US3629052A

US3629052A - Process for imparting flame-retardancy to resin-treated cotton batting

Info

Publication number: US3629052A
Authority: US
Inventors: Nestor B Knoepfler; Paul A Koenig
Original assignee: US Department of Agriculture USDA
Current assignee: US Department of Agriculture USDA
Priority date: 1970-06-26
Filing date: 1970-06-26
Publication date: 1971-12-21
Anticipated expiration: 1988-12-21

Abstract

Flame retardancy, resiliency, dimensional stability, coherence, and moldability are imparted to fibrous cellulosic batting upon treatment wherein the batting is impregnated with an aqueous mixture containing a certain combination of thermoplastic and thermosetting resins selected for their compatibility with ureaphosphate complexes, or with borated urea formaldehyde; or alternately, the batting is impregnated with an aqueous mixture containing vinyl chloride-type thermoplastic polymer mixtured with certain salts, such as diammonium phosphate or boroncontaining compounds.

Description

United States Patent 72] Inventors Nestor B. Knoepller;

Paul A. Koenlg, both of New Orleans, La.

[2]] Appl. No. 50,306

[22] Filed June 26, 1970 [45] Patented Dec. 21,1971

[73] Assignee The United States of America as represented by the Secretary of Agriculture Continuation of application Ser. No. 728,162,May 10, 1968, now abandoned. This application June 26, 1970, Ser. No. 50,306

[54] PROCESS FOR IMPARTING FLAME- RETARDANCY TO RESIN-TREATED COTTON Primary Examiner-William J. Van Balen AtrorneysR. Hoffman and W. Bier ABSTRACT: Flame retardancy, resiliency, dimensional stability, coherence, and moldability are imparted to fibrous cellulosic batting upon treatment wherein the batting is impregnated with an aqueous mixture containing a certain combination of thermoplastic and thermosetting resins selected for their compatibility with urea-phosphate complexes, or with borated urea formaldehyde; or alternately, the batting is impregnated with an aqueous mixture containing vinyl chloride-type thermoplastic polymer mixtured with certain salts, such as diammonium phosphate or boron-containing compounds.

PROCESS FOR IMPARTING FLAME-RETARDANCY TO RESIN-TREATED COTTON BATTING This is a continuation-in-part of Ser. No. 728,162, which was filed May 10, 1968, now abandoned.

A nonexclusive, irrevocable, royalty-free license in the invention herein described throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to fibrous cellulosic batt with flameretarding properties, and to a method of producing the said batt. More particularly this invention relates to a fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience that is flame retardant, and to a method of producing the said batt by means of an aqueous single mixture chemical treatment, thus improving the state of the art.

The invention relates to and supplements the invention of US. Pat. No. 3,181,225, which issued May 4, 1965, and US. Pat. No. 3,350,486, which issued Oct. 31, 1967.

The process of the former deals with the treatment of fibrous cellulosic batting with thermoplastic and thermosetting resins in various combinations to achieve a product with resilience and dimensional stability concurrent with an improvement in tensile strength and resistance to compaction, which is not present in conventional batting. The process of the latter teaches that by properly selecting the thermoplastic and the thermosetting components and applying them to webs of cotton fibers which are molded while wet, dried, and cured to produce a product that conforms to a desired shape while simultaneously exhibiting improved resilience, tensile strength, dimensional stability, and resistance to compaction in use. The instant invention differs from this prior art in that the products of the known art, including the products of these patents, are further enhanced in that the added characteristic of flame retardancy is imparted to the batting while retaining the good qualities imparted by the known processes.

The main object of the instant invention is to provide a formulation for use in a process for the manufacture of a fibrous cellulosic batt with an ability to resist damage by fire, said imparted properties to include the ability to retard the propagation of flame when the external source of the said flame is removed.

A second object of the instant invention is to provide the characteristics of the main object while imparting the added characteristic of a lack of afterglow once the source of pyrolysis is abated.

A third object of the instant invention is to provide a formulation which when applied to a batting material can impart to said material the property of being able to hold the fibers together even though the treated material may be severely charred.

This invention is a product of investigative effort to combat the increasing competition to cotton material by the recent advances of natural and synthetic foamed products, and to comply with the evident intent of the Congress of the United States of America to render cushioning materials used in places of public accommodation, at home, and in automobiles safer in every possible respect.

