CN1011319B - Foamed synthetic fiber and its manufanturing method - Google Patents

Abstract

Disclosed is a foamed synthetic fiber characterized in that an organic solvent solution of a thermoplastic polymer admixed with 3-100 weight percent of a compound scarcely soluble or insoluble in the aqueous coagulating bath for wet spinning, which is liquid under normal pressure and has a boiling point of 120 DEG C or less, as foaming agent is injected as spinning dope into said aqueous coagulating bath and it is foamed in a drying atmosphere at the boiling point or more of the foaming agent and 100 DEG C or more and has an expansion ratio of 3 percent or more, and the manufacturing method thereof. The foamed synthetic fiber of the present invention is light and bulky, being excellent in warmth-keeping and heat-insulating performance with its appearance, touch and development of color similar to those of an animal hair.

Description

Foamed synthetic fiber and its manufanturing method

The invention relates to porous synthetic fiber and preparation method thereof, especially about a kind of novelty and useful fiber, the characteristics of its existing known porous fibre have improved low intensive utmost point critical defect again, and make it have the feel of having improved to have the color of similar animal wool simultaneously again.

Except by new fabric component being designed and making it have textile properties and fiber and its function are carried out the so-called requisite improvement, also taked various measures in recent years, the design of the three-dimensional structure by fiber increases its value.Wherein once the someone is devoted to the further segmentation again of the fiber cross sections of so-called island type, viewed the sort of situation in animal wool for example, and carried out various innovations by the microgroove surface of adopting special-shaped cross section and further improving fiber.Porous fibre belongs to back one class, various trials have also been carried out simultaneously, come to form isolated or continuous bubble mutually, or the combining form of isolated bubble and continuous mutually bubble, make it have character such as improved in light weight, bulk, comfortable feel and elasticity in the inside of fiber.

Typical example is listed in patent publication No. 4536/68, patent publication No. 850/71 and the publication application number 36208/83, but, these patents are to handle a large amount of synthetic resin and industrial materials or house decorative material all the time, and do not handle so-called general fiber, be used for the fiber of clothing comprising those.What is worse, recommend the material of those its structures shortages needed mechanical performance when spinning, knitting and weaving general fibre of employing, will stand especially mechanical strength and elongation, and more seriously, their dyeability very poor (solution dyeing, printing and dyeing property), the gloss of the product after the dyeing and transparent extreme difference.Simultaneously, patent publication No. 21300/67, patent publication No. 210/76, patent publication No. 38527/83 etc. all are considered to and can use in the art, but has only bubble seldom on the cross section of fibre structure at every fiber of in these inventions, being recommended, therefore, deficiency so that the characteristic of porous fibre fully show.

In addition, publication application number 77616/75 discloses a kind of composite fibre, but does not have advantage economically, because:

(1) skin and core can not become to assign to make with same;

(2) require more than one spinning solution; With

(3) need complex apparatus, wherein, especially need composite nozzle; And

(4) desired being very different of reaching of performance and the present invention.

Main purpose of the present invention provides the textiles of a kind of in light weight, bulk, insulation and insulative properties, and improved because the economic traits of bringing in light weight.

Another object of the present invention provides a kind of fiber that is similar to animal wool in outward appearance, feel and colour developing.

These purposes and other purposes and advantage can be found out from following narration.

The present invention finishes, and this is a kind of achievement to achieve the above object diligent in one's studies.By under the condition of a given expansion ratio, inside at thermoplastic fibre forms bubble, provide a given length/minor axis ratio and be more preferably by cross section to fiber, the inventor has successfully eliminated the shortcoming of above