KR880000927B1 - Impregnated non-woven sheet material and products produced therewith - Google Patents

Abstract

The resin-impregnated fibrous sheet consists of a stitched fibrous mat and a polymeric resin distributed throughout the mat, to form a resin-impregnated sheet which has a uniform bulk wt. at all points. The apparent density of the sheet is lower than the actual bulk wt., and the sheet is thus porous. The impregnated sheet has filaments which are both coated and uncoated with resin. The sheet is used to produce artificial leather. The prod. has high resistance to tearing, and has the appearance and certain physical properties of leather.

Description

Non-woven sheet material impregnated with resin, products made therefrom and manufacturing method thereof

1 is a plan view before the resin impregnated fiber prepared according to Example 1 is divided into two.

FIG. 2 is an optical microscope photograph of the thickness of the II-II partial fiber of FIG. 1. FIG.

FIG. 3 is an optical microscope photograph of the III part of FIG.

FIG. 4 is an optical microscope photograph of the IV portion of FIG.

FIG. 5 is an optical microscope photograph of the V portion of FIG.

FIG. 6 is an optical micrograph magnified 100 times after the resin impregnated fiber prepared according to Example 1 was separated.

FIG. 7 is an optical micrograph at 100 times magnification of the cross section of the thickness of the imitation leather sheet material prepared from the quilt cotton fibers of FIG.

FIELD OF THE INVENTION The present invention relates to resin impregnated fibers, in particular resin impregnated nonwoven fabric sheet materials having a uniform density throughout, products made therefrom, and methods of making the same.

Resin impregnated sheet materials such as cloth, duvets and waterleaves are well known in the art. Such resin impregnated sheet materials are useful for a variety of purposes, including mimic leather in the form of vinyl, such as structural sheet materials for conveyor belts and similar products.

Previous methods of impregnating certain fibers include impregnating or coating the porous material with a polymer resin of polyurethane, vinyl or the like. Polyurethane is recognized as a coating or impregnating component because it can be widely modified in terms of chemical and physical properties, especially in terms of flexibility and chemical resistance. Several techniques are used to impregnate the porous sheet material with a polymer resin.

One such previous method is the use of polymer resins in an organic solvent system where the sheet material is immersed slightly in the solution and the solvent is removed here. The use of such solvent systems is undesirable because in many cases the solvent is toxic and must be recovered or discarded for reuse.

Such solvent systems are expensive and do not necessarily provide desirable products. This is because evaporation of the solvent from the impregnated porous sheet material causes the resin to move and cause the porous sheet material to be impregnated unevenly, thereby causing the resin to be abundant on the surface of the sheet material rather than causing uniform impregnation.

Some aqueous polymer systems have been proposed to alleviate problems with solvent systems. This aqueous portion must be removed when forming the impregnated sheet material by impregnation with an aqueous polymer. Heating is also required and the polymer migrates to the surface of the impregnated sheet material.

One method of associating a polyurethane solution with a porous substrate is to apply this polymer in an organic solvent to a substrate, such as needled polyester quilting fibers. The composite of polymer and substrate is then washed with a mixture of organic solvent and non-solvent, in which the polymer can be partially mixed with the solvent, until the composite layer solidifies and enters into the cell structure of the interconnected micropores. This solvent is removed from the coating layer using a non-solvent to produce a microporous layer free of solvent. Although the polyurethane impregnated fiber has satisfactory properties through this method, it has the disadvantage of an organic solvent system that requires a relatively toxic and high boiling point solvent when using polyurethane. Embodiments of this method are described in US Pat. No. 3,308,875.

In another way, polyurethane dispersions containing organic excipients have been proposed and used to coat porous substrates such as those described in US Pat. No. 3, 100, 721. In this system, the dispersion is added to the substrate and solidified by adding another nonsolvent. This approach, although successfully used in some cases, has two important limitations: (1) The excipients of the dispersion are virtually organic, since a relatively small amount of nonsolvent, preferably water, is required to form the dispersion: ( 2) The useful limits of the added nonsolvent are narrow, making it difficult to obtain reproducible results.

One method that is particularly useful as a method of making a composite sheet material by impregnating a porous substrate is described in US Pat. No. 4,171,391, which is incorporated herein by reference. In this system, the porous sheet material is impregnated with an aqueous dispersion of polyurethane and the impregnation liquid is solidified therein. This composite is then dried to form a composite sheet material. The present invention has evolved this basic process and in some cases is broader in scope.

Impregnated porous substrates and similar materials have been proposed as leather substitutes for the purpose of producing products having the same properties as natural cords.

Properly finished natural leathers are valuable for many applications because of their durability and beautiful properties.

