. Laser-structurable substrates contain components which can interact with an IR laser and leave visible traces on the substrate as a result of the interaction. Suitable laser-structurable substrates can be obtained, for example, by incorporating the thermochromic systems described above directly into the substrate sheet during the production of a substrate sheet from a transparent polymer. Furthermore, suitable substrates can be obtained by incorporating IR-absorbing materials having high absorption in the wavelength range from 750 to 20000 nm into the substrate sheet. The sheet containing IR-absorbing materials should have an optical density of at least 0.5, preferably at least 1.0, in the wavelength range from 400 to 750 nm. By exposure to an IR laser, material of the polymer sheet is superficially ablated so that structures are detectable on the substrate sheet. In this process, the laser power must be carefully set. It is chosen so that, on the one hand, visible marks appear on the substrate but on the other hand a reduction in strength or even complete parting of the sheet is avoided. The laser-structurable substrate or the substrate coated with a laser-structurable layer is provided in the next step with positioning marks for the individual photopolymer printing plates comprising an IR-ablative layer by inscribing marks with the aid of IR lasers. Suitable IR lasers for writing on the laser-structurable layer on the substrate are, for example, Nd/YAG lasers (1064 nm) or diode lasers (830 nm). It is possible to use both those laser apparatuses in which the substrate is installed lying flat and those in which the substrate is mounted on a rotating cylinder. Although not absolutely essential, it is advantageous for the novel process to use the same laser apparatuses as those used for subsequently inscribing the image masks. A suitable laser system is, for example, the diode laser system OmniSetter(copyright) (from Misomex, laser wavelength 830 nm, working width 1800 mm). Fixing of the substrate sheet with exact positioning in the laser apparatus is of major importance for the quality of the subsequent print. For example, in the case of mounting on a cylinder, the substrate sheets are oriented by means of angle bars or register pins in the exact position on the cylinder and are fixed by means of reduced pressure or double-sided adhesive tape for the laser exposure. This fixing with exact positioning in the laser apparatus is the basis of fixing with exact positioning on the printing cylinder.
For example, the contours of the photopolymer relief printing plates to be applied can be inscribed as positioning marks. However, it is also possible to inscribe angles or crosses which mark the corners of the printing plates. Any marking which makes it possible to position the printing plate unambiguously and precisely is possible. The number, size and position of the individual photopolymer printing plates to be applied to the substrate are advantageously calculated using layout data stocks, and the information for writing the positioning marks is transmitted directly from the computer to the laser system.
In the next step, photopolymer relief printing plates are applied to the substrate with the aid of the positioning marks. The application can be effected by methods known to a person skilled in the art, for example by adhesive bonding with the aid of a double-sided adhesive tape. The individual printing plates are, if required, cut to the required size before application. For the novel process, it is sufficient if the plate has at most only a xc2xd cm edge on which an image is not to be recorded. The number of individual printing plates depends on the desired printed image. For application of the photopolymerizable printing plates, the substrate advantageously remains fixed in the laser apparatus, for example on the cylinder. This procedure avoids further positioning for inscribing the image masks.
The photopolymerizable relief printing plates are conventional photopolymerizable flexographic or letterpress printing plates which are provided with an IR-ablative layer. Such printing plates are known in principle to a person skilled in the art. They usually comprise a dimensionally stable substrate sheet, at least one photopolymerizable layer and an IR-ablative layer present thereon. The IR-ablative layer has an optical density in the actinic range of at least 2.5 and furthermore possesses high absorption in the infrared range of the spectrum. Advantageously, it contains at least one finely divided substance having a high absorption from 750 to 20000 nm. It may furthermore contain a binder. This is advantageously a film-forming elastomeric binder, for example a polyamide resin (e.g. Makromelt(copyright) from Henkel) or a polyvinyl alcohol/polyethylene glycol graft copolymer (e.g. Mowiol(copyright) GE 597 from Hoechst). A protective film may additionally be present on the IR-ablative layer. It may also comprise further layers, for example adhesion-promoting layers or non-tacky release layers. The photopolymerizable layer usually comprises binders, ethylenically unsaturated compounds, photoinitiators and, if required, further additives and assistants, for example plasticizers, dyes, antioxidants or thermal polymerization inhibitors. Suitable photopolymerizable relief printing plates having an IR-ablative layer are disclosed, for example, in EP-A 767 407 or U.S. Pat. No. 5,262,275 and are commercially available under the name Cyrel(copyright) DPS (from Du Pont) or digiflex(copyright) (from BASF).
If required, exposure through the back is carried out in a known manner with the individual photopolymerizable printing plates prior to application.
After the application of the photopolymerizable printing plates to the coated substrate sheet, an image mask is written into the IR-ablative layer of the individual printing plates of the plate composite with the aid of an IR laser or IR laser system. Suitable IR layers for the ablation are, for example, Nd/YAG lasers (1064 nm) or diode lasers (830 nm). Suitable laser systems for the ablation are commercially available, for example the diode laser system OmniSetter(copyright) (from Misomex, laser wavelength 830 nm, working width 1800 mm). The image information is transmitted directly from the computer to the laser system.
After the image mask has been inscribed in the IR-ablative layer, the plate composite is exposed uniformly to actinic light. This can be effected either directly on the laser cylinder, or the plate is removed and is exposed in a conventional flat-plate exposure unit (e.g. F IV exposure unit from BASF). The entire exposed plate composite is then developed to give a printing plate. Commercial continuous or rotary washers may be used for this purpose. Depending on the chemistry of the plate, aqueous or organic solvent mixtures are chosen for developing the plate composite. Suitable aqueous solvent mixtures are, for example, water/alcohol mixtures. Suitable organic solvent mixtures are, for example, perchloroethylene/butanol mixtures or Nylosolv(copyright) (hydrocarbon/alcohol mixture). In the course of the development, the uncrosslinked components of the photopolymerizable layer are washed out. It is also possible first to remove the residues of the IR-ablative layer with a preliminary developer before developing the plate. The crosslinked, laser-structurable layer on the substrate is retained in the course of development and does not become detached from the substrate. After the development, the entire plate composite is dried. It can then be subjected to conventional aftertreatment methods, for example an aftertreatment with UV-C light or a detackifying treatment with Br2.
By means of the novel process, a composite relief printing plate is produced for each printing color. Said relief printing plates can be mounted quickly and directly on a multicolor printing unit with exact registration and without the adhesively bonded individual printing plates having to be readjusted, and can be printed with excellent registration. The resolution of up to 2540 dpi which is permitted in principle by the laser system can thus also actually be utilized for the multicolor halftone flexographic printing.
The example which follows illustrates the invention without restricting the scope of the invention.

Production of large-format composite relief printing plates by laser positioning and subsequent image recording by means of a laser