US3067152A - Aqueous solution of polyvinyl alcohol containing insoluble starch derivative and proces of preparing fibers therefrom - Google Patents

Description

United States Patent C) AQUiEDUS SOLUTION F POLYVINYL ALCOHOL This invention relates to a process of producing fibers of polyvinyl alcohol and is more particularly concerned with a process of forming such fibers which are characterized by desired properties.

As described in US. patent application Serial No. 856,334, filed December l, 1959, now US. Patent 3,007,228, dated November 7, 196d, the dyeability of polyvinyl alcohol fibers can be markedly increased by spinning the fibers from a mixture of an emulsified polymer formed from basic monomers and a water solution of poly-vinyl alchool. When fibers spun from such a mixture are subjected to heat-treatment and benzalization, fibers can be obtained which have excellent dyeability. It has also been found that the same effect can be obtained when an emulsion or a fine powder of waterinsolu-ble polyvinyl alcohol derivatives obtained by acetalization of polyvinyl alcohol with aldehydes having basic nitrogen, and, if necessary, by acetalization with aldehydes having no basic nitrogen at the same time, or before or after the first acetalization, are moved with a water solution of polyvinyl alcohol, followed by spinning and heat-treatmtent and benzalization of the fibers.

It is an object of this invention to provide a process for producing fibers of polyvinyl alcohol having high hotwater resistance and heat-resistance and desirable mechanical properties at least equal to fibers produced solely from polyvinyl alcohol, yet characterized by a particularly high dyeability.

In accordance with this invention, spinning of fibers is effected from a spinning fluid prepared by dispersing in a water solution of polyvinyl alcohol an emulsion or fine powder of water-insoluble starch derivatives containing basic nitrogen introduced into the starch molecule by etherification with epoxy compounds containing basic nitrogen, ethyleneimine or its derivatives, or B-aminoethylsulfuric acid.

We have studied extensively the manufacture of emulsions or fine powder of polymers which are water-insoluble and contain basic nitrogen. We have found that the desired objective can easily be achieved by spinning fibers from the spinning fluid composed ofta water solution of polyvinyl alcohol in which has been mixed and dispersed emulsion or fine powder of Water-insoluble starch derivatives containing basic nitrogen introduced by etherificatio-n with epoxy compounds containing basic nitrogen, ethyleneimine or its derivatives, or El-aminoethylsulfuric acid, and that the dyeability of such fibers, particularly afterbenzalization, have a greatly improved dyeability compared with polyvinyl alcohol fibers alone.

In the methods described in said application Serial No. 856,334, the particle sizes produced are below 0.5a, and it is very difficult to change the particle size. In accordance with the present invention, however, the waterinsoluble starch derivatives containing basic nitrogen can be produced with any desired particle size by selecting 3,067,152 Patented Dec. 4, 1962 if necessary, so as to conform with the denier of the fiber to be manufactured, as well as the color-fastness and physical properties required in the fiber. In case of such mixed spinning, and when the fiber is given an insolubilization treatment e.g. acetalization, after heattreatment, fine particles of the starch derivatives containing basic nitrogen as dispersed in the fiber and are difficultly influenced by the hydrophobic character imparted to the fiber by acetalization. Particularly when acetalization is effected with benzaldehyde, a portion of the polyvinyl alcohol molecule will have imparted to it hydrophobic p-roperties as benzalization progresses and this serves to promote the elasticity of the fiber itself, but the fine. particles of the starch derivatives containing basic nitrogen are not thus affected by the benzalization reaction despite the fact that they contain hydroxyl groups. As a result, the hydrophilic property indispensable for dyeability is not changed even after the benzalization treatment. Hence, the fiber has very good dyeability.

However, when the particle size is unduly large, broken or nappy filaments may result at the time of spinning, with subsequent deterioration of the physical and mechanical properties of the fiber. Hence, it is important to restrict the size of the particles to below 3 0 1. diameter.

The amount of basic nitrogen introduced into the starch molecule is suitably 0.02%'3% by weight. When a mixture of such starch derivatives and polyvinyl alcohol are spun, a marked elevation in dyeability 0f the resultant fibers is observed with direct cotton dyes and acid wool dyes.