As leather is scarce and the cost of manufacturing processed leather increases, replacing synthetic materials has become desirable in light of economic circumstances when livestock products have to be used. These synthetics have been proposed for use in shoe uppers, upholstery, clothing, luggage making, bookmaking and similar applications. These different uses require different physical, chemical, and aesthetic properties, so different materials can be used in different processes to achieve a good product comparable to natural leather. In most cases, however, these synthetic products can be easily distinguished from natural leather.

Natural leather from animal skins consists of two surfaces: one side is the grain layer, which in most cases is most aesthetically pleasing, while the other side is the split layer. The nasal layer is the epidermis of the animal and is very flat, while the dividing layer is usually bumpy and fibrous.

One way to produce leather substitutes is by impregnating or coating porous materials, ie, cloth, with polyurethane, vinyl or the like. Polyurethanes are widely recognized as coating or impregnating components because they can be widely modified in terms of chemical and physical properties, especially in terms of flexibility and chemical resistance.

The purpose of producing a composite of leather substitutes is to (1) provide a sheet similar to leather and particularly suitable for upholstery applications; (2) providing a sheet with the same width as is commonly used in the textile industry (unlike natural leather, which loses part during cutting and finishing while maintaining actual weight); (3) provide some variability in end use under various exposure conditions when certain chemical treatments are used to maintain the properties of the fibers and extend their shelf life; And most importantly, (4) to provide products with strength, hand, drape and softness comparable to natural leather.

Also, when used for shoe uppers, the imitation leather sheet material has a leathery appearance, does not have the undesirable properties of brightening the back of the fabric, vapor penetrates well into the uncoated inside of the upper, and fine lines of leather. It is characterized by ruptures (minimum grainy wrinkles). Known in the leather and upholstery industry, "leather-like crease rupture" is evident by the nature of folded or creased, well-furnished leather. The pleats of this leather are characterized by a flat, curved appearance with several delicate folds in the crimped area of the pleats. This is in contrast to the sharp creases or rough wrinkles that occur when paper or film is folded. This kind of undesirable appearance is known as "pin wrinkling."

The "hand" of this leather is very unique and the composite feels like a rubbery contrast to ordinary leather.

Polyurethane polymers for coating or impregnating fabrics have long been known to be used to make leather substitutes. For example, polyurethanes can be produced that are very resistant to solvents and abrasion, are dry washable and provide significant durability to coated fabrics. The basic chemistry of polyurethanes involves the reaction between isocyanate groups and molecules containing many active hydrogens, such as polyols or polyamines, and, depending on the choice of intermediates, is highly compatible with the final chemical and physical properties. And variability to obtain the desired balance of processing capability and the requirements needed to perform the end use.

There are many ways to apply polyurethane solutions, or other post-treatment liquid polymers, to porous substrates well known in the art.

Journal of Coated Fabrics, Vol. 7 (July 1977), pp. 43-57, describes several commercial coating systems, such as reverseroll coating, pan fed coater, and gravure printing. Brushing and spraying can also be used to cover polyurethane with a porous substrate.

After impregnating or coating the porous substrate, these polyurethane solutions are dried or treated by heating air, infrared irradiation or the like. A feature of this process is that the polymer and film-like layers are precipitated, which tends to produce unfavorable sharp wrinkled coated fabrics rather than fine wrinkle tears such as leather. Another method of combining a polymer solution, especially a polyurethane solution, with a porous substrate is described in US Pat. Nos. 3, 208, 875 and 3, 100, 721.

A more advanced method of impregnating a fabric is described in US Pat. No. 4, 171, 391, which comprises several steps necessary to form the mimic leather sheet material according to the present invention.

According to the present invention, a method of impregnating a porous sheet material, in particular a quilted duvet fiber, has been found, in order to make the impregnation homogeneous, a product with high tensile strength and preservation in an aqueous system must be formed.

Impregnated fibers also have new and useful structures that are not common and can be used to form or process fibers with better advantages.

According to the invention, the imitation leather sheet material has the appearance and properties of natural leather and has some physical similarities.

The resin impregnated fiber is composed of a quilted duvet fiber and a polymer resin evenly distributed therein. The density of the impregnated fibers is uniform throughout and the bulk density is less than the actual density of the fibers because the fibers are porous. Impregnated fibers have two filaments, coated and uncoated with a polymer resin, and a method for forming impregnated fibers is also described herein. Imitation leather sheet material is produced from impregnated fibers. The mimic leather sheet material consists of a mass of fibers impregnated with a polymer containing both a silver layer forming one side and a dividing layer forming the opposite side. The masking layer has an actual density equal to the bulk density, and the partition layer has a bulk density less than the actual density. The sheet material decreases in density as it passes from the silver layer to splitting.

As used herein, "volume density" refers to the density of a material including spaces and "actual density" refers to the density, or specific gravity, of a material that does not include spaces.

