DE1446615A1 - Process for the manufacture of paper products - Google Patents

Description

DR. E. WIEGAND · MÖNCHEN 15, August 10, 1960

MÖNCHEN NUSSBAUMSTRASSE 1β _ _Λ

DIPL-ING.W. NIBMANN phone, 55547 * 14466 1

HAMBURG
PATENT LAWYERS

10351/60 ll / Hei

Dr, Expl.

The Ohemstand Corporation Decatur, Alabama (VoSt ₀ Ao)

Process for the manufacture of paper products.

. The invention relates to the manufacture of paper, non-woven products or the like, which are arbitrary made discontinuous fibers comprised at least in part of strongly fibril H. having, from composed of a mixture of polymer naßg'espomaenen fibers sindo The "invention relates in particular to the manufacture of paper products made from strong "Thermoplastic" pibrils made of a mixture from polymerizates wet-spun fibers together

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which are a long-chain synthetic polymer, from which an acrylic fiber can be formed, and a gelulose ester polymer of the fiber-forming type.

In the usual paper production, natural, unmodified cellulose fibers such as Z ₀ Bosolche, which come from wood pulp, and other natural cellulose fibers !! beaten with similar properties in an aqueous medium in order to disperse the fibers therein and bring them to a length and fineness suitable for use in conventional papermaking. These cellulose fibers form during the beating process. Fibrils, or fluff, where fibril formation is manifested by fraying or fraying the surfaces and ends of the fibers to create tiny hooks or fluff that serve to lock the fibers together when they are deposited on the forming screen of a papermaking machine and dried to make a sheet or a ball. The interlocking or locking of these fibrils protruding from the separated fibers gives the paper cohesion and strength large number of fiber branches, or fibrils, obtained during the formation and drying of the sheet or web "

Only recently has it been possible to

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without making solid paper, the $ 100 synthetic contained hydrophobic fibers which, as in the case of ordinary paper made from natural cellulose fibers, are arranged heterogeneouslyo The obstacle to the use of synthetic fibers was based on the fact that synthetic or Artificially formed fibers do not fibrillate satisfactorily when whipped in water previous efforts regarding the use of these synthetic fibers have been directed to paper or non-woven To create structures by bringing about a fiber bond in various ways. One way of bringing about it A fiber bond involves the application of heat and pressure to soften and fuse the fibers together. "The fiber bond can also be achieved by an inorganic salt softening process which involves the use of inorganic chemicals required to swell the fiber surface in connection with heat and / or pressure. A Another method for bringing about a fiber bond in synthetic fibers is the fiber bonding process with organic solvents in which the fibers are swollen or partially dissolved in the solvent. In addition, the fibers can be bonded together through the use of adhesives «Any of these methods however, it has drawbacks and shortcomings in terms of the specific stages of manufacture and properties

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of the bonded products cut to paper from a mixture of natural OtI * IuIoi «fibers and changing characteristics of regenerated cells

luloBtfaetrn or * Oelluloeeeaterfaeern divide · tracks « which have been formed from a mixture of these fibers are mixed with a solvent or varnish or in some Cases treated with both to 'connect the fibers induce · both dice · treatment! as well as others earlier proceedings «which serve to divide the Faeern with one another to connect are costly and difficult to pay for

linlge n * uer · Developments Ader Papierholdingsteohnlk, but have intereeietite aspects the use of eynthetieoh formed fibers in the Distribution of paper products or the like opened} without . resorting to the use of adhesives and expensive Sind procedures · His way of making Waee-laid webs, including paper, made of synthetic fibers without the use of binding chemicals or the like » includes the beating of wet-spun fibers of acrylic polymers, i.e. polymers made from polymerized acrylonitrile or a miso-polymerized mixture of acrylonitrile and bit to 15% by weight of another, so that / ' Polymerizable monomers in aqueous suspension produced and until the fibers have sufficiently formed fibrils.

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wherein danaoh heat is applied to the web by the yaeefrn provided in this way with Pibrillen or Pluaen were formed "from the Aorylpolymerisat, deposited on a screen to, for example, _o a web to form" in order to dry au and a meshing of parsers are In the known procedure for the production of paper products from wet-spun aoryl fibers, if the fibers, which are regarded as incapable of forming pluses, are brought together with wet-spun aoryl fibers and bottomed in aqueous suspension for a long time, the sheets or webs formed are like that Sure enough, that in many cases they cannot be removed from the web or sheet ejection device. Particularly when polymeric ethylene terephthalate fibers, polyamide fibers, oellulose acetate fibers, vinyl chloride fibers or the like are bottomed with wet geapon & exL acrylic fibers, the investigation under the shown a microscope, dad ke on these Pasern A substantial pibril or ileal formation takes place, with the exception of the wet-spun aoryl fibers, which naturally form pibrils or flueeri "2Mtn.tr affects the addition of non-fibril-forming".; Fit wet spun aoryl fibers for the production of water-laid webs, the desired BigeneohAftta dej synthetic Paser paper, since it contains some haoh, including, finally, greatly reduced activity, a "bark reduced" resistance to tearing and bursting or the like. "It eloh