The application of the chemical substances is done, generally, through a single or a plurality of nozzles, which wet the web as it moves past a fine spray controlled as to avoid extremes in wetting the web, and at the same time to assure optimum droplet size that results in uniform deposition of the chemicals on the web.

The chemicals employed are applied in formulations consisting of both thermoplastic and thermosetting resin species either in combination or alone. The resilience and dimensional stability characteristics of the products depend upon the proper selection of the thermosetting resin and the filmforming thermoplastic resin because their functions must of necessity be complimentary. The thermosetting resins of choice must be capable of being cross-linked with the cellulose to chemically enhance the resilience characteristics of the fibers,

while the thermoplastic resin must be of a film-forming type whose physical characteristics such as bending moment, elongation, and strength must closely approximate that of cotton since the function of the thermoplast is to bind the fibers together at points of contact to contribute tensile strength and dimensional stability to the products.

A most important feature of the instant invention is the use of a urea resinous complex compatible with both the thermosetting and thermoplastic resinous systems to contribute the ability to resist rapid pyrolysis while at the same time not interfering with the basic function of the thermoplastic and thermosetting resins as described immediately above, so that a great degree of uniformity of treatment can be obtained while the operation is of a continuous economic character.

In specific examples of this invention the optimum wet addon varied from 70 to percent, depending on the properties desired in the finished products.

The concentration of the spray solution or suspension mixture can vary from 1 to 35 percent by weight total solids, depending on the resin to latex ratio, the nature of the reagents, and the properties desired in the finished product.

FIGS. 1A, 1B, 2, and 3 are provided to assist the reader in visualizing some of the points pertinent to the following discussion. The instant invention does not claim any of these points as part of the invention but merely utilizes these to illustrate the manner in which the batts are prepared with the formulations which are the invention.

After being sprayed, the web or layer of fibers in either crosslapped conventionally as in FIG. 1A and then condensed through suitable rolls or other means to assure good contact between successive layers or web s, or collected on a reel, where condensing is done on a layer for layer basis, as shown in FIG. 1B. The formed batts, item 12 (FIG. 2), are then constricted, see item 13 (FIG. 3), in such a manner as to maintain a specific height during drying and curing; or dried and cured without restraint depending on the desired physical properties, such as density. Since a structure consisting of cellulosic fibers which have been formed into batts tends to expand in volume when subjected to heat or hot air circulation, this inherent characteristic is capitalized upon in order to achieve a more open (less dense) finished product. The density of the product therefore can be varied by either varying the weight of the webs, the number of webs, or layers of fibers used in the batt, or by varying the spacing between frames as in FIG. 3, or by adjusting the spacing between suitable open mesh dual belts for continuous drying, or by changing the ratio of thermoplastic to thermosetting resin in the treating formulation.

Drying temperatures up to 345 F. can be used depending on whether drying will be carried out simultaneously with ouring or as a separate unit operation to be followed by curing. In the latter instance drying temperatures up to 220 F. would be adequate for drying if followed by temperatures of up to 345 F. for curing. Suitable temperatures within this range can be selected depending upon the requirements of the chemicals employed. Evidence exists that the degree of expansion obtained in the finished product depends upon a relationship between the time of drying and the temperature employed. In general longer times at lower temperatures will result in a more expanded structure in the finished product.

Upon the completion of the drying and curing step or steps the product retains its preselected height, width, and length. Furthermore, the product is one having improved resilience, a resistance to deformation from compressive loading much greater than untreated cotton batting, demonstrates a cohesive structure and resistance to compaction in use, and has significantly greater tearing and tensile strength, up to twenty times as great as untreated cotton batting. The perfonnance of the improved product can be demonstrated both at high and low relative humidities.

The spray from a single media has been accomplished by investigative formulation, which included the search for compatible systems which can contain the resin, the latex, the catalyst, the thickening agent, the flame retardant, the dyes,

and the solvents, which go into the spray application in a single solution or suspension or both.

Pretreatment of the raw stock feed, such as mercerization, scouring, and wet processing with chemicals such as formaldehyde, significantly enhance the properties of the finished product. Likewise, the flame retardant can be applied as a pretreatment for the cotton raw stock followed by drying. in this case the flame retardant could be eliminated from the subsequent formulation.