내지 3인치이다.Fibrous materials useful in the practice of the present invention include wovens and knits, and nonwovens such as sheets with felt and spun attached, quilted duvet fibers and water ribs. Suitable fibers for the substrate include natural fibers, in particular cotton and wool, and synthetic fibers such as polyester, nylon, acrylic, modacryl and rayon. The most preferred fibers are quilted duvet fibers in the form of natural fibers and synthetic fibers. In particular, these fibers are usually 1 to 6 inches in thickness, preferably 1 to 5 denier in length and suitable for lint lining.

To 3 inches.

Nubin quilt fibers have a high or low density of intermediates. Dense quilt cotton fibers have a peak density of about 0.5 g / cc. These dense quilts are usually composed of hair, and when synthetic fibers are used to form these quilts, the density is up to 0.25 g / cc. The density of the quilt fiber used in the practice of the present invention may be 0.08 g / cc to 0.5 g / cc. The duvet fibers can be up to 0.5 inches thick with a minimum thickness of 0.030 inches and most preferably between 0.12 inches and 0.4 inches. In addition, since the duvet fibers were needled, the slightly bonded duvet fibers, which were hardly needled, were characterized as "saturated duvet fibers" having high preservability, as opposed to little preservation.

Polymer resins useful in the practice of the present invention are preferably polymer resins which are capable of dissolving, dispersing and emulsifying in water as soon as possible and immediately solidifying using an ionic coagulant from this aqueous system. Preferred polymer systems are those synthesized from acrylic acrylates and acrylic monomers such as methyl acrylate, acrylonitrile, methylacrylonitrile and other well known acrylic monomers. These acrylic monomers can be polymerized by emulsification polymerization to form an emulsion, or by other free radical polymerization mechanisms, which are then dissolved or emulsified in water. In emulsifying or dissolving systems, when the emulsion comes in contact with concentrated acids or bases, the polymer solidifies from the aqueous system and is actually insoluble.

Most preferably, polyurethanes that are fused or dispersed in water are used. Representatives of emulsified polyurethanes are described in US Pat. No. 2,968,575, which are prepared in this manner and are dispersed in water by detergent under the action of strong shear forces. For such polyurethane emulsions to be formed, the emulsifier or detergent must be ionic in nature in order to solidify the polymer by adding counter ions to the aqueous system.

It is known in the art that polyurethanes useful in the practice of the present invention can be ionically dispersed in water.

A preferred system for the preparation of ionic aqueous polyurethane dispersions is the preparation of polymers having free acid groups, ie carboxylic acid groups covalently bonded to the backbone structure of the polymer. This occurs. Since isocyanate, which is a necessary component in any polyurethane system, is generally reactive with a carboxyl group, care must be taken when selecting a compound having such a carboxyl group. However, as described in US Pat. No. 3, 412, 054, carboxylic acids substituted with 2,3-hydroxymethyl can react with organic polyisocyanates without significant reaction between acid and isocyanate. This is because the carboxyl group causes steric hindrance due to the alkyl group. This treatment method neutralizes the carboxyl groups with tertiary mono-amines to supply internal quaternary ammonium salts, making polymers containing the desired carboxyl groups and having water dilution.

Suitable carboxylic acids, preferably those which cause steric hindrance, are well known and readily available. For example, these carboxylic acids can be prepared from aldehydes containing at least two hydrogen atoms in the α position, which react with two equivalents of formaldehyde in the presence of a base to form 2,2-hydroxymethyl aldehyde. . The aldehydes are then oxidized to acids using methods known to those skilled in the process. The structural formula of these acids is as follows.

R in the formula represents hydrogen or an alkyl group up to C ₂₀ , in particular an alkyl group up to C ₈ , and more preferred acids are 2, 2-di- (hydroxymethyl) propionic acid. Polymers with pendant carboxyl groups are characterized as anionic polyurethane polymers.

In addition, according to the present invention, another method of making water dilution is to use a cationic polyurethane having a pendant amino group. Such cationic polyurethanes are described in particular in Example 18 of US Pat. No. 4,066,591. In this invention, it is preferable to use anionic polyurethane.

Polyurethanes useful in the practice of the present invention include the reaction of di- or polyisocyanates with compounds containing a number of active hydrogens suitable for the production of polyurethanes. Such diisocyanate active hydrogen compounds are described in more detail in US Pat. Nos. 3,412,034 and 4,046,729. In addition, methods for producing such polyurethanes are well known as exemplified by the above patents. According to the invention aromatic, aliphatic and cycloaliphatic diisocyanates or mixtures thereof can be used to form the polymer. Such diisocyanates include tolylene-2, 4-diisocyanate, tolylene-2, 6-diisocyanate, meti-phenylene diisocyanate, biphenylene-4, 4'-diiso Cyanate, methylene-bis (4-phenylisocyanate), 4-chloro-1, 3-phenylenediisocyanate, naphthylene-1, 5-diisocyanate, tetramethylene-1, 4-diiso Cyanate, hexamethylene-1, 6-diisocyanate, decamethylene-1, 10-diisocyanate, cyclohexylene-1, 4-diisocyanate, methylene-bis (4-cyclohexyl isocyanate Acid salts), tetrahydronaphthylene diisocyanate, isophorone diisocyanate, and the like. Preferably arylene and cycloaliphatic diisocyanate are most usefully used in the practice of the present invention.