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o During this procedure a "considerable port". step in technology, it is desirable that the strength and resistance to tearing and bursting, shrinkage and elasticity, electrical performance and other physical properties both dry and wet at aus jyn * to improve paper made from synthetic fibers »

It is a purpose of the invention to provide a highly fibrillated fiber which, by wet spinning a Mixture of polymers is formed, which is a long-chain, synthetic polymer from which an aoryl fiber may be formed, and comprise a fiber-forming type olulose ester polymer, Another purpose The invention is to provide paper products or the like. Which have improved and valuable physical properties exhibit. Another purpose is to create a »process for the manufacture of paper products, in which the material cost and the manufacturing cost are much lower, with the reduction in cost and improvements in physical properties new • Jebiett ittr application of synthetic fibers containing Open up paper. Other purposes and advantages of the invention are will be apparent from the detailed description of the invention below. '

it has been found that one has a strong fibrillar

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. forming fiber, solid paper products or the like.

■ ·] ■■ -.

■ · Äfcduroh / that one receives an aoryl- ■ i, ^1. ·· · serving as a basis. · ·

^j .; ■■ nitrltpolyaerilsat ie a long-chain synthetic

^r 'lyaltfiBiit, from which aoryl textile fibers are formed <| c * nn uhd the at least 85 wt The resulting solution is able to form a solution with a concentration of at least 5% by weight in ,-dimethylaoetamide and that the resulting solution is processed into fibers by conventional wet spinning processes. In the wet spinning process, the polymer hollow is dissolved in a suitable solvent, such as eB N ₁ N-dimethylaoetamide, Ν, Ν-dimethylformamide or the like, and the solution is dissolved through small openings in a spinneret. Pressed liquid in which the solvent dissolves, but the polymer is insoluble. The fibers are manufactured under conditions such that they have a predetermined papermaking quality and are generally characterized by a valuable tendency to form glasses or pits when whipped in aqueous suspension. These products those produced by wet-rubbing the fibers, which have been wet-spun from the polymer mixtures described above, in an aqueous medium, after sufficient fibril formation to achieve a satisfactory one

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Paper product, the abraded fibers from the medium settles and danaoh dae product using heat dries to obtain an annealed paper product · Unexpected results and results that could not have been foreseen in the manufacture of paper from fibers,. which were generated from a polymer mixture containing the composition described above, in insight achieved on the fact that gelulose ester fibers ale sol- ' before, both wet-spun and dry-spun, are viewed as essentially non-fibril-forming

The polymer mixtures according to the invention have an average specific viscosity of not less than 0.10 or not more than 0.4-0 as by usual Viscosity measurements for 0.1 g of the polymer mixture in 100 ml of υ, Ν-Dimethylaoetaiiid has been replanted

As stated, "the base polymer is an aoryl fiber-forming one Substance that consists of a long-chain, synthetic polymer, which consists of at least about 85 wt. bonded aorylnitrile units is composed «So is the polymeric base material is an acrylonitrile polymer, the term polyacrylonitrile, including binary and ternary polymers that contain at least about 85 wt. of acrylonitrile bound in the polymer molecule, or a mixture comprising polyacrylonitrile or Copolymers of polymerized acrylonitrile with 2 to

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Includes 50% by weight of another bound monomer, ■ with the mixture having a total content of polymerized Acrylonitrile of at least about 85 Gew.jfi,

For example, the polymer can be a copolymer which contains between 85 to 98% aorylnitrile and between 2 and 15% of another monomer which has the OaCv group and which can be misopolymerized with acrylonitrile. Suitable mono-olefinic monomers are »acrylic, oC-chloroacrylic and methaoryl acids, the acrylates, such as Z ₀ B ₀ methyl methaorylate, ethyl methaorylate. Butyl methaoryate, methoxymethyl methacrylate, / p -Ohioräthy1-methaorylat and the corresponding esters of aoryl and C £ / -Ohloracrylsäuren; Vinyl chloride, vinyl fluoride, vinyl bromide, vinylidene chloride, l-chloro-1-bromoethylene; Methacrylonitrile, acrylamide and methacrylamide; eC-Ohloraorylamid, or d monoalkyl substitution products; Methyl vinyl ketone, vinyl carboxylates such as vinyl acetate, vinyl chloroacetate, vinyl propionate, vinyl stearate; N-vinylimides, such as N-vinylphthalimide and N-vinylsuooinimide, methylenemalonic acid esters, itaconic acid and itaconic acid esters, N-vinyloarbazole, vinylfuran, alkyl vinyl esters, vinyl sulfonic acid; Ethylene <(L> , ρ-dicarboxylic acids or their anhydrides or derivatives, such as diethyl fumarate, diethyl maleate, diethyl citraoonate, diethyl mesaconate, styrene, vinyl naphthalene; vinyl-substituted tertiary heterooyolisohe amines, such as the vinylpyridines and alkyl-substituted vinylpyridines, 2- vinylpyridines, zo-pyridines -Methyl-2-