The many facets of this process, and their proper application by adjusting to the most suitable variables make it evident that there are many advantages to be gained in the practice of this invention. The following specific examples refer to materials actually produced on an experimental basis, and are in no way to be construed as specific limits to the flexibility of the system.

The batts produced by the use of this invention are dimensionally stable and resilient, and demonstrate a marked ability to reproduce contours of the material used to restrain them during drying and curing.

Thermoplastic substances which may be employed are vinyl acrylate, vinyl acetate, vinyl acrylate-acetate, styrene, butadiene, vinyl chloride, vinyl acrylate-chloride, vinylidene chloride, vinyl acetate chloride, and the like. Thermosetting polymer-forming substances which may be employed are ethyl triazones, urea formaldehydes, cyclic urea formaldehydes, methylated methylol melamine, dimethylol dihydroxy ethylene urea, and ethyl or methyl carbamate. Flame retardant substances which may be employed are urea-phosphate complexes, borated urea formaldehyde, borated amide polyphosphate, and dicyandiamide phosphoric acid derivatives.

Since the resins found to contribute the enhanced properties described herein for cotton fibers are known to chemically react with the cellulose of the cotton fibers such resins can be expected to react equally well with synthetic cellulosic fibers such as rayon. For this reason the process described herein for the manufacture of a fibrous cotton batt is equally applicable to the fibrous cellulosics or blends of these materials with cotton.

Such resins as the urea formaldehydes, tris(l-aziridinyl)phosphene oxide, melamines, triazines and others will react equally well with wool as with cotton. For this reason the process described herein for the manufacture of a fibrous cotton batt is equally applicable to wool or blends of wool and cotton.

Because textile wastes normally used in the production of cotton batting are derived from diverse sources, on occasion these wastes may contain varying nominal amounts of synthetic fibers such as polyesters or acrylics, polyether or others either by chance or design. The presence of these synthetic fibers would not preclude the use of the waste in the practice of this invention.

in general, according to the instant invention, the method used for producing fibrous cotton batts with improved dimensional stability, coherence, moldability, and resilience that are flame retardant, comprised the following operations carried out in sequence:

a. forming webs of opened cellulosic fibers of the group consisting of cotton fibers and chemically modified cotton fibers,

b. treating the webs with an aqueous 5 to 40 percent solids formulation consisting of about 30 to 70 percent of a thermoplastic substance, about from 68 to 12 of a thermosetting polymer-forming substance, and about from 2 to 20 percent of an agent capable of imparting flame-retardancy to cellulosic materials, respectively, plus an appropriate catalyst and buffer when necessary, the ratio of thermoplast to thermoset to fire-retardant depending upon the desired density of the product being produced, to obtain a wet-pickup of about 70 to percent which treatment yields a product with a chemical add-on of about from 5 to 25 percent by weight of the cellulose component.

. collecting and condensing the treated webs to form a batt of layered, treated webs, and

. curing the batt of layered treated webs under compression less than the ultimate use compression of the finished batt.

in reference to step (b), the preferred quantities of thermoplastic substance-thermosetting polymer-forming substance-flame retardant is 46:46:8.

The figures and disclosures thus far discussed are meant as illustrations of the invention and should not be construed as limiting the invention in any way whatever.

EXAMPLES Ten different formulations were prepared in the process of investigation, were labeled A, 8", and K", and applied to batting material which was prepared especially for the series. Significant factors were selected, and the work was planned with these factors in mind. The organization of the investigations is elaborated on, fully explained in the following paragraph, and tabulated in tables I and ll.

Table 1 comprises two areas of work. The top area presents information pertinent to the formulations, and the bottom area presents information pertinent to the physical properties of the treated and tested batting. For example, if"overall char length" would be compared for Samples A through K, the reader would simply read across the table horizontally. Any other selected physical property which would be significant to this series can likewise be read horizontally. On the other hand, details of specific formulations can be read vertically for each of the formulations A through K.

Table II covers the extension of the work corresponding to the same physical tests except that the testing of the treated batting samples was done on the same samples after said samples were submitted to leaching tests, and after exposure to l00 percent relative humidity for 3 days.

