DE1444166A1 - Process for impregnating nonwovens - Google Patents

Description

Patent attorneys DR.-ING. WALTER ABITZ

DR. DIETER MORF i /// iec

Monks 1444166

10 July 1963 PPD-732

B. I. DU POHT DE NETiOURS AND COMPANY 10th. and Harket Streets, Wilmington 98, Delaware, Y.St.A.

Process for impregnating nonwovens

The invention relates to a method for impregnating nonwovens made of shrinkable fibers.

Bs is known to produce synthetic shoe upper leather by a non-woven web of heat-shrinkable fibers, e.g. aue Polyäthylenteropkthalatfibres, processed in the needle loom, the needled fleece shrinks, it is then impregnated and Finally, a microporous surface covering is provided.

In the production of γοη Sciiiüien auo such substances occurs however, when stretching on ledges, the difficulty arises from that in those places where there is a certain tension over the

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perform require, a.B. la toe and in upper part of the thrust, a roughness develops · this roughening becomes deo tenant Bugesehrieben, which at »Threading the Unwoven Fleece Gate from impregnation

Zveok of the invention is a process for the production of Make artificial »suede suede at the disposal, with which» a non-woven tea. Fleece, which before the impregnation and Coating has a! Tester on its surface, is impregnated and coated, the pattern being covered by the impregnating agent and the surface covering and in stretching the impregnated and coated nonwoven, such as it in the shoe production when stretching on lasts in the Toes and tops are made, it is not »more visible»

This is achieved according to the invention by adding a wäraeeohrunpfbaren, non-woven fleece, which is placed on its surface has a pattern, it is impregnated with an aqueous dispersion of a polymeric material, the dispersion in place coagulated, the impregnated fleece is subjected to heat shrinkage before the impregnation agent has dried, and the impregnation agent then dries. According to a special embodiment of the invention, the nonwoven impregnated in this way becomes no-nonsense provided a surface covering, whereby it is achieved that the pattern on the surface of the non-woven fleece is not very

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noticeably let »when the coated material is stretched, e.g. when stretching it on a skirting board.

The degree of roughening or the absence of any tinting in the toe parts and the upper parts of the soles made from the impregnated and coated ear-pinned nonwoven webs which have been patterned on their surface prior to impregnation and coating, depends on the amount of the Impregnating agent that has been absorbed by the fleece before shrinking. The amount of impregnation agent as well as the temperature and also the method of thermal cladding influence the degree of shrinkage. The larger the amount of the non-volatile constituents of the impregnating agent that is introduced into the nonwoven fabric, the lower the degree of heat shrinkage of the nonwoven fabric. The amount of non-volatile impregnant ingredients introduced into the web depends primarily on the concentration of the solids (the non-volatile ingredients) in the dispersion. Is the maximum Fläclienschrumpfung of a web which is capable of a su Släohenschrumpfung $ 90 is reduced to approximately 60 i ", separating the web with an aqueous dispersion saturated, whose amounts Konsentration nonvolatile Beetendteilen about 50 1>. Nonwoven nonwovens which are impregnated with dispersions of lower concentrations of pesticides suffer, if the same type of heat-

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shrinkable nonwovens, a greater area shrinkage.

The amount of impregnant that is incorporated into the web depends largely on the end use of the product. For artificial shoe upper, the preferred amount of dry impregnant, based on the weight of the fibers, is about 100-400%; a particularly preferred range is about $ 200 to $ 300. If the amount of dry impregnating agent in the fleece is less than about 100% based on the weight of the fibers, roughening takes place when the impregnated and coated fleece experiences about 35 days of ripening in the width and / or length direction is subjected. The upper limit on the amount of dry impregnant is controlled by the non-volatile concentration of the impregnant. Concentrations higher than those required to load the fleece with about $ 400> of dry impregnating agent, based on the weight of the fibers, no longer lead to uniform impregnation *

The impregnation of heat-shrinkable, non-woven fleece with Aqueous dispersions of heat shrinkage offer other advantages besides the reduction in roughening, which can be found in the Noticeable aaoht when the impregnated and coated fleeces are stretched out, e.g. when putting the shoes on.

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As a result of the rapid absorption through the less dense fleece the impregnation with aqueous dispersions takes place before the Wlraesehruapfung more even and faster * Due to the more open structure of the fleece, it is also possible through. Xapregnate a higher ratio of Iapregnant to fiber before shrinkage. reach.