Characteristically, arylene diisocyanate includes all diisocyanate salts in which isocyanate groups are attached to the aromatic ring. The best isocyanates are the 2, 4 and 2, 6 isomers of tolyenedi isocyanate or mixtures thereof, which are good because they are readily available and active. Furthermore, the cycloaliphatic diisocyanates most advantageously used in the practice of the present invention are 4, 4'-methylene-bis (cyclohexyl isocyanate) and isoprondiisocyanate.

The choice of aromatic or aliphatic diisocyanates depends on the end use of the particular substance. As is well known in the art, aromatic isocyanates can be used when the end product is not overexposed to the ultraviolet rays yellowing such polymer compositions. However, aliphatic diisocyanates have less tendency to yellow when exposed to ultraviolet radiation, and thus may be more advantageous for external use. While this principle is a general basis for selecting the particular isocyanate to be used, aromatic diisocyanates can be stabilized again with known UV stabilizers to enhance the final properties of the polyurethanes impregnated with the sheet material. In addition, it is possible to add levels of antioxidants known in the art, which are necessary to enhance the properties of the final product. Typical antioxidants include thioethers, 4, 4'-butylidinebis-methi-cresol and 2, Phenolic antioxidants such as 6-ditert-butyl-party-cresol.

Isocyanates react with many active hydrogen compounds such as diols, diamines or triols. In the case of diols or triols these are typically polyols of polyalkylene ethers or polyesters. Polyalkylene ether polyols suitable for the production of polyurethanes are polymerizable substances containing active hydrogens. The most useful polyglycols are most preferably 400-7,000 in the present invention as long as they have a molecular weight of 50-10, 000. Poly ether polyols increase flexibility proportionally with increasing molecular weight.

Examples of polyether polyols include, but are not limited to, polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyoctamethylene ether glycol, polydecamethylene ether glycol, polydodecamethylene ether glycol and mixtures thereof. . Polyglycols containing several different radicals in the molecular chain, for example the compound HO (CH ₂ OC ₂ H ₄ O) nH (where n is an integer greater than 1) may also be used.

The polyols may also be polyesters terminated with hydroxy groups or with hydroxy groups bound, which may be used in place of or in combination with or in combination with polyalkylene ether glycols. These polyesters are those formed by reacting an acid, ester or acid halide with glycol. Suitable glycols include polymethylene glycols such as ethylene, propylene and tetramethylenein decamethylene glycol, substituted methylene glycols such as 2, 2-dimethyl-1 and 3-propanediol, and cyclic glycols such as cyclohexanediol. Aromatic glycols and the like. In general, when flexibility is required, it is preferable to use aliphatic glycols. These glycols are reacted with aliphatic, cycloaliphatic, aromatic dicarboxylic acids or lower alkyl esters, or esters forming derivatives to form relatively low molecular weight polymers, i.e., melting points of up to 70 degrees Celsius and molecular weights in polyalkylene ether glycols. To produce the polymer as indicated. Acids for making such polyesters include phthalic acid, maleic acid, succinic acid, adipic acid, suberic acid, terephthalic acid, hexahydrophthalic acid and derivatives in which these acids are substituted with alkyl and halogen.

In addition polycaprolactone terminated with hydroxy groups can also be used.

One particularly useful polyurethane system is a crosslinked polyurethane system, which is a U.S. patent filed under the title "Cross-linked Polyurethane Dispersion" by Andrea Luciello on October 2, 1978, which is incorporated herein by reference. Application number 947, 544 is described in more detail.

As used herein, "ionic dispersant" refers to an acid or base that can form salts with solubilizing agents and can be ionized by dissolving in water. These "ionic dispersants" are amines, preferably water-soluble amines such as triethylamine, tripropylamine, N-ethylpiperidine, and as the acid, water-soluble acids such as acetic acid, prephosphonic acid, lactic acid and the like are preferred. Acids or amines are selected depending on the solubilizing groups that depend on the chain of the polymer.

The desired elastomers generally require about 25-80% by weight of long chain polyols (ie 700-2, 000 equivalents) in the polymer. The elongation and elasticity of the chain varies greatly from product to product, depending on the desired properties of the final product.