While the tables show the overall picture of the work a more detailed general outline of the work which is the practice of the instant invention is as follows:

THE BATTING MATERIAL:

A mixture of cotton fibers consisting of 60 percent first cut linters and 40 percent of various grades of textile wastes (fly, sweeps, motes, picker) was formed into a picker lap for use with the formulations which are a facet of the examples of this series. Neither the exact proportions of the selected components nor the formation of the fibers into a picker lap were considered critical to the findings. The picker lap was fed to a sample card which was equipped with garnetttype wire, and a web weighing approximately 3 ounces per square yard was produced. Earlier probing experiments have shown that the weight of the web is, within certain limits, not critical to the process. If, however, the web is of too low a weight (per square yard) the chemical ingredients may strike through and cause processing problems, while on the other hand, if the web is of too great a weight, there is a potential hazard in that improper and/or nonuniform penetration is obtained. Having observed this phenomenon in the probing experiments the work was planned within the predetermined reasonable limits.

TABLE IL-FLAME RETARDANCY AFTER LEACHING AND EXPOSURE TO 100% R.H.

Sample Number Control A B C D E F G H J K 1 2 3 Leeched with ambient temperature water:

After flame (second) 0. 0. 0 0. O 0. 0 2.0 0. 0 O. 0 0. O 6. 0 0. 0 3. 1 4. 7 B.E.L. After glow (second) 0. 0 6. 0 0. 0 4. 0 5.0 l. 0 6. 0 0. 0 5. 0 0. 0 17. 4 2. 5 B|E.L. Overall char length (cm.) 6. 2 4. 2 2. 0 6. 0 4. 5 3. 0 8. 7 5. 8 9. 0 4. 0 10. 3 11. 1 B.E.L. Main char length (0111.) 3. 5 2. 0 l. 2 2. 5 3. 0 1. 3 6. 0 3. 3 3. 0 l. 6 7. 0 8. 6 B.E.L. 100% r.h. for three (3) days at 100 F.:

After flame (second) 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 8. 5 0. 0 0. 0 8. 5 B.E.L, After glow (second). 0 1. 0 1. 0 2. 0 3. 0 0. 0 0. 0 0. 0 6. 0 0. 0 l3. 3 46. O B.E.L. Overall char length ((2 .0 3. 5 1. 6 5. 1 2. 7 2. 8 5. 3 3. 3 8. 8 4. 8 7. 7 7. 8 B.E.L Main char length (ern.) 5 2. 2 0.6 1.8 1.3 1.8 3. 8 O. 5 2. 5 1. 6 3. 9 3. 2 B.E.L" B.E.L.= Burned entire length.

. Lm I S .4

THE CHEMICAL APPLICATION:

Each of the formulations of the series of examples was designed so as to include a thermoplastic and/or a thermosetting resin, a flame-retarding chemical compound, a catalyst, and a chemical buffering compound. For instance, in example A, a percent solids spray solutionmade up of a percent urea formaldehyde condensate, percent vinyl acetate, and 25 percent of a urea phosphateto which had been added 2.75 percent magnesium chloride hexahydrate (based on the weight of the urea formaldehyde condensate, and sufficient to catalyze the cross-linking of the urea fonnaldehyde with the cellulose of the fibers) was applied by spraying in such a manner and at such a rate that the in-process web was increased in weight to twice its original weight, a 100 percent wet-add-on thus being achieved.

The spray-damp web was collected on a reel until the desired number of webs needed to achieve the selected thickness and density of the finished product were obtained. A reel was used for this series, but other equipment has been used to perform this facet of the operation. The web can be lapped on a continuous basis to a preselected number of thicknesses ifso desired.

The spray-damp web was removed from the reel and fed to a continuous pilot plant dryer at the rate of 4 feet per minute. The pilot plant dryer employed was compartmentcd into 14 equal sections, with overhead dryer vent, through which the drying air can be pumped. In this dryer, which was designed for the drying and curing of chemically treated batting, the first 8 sections were maintained at a temperature of about from 200 to 2l0 F. with the drying air circulating through the in-process product at a static head of 0.25 inches of water. Drying was achieved in 2 to 4 minutes under these conditions.

The latter six sections of the dryer were maintained at 325 F. to accomplish the curing of the dried product by the circulation of air at a static head of 0.20 inches of water, with the travel rate maintained at 4 feet per minute. The curing of the dried product under these conditions was accomplished within l minutes oftime.