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vinylpyridine, etc. _A, 1-vinylimidazole and alkyl-substituted · 1-vinylimidazoles such as 2-, 4-, or 5-methyl 1-1-vinylimidazole and other .P = C containing polymerizable materials _o

The polymer may be composed of a ternary copolymer - sat · or interpolymer made, for "B _o products duroh Misohpolymerisation of acrylonitrile and two or more of the monomers listed above, except acrylonitrile, ₀ received particular, the ternary polymer of acrylonitrile, methacrylonitrile, and 2-vinylpyridine include "The ternary polymers preferably contain 85 to 97 $ aorylnitrile, 1 to 10 $ vinylpyridine or a 1-vinylimidazole and other substances such as methacrylonitrile or vinyl chloride"

The base polymer can consist of a mixture of polyacrylonitrile or a binary copolymer with 85 to 89 Grewo $ acrylonitrile and 1-15 ;. $ at least one other 0 = 0. containing substance with 2-50 wt _o $ the mixture consist of a copolymer of acrylonitrile and 10-70 $ 80-90 $ · at least one other .C = C _V containing polymerized monomers sierbaren "If it is in the polymeric base material to form a mixture , it is preferably a special mixture of a copolymer of 90-98% by weight of aorylnitrile and 2-10% of another mono-olefinic monomer, such as vinyl acetate, with a sufficient amount of a copolymer of 10-70% by weight of acrylonitrile and 30% by weight 70 # of a vinyl substituted tertiary heterocyclic

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Amine, such as vinyl pyridine or 1-vinyl imidazole, where sioh results in a solution which has a total content of vinyl-substituted, tertiary, heterocyclic amine of 2 ~ 10? ί, equal to the weight of the mixture. - Modified oleulose ester polymers of polymeric breathing can be any suitable lower cellulose * fatty acid ester »such as cellulose acetate j Oellulose propionate, Oellulose acetate formate, Oellulose acetate butyrate or the like .. The degree of substitution of the cellulose ester can, depending on the particular ester used, and the desired effect fluctuate. For example, in the Pail of cellulose acetate its combined acetic acid content in the range between about 48.5 # up to that which corresponds to the normally obtainable Trieste corresponds to, namely 8156, the preferred value in the range between shit about 52-57? ί acetic acid lies. Me other, lower ones Cellulose fatty acid ester is an approximately equivalent substitution aguad .. suitable. j

In general, the mixtures according to the invention are characterized by the unexpected fact of pibril or plus formation the fibers made from it labeled in water; ι and paper products made from the pibrillated Fibers formed have improved physical properties Properties on

The base acrylic polymer and the modifying cellulose ester polymer are preferably by intimate mixing

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see in the required quantities with a usual Solvent mixed under scrubbing to form a solution of the To obtain mixture, which can be spun through openings in a conventional spinneret, which in a coagulation bathing bath submerged iat. "The physical form

It--

of the aorylsauren * base polymer as well as of the oleulose ester polymer is preferably that of fine, thick grains or a powder modifying cellulose ester a solution in HfIT dimethyl

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aottamide, which can be formed into fibers using the usual wet spinning processes * Di

- Esterpolymerisats in NjN-Dimethylaoetamid forms · However · * Excludes the characteristic solubility of the base polymer in Ν, Η-dimethylaoedamid not the use of others Solvent in which the mixture of the base polymer and the Oelluloeeesterpolymerisats a Lo-

- forms solution which can be made into fibers by making a spinnable solution of it. However, one of the advantages of the blends according to the invention lies in their ability to be wet spinnable. Form solutions in Ν, Ν-dimethylacetamide, a LUsUHg ₁ which is particularly useful in large-scale fiber production. The mixes

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_: can be produced by using solid, polymeric materials

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The materials are mixed in conventional mechanical mixing systems in the presence of the solvent} or they can be mixed dry and then dissolved in the chosen solvent «, The spinning solution, which is the polymer solution of a solvent • solution polymerisats and contains the oleellulose, is pressed through small openings in a spinneret} then the ejected solution is precipitated in a coagulating bath, creating continuous filaments of any desired Diameter, which can later be cut to any desired lengths. examples for suitable coagulant baths for wet spinning polymeric mixtures include mixtures of the spinning solution and water such as mixtures of N, N-dimethylformamide and water and Ν, Ν-dimethylacetamide and water. Other suitable bath compositions can also be used.