In preparing polyurethanes useful in the practice of the present invention, polyols and excess moles of diisocyanates are reacted to form polymers having isocyanate groups at their ends. Appropriate reaction conditions, reaction times, and reaction temperatures may vary within the context of the particular isocyanate and polyol used, but those skilled in the art are fully aware of these changes. The skilled artisan knows that the reactivity of the components requires a balance of reaction rates, with undesirable side reactions leading to a decrease in color or molecular weight. The reaction is typically agitated at about 50-120 degrees Celsius for about 1 hour-4 hours. In order to provide a pendant carboxyl group, a polymer having an isocyanate group bound at its end is reacted with an acid lacking 1 mole of dihydroxy group at 50-120 ° C. for 1-4 hours at an isocyanate group at the end. To make a prepolymer bound. The acid is preferably added, for example, by using N-methyl-1, 2-pyrrolidone or N-N-dimethylformamide as a solution. The solvent for the acid is in principle not to exceed about 5% of the total amount in order to minimize the concentration of the organic solvent in the polyurethane composition.

The dihydroxy acid is reacted in the polymer chain, the pendant carboxyl group is neutralized with an amine for about 20 minutes at about 58-75 degrees Celsius, and water is added while stirring to extend and disperse the chain. A water soluble diamine may be added to the water as an additional chain additive. This elongation of the chain involves the reaction of water with the remaining isocyanate groups to form urea groups, and the polymerization of the polymerizable material as a result of reacting all isocyanate groups by stoichiometric addition of water. do. It is noteworthy that the polyurethanes of the present invention are originally thermoplastic, that is, they cannot be cured again after production without adding a curing agent externally. When making a synthetic sheet material, it is preferable not to add such hardening | curing agent as much as possible.

Sufficient water is required to disperse the polyurethane at a solid weight of about 10-40% concentration and the dispersion viscosity in the range of 10-1, 000 centipoise. Viscosity can be adjusted according to the specific impregnation desired and the composition of the particular dispersion indicated by the properties of the final product. It is noteworthy that no emulsifier or thickening agent of Hadong is required to stabilize this dispersion.

Depending on the end product's use, those of ordinary skill in the art know how to modify the primary polyurethane dispersion by adding colorants, compatible vinyl polymer dispersions, ultraviolet filterable compounds, stabilizers to oxidation, and the like. .

Characterization of the dispersions prepared according to the invention is made by measuring the non-volatile content and particle size, measuring the viscosity and strain deformation of the cast film pieces.

The concentration range useful in the practice of the present invention is determined by the percentage required to add the polymer to the nubin quilt fiber bundle.

Dispersion viscosity is generally in the range of 10-1,000 centipoise, and as far as the viscosity of the same polymer is concerned at the same solid level in the polymer solution with organic solvents, the low viscosity helps the rapid and complete penetration of the aqueous acid solution followed by the penetration of the coagulant. Help In contrast, useful solutions of polyurethanes generally have viscosities of thousands of centipoise, reaching as high as 50, 000 centipoise at concentrations of 20-30%.

The polymers should be contained in the fiber bundle at least from about 70% to about 400% by weight based on the weight of the quilt fiber. It is most preferable if this polymer resin is impregnated by about 200 to 300% by weight based on the weight of the quilt fiber.

Condensation is completed by contacting the saturated substrate with an aqueous solution of an ionic medium designed to ionically dissolve soluble ions. In theory, in the case of anionic dissolved polyurethanes (though not intended to be bound by this theory), the amines that neutralize the polyurethanes containing carboxyl groups are replaced by hydrogen ions that return to the anionic pendant carboxyl ions. To convert the polyurethane polymer into a state of "non-dilution" in principle. This causes coagulation of the polymer in the substrate structure.

In the case of anionic polymerizers, an aqueous acetic acid solution at a concentration of about 0.5-5% is suitable as an ionic coagulant for the anionic dispersion. It is also preferred over stronger acids because of its relatively easy handling, low corrosiveness, and ease of treatment. Other acids that are substantially water soluble may be used at the same concentration. The condensation is very fast and indeed very fast so that the polymer is substantially entirely in the substrate so that there is no loss of the polymer due to migration into the ionic solution. "Salt", which neutralizes the dispersion with the addition of neutral salts, is feasible but not desirable because it requires a large amount of salt, requires about 10 times the temperature of the acid, and contaminates the product.

When saturating the nubine quilt fiber with a polymer resin as described herein, the fiber is immersed in an aqueous ionic emulsion or dispersion at a concentration sufficient to increase at least 70% by weight. Soak the quilt fibers in an aqueous emulsion or dispersion and then compress the fibers to remove air and thus completely impregnate the emulsion or dispersion in the fibers. An aqueous dispersion or an emulsion that has been fully saturated with an emulsion is passed through something like a wiping roll to remove excess dispersion or emulsion remaining on the surface of the saturated fiber. The fiber is then immersed in a bath containing counter ions, and the fiber is coagulated using counter ions that contain a substance that penetrates the fiber by diffusion and coagulate the resin in the fiber tissue. After coagulation, the fibers are compressed to remove excess water and dried to form impregnated fibers.