Until the end of the use of aqueous dispersions as impregnating agents * In addition to the use of solutions of polymers in organic solvents, there is the further advantage that the aan A with much higher solids concentrations of the aqueous dispersions work at lower viscosities and on this basis a thorough and even impregnation of the fleece can be achieved. No earthening occurs with aqueous dispersions Try solvent recovery or toxicity, the water does not destroy the shrinkability of the shrinkable ones Vasers, as is the tall of most organic liquids, and it is much lighter, fragile, "unwoven." Nonwovens to be soaked with dispersions of low viscosity as all old solutions of the same polymer of high viscosity

The impregnating agents in the form of aqueous solutions can be used in Coagulate the fleece according to various methods, eg. by. Freeze coagulation, by immersing the fleece in an aqueous electrolyte solution, by heating the soaked fleece

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and, in the case of non-coagulable dispersions, through. Allow to dry at room temperature.

In making you water vapor permeable artificial Upper leather by soaking heat, shrinking tiaras unwoven In fleece with an aqueous dispersion, freeze coagulation is particularly preferred because it contains the coagulate in the ganeen fleece is deposited evenly in a highly porous form and in this way contributes to the permeability of the end product · In addition, freeze coagulation involves drying and heat shrinkage of the nonwoven web hardly any migration of the impregnating agent instead.

The aqueous dispersions that are suitable for carrying out the Process according to the invention proved to be particularly sweek are aqueous dispersions of rubber-like polymers with a low modulus, such as neoprene (polychloroprene), Butyl rubber, "Hycar" (mixed polymer of butadiene and Aoryl acid nitrile), "Buna S" (mixed polymer of butadiene and Styrene), natural rubber, aqueous dispersions of thermoplastic polymers and copolymers, e.g. from "(Jeon 351" (a plasticized polyvinyl chloride), oil-modified Alkyd resins, aoryl resins and methacrylic resins, as well as various mixtures of the above dispersions.

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Polyalkylene terephthalate is particularly preferred as a heatable fiber for the production of nonwoven webs. Other suitable heat-shrinkable fibers are those made of cellulose acetate, polyhexamethylene adipamide, a * mixed polymer of 40% by weight 6 aoryl acidic acid and 60% by weight vinyl chloride, polyethylene, polypropylene, polystyrene and polytetrafluoroethylene be used. Likewise nan shrinkable fiber with nichtsohruepfbaren fibers can mix when the proportion of the shrinkable fibers en nindestens 50 i * of Oesamtfäsermenge in de "is ungewehten Tlies. Examples of non-shrinkable fibers are all of the above-mentioned shrinkable fibers if they have been shrunk before the manufacture of the unwoven fleece, as well as natural fibers, eB cotton, jute, flax, wool, etc.

example 1

Am fluffy, looker-bound, non-woven fleece with a Flat weight of 495 g / m made of polyethylene terephthalate fibers of 1.25 den, which is produced on a card and cross-over storage device, is passed six times through a chair. Me sight of the pinpricks is about 238 / om The needled fleece has a weight per unit area of 403 g / omega and has a very pronounced herringbone needle pattern tige »appearance.

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The needled fleece is immersed in an aqueous neoprene dispersion like example 1 of French patent specification 1 289 754 * the 30 # non-volatile solid © including polychloroprene! Contains oxygen retardants, hardeners, accelerators, etc. The fleece is saturated with the aqueous dispersion and impregnated equally. The impregnated fleece is prepared from the impregnation bath and the excess slide is allowed to drip off the fleece. Before the fleece has time to dry in the sun, it is exposed to a temperature of -40 ° C until the impregnating agent has frozen xoid coagulated in the entire fleece as "impregnating agent dries out completely, the impregnated nonwoven 5 minutes, immersed in a water bath of 65 ° C where it xm a Flächensohrumpfimg 53 $ suffers. the shrunken impregnated Yliee is thoroughly Rait water washed to all of the DieperBion in üew nonwoven cbgeochiedenen W8, soerlöslichen ingredients such as Eispor ^ i ^ J ^ edium, su entfeiiion. The washed fabric is eriiitpät 1 Stunäe in the oven at 100 ° 0 dried and for 30 minutes at 140 ° C, we ausEUhärten fi & s Esopsen. The dry impregnant It is deposited in a porous form through the entire fleece, so that both micropores and macropores can be detected.

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Bae trookene! Stagnant yliee is bent on both sides to remove the surface skin of the impregnating agent. At this stage of the process, the 3.8 cm thick fleece is made into split three solids, each about 1.27 a thick.