THE PRODUCT:

After drying and curing the samples were stored under ambient conditions to equilibrate for 5 days before any testing was attempted. Sample A was calculated to be l6.6 percent chemical add-on by weight, of which 25 percent was flame retardant. This product was conditioned the same as the products of the other examples, that is the treated batt was kept for 24 hours in an atmosphere of 70 F. (12) and percent (:2 percent) relative humidity before any testing was undertaken. Under these conditions the sample used to illustrate the technique of the work, Sample A, was found to have a recovery from cyclic compressive loading of 80.7 percent in 4 minutes when tested at 60 percent relative humidity; and 68.7 percent when tested at 100 percent relative humidity. Under a LG pound per square inch load Sample A had a 64.9 percent compression.

THE FLAME TESTS:

All batting samples were submitted to the flame test offlcially known as Fire Resistance of Textile Fabrics, Standard Test Method AATCC 34-1966. Sample A showed an after flame time of 0.0 seconds, an after glow time of 3.2 seconds,

an overall char length of 8.5 cm., and a main char length of 6.5 cm. with the difference between the overall char length and the main char length giving an index of the propensity of the product to flash. The sample was tested after exposure to I00 percent relative humidity for 72 hours and showed an after flame time of 0.0 seconds, an after glow time of 0.0 seconds, an overall char length of3.0 cm., and a main char length of 1.5 cm. Sample A, the same as the others, was then subjected to a procedure wherein the sample of batting was soaked in water at room temperature by incrementally adding water until no more absorption of water took place, then the sample was dried at l58 F. and retested for flame retardancy. Under these conditions the sample had an after flame time of 0.0 seconds, an after glow time of 0.0 seconds, an overall char length of 6.2 cm., and a main char length of 3.5 cm.

Note: The Flame Test Method employed in testing the treated and control batts was designed for the testing of fabrics; therefore, certain adjustments of necessity had to be made. The batt sample was cut so as tojust fit in place by friction within the vertical edges of the sample holder in order to prevent distortion of the shape of the specimen. In the adaptation the place of measurement of the scorched sample is different from that of a scorched sample of fabric.

In addition to the examples of batting, each of which were treated with the ten varying formulations and labeled "A" through K, three other vertical columns appear in the tables. For comparison, three control samples are listed. One of these is simply a Control" batt of conventional cotton batting (Control 3). The other two vertical columns are respectively typical samples of chemically treated cotton batting made under the process disclosed by U.S. Pat. Nos. 3,l8l,225 and 3,350,486, differing in the thermoplastic resin used in the treating formulation, and in that no flame retardant is included in the formulations.

Under all the test conditions for flame retardancy conventional cotton batting burned its entire length. Likewise under all of the test conditions for flame retardancy two control samples that had been treated with similar formulations except that no flame retardant was included showed considerably greater propensity to support combustion. For instance, in the case of control number 2 an after flame time of 3.3 seconds, an after glow time of 20.8 seconds, an overall char length of I l.7 cm., and a main char length of 7.5 cm. were obtained on the conditioned sample. After the mild leaching with water, the control number 2 sample had an after flame time of 4.7 seconds, an after glow time of 2.5 seconds, an overall char length of ll.l cm., and a main char length of 8.5 cm. After being subjected to percent relative humidity for 3 days, a sample of control number 2 showed an after flame time of 8.5 seconds, an after glow time of 46 seconds, an overall char length of 7.8 cm., and a main char length of 3.2 cm.

Referring again to table I, chemical formulations used to produce cotton batting products having varying degrees of flame retardance are shown for samples A through K and for control samples 1 and 2 which used essentially similar formulations with the exception that no flame retardant was included. The formulations shown for samples A and B yielded products that exhibited an acceptable level of flame retardance under all test conditions when produced in pilot plant, scale equipment; however these formulations were found to be impractical for use on commercial scale because when mixed in large quantities for extended periods of hours they either polymerized, coagulated, or precipitated.

Examples D, E, and H (table I) are typical of formulations which contribute enhanced resilience, dimensional stability, and flame retardance, both in pilot plant and on large scale tests.

EXAMPLES ILLUSTRATING SYNERGISM AND COMPATIBILITY A series of formulations was prepared to investigate synergism of nitrogencontaining thermosetting resins with selected flame retardants. By way of example, eleven such formulations are presented to illustrate the findings. Two thermosetting resins were studied: a methylated methylol melamine (MMM) and dimethylol dihydroxyethyleneurea (DMDHEU). Four flame retardants studied were a ureaphosphate (UP), a borated amido polyphosphate (BAP), a

.borated urea formaldehyde (BUF), and dicyandiamide phosphoric acid reaction products. Tables Ill and IV present some of the pertinent data of the investigation which is supplemented, elaborated, and explained in the following paragraphs.