This method is a further development of the method described in US Pat. No. 4,171,391 in terms of providing a particular product. The difference between the referenced patent and the present method is that it completely saturates the quilt fiber.

That is, there is no space left to contain an aqueous dispersion or emulsion that increases at least 70% by weight of the polymer resin based on the weight of the duvet fiber. Due to this difference, a new structure is created and the quilt fiber of the present specification has a uniform density as a whole, and the bulk density of the fiber is smaller than the actual density.

Impregnated fibers are formed and then the density differential is used to produce mimic leather sheet material. To form the mimic leather sheet material, the fiber impregnated material is preferably a polymer in the form of particles that can fuse under conditions of heat and pressure. Generally these polymers are thermoplastic resins but some gyolyzed polymers that are easy to bond may be used. Also described by U.S. Patent Application No. 947,544, filed October 2, 1978, entitled "Cross-linked Polyurethane Dispersion" by Andrea Luciello, polyurethanes are particularly useful in the practice of the present invention. It is useful and overcomes the desired density difference through the thickness of the material.

Characteristic of the mimic sheet material produced according to the present invention is, among other things, a physical feature where density differences exist everywhere from one side of the sheet material to the opposite side. The difference in density is preferably uniform. One surface of the impregnated fiber is a layer of silver that has an actual density equal to the bulk density.

This layer of silver is very similar to that of natural leather. On the other side of the sheet material there is a surface defined by a divided layer whose bulk density is less than the actual density and it is desirable to have a uniform density differential throughout the material. This partition is somewhat fibrous and resembles that of natural leather.

The mimic leather sheet material is present so that the polymer increases at least 70% conductivity based on the fiber weight.

In general, the dividing layer reaches about 75% of the density of the masking layer and provides a porous masking layer that mimics the layer of leather. It can also be seen that the polymer is uniformly distributed throughout the fiber as the ratio of fiber to polymer is uniform throughout.

The mimic leather sheet material is produced by processing impregnated fibers, preferably the impregnated nonwoven sheet material as described above. The polymer used as the impregnating agent is best selected from those of the type described in US Patent Application No. 947,544 cited above.

As a method of processing the impregnated nonwoven sheet material to produce a mimic leather sheet, the impregnated nonwoven sheet material is placed in a compactor and heat and pressure are applied to both sides. This heat and pressure is sufficient to dissolve the polymer in the impregnating agent on the surface of the material, but insufficient to completely dissolve the polymer inside the sheet material. This method develops a density difference from the interior of the nonwoven sheet material to the two outer surfaces. Let's do it. The gauge size of the heated and pressed sheet material can be adjusted by the pressure applied during heating and pressing, or by inserting spacers between the pressing plates, or by using a static load press.

The plate of the compactor may also be embossed to provide a specific design for the surface of the material. After compression, the sheet material is split in two to provide two imitation leather sheets each having a silver and split layer.

Another method of making mimic leather sheet material is to impregnate the impregnated nonwoven starting material described above in a compactor having only a heated plate to form a laminar layer and the opposite side to a cold plate to form a partition layer.

Another method of making mimic leather sheet material was to place the two pieces of impregnated nonwoven starting material mentioned above in a compactor and apply enough heat and pressure to melt the polymer in the impregnating agent on the outside of each piece. After compression, each piece was separated to produce two imitation leathers. The imitation leather can be made and then buffed, coated or processed according to known leather finishing techniques.

As an alternative, a layer of silver is produced using unsensed strips of the starting material of the impregnated nonwoven released from the package and then passed through a pair of rolls by duct operation. One of the rolls is heated to 300 degrees Fahrenheit to 400 degrees Fahrenheit, preferably a flat or moderately embossed metal, and the other roll is a softer, more elastic material, such as rubber. The silver face layer is produced on the metal roll side of the sheet. To shine effectively, it is usually best to load 5-15 tonnes per yard area of the sheet through the roll. It is helpful to wet the sheet by adding 50-100 plentifuls of water in the weight ratio of the sheet before the mining operation.

The structure of the impregnated fiber and imitation leather sheet material is shown in more detail in the accompanying drawings, in which the cross sections of the impregnated fiber and imitation leather sheet material produced by the present invention are taken with an optical micrograph. Referring to FIGS. 1 to 5, reference numerals refer to portions of the resin impregnated fiber 10 made according to Example 1. FIG. In particular FIG. 2 to FIG. 5 show a cross section of the thickness of the fiber 10. The fiber 10 consists of an upper face 12 and a lower face 14 and when viewed through the fiber 10 a large number of fibers 16, uncondensed resin 20, voids 18 are virtually uncoated. And fibers 22 coated with resin. Under the microscope the structure is not homogeneous, but through the thickness of the material the structure and its bulk density are virtually uniform.

The structure shown in FIGS. 2 to 5 is produced by completely impregnating the quuven duvet fibers with an aqueous emulsion or dispersion and then solidifying the polymer while the fibers are fully impregnated using an aqueous resin system.