To form a stable dispersion of the above-described solid polymer particles in a water solution of polyvinyl alcohol, various procedures may be employed. Thus when the starch derivative is in the form of an emulsion, the emulsion may be directly mixed with a water solution of polyvinyl alcohol, or it may be mixed with polyvinyl alcohol powder and water may then be added to dissolve the powder. Alternatively, the emulsion may be heated, and polyvinyl alcohol powder or moist polyvinyl alcohol powder may be slowly added and dissolved in the emulsion. When the starch derivative particles are in the form of a fine powder, the powder particles may be mixed with polyvinyl alcohol powder and water added to dissolve the powder mixture or the starch derivative particles may be mixed with a small amount of water or a water solution of polyvinyl a1- cohol, and the paste of fine powder thus obtained may be mixed with polyvinyl alcohol. It will be understood, however, that various other procedures may be used. If desired, any of the various known surface active agents or protective colloids may be added to the solution. As surface active agents, various anionic, non-ionic, and cationic surface active agents are suitably used, but in asmuch as an anionic surface active agent may occasionally tend to coagulate solid particles by forming a bond with basic nitrogen, it is preferred to use a nonionic surface active agent such as polyoxyethylenedodecyl ether, or a cationic surface active agent such as dodecyltrimethylamrnonium chloride. As protective colloids, compounds such as water-soluble starch, partially aminoacetalized polyvinyl alcohol, and the like are suitably used.

The fiber spun by the method of this invention may be subjected to thermal elongation, i.e. hot-stretching, heat-treatment and insolubilization treatments in the same manner as fibers formed solely from ordinary polyvinyl alcohol. For effecting insolubilization treatments there may be employed acetalization by means of aldehydes such as formaldehyde, acetaldehyde, chloracetaldehyde, butylaldehyde, nonylaldehyde, benzaldehyde, mono chlorbenzaldehyde, l-naphthaldehyde, glyoxal, malonan autoclave at 130 C. for 3 hours.

aldehyde, glutaraldehyde, terephthaldehyde, and the like. The fibers may also be subjected to treatments with inorganic reagents such as titanation, and chroming. Various other known insolubilization treatments may also be employed.

It is also preferable to carry out spinning by means of the spinning fluid prepared by dispersing an emulsion or a fine powder of the starch derivatives with polyvinyl alcohol by the method of this invention, with the addition of various types of water-soluble polymers such as soluble starch, polyvinylpyrrolidone, aminoacetalated polyvinyl alcohol, various kinds of pigments such as titanium oxide, and acids, alkalis, and salts such as sodium sulfate, and the like. Accordingly, it is possible to simultaneously effect improvements in the transparency and in the form of the cross-section of the fibers particularly when the fibers are formed by wet spinning.

Compounds containing basic nitrogen suitable for use in accordance with the method of this invention include epoxy compounds containing basic nitrogen which may be formed by the reaction of epichlorohydrin with any alkyl or cycloalkyl secondary amine such as diethylamine, dibutylamine, didodecylamine, dihexylamine, methyl-ethylamine, cyclohexylamine, ethyl-butylamine, ethyleneimine, and the like, any of the derivatives of ethyleneimine having the ethyleneimine ring such as those formed by the reaction of ethyleneimine with melamine and phosphoric acid, and the like, and compounds such as fieamino-ethyl sulphuric acid.

The starch usable in the method of the present invention, is any of the known starches such as potato starch, Japanese arrowroot starch, sweet potato starch, wheat starch, rice starch, corn starch, tapioca starch, arrowroot starch (maranta starch) sago starch and like substances having the starch molecular structure. In addition, starch derivatives, such as acetyl starch, may be used.

The invention will be further understood from the following specific examples of practical application. However, it will be understood that these examples are not to be construed as limiting the scope of the present invention in any manner. In these examples, all parts are by weight, unless otherwise indicated.

Example 1 Ten grams of Wheat starch (particle size: 2-3 1) were thoroughly mixed with 2 g. of l-dimethylamino- 2,3-epoxypropane. The mixture is allowed to react in The reaction product was then thoroughly washed, and unreacted l-dimethylamino-2,3-epoxypropane was removed. The were thus obtained in the form of fine particles, a wheat starch derivative containing basic nitrogen. These fine particles were dispersed in water to form a water dispersion and thus a slightly viscous emulsion was obtained.

This emulsion of fine particles was mixed with polyvinyl alcohol in the amount of 10% of particles based on the polyvinyl alcohol and the polyvinyl alcohol was dissolved by the addition of further quantities of Water. The resultant solution was wet-spun into a sodium sulfate coagulation bath, and the fibers were subjected to heat-treatment at 235 C. for 30 seconds at a fixed yarn length. The heatatreated fibers were benzalized in a water solution containing benzaldehyde (1.5%), sulfuric acid and methanol (40%) at 60 C. for 4 hours. The degree of benzalization after the treatment was 32.0%.

When these fibers were dyed with Acid Brilliant Scarlet 3R (4%) and sulfuric acid (3%) (percentages by Weight based on the fiber to be dyed) with a bath ratio of 1:100 at 90 C. for one hour, the dyestulf was completely absorbed with no sign of any drop in dyeability when compared with dyed heat-treated fiber.