It is known that during coagulation in a wet spinning process both an inward diffusion of bath liquid takes place in the coagulating threads, as well as a corresponding outward movement of solvents in the bathroom. Usually the solution and the bath liquid are composed in such a way that that the resulting threads empty spaces or unfilled spaces along their. May contain length. Expressed differently, the threads have a coarse, spongy structure which can be clearly seen with an electron microscope with such a structure are considered non-collapsed

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Fibers Known In order to produce satisfactory textile fibers Conceive, steps are usually taken to make these spaces in the thread coincide or coincide Bringing collapse to a dense, solidified structure to "form, this usually being done by tensioning the threads strongly and keeping them relatively high temperature under considerable pressure or treated by other known methods, after Standard methods performed measurements of the densities of non-collapsed filaments and corresponding collapsed ones Threads show a marked difference between them, the extent to which the fiber not collapsed or collapsed, by these measurements is indicated »Obviously are the Densities of the collapsed fibers greater than the densities of the corresponding non-collapsed fibers » According to the invention it is preferred that the density of the fiber used in papermaking be at least 15% to about $ 65 less than the density of a corresponding one collapsed fiber »

Contrary to previous teachings as to the collapse required for a satisfactory one Making textile fiber is an important feature of the invention based on the discovery that when care is worn so that the wet-spun threads from the

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Polymerization mixture according to the invention essentially not collapsed bind before going into the papermaking process be used, from them an improved paper can be made, and that the threads that have not fallen from the seed can be comfortably and easily attached to the threads Plants and according to the same working methods and within a comparable time as those usually used for paper production used, natural cellulose fiber ™ with fibers or fibrils can be provided. In particular, superior surfaces can be used in papermaking be generated by a water-coagulable solution of a Polymerisatmisohung from a fiber-forming aoryl polymer and an oleulose ester the fiber-forming type spins in certain dimensions in an aqueous precipitation bath under 'regulated conditions, in which the solvent and the bath liquid mix with each other in such a way that threads with a swan-like or non-collapsed structure are produced, and that the threads are cleaned and partially or the water content is completely removed from the threads without noticeably destroying the structure that has not collapsed

IWLe wet spun filaments of the invention made with a view to use in accordance with the invention are preferably subjected to a stretching treatment while in a gel state to

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to achieve a desired weakening and molecular orientation according to different working methods. The stretch is usually at least $ 200 at an elevated temperature. This stretching is preferably done after the residual dope carried by the filaments has been reduced to no less than 2 threads and preferably to no more than 10 threads. During spreading, the fiber can have temperatures in the range of 90 ⁰ O or more 'as long as the pore structure is not destroyed. The filaments may be stretched while passing through a heated liquid, such as water, to pass _e The threads can also be heated while being stretched hot air or hot steam in an atmosphere comprising dry may be saturated or saturated. In addition to the stretching treatment, other treatment and processing stages can be applied to the coagulated threads, such as washing, crimping, cutting or the like. In addition, the water content in the threads can be reduced by partially or completely cleaning them with air, steam or the like, by centrifuging, by using a vacuum or the like. dries without significantly reducing the tendency of the threads to form lint. It is important to note, however, that it is a prerequisite for best practice of the invention that the non-collapsed structure of the fibers not

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is destroyed before it is written on paper or the like. are processed.

After the porous threads have been cleaned and partially or completely dried, they are cut into staple lengths. Fibers can be used which are shorter or longer than the usual staple textile fibers. If short fibers are used it is possible to load the beater quickly. If a longer stack is used, the fibers should slowly introduced v / ground in order to avoid clogging of the percussion device _e deh The ratio between the number of lengths and short fibers or the fiber ratio in terms of the number of thick and thin fibers (. with different 'fitem) is determined by the desired properties of the end product. Therefore, the fibers according to the method according to the invention can have any suitable denier or a mixture of fibers with different deniers can be used. For example, fibers with titers between 0.3 and 20 or more can be used. On the basis of the values obtained, it has been found that the best paj) ier is produced when the polymer mixture is spun under conditions which produce a fiber of high strength.

While the fibers, which are made from the polymer mixture of a fiber-forming acrylic polymer and a cellulose ester Wet spun, as the only fibrous material that can be used to make strong, sheet-like materials manufacture, it can be seen that such fibers with others

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Pasers can be combined, the fibrils or fluff. can form, including synthetic, artificial and natural fibers to make satisfactory sheet-like materials. For example, the fibers according to the method according to the invention with natural cellulose fiber, over a wide range of proportions compatible and paper with improved physical properties can be obtained therefrom,

According to the invention, at least the amount of fiber used here, as it is necessary to create a desired paper product, is whipped or whipped in the presence of water in the form of an aqueous suspension, whereby the fibers form fibrils or lint are dispersed as they are commonly used in papermaking, are satisfactory "Obviously depends the time during which the fibers are subjected to beating, expressed uavon of particular used percussion device from _o in general, the fibers should v sufficiently beaten / he to she so up to form fibrils or fluff to such an extent that the fibrils produced serve to subsequently interlock in the papermaking process to produce a satisfactory paper product nd in a shorter period of time at ^ egebe-

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ner severity of the striking process than the collapsed Paser of the same composition or ordinary, wet-spun aoryl fibers. So can the paser who has not collapsed, which was wet-spun from the polymer mixture according to the invention, a comparatively less strict one Subject to the whipping process and still form enough fibrils. Avoidance of a severe whipping process is desirable in some cases because a sharp chop creates fibers of undesirably short lengths. Furthermore, given the severity of the strike, under conditions under which collapsed, wet-spun Acrylic fibers of the common textile type shredded or broken into undesirably short lengths and broom-like Ends, and very short lint along the length of the fiber, would have the non-collapsed fibers coming out the polymer mixture according to the invention were wet-spun, advantageously comminuted with less beating, so that longer fibrils are created along the length of the fiber, resulting in a more tensile interlocking of the fibers contribute to the end product.