Referring to FIG. 6, this is an optical micrograph of a 100-fold magnification of a separated impregnated quilted duvet fiber 24 having an overall uniform density as shown in FIG. The impregnated duvet fibers 24 consist essentially of uncoated fibers 26, polymer agglomerates 28, coated fibers 32 and voids 30. It should be noted that although the impregnated quilt cotton fibers are not homogeneous under the microscope, they have a uniform volume density throughout.

Referring to FIG. 7, this is an optical micrograph at 100 times magnification of the imitation leather sheet material 32 prepared according to Example 4. FIG. This material 32 has a masking layer 34 with a minimum amount of space and the bulk density of the masking layer 34 is equal to the actual density. In the masking layer 34, heat and pressure were applied to form the fiber composite 36 in the continuous resin matrix. Moving along the A direction, it can be seen that the space 30 increases along the direction approaching the dividing layer 38. There are virtually a lot of space 30 and uncoated fiber 26 and polymer mass 28 in the dividing layer 38. The structure of the partition layer 38 is similar to the structure shown in FIG.

The following examples describe the products produced according to the invention.

Example 1

Andrea Luciello cited earlier in this specification for a heated quilted duvet fiber consisting of polyester, polypropylene and rayon fibers with a density of 1,200 grams per square meter and a volume density of 0.16 g / cm 2 0.3 inch thick It was immersed in a polyurethane prepared according to Example 3 of U.S. Patent Application No. 947,544. This polymer dispersion had a solids content of 22% in total, weighting 120% of the duvet fiber weight. The duvet fibers were immersed in a polyurethane dispersion for 10 minutes at room temperature until all air in the fibers escaped and the dispersion completely permeated. Excess dispersion was removed by rubbing both sides of the surface of the quilt cotton fiber using a straight ruler, and then immersed in a 10% acetic acid bath for 10 minutes at room temperature. Soaking in the acid causes the polyurethane in the fiber tissue to completely solidify. Excess acetic acid is washed away from the quilt fiber and the excess fluorine fiber impregnated with resin is pressed to remove excess water. The resin-impregnated quilt cotton fibers were divided into four pieces according to thickness and each was dried in a circulating air oven at 300 to 350 degrees Fahrenheit to produce four resin impregnated cloths with a bulk density of 0.41 g / cc. This final product was photomicrographed as shown in the figure.

Example 2

Example 1 was repeated but 100% polyester duvet fibers having a density of 0.13 grams / cc and 0.2 inch thickness were saturated with the 22% solid dispersion of Example 1. The resulting saturated fabric has a uniform density, high shelf life and a bulk density of 0.38 grams per square centimeter.

Example 3

Example 1 was repeated but 100% polyester quilted duvet fibers of 0.22 inch thick and 0.23 g / cc density were saturated with a 32% solid dispersion to form a quilted resin impregnated fiber having a bulk density of 0.56 g / cm 2. . This product, according to Example 3, was used as a calendering cloth, which was tough, high in tensile strength and elastic and completely recovered after compression.

The process of the invention and the product according to the invention thus have high preservation properties and provide impregnated fibers useful as the product itself and provide impregnated fibers necessary for the formation of other products. This impregnated fiber may also be puffed to the desired finishing process.

Example 4

Two pieces of non-woven impreg-nated web having a thickness of 0.07 inch prepared by Example 1 were superimposed on each other and placed for 30 seconds between pressure plates heated to 300 degrees Fahrenheit at a pressure of 500 psi.

The two pieces are then separated separately to obtain two imitation leather sheet materials. The silver face layer of this sheet corresponds to the surface which is in contact with a hot pressure plate. The inside of this sheet maintains a fibrous structure similar to an unpressed sheet. Microscopic examination has found that the mimic leather sheet material has a density difference from the silver layer to the split layer as shown in FIG.

Immediately after the imitation leather sheet material is produced, it can be post-treated with other polymers using known techniques for surface finishing.

Although the present invention has been described with respect to specific materials and specific methods, the present invention applies only to the extent set forth in the appended claims.