An optical microscopic observation of the cross sec tion and the sides of the dyed fibers revealed the presence of dyed fine grains.

Example 2 Ten grams of potato starch (particle size: 2-3 t) were mixed with 3 g. of ethyleneimine and the mixture was reacted in an autoclave at 130 C. for 3 hours. The product obtained, which was a starch derivative containing basic nitrogen and was in fine powder form, was thoroughly washed to remove unreacted ethyleneimine, and by air-drying, a fine powder with a water content of 15% was obtained having a basic nitrogen content of 1.5%.

The fine powder was thoroughly mixed and dispersed with polyvinyl alcohol in the proportion of 10% of powder based on the polyvinyl alcohol and water was added to prepare a spinning fluid with a polyvinyl alcohol content of 30%. This spinning fluid was forced into hot air to efiect dry-spinning in conventional manner and polyvinyl alcohol fibers were produced. After hotstretching by 500% at 230 C. at fixed yarn length, the fibers were heat-treated at 235 C. for 10 min. Some of the heat treated fibers thus obtained were formalized in a water solution containing formaldehyde (5%) and sulfuric acid (15%) at 70 C. for two hours, and the remaining fibers were benzalized in a water solution containing benzaldehyde (2%) and sulfuric acid (15 and methanol (40%) for two hours. The degree of acetalization grade was 42.0% and 31.0%, respectively.

When samples of these fibers were dyed in a dyeing bath consisting of Acid Brilliant Scarlet 3R, an acid dye (4), and sulfuric acid (3%) (percentages by weight based on the fiber to be dyed), or in a dyeing bath consisting of Sunchrome Brown RH (4%) and sulfuric acid (3%) (percentages by weight based on the fiber to be dyed) at C. for one hour, this mordant dye being developed by the use of potassium bichromate, the dyestufis were completely absorbed in the case of both the formalized and the benzalized fibers.

Before spinning, the spinning fluid was heated to 150 C. under a pressure of 10 kg./cm. but nothing abnormal was observed as to the condition of either the dispersion of fine grains or their particle size.

Example 3 With 10 g. of arrowroot starch (particle size: 1-2;/.), were mixed 5 g. of 1-diethylamino-2, 3-epoxypropane, and the mixture was dissolved and dispersing in dioxane (50 cc.). The solution was allowed to react in an autoclave at 90 C. for 5 hours. After the reaction was completed, the reaction mixture was filtered and washed and there was recovered a fine powder consisting of a starch derivative containing basic nitrogen. The basic nitrogen content being 1.2%.

This fine powder was mixed with polyvinyl alcohol in the amount of 15% based on the polyvinyl alcohol and a spinning solution was formed and spun as in Example 1 and the fibers were heat-treated, and acetalized as described in Example 1. When the treated fibers were dyed with the dyestuffs and under the dyeing conditions specified in Example 1, the dyestuffs were found to the completely absorbed by the fibers.

Example 4 A fine powder (particle size: 2-3;) containing basic nitrogen obtained by treating a water solution containing potato starch (10 g.) with fi-amino-ethylsulfuric acid (5 g.) and caustic soda (2 g.) at C. for 2 hours, was mixed with polyvinyl alcohol and spun as described in Example 2 and the resultant fibers were heat-treated and acetalized in the manner set forth in Example 2. As in the case of the fibers of Example 2, the fibers thus produced had very good dyeability.

The surface-active or dispersing agents or dispersants and protective colloids which are suitably employed are, in addition to those mentioned above, any of the many dispersing agents and protective colloids known to those skilled in the art of making emulsions or dispersions of polymers. in the foregoing examples, for instance, polyoxyethlenedodecyl ether is suitably used as the dispersant or surface-active agent.

It will therefore be understood that, unless otherwise indicated, conventional operations and conventional apparatus are employed in carrying out the process of this invention including conventional mixing and emulsifying units. Similarly, conventional dyeing techniques and apparatus are suitably employed upon the fibers produced by the process of this invention. The conditions and the relative relationships set forth in the examples are those preferred in carrying out the process of the invention but it will be understood that other conditions and relationships may be used within the scope of the invention.

The spinning fluids produced in accordance with the present invention are particularly suitable for the spinning of the fibers in accordance with known processes used in the spinning of polyvinyl alcohol and polyvinyl alcohol derivatives, particularly the so-called wet-spinning techniques as described, for example, in Cline et al. US. Patent 2,610,360 and Osugi et al. Patent No. 2,906,594. An especially preferred spinning technique is described in copending application Serial No. 336,166 of Tomonari et al. filed February 10, 1953, now US Patent 2,988,802, dated June 20, 1961.