A control sample, in the same manner from the above "described ingredients sit dea difference produced in that the impregnation is performed after the WärmaBchruapfung and Ie" temperature of Vasaerο including shrinkage not ° C is ₁ but 63 C 65, inter alia, a comparable degree of shrinkage au The 33 degree of surface scuffing of the unimpregnated fleece of the control sample is £ 50.

The product manufactured according to Example 1 and the control sample have the following physical properties:

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density

thickness

Permeability value

tensile strenght

Elongation at break, & cross- machine direction

Tensile strength, kg / cm machine direction, cross machine direction

Initial modulus, kg / cm machine direction cross machine direction

Resistance to travel, kg / 2.54 cxa thickness

Machine direction across the machine opening

example 1

764 g / cm * 1.27 mm 6900

240
230

112.5
66.8

196.9
1.19.5

53
91.6

Control sample

0.434 g / cm ⁵ 1.27 mm 8700

150 140

70.3 77.3

133.6 133.6

44.5 47.6

The Durohläasigkeitawerte turn to beetiouat, in which a B ^ istallizing shell of 7, β2 om Turchiaaseer filled with Oaleituacilcrid a grain size of 1.63 mm, with a membrane from the sample to be examined and in an atmosphere of high humidity (90% relative humidity is kept at 23 ° C). From time to time the dish is weighed and the equilibrium rate of absorption is expressed in grams of water

ρ
per 100 m of surface per hour recorded as the leather permeability value. This is an amendment to that proposed by the Bureau of

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Standards, by Kanogy & Yickere, J. Res. Nat. Bureau of Standards, 44 # pages 347-362 (April 1950) tests described ».

The impregnated article described above is both before and after removing the skin from the surface as well after splitting a commodity for a wide variety of applications, such as sealing rings, diaphragms, bearing seals, Plane tokens, etc. The pimped and split product is particularly valuable as a base for surface coverings for the manufacture of artificial »shoe upper leather, as described below.

The 1.27 ram thick impregnated material produced according to Example 1 and the likewise 1.27 ram thick control sample are each provided on one side with a surface covering made from the Maose described below. The coating compound is applied in such a thickness that a dry surface film with a thickness of 0.254 mm results. The coating aasse consists of 10.5 parts of a PolyurethanclaetoiserGn, 5.7 parts of polyvinyl chloride and 83.8 parts of Ν, Ν-dimethylformamide (hereinafter referred to simply as dimethylformamide). The coating aaese is prepared by gexeiaclit 52.5 ropes of a 20% solution of the Polyurethanolaet ^ iaeren ⁴ in Diinethylfonaaiüiu with 47.5 parts eliix-r 12 ^ igen Lb "atmg of 'PaIyvinylchlorid in Dimethylforwamid. ALa non-solvent for the Poly-

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kidney is so much from a mixture of 80 parts of dimethylformamide and 20 ropes waeoer attached, "until the gel formation starts *

The 20% polyurethane solution is prepared by mixing 3343 parts of polytetrassethylene ether glycol with a molecular weight of about 100 ° C. with 291 parts of oluene, 2,4- & iiso ~ oyanate, and heating the mixture to 90 ° for 3 hours. 2465 ropes of the dimer with terminal hydroxyl groups obtained in this way are used as 570 ropes of methylene ™ "bis (4-phenyl isocyanate). This mixture is heated at 80 ° for 1 hour, with terminal Ieoeyanatgruppea The YorpolyFsriisat nrd dissolved in 10,000 parts of Diffiethylforraasiä and the solution slowly su a solution of 50 ropes Qinoe PöX ^^ isaticeütenvei'llüigereES in Tt 710 files MisethylforHiainid suge ^ o ^ & i. 5) or ICet ^ enverlan ^ ex-er from li-Hethyl-'biB-aiiiiiiQproiiyla'.iiiii unfl D.ydraeinhydrat i ratio 4-0 % 60. The reaction vessel is stirred for 30 hours at C0 ° C, where "a l ^! ol ^ niret> ianlösi-jig of a-Yisooeit ^ t of 115 P and a polymorisate content of 20 ^ "forms.

Immediately after doia apply the B © scMehttuigSB? .Cae to the Underlay and "before © ine a noteworthy amount of ÜiEethylforEiaiBid evaporated iat, the coated base is 2 face in Immersed in water at room temperature. This is where the

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Power solution coagulates and turns into a gelatinous polymer Layer old of a cell structure also interconnected Micropores converted ', and practically everything is dinethylformaaid is extracted from the coating.

The coated VIi θ a is treated with steam for 15 minutes and then dried at 100 ° C in a dry heat zone. After drying, the surface covering has a white milky appearance Appearance and is extremely permeable to water vapor.