Claims (42)

It consists of a polymer resin that is distributed throughout the quilt cotton forming the quilted cotton fiber and the resin impregnated fiber, the density of the impregnated fiber is uniform throughout, and the bulk density of the fiber is porous A resin impregnated fiber that is less than actual density and that the impregnated fiber has both coated with polymeric resin and uncoated short fibers. The resin impregnated fiber according to claim 1, wherein the quilted duvet fiber has a bulk density of less than 0.5 g / cm 3. The resin impregnated fiber according to claim 2, wherein the quilted duvet fiber has a bulk density of less than 0.25 g / cm 3. The resin impregnated fiber of claim 2, wherein the quilted duvet fiber has a bulk density between about 0.12 and 0.4 g / cm 3. The resin impregnated fiber of claim 1, wherein the quilted duvet fiber has a thickness of at least 30 mils. The resin impregnated fiber of claim 1, wherein the quilted duvet fiber consists of substantially insoluble fibers. The resin impregnated fiber of claim 1, wherein the polymer resin is a polyurethane. 8. The resin impregnated fiber of claim 7, wherein the polyurethane is a polyurethane that can be dispersed in water. 8. The resin impregnated fiber of claim 7, wherein the polyurethane is a crosslinked polyurethane. The resin impregnated fiber of claim 1, wherein the polymer resin is a polyacrylate. The resin impregnated fiber according to claim 1, wherein the polymer resin is present at least about 70% by weight of the quilt fiber. 12. The resin impregnated fiber of claim 11, wherein the polymer resin is present in less than about 400% by weight of the quilt fiber. 13. The resin impregnated fiber of claim 12, wherein the polymer resin is present in an amount of about 200 to 300% by weight of the quilt fiber. The resin impregnated fiber of claim 1 having a density of up to about 0.75 g / cc. The resin impregnated fiber of claim 14 having a density of about 0.4 to 0.75 g / cc. In the process for producing impregnated fibers, the quilted quilt fibers are completely saturated with an aqueous dispersion or emulsion of an ionically dissolved polymer resin, and the fully saturated quilted quilt fibers are contacted with an ionic coagulant to form an aqueous dispersion. A method for producing impregnated fibers, comprising the step of solidifying the polymer resin and then accumulating the polymer resin in the quilted duvet fiber. The method of claim 16, wherein the bulk density of the quilted duvet fiber is less than 0.5 g / cc. 18. The method of claim 17, wherein the bulk density of the quilted duvet fibers is less than 0.25 g / cm 3. 18. The method of claim 17, wherein the bulk density of the quilted duvet fibers is between 0.12 and 0.4 g / cm3. 18. The method of claim 16 wherein the thickness of the quilted duvet fibers is at least 30 mils. 18. The method of claim 16, wherein the quilted duvet fibers are substantially composed of insoluble fibers. The method of claim 16 wherein the polymeric resin is polyurethane. 18. The method of claim 16 wherein the aqueous dispersion or emulsion has a solids content of about 5 to 60% by weight. The method of claim 22 wherein the polyurethane is crosslinked. The method of claim 16, wherein the polymer resin is present in the impregnated fiber at least 70% by weight based on the weight of the quilt cotton fiber. 27. The method of claim 25, wherein the polymer resin is present in less than about 400% by weight of the duvet fiber. 27. The method of claim 26, wherein the polymeric resin is present at about 200 to 300% by weight of the quilt cotton fibers. The method of claim 16 wherein the density of the impregnated fiber is up to about 0.75 g / cc. 29. The method of claim 28, wherein the impregnated fiber has a density of about 0.4 to 0.75 g / cc. Product prepared according to the method of claim 16. One side consisting of a layer of polymer-impregnated fibers consisting of a dividing layer having a bulk density of less than the actual density, the other side being a silver layer having the same bulk density as the actual density. The sheet material decreases in density from the silver layer to the split layer, wherein the ratio of fibers to polymer is uniform throughout the sheet material. The sheet material of claim 31, wherein the fiber mass is a quilted duvet fiber. 32. The sheet material of claim 31, wherein the polymer is polyurethane. 34. The sheet material of claim 33, wherein the polyurethane is crosslinked. The sheet material of claim 31, wherein the polymer is present at least 75% by weight of the fiber mass. 36. The sheet material of claim 35, wherein the polymer is present up to about 400% by weight of the fiber mass. 37. The sheet material of claim 36, wherein the polymer is present at between 200 and 300% by weight of the fiber mass. 32. The sheet material of claim 31, wherein the partition layer reaches 75% of the density of the silver face layer. 32. The sheet material of claim 31, wherein the polymer is uniformly distributed throughout the mass of fibers. 32. The sheet material of claim 31, wherein the density of the sheet material has a uniform difference from the dividing layer to the silver face layer. A method of making a mimic leather sheet material, wherein the mass of fibers is uniformly impregnated with a polymer to form a porous sheet material, and the heat is applied to at least one side of the material by heating the porous sheet material under heat and pressure. The process consists of producing imitation leather sheet material with a silver layer on the applied surface, where the silver layer has the same bulk density and actual density, and the partition layer has a smaller bulk density than the actual density, so that the density of the sheet material goes from the silver layer to the split layer. Wherein the ratio of fibers to polymer is uniform throughout the sheet material. 42. The method of claim 41, wherein heat and pressure are applied to both sides of the sheet material to create a density difference from the outside of the sheet material to the interior, wherein the half of the sheet material is divided so that the outer surface forms a silver layer and the inner surface forms a divided layer. A method for producing imitation leather sheet material.

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