After formation of the fibers by Wet spinning the fibers can be further treated by stretching, heat-treating, acetalization, and the like to produce fibers with desirable and outstanding properties, using known techniques as described in said patents.

Examples of starches and starch derivatives suitable for use in the invention have been given above, but it will be understood that any of the known starches and starch derivatives, such as these described in Starchlts Sources, Production and Uses by Charles A. Brantlecht (Reinhold Publishing Corp.) may be used.

It will also be understood that various changes and modifications in addition to those indicated above may be made in the embodiments herein described Without departing from the scope of the invention as defined in the appended claim-s. 'It is intended, therefore, that all 6 matter contained in the foregoing description shall be interpreted as illustrative only and not as limitative of the invention.

We claim:

1. A process of producing fibers of polyvinyl alcohol of improved properties which comprises adding to an aqueous solution of polyvinyl alcohol, water insoluble starch derivatives with a particle size below 30p, mixing and dispersing said derivatives in said solution and spinning said fibers from the resultant spinning solution, said derivatives containing 0.02% to 3% by weight of basic nitrogen and being the products resulting from reaction of starch with a member of the group consisting of epoxy compounds containing basic nitrogen and obtained by the reaction of epichlorohydrin with secondary amines selected from the group consisting of alkyl amines and cycloalkyl amines, ethylene-imine, the reaction product of ethylene-imine with melamine, the reaction product of ethylene-imine with phosphoric acid, and fl-amino ethyl sulfuric acid.

2. A polyvinyl alcohol spinning solution effective to provide fibers of polyvinyl alcohol of improved properties formed by adding to an aqueous solution of polyvinyl alcohol, water insoluble starch derivatives with a particle size below 30, and mixing and dispersing said derivatives in said solution, said derivatives containing 0.02% to 3% by weight of basic nitrogen and being the products resulting from reaction of starch with a member of the group consisting of epoxy compounds containing basic nitrogen and obtained by the reaction of epichlorohydrin with secondary amines selected from the group consisting of alkyl amines and cycloalkyl amines, ethylene-imine the reaction product of ethyIene-imine with melamine, the reaction product of ethylene-imine with phosphoric acid, and fi-amino ethyl sulfuric acid.

References Cited in the file of this patent UNITED STATES PATENTS 2,265,283 Herrmann et a1. Dec. 9, 1941 2,808,380 Olsen Oct. 1, 1957 2,906,594 Osugi et al. Sept. 29, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OF Patent No. 3 067 152 CORRECTION December 4,, 1962 Osamu Fukushima et alo It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Column I line 18,, for desired read desirable line 25 for "'alchool" read alcohol =-=g line 35 for moved read mixed line 37 for "'heat=treatmtent" read heattreatment column 3,, line 550 for "The" read There column 4 line 29 for "(4) read (4%) 'the first oceurrence read be 2 for "'polyoxyethlenedodecvl" read column 6 line 25 for 30 read Signed and sealed this 23rd (SEAL) Attest:

ERNEST w. SWIDER Attesting Officer line 59 for column 5 lines 1 and polyoxyethylenedodecyl day of July 1963o DAVID L. LADD

Claims (1)

1. 2. A POLYVINYL ALCOHOL SPINNING SOLUTION EFFECTIVE TO PROVIDE FIBERS OF POLYVINYL ALCOHOL OF IMPROVED PROPERTIES FORMED BY ADDING TO AN AQUEOUS SOLUTION OF POLYVINYL ALCOHOL, WATER INSOLUBLE STARCH DERIVATIVES WITH A PARTICLE SIZE BELOW 30, AND MIXING AND DISPERSING SAID DERIVATIVES IN SAID SOLUTION, SAID DERIVATIVES CONTAINING 0.02% TO 3% BY WEIGHT OF BASIC NITROGEN AND BEING THE PRODUCTS RESULTING FROM REACTION OF STARCH WITH A MEMBER OF THE GROUP CONSISTING OF EPOXY COMPOUNDS CONTAINING BASIC NITROGEN AND OBTAINED BY THE REACTION OF EPICHLOROHYDRIN WITH SECONDARY AMINES SELECTED FROM THE GROUP CONSISTING OF ALKYL AMINES AND CYCLOALKYL AMINES, ETHYLENE-IMINE THE REACTION PRODUCT OF ETHYLENE-IMINE WITH MELAMINE, THE REACTION PRODUCT OF ETHYLENE-IMINE WITH PHOSPHORIC ACID, AND B-AMINO EHTYL SULFURIC ACID.