The dry, coated YIiea is immersed for 30 minutes in an aqueous boiling PayMlotts containing a black chromated Moaioaaofw ^ bntoff, namely, oil dye GI-15711 (cf. "Color Xndex", 2nd edition, Volume 3? 1957, published by ds ** Avieriean Aosooi.ation of fesrtile Ohcöiists and Colorants) in a Sonaentration you. 5 $ o

Bas geü'bta boeöhie'vitev'v · ¹ JIiCa is 15 lunutes in a siedeiiä \ i &"5years Έ & Α Gewr.; Chöii, which3 a non-ionic cleaning3it, t @ l in ei» .3i ^l tJsBjö From 0.5 $ _f related to the Gewibhtsfflenge äes Wpoae ^ s, sathält. The detergent is a condensation problem on 0 moles of Athjlenoxycl. about 1 mole of a value

The kneaded and washed, impregnated and coated fabric has a deep look. Br iet extremely what s steam-

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permeable, tough, abrasion-resistant and very suitable for use as artificial leather for men’s and Baaenechuhe «

Both over-soaked nonwovens, namely the one according to the example 1 and the control sample are prepared according to the usual procedures used to manufacture men's shoes, where the Material subjected to stretching when stretched on lasts and held in an extended state during the shoe manufacturing process.

The needle pattern in the non-woven fleece, which had been covered by the impregnating agent and the "BesohichtiragsBiasse" reappears in the control test when the shoes are stretched out while the shoes are being put on the last in the surface covering and remains attached to the areas of the strongest heckling the toe and upper styles of the shoe, after the shoe has been removed from the last. the spawning has been lifted *

In the case of the material produced according to Example 1 (according to the invention), the Haßelfflueter of the woven Ylies - also through the Impregnlerraittel and the - Oberfläohenbeliie; Textcover · -. During this period, however, the pattern is not perceivable as the shoes are stretched onto the lasts in the course of the surface covering.

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On an evenly divided scale on which the value KuIl means the complete absence of the Ifadelmueter in the surface covering, if this "in the shoe production one Is subjected to tension, while the value 6 has a strong roughening, i.e. the appearance of the Ha & elrausfcere, "means the product according to Example 1 impregnated and coated the value 1, while the control sample has the value 6.

Example 2

The procedure is as in Example 1, but using a fluffy, deliciously bound non-woven fleece with a surface weight of 451 g / s made of polyethylene terephthalate fibers of 1.25 denier, which is produced in a carding and covering device and then passed through a handle chair . The number of stitches is 425 / ob.

Bas Plächengevicht de «fleece after processing ira Hadel-

2
stuhl bati'äge 349 & / ^ffi » v & - & daa fleece has a pronounced needle-shaped structure with an unlike fisclet appearance«

Another modification /: öos method of Example 2 compared to ßsBjsnijgen de «Beispr'.olö 1 is that the temperature of the sum fichrunjyf (; n cles soaked fleece used hot Vfassers n5.cht 65 ° <" U eoiid'ern 70 ° C. The impregnated non-woven fabric according to Example 5 suffers planar shrinkage

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63 # in? Equal to the shrinkage of 53 # for the genes Example 1 impregnated fleece.

A control sample for example 2 is prepared in the same way with the only difference that the seeding is carried out in this Palle before the impregnation.

The product made according to the invention (Example 2) and the control sample have the following physical properties

Example 2 Control sample Filing, g / cm ⁵ 0.799 0.460 Sioke, ma 1.55 1.35 Suro leakage value 4100 7600 Tensile strength values Elongation at break, f (
Maeohinenriohtung
across the Maeohinenriohtung 100
100 90
140 Tensile strength, kg / o · ²
Kasohinenriohtung
across the nasal alignment 84.4
57 70.3
59.8 Initial modulus «kg / one
Kaaohintnrichtung
qver to the casino direction 267.2
196.9 225
161.7

The iapregnated Vlieeo cut example 2 and cut the con trollvtreuoh are dressed with the wet soles described in example 1 and then processed on men's shoes.

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belt et, whereby the material is stretched on bars in the usual way. Bas ffadelmuater, which was covered by the impregnation agent and the surface covering, is in YaUe of the product manufactured according to the invention in the * Stretching on the lasts subject to stretching Boho upper leather, in the toe and upper parts, kai » and corresponds to a value of 1 on the scale given above, while the control sample has a value of 6.