Each of these formulations was sprayed on the webs of cotton and formed into batting by the technique of Examples A through K previously described. In all cases, the wet add-on ing for flame retardancy in the same manner as was used for Samples A through K. Only samples tested after conditioning at 70 F. and 65 percent Rl-lare shown in table [II as the results obtained under other conditions showed the same general trend. Comparing the flame retardance that resulted with urea-phosphate (UP) alone, with that achieved in combination with the melamine resin (MMM) indicates an im provement in retardancy that is more than additive. The thermosetting resins by themselves impart no flame retardancy to cotton batting. Yet Sample M exhibited improved flame retardancy over Sample L. Sample N illustrated that not every nitrogen containing thermosetting resin exhibited this beneficial effect. When the DMDHEU resin was added to the ureaphosphate flame retardant, the degree of flame retardance actually decreased when compared to Sample L.

Samples and P are used to illustrate the improvement in flame retardance when DMDHEU resin was combined with vborated amido polyphosphate (BAP). The afterglow was reduced from l2 seconds to zero seconds when the DMDHEU was present.

Samples Q and R showed that DMDHEU when combined with borated urea-formaldehyde (BUF) gave a degree of flame retardancy unattainable with the flame retardant alone.

In every case these samples were used as examples which are representative of many formulations of that general type which have demonstrated the benefit of including selected nitrogenous resins with the flame retardant.

.. Bessie?! table IV ai en tr ts the need for ar TABLE III Sample Number L M N O P Q R Flame retardant UP UP UP BAP BAP B UF B UF Percent 10 10 10 12 12 7. 7, 0

Thermosetting resin MMM DMDHEU DMDHEU DMDHEU Percent 6 6 3 5 Catalyst MgCh Z1101: ZIlCIz ZnOlz Percent (based on wt. of resin) 5 After flame (secondsY 0 0 2 0 0 0 0 After low (seconds)" 0 0 2 12 0 0 0 Overa 1 char (cm.)*- 8 5 F 10 6 6 Main char (om.)* 3 1 8 2 2 3 2 N OTE;

F=Flashed to top of sample. {Iestedafteggonditioning at 70 F. and RH for 24 hours. A

- TABLE IV Sample Number Flame retardant BAP BAP UP UP Percent 5. 0 5. 0 2. 0 2. 0

Thermosetting resin DMDHEU MMM MMM DMDHEU Percent 7. 5 7. 5 9.0 9. 0

Latex Polyvinyl Polyvinyl Vinyl Vinyl chlorid chloride acrylate acrylate Percent 7. 5 7. 5 9. 9.0

Catalyst ZnClz MgClz MgClg ZnCh Percent 6 6 8 After flame (second)" 0 0 0 1 After 10W (second)" 0 0 0 3 Overs. 1 char (cm.) 6 2 6 12 Main char (cm.)" 1 1 2 3 NOTE Based on the Welglilt of resin. "Tested after con tioning at 100 F. 190% RH for 72 hours.

of these formulations onto the cotton was about 100 percent. The drying and curing was carried out as in Examples A through K.

Table III demonstrates results obtained with selected combinations of thermosetting resins and flame retardants. Sample L contained 10% UP and no thermosetting resin. Samples M and N also containing 10% UP and 6% MMM and DMDHEU respectively. The degree of flame retardancy achieved can be determined by reading down each column. The products were c nditionedusnsier fourcen ironmental conditions before test:

ful selection of ingredients in a flame retardant formulation to achieve the synergistic results desired in a flame retardant product. Samples S and T contained DMDHEU and MMM as the thermosetting resin, respectively, and BAP as the flame retardant. The flame test was performed after conditioning the samples at F. and 100 percent RH for 72 hours. Samples U and V contain urea-phosphate as the flame retardant. The formulations which contained the melamine resin gave superior results in each case.