While excessive sudsing is usually not contemplated during whipping, if desired, can Antifoam agents, such as octyl alcohol or the like., Can be added to the aqueous whipping medium. The fiber suspension can by known suspending agents, such as fresh

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deaoetylated karaya ruby, cut more uniformly will. When such an agent is used appropriately the fibers do not settle or flocculate excessively, making a desired one Sheet formation facilitated. Although not required, the fibers can use the better whipping method or water-laid webs of the fibers provided with lint or fibrils are determined in their G-feet Although the additional cost is uncertain in some cases, it is within the scope of the invention to provide a resinous one To apply cloth or a substantially resinous material to the fibers or the webs formed from the fibers.

The beaten, fibrillated fibers, wet spun from the polymerizate composition according to the invention, are then passed through any suitable one Process transformed into a paper product. For example, such a product can be achieved through the use of conventional Paper machine systems of various types to a self-supporting, continuous sheet to be formed. The self-supporting sheet of paper is then put through a drying process guided. The troubling of the paper can then be carried out be that the paper is continuously fed in a known manner over heated drums. A moving one The web of paper can also be fed through a battery of drying lamps. Others can also Hot rubs are used to dry the product,

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\ The drying temperature may be in the same range and is usually in the same range, which is generally used for drying natural, cellulosefaserhaltigem paper and is to a considerable extent, ■ determined by the properties that are desired for the final paper product. The paper products according to the invention can be dried at room temperature and up to a temperature at which the fiber largely decomposes or melts. The drying temperature influences the properties of the paper product. In this regard, it has been found that the physical properties of tensile, tear and burst strength are usually directly related to drying temperature. That is, if a higher drying temperature is used, improvements in these properties can be expected. For example, the properties of ^{handsheets dried at 21 0} O (70 ⁰ P) are usually worse than those of a second, identical handsheet that has been ^{dried at 93 0} O (200 ⁰ P) and which in turn is generally worse than a third, identical handsheet which was dried at 204 ° 0 (400 ⁰ P).

The term "paper products ^{1. 1} are products. Understood that comprise a plurality of discontinuous fibers ^ Fa of suitable papermaking length which are interconnected so 'that it comprises a coherences

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forming the product that is pliable or stiff, thick or can be thin, soft, or hard; these paper products include webs, sheets, paperboards, filters and molded Paper objects of all kinds a »

The invention is explained in more detail below with the aid of a few examples. All parts and percentages are unless otherwise stated, on a weight basis

example 1

A Valley laboratory whipping device (Holländer) for about 700 g was charged with 150 g of oriented acrylic fibers in 20 l of water (consistency $ 0.75) 6.35 mm (1/4 ") was cut and, after wet spinning, was made from a mixed polymer mass of 9416 $ acrylonitrile and 6.4 $ vinyl acetate. The fibers had a low air pore volume, as was evident by microscopic examination The density of the fiber was 1.17 g per cm and the fibers had the commercial textile quality of acrylic fibers _{or the like}

The strength of the impact process of the Valley impact device is determined by the bed plate load or the counterweight regulates, which presses the bed plate against the rotating beater bars. During the work process The paserci will fish for the striking device

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Bohlag rods and the bed plate move through the circulation stretched therein. The 150 g sample of the fibers was tested in the Valley beater using . Counterweights of 5.44 kg (12 Ib) handled «samples that SU hand sheets to be processed were all Taken for 10 minutes. The handsheets, which weighed approximately 2.5 grams, were obtained using a laboratory handsheets machine IToble and Wood manufactured and dried. The machine

includes an 8 inch mold, pressure rollers and felt, and a steam heated drying drum with felt. The hand sheets were supported by a wire dried by being guided around at about 93 O ⁹ (198 ° F) a! Drying drum. The physical property values of these handsheets with an average thickness of 0.02 cm (0.008 inch) bind are given in the table below. The handsheets were weighed on a weight basis. The physical strengths of the handsheets were measured on an Elmendorf tear tester, a Mullen burst strength tester, and a Seott Model DH tensile tester according to TJÜPPI standard methods. All values were based on a hand sheet of 203x203 mm (8x8 inches | 44 lbs per ream, 25x40-500)

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train
δ Tabel 1 tensile strenght
engle pound / inch Floor time
Min. 4th
■ 8 Burst
pi _ "_ ♦
; ♦ 30th
50 *
1
0.8

Values too low to measure

Example 2

99 ropes of a polymer made by polymerizing $ 94.6 acrylonitrile and $ 5.4 vinyl acetate (base polymer) were mixed with 1 part of cellulose acetate (modifying polymer) with a bound acetic acid content of $ 52 G-Rundmischpolymerieat and des. Modifying Oellulosepolymerisats in each powder 'form in Ν, Ν-Dimethylaoetamid to produce an 18 $ strength spinning solution containing water at a temperature of 32 ° 0 mm, a bundle of fibers to form ,, the bundle was removed from the bath and there was a stretch of 400 $ · in boiling water containing a small amount of dimethylacetamide, issued it. Then the threads were partially dried.