Example 3

A non-woven web of crimped polyethylene terephthalate staple fibers of 0.8 denier is produced in a carding and cross-laying device. The weight per unit area of this fleece * is 305 g / a. The fleece is passed through the needle frame, including some of the fibers perpendicular to the plane of the fleece align and bring about reinforcement

The fleece is then thawed until the following impregnation solution it is completely saturated:

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Heoprendl dispersion according to example 1 of the French patent specification 1,289,754

Vaeeer

2 · 2 · -Metnylen-bia- (6-tert ο butyl-p-cresol) ("Oaloo A-2246»)
(as 33% aqueous dispersion)

Zinc oxide (as a 50 # aqueous dispersion)

Hatrumale of sulfated ethyl oleate ("Aquarex SMO")
(as a 33% aqueous dispersion)

Sodium dibutyl dithiocarbamate ("Iepidone") (all 50 $ aqueous dispersion)

Qtwiohtteil ·

180.0 157.0

5.4

9.0

- 8.1

(as 33

aqueous dispersion)

Prepared polyvinyl chloride ( ^H Geon Latex 351 ") (as a 57% aqueous dispersion)

water

1 * 8 2.7

10.0 13.4

The impregnated Vliea is _S 3näss Example 1 dvircii freezing and thawing coagulated "Yor iam üürocknenlassen of βλι: ^λ; οtauten impregnating agent is impregnated daa Tlies immersed for 15 minutes in 70 ° C water aeisBes. Then äu & Yliea are troubled. At influence dea hot water KISSING ßohruiapft the soaked fabric uüB $ 55> its ori ^ ingliclien surface. The impregnation agent is then heard from 60 to 120 ° G. The ratio of paser to binder is 100 ± 274.

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The hardened impregnated Yliea is made with on both sides dea sandblasting blower worked to remove the skin from tibereehttigee impregnant. The iapregnated product 1st microporous, smooth and free of macroscopic cavities. That The product is flexible, and if it is stretched longer than 35 pounds in the direction of rotation and stretched for 55 pounds in the longitudinal direction, there is no expansion. roughness is noted, i.e. the fleece has a roughness value of Hull on the scale given above. The stretched out sample surttok returns to its original dimensions after the tension is removed.

The impregnated fleece is ideally suited as a basic material for besohiohten in the production of clay Sohuhoborieder.

Good results with regard to the non-appearance of the needle pattern on the surface of the impregnated and coated woven nonwovens produced according to the invention are obtained in the manufacture of shoes by the usual methods when the aqueous dispersions contain about 20 to 60% solids. Dispersions ax Fesi kept material from 25 to 40 1> are berorsugt, and the bee th lifrgebnlßse be held with solid tone achieved about 30 #. If you work with higher consistencies, the surface ear lump of the applied fleece is no longer removed, and there is also a decrease in the roughening of the covering when the coated fleece is stretched onto strips

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sur Yerarlieitung ssu shoes is used; However, other valuable properties are degraded ₉ ss.B · the h & sslicae appearance in the (iegenct of Sehuhvorderfelattes belsi bending, which is also known as poor "break" the Beders ·

τ: οκ sent rat ionen der Iprägnieraitteldisperaion does less impregnation agent get into the tliee _? "Nd ee finds an increased soak damming of the impregnated tmwoven a Ylifiee stfttt" which goes hand in hand with a strengthening of the roughening (ie the lines of the hips) during and after the stretching on el * th in the division of vision.

Coated nonwovens have an honesty value of "or rather than are considered to be technically acceptable as high-grade shoe upper leather ereats. Such products are also suitable for? other inwendiangssweoke "where the roughening of" Ausiraeken is not harmful, e "B. for sealing rings * Brennetoffpuspen _e upholstery, l "adecken paperbacks, men's and Damenjaoken, etc?

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Claims (2)

PFD-732 Claims 1". Process of impregnation of nonwovens, known as the aan (a) Manufactures a woven nonwoven fabric which has the ability to suffer from 20 to 80 % area ear slack and which has a mister on its surface, (b) the fleece is soaked in an aqueous dispersion of a polymeric substance, Co) the impregnating agent contained in the aqueous dispersion coagulates and (d) the impregnated fleece is subjected to a 20-Ms 70 igen surface cupping at higher temperatures 2. The method according to claim 1, characterized in that the. Step (d) is carried out by nan the soaked The fleece is immersed in a 63 to 90 ° C hot water. 3 * Method according to claim 1, characterized in that the Coagulation by freezing out the aqueous suspending agent for the dispersing substance takes place. 4. The method according to claim 1, characterized in that the impregnated fleece is provided with a surface covering next to it. 5CT9810 / 0657 - 21 -