Compatibility of the ingredients was often found to be crucial in many instances, All the samples cited above mixed well and sprayed easily. Incompatibility of ingredients of a formulation would compel the use of a two-step treatment and the added expense would make it impractical. The following formulation, given as a typical example, was found to be incompatible after trying several alternative means of mixing and diluting:

Sample W DMDHEU resin 9% polyvinyl chloride latex 9% dicyandiamide-phosphoric acid 2% 5% (based on weight of resin solids) zinc chloride catalyst The following formulations using the dicyandiamidephosphoric acid flame retardant was found to give a stable solution with sufficient pot-life" to allow easy spraying:

This invention comprises batts and the formulations used in the preparation of the specific batts. Each of these batts can be described as being a fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and the batt is flame retardant and is made upon carrying out the following operations in sequence:

a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers;

b. treating the webs with the formulation (selected from one of those herein disclosed);

c. collecting and condensing the treated webs to form a batt of layered, treated webs; and

d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.

The formulations although each different from the other can all be described as being a chemical formulation for use in treating cellulosic fibers during their processing into batting, which in addition to imparting improved dimensional stability coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith. Each of these specific formulations can be found in the tables except example X which is presented in the body of the specification.

We claim:

I. A chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising:

a. about from 6 to 10 percent urea phosphate flame retardant,

b. about from 3 to l percent methylated methylol melamine resin cross-linking agent, and

c. about from to percent based on the weight of the resin magnesium chloride hexahydrate catalyst.

2. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

b. treating the webs with the fomtulation of claim 1;

3. A chemical formulation for use in treated cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising:

a. about from 8 to l2 percent borated amido polyphosphate flame retardant,

b. about from 3 to 10 percent dimethylol dihydroxyethylene-urea resin cross-linking agent, and

c. about from 5 to 10 percent based on the weight of the resin zinc chloride catalyst.

4. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

b. treating the webs with the formulation of claim 3;

5. A chemical formulation for use in treated cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising:

a. about from 5 to 10 percent borated urea formaldehyde,

flame retardant,

b. about from 3 to 10 percent dimethylol dihydroxyethyleneurea resin cross-linking agent, and

c. about from 5 to 10 percent based on weight of resin zinc chloride catalyst.

6. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

b. treating the webs with the formulation of claim 5;

7. A chemical formulation for treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising:

a. about from 2 to 4 percent urea phosphate flame retardant,

b. about from 9 to 10 percent methylated methylol melamine resin cross-linking agent,

c. about from 9 to 10 percent vinyl acrylate latex binder,

and

d. about from 5 to 10 percent based on the weight of the resin magnesium chloride hexahydrate catalyst.

8. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

b. treating the webs with the formulation of claim 7;

9. A chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprismg:

a. about from 3 to 7 percent borated amido polyphosphate flame retardant,

b. about from to 8 percent dimethylol dihydroxyethyleneurea resin cross-linking agent,

c. about from 5 to 8 percent polyvinyl chloride latex binder,

and

d. about from 5 to percent based on the weight of the resin zinc chloride.

10. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

b. treating the webs with the formulation of claim 9;

11. A chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprismg:

a. about from 2 to 5 percent dicyandiamide-phosphoric acid flame retardant,

c. about from 9 to 10 percent vinyl acrylate latex binder,

and

d. about from 5 to 10 percent based on the weight of resin magnesium chloride hexahydrate catalyst.

12. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

b. treating the webs with the formulation of claim 11;

c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt. 13. An aqueous percent total solids chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the total solids of said chemical formulation comprising:

a. about 20.2 percent urea phosphate flame retardant,

b. about 21.7 percent vinyl acrylate latex binder,

c. about 8.6 percent vinyl chloride binder,

d. about 49.5 percent dimethylol dihydroxy ethylene urea resin cross-linking agent, and

e. about 5 percent based on the weight of the resin zinc chloride catalyst.

14. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

b. treating the webs with the formulation of claim 13;

d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt. 15. An aqueous 20 percent total solids chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the total solids of said chemical formulation comprising:

a. about 20 percent urea phosphate flame retardant,

b. about 40 percent vinyl acrylate latex binder,

c. about 40 percent methylated methylol melamine resin cross-linking agent, and

d. about 5 percent based on the weight of the resin magnesium chloride catalyst.

16. A fibrous cellulosic batt with improved dimensional stability, coherence moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

b. treating the webs with the formulation of claim 15;

17. An aqueous 40 percent total solids chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieved compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the total solids of said chemical formulation comprising:

a. about 10.5 percent borated urea formaldehyde flame retardant,

b. about 53.7 percent vinyl chloride binder,

c. about 35.8 percent dimethylol dihydroxy ethylene urea resin cross-linking agent, and

d. about 5 percent based on the weight of the resin zinc chloride catalyst.

18. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence:

a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically 3,629,052 is l6 modified cellulosic fibers; d. curing the batt of layered, treated webs under compresb. treating the webs with the fonnulation of claim 17; sion less than the ultimate use compression of the finished c collecting and condensing the treated webs to form a batt batt.

of layered, treated webs; and a e a a

Claims

2. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 1; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.
3. A chemical formulation for use in treated cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising: a. about from 8 to 12 percent borated amido polyphosphate flame retardant, b. about from 3 to 10 percent dimethylol dihydroxyethylene-urea resin cross-linking agent, and c. about from 5 to 10 percent based on the weight of the resin zinc chloride catalyst.
4. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 3; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.
5. A chemical formulation for use in treated cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising: a. about from 5 to 10 percent borated urea formaldehyde, flame retardant, b. about from 3 to 10 percent dimethylol dihydroxyethyleneurea resin cross-linking agent, and c. about from 5 to 10 percent based on weight of resin zinc chloride catalyst.
6. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 5; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.
7. A chemical formulation for treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising: a. about from 2 to 4 percent urea phosphate flame retardant, b. about from 9 to 10 percent methylated methylol melamine resin cross-linking agent, c. about from 9 to 10 percent vinyl acrylate latex binder, and d. about from 5 to 10 percent based on the weight of the resin magnesium chloride hexahydrate catalyst.
8. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 7; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.
9. A chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising: a. about from 3 to 7 percent borated amido polyphosphate flame retardant, b. about from 5 to 8 percent dimethylol dihydroxyethyleneurea resin cross-linking agent, c. about from 5 to 8 percent polyvinyl chloride latex binder, and d. about from 5 to 10 percent based on the weight of the resin zinc chloride.
10. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 9; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.
11. A chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the chemical formulation comprising: a. about from 2 to 5 percent dicyandiamide-phosphoric acid flame retardant, b. about from 9 to 10 percent methylated methylol melamine resin cross-linking agent, c. about from 9 to 10 percent vinyl acrylate latex binder, and d. about from 5 to 10 percent based on the weight of resin magnesium chloride hexahydrate catalyst.
12. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 11; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.
13. An aqueous 20 percent total solids chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the reSulting flame resistance of the batt product treated therewith, the total solids of said chemical formulation comprising: a. about 20.2 percent urea phosphate flame retardant, b. about 21.7 percent vinyl acrylate latex binder, c. about 8.6 percent vinyl chloride binder, d. about 49.5 percent dimethylol dihydroxy ethylene urea resin cross-linking agent, and e. about 5 percent based on the weight of the resin zinc chloride catalyst.
14. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 13; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.
15. An aqueous 20 percent total solids chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieves compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the total solids of said chemical formulation comprising: a. about 20 percent urea phosphate flame retardant, b. about 40 percent vinyl acrylate latex binder, c. about 40 percent methylated methylol melamine resin cross-linking agent, and d. about 5 percent based on the weight of the resin magnesium chloride catalyst.
16. A fibrous cellulosic batt with improved dimensional stability, coherence moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 15; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.
17. An aqueous 40 percent total solids chemical formulation for use in treating cellulosic fibers during their processing into batting which, in addition to imparting improved dimensional stability, coherence, moldability, and resilience thereto, also achieved compatibility of the ingredients therein correlated with synergistic effects which are manifested in the resulting flame resistance of the batt product treated therewith, the total solids of said chemical formulation comprising: a. about 10.5 percent borated urea formaldehyde flame retardant, b. about 53.7 percent vinyl chloride binder, c. about 35.8 percent dimethylol dihydroxy ethylene urea resin cross-linking agent, and d. about 5 percent based on the weight of the resin zinc chloride catalyst.
18. A fibrous cellulosic batt with improved dimensional stability, coherence, moldability, and resilience, and which is flame retardant and made upon carrying out the following operations in sequence: a. forming webs of opened cellulosic fibers selected from the group consisting of cotton fibers and chemically modified cellulosic fibers; b. treating the webs with the formulation of claim 17; c. collecting and condensing the treated webs to form a batt of layered, treated webs; and d. curing the batt of layered, treated webs under compression less than the ultimate use compression of the finished batt.