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net by passing them around an array of drying drums - "After the filaments were moisture content lowered to about $ 10, they were stripped from the drums and cut into 1/4 inch lengths." Examination of the cut fibers under an electron microscope shows that the fibers were porous and had a spongy structure. In other words, the fibers had what is known as a non-collapsed structure _- these non-collapsed fibers

3 had an average density of only 0.75 g per cm

A Valley Laboratory Bottom Device for about A sample of 150 g of the non-collapsed fibers in 20 l of water was charged to 700 g. The fibers had a titer of approximately 3 den, per thread «The sample was placed in the beater using a counterweight beaten by 5 "44 kg (12" pounds) "samples of the handsheets were taken at intervals as given in Table 2 below and handsheets were prepared as described in Example 1. The properties, which are also given in the table, were measured as described in Example 1,

Table 2

Impact Time Tensile Burst Tensile Strength Min. G psi. englo pound / inch

40 8 1.1 0.3

50 8 0.8 1.0

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Example 3

Different parts of a polymer made from 94.6 $ acrylonitrile and 5.4 $ vinyl acetate (base polymer) were mixed with different parts of cellulose acetate (modifying polymer) having a bound acetic acid content of 52 $, the parts being shown in Table 3 below The resulting polymer mixtures were separately dissolved in Ν, Ν-dimethylacetamide to form an equal number of spinning solutions, each containing approximately 18 $ solids with a non-collapsed structure and an average density of 0.75 g per cm,

The fibers sucked from these solutions were separated treated in the Valley impact device, again with a counterweight of 5.44 kg (12 pounds) was used. Samples were taken every 10 minutes using the sheets according to that described in Example 1 above Hand sheet methods were produced, The physical Properties of the Iland leaves are in the following Table 3 and were, as indicated in Example 1, measured «

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20th
30th 28
15th 3 Burst
psi. tensile strenght
English pound / Zο11 40 9 1.7
: 2.1 1.8
1.6 Tabel 10 47 1.5 1.6 Misohungszueammensetzge Sohlagzeit .Zug
I. / Loryl / oil-cellulose ester Min. G 30th 61 4.0 1.3 95 - 5
.95-5 30th 58 4.7 2.8 95-5 40 28 • 4.6 3.5 90-10 50 20th 4.0 3.6 90-10 10 102 3.7 3.0 90-10 20th 129 12.2 3.3 90-10 30th 95 13.0 5.0 90-10 40 56 11.9 6.1 88-12 50 26th 9.9 6.1 88 - 12 10 124 7.4 5.5 88 - 12 20th 142 13.7 5.0 88 - 12 30th 92 14.2 6.4 88 - 12 40 45 13.2 7.2 85-15 50 27 10.0 6.5 85-15 20th 35 8.5 6.4 85-15 30th 28 2.9 1.4 85-15 40 15th 2.9 2.6 85-15 50 9 2.6 2.8 75-25 2.2 2.6 75 - 25 75 '- 25 75 - 25

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The beaten fibers were examined under a microscope and compared with the beaten fibers according to Example 1 and 2 were produced, compared · In the. same Adjustment of the impact device and the equal ground time the fibers of the present examples had stronger Fibrils or iluses formed, i.e. the number of fibrils

len protruding from the fafer body was taller. Also was the number of fibrils that sioh from the body of the fiber according to the present example had separated, substantially less «Dae showed that the fibrils of the Fibers - which had been beaten according to the example, were bower and adhered more firmly to the fiber body

Example 4

Ea became palm leaves made of collapsed fibers, which had formed fibrils and had been wet-spun from a solution of polymeric respiration obtained from .9OjS of a copolymer of 94.6 $ acrylonitrile and 5.4 $ Vinyl acetate, and lOji cellulose acetate with a bound Acetic acid content was composed of 5296. The spinning conditions were similar to that. used in Example 2, except that the hair-spun threads are completely were dried while they were being wrapped around the trouser drum were led around to collapse the resulting thread structure. The properties of the handsheets are given in Table 4 below and were measured as described above ,, '...'. ·

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train
G Table 4 tensile strenght
'English pound / inch aohlagzeit
Min. 29 Burst
psi. 1.0 20th 21 2.2 1.4 30th 18th 1.7 1.8 40 12th 2.0 2.2 50 1.8

Duroh comparison of the values in Example 3, which are for a similar ($ 90 aoryl polymer - $ 10 cellulose acetate), however, non-collapsed fibers are given, with the values for the collapsed fiber in this example it can be seen that the non-collapsed fibers are used to make better paper can. .

example 5

There were leaflets made from non-collapsed Pasers with fibrillation resulting from a solution of a Polymerisatmisohung were wet spun, which from 38 $ a Copolymer of 94.6 $ acrylonitrile and 5/4 $ vinyl acetate and composed of 12 $ cellulose acetate with a bound cellulose content of 60.4 $ (cellulose triacetate) was. The spinning conditions were similar to those used in Example 2, with the resulting yarns being one did not have a collapsed structure. The properties of the handsheets made from these pasers are shown below in

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Table 5 and were as described above, measured.

train
G Table 5 tensile strenght
englo pound / inch Floor time
Min. 12th Burst
psio : .1,2 20th 7th 1.4 1.5 30th 1.3 Example 6

Hand sheets were made from non-collapsed fibers that had formed fibrils and from a solution of a polymer mixture had been wet-spun from $ 38 of a copolymer of $ 94.65 Acrylonitrile and 5 »4 $ vinyl acetate and from 12 $ technical available Oellulose Propionate was composed. The spinning conditions were similar to those used in Example 2, the resulting fibers exhibiting a non-collapsed structure. The fibers were in the Valley shifter handled with a counterweight of about 1.4 kg (3 Ib) was used .. The properties of the handsheets., from these fibers are given below in Ta ~ belle 6 and were as described above

^measured table 6

Burst tensile strength psi. English pound / inch

4.7 1.3

4.1 2 ₉ 2

5.0 2.7

4.6 2.6

4.9 3.5

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SQhlagzeit train Min » -G 30th 34 45 71 50 63 75 49 105 45

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Example 7

This example illustrates an attempt to make a paper handsheet made from wet-spun gelulosic fibers, as well a hand sheet made from a mixture of wet-spun acrylic * fibers and wet-spun cellulose acetate fibers.

Cellulose acetate with a bound acetic acid content of 52j <was dissolved in Ν, Η-dimethylacetamidiR in an amount sufficient to give a spinning solution with 15 # solids EU temperature was maintained from 50 ⁰ O, "to form a filament bundle the bundle was gewasohen with water and it was granted -ihm a Nachstreckung of 17O? 4 the filaments were partially dried by being guided around a dryer apparatus · Once the The threads were dried to the point that they were only slightly damp, they were stripped from the drums and sunk into lengths of about 1/2 cm (1/4 inch) ". The fibers had a non-collapsed structure, a tenacity of 1.3 g / denier and an elongation · of 5 # · A sample of 150 g of these wet-spun cellulose acetate fibers in 20 liters of water was charged to the Valley beater mentioned above

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a liter of approximately 3 den »The sample was in the Impact device struck using a counterweight of 5 "44 kg (12 englo pounds)", samples were taken taken from the hand sheets at suitable time intervals, whereby the sheets according to the hand sheet production process, described in Example t above. The physical properties of the leaflets, including ice, burst and tensile strength were too low for measurement purposes

85% of the wet-spun acrylic fibers prepared according to Example 1 except that the fibers were dried during formation as in Example 2 so that they had a non-collapsed structure, were mixed with 15 parts of wet-spun cellulose acetate fibers prepared according to this example were prepared "the Valley beater was mixed with a sample of 150 of fiber blend formed g in 2G 1 water charged the fiobe would hit in the impact device, wherein a counter-weight of 5.44 kg of _o was (12 Englo pounds) used were Hand sheet samples taken at appropriate time intervals, the hand sheets being prepared according to the hand sheet production process as described above "The physical properties of the hands sheets, including bite, burst and tensile strength, were too low for measurement purposes"

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Bs iat apparent that although the above examples have described in detail some specific features of the invention, they are given primarily for purposes of illustration and that the invention nioht limited to _e Although the invention in the specific examples in conjunction with the manufacture illustrated by hand-formed sheets, it is also applicable to the continuous production of paper webs of unlimited length. Thus the fibers _β · are continuously opened and the resulting beaten fibers ζ, Β "are processed into webs on a Fourdinier Masahine." In such a pail the leaf can be dried by passing it over drying cans is taken up in roll form _o If the basic polymer mixture from other acrylonitrile polymers and the modifying öelluloseesterpolymere from other Celluloseestern, are prepared as described above in the manufacture of paper products, similar remarkable improvements can be obtained regarding the physical properties of the paper.

It can therefore be seen that an important feature of the invention is based on the plague position that pasern, the spinning process from special polymer mixtures and can form pibrils to a greater extent than ordinary wet-spun ones Acrylic fibers «, in addition, is such a

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improved fibril formation is even more meaningful when the fibers according to the invention are made under conditions causing a porous or non-collapsed structure. The number of fibrils per fiber is enlarged and the possibility etoo · separation of the. Fluff from the paser is reduced Lower costs for the resulting fibers.

The fibers according to thee invention are particularly suitable ₀ As indicated in the production of PapiernacH din wet or Wasserlegverfahren by the sheet or sheet formation of the open, highly fibrillated fibers from an aqueous medium on any conventional paper machine above, this web or sheet formation may be at a Fourdinier machine are brought about. Optionally, the fibers can be water-laid on a porous frame such as that used in the manufacture of handsheets. The water can be separated from the fiber by any suitable means while the fibers are being converted into the desired shape. The sheets or webs made in any of the ways outlined above can be either a few thousandths of an inch or several inches thick. "Shaped articles can of course be made by other, similar methods "

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Bie mowing paper products, which have a significant degree of flexibility and a relatively weiohen handle _r • can be produced; other products can be relatively stiff and tough. The products have a high resistance to bursting and tearing, both when wet and when dry. * An important feature of paper products is their inherent ability to withstand exposure to various chemicals Strength and are porous Filters made from the paper have improved filtering efficiency and therefore can be used successfully in the manufacture of filters for cigarettes, for chemicals that do not attack the fibers under the conditions used, and filters for other purposes. While excellent paper products can be made without the use of binders, adhesives, resins, potential resin materials, or the like, it is understood that such agents can also be used in the process of the invention if desired.

The fibrillated fibers produced according to the invention are particularly useful for mixing with ordinary cellulose pulp made from wood, cotton seed waste _{or the like.} For example, a paper made from a mixture of only $ 10 fiber and the remainder of natural, unmodified cellulose fiber has markedly superior dimensional stability,

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better aging properties, etc. _e than paper dae from IOO96 consists of cellulose fiber ^. With regard to this. The fibers according to the invention can be used with improved properties as "a single type of fiber or in combination with other fibers for selected final production purposes for paper, ζ.E. note paper, sandpaper, punched card paper, card card paper, paper for photographic purposes, material for maps and plans, Impregnation paper, filters or the like «are used.

The invention enables the manufacture of a fiber that is feltable and extremely suitable for use in Papermaking is. The brilliant fiber realized according to the invention is desirable insofar as stronger and stronger than the dardota manufactured paper products are better suited to absorbing energy without bursting. In addition, the strength that sioh from the tenacious adhesion of the lint to the fiber body results in a higher resistance to breakage when bending at. The fibrillated. laser is particularly characterized by that they are wet from mixtures of certain polymers * = was spun and has a porous, spongy structure, the fluff being tough, flexible and unbreakable on the Adhere fiber surfaces and fiber ends.

BATH ORIQINAL

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Claims (1)

Patent claims A process for the manufacture of paper products, daduroh in that wet-spun fibers prepared from a solution fo comprises a blend of a base polymer from an acrylic textile fiber can be formed and at least 85 percent of a long chain synthetic polymers. Bound acrylonitrile, and öelluloseesters includes modifying polymer of a lower fatty acid to the fiber-forming type, which mixture can form a solution of a concentration of at least 5 wt. fo in ϋΓ, ϊί-dimethylacetamide,! whipping the fibers in an aqueous slurry to fibrillate them, converting the whipped fibers into webs or sheets of predetermined shape and thickness, and drying the resulting sheet or sheet material to produce a strong, coherent paper product. 2.) A process according to claim 1, characterized in that the base polymer is to blend of a copolymer containing at least 85 wt. $> bound acrylonitrile and up to 15 wt. fo con- tains another so interpolymerized monoolefinic monomers'. 3.) The method according to claim 2, characterized gekennzeiohnet, that the other monoolefinic monomer from vinyl 909818/0244 1U6615 acetate. 4.) Method naoh one of claims 1 to 3, characterized in that the cellulose ester consists of cellulose acetate, the content of bound acetic acid in the range of 48.5 to 57 wt. Fo acetic acid. ' 5.) The method according to any one of claims 1 to 4, characterized in that a solution of the mixture _{% is} spun out in an aqueous coagulating bath for the production of threads, the threads cut into fibers of short length, the fibers beats in an aqueous sludge To form pibrils, and then further processed. 6.) Method according to one of claims 1 to 5, the
characterized in that many solvent a mixture of 95 to 75 wt. fi of Grundpolymerisats and 5 to 25 wt. f dee modifying polymer of Celluloseester into an aqueous coagulating bath spins out, which contains a proportion of the solvent to produce filaments under such conditions that the solvent and bath liquid exchange to impart a non-collapsed structure to the filaments, stretch and clean the filaments, lower the water content of the filaments without appreciably destroying their non-collapsed structure, and then cut them into fibers of short length and then processes them further. 9 0 9 818/0 2 kk 1U6615 - 7) method according to one of claims 1 to 6, daduroh marked that the solvent from N, N-Dimtthy! acetamid beeteht. 8.) The method according to claim 6 or 7, characterized daduroh that the threads are passed through a second aqueous bath after they have been removed from the coagulating bath, which maintained at a temperature in the range of 90 to 250 ° 0 is stretched, partially dried, and at least 200 # during its passage through the second bath cuts to papermaker's lengths and processes the fibers further. 909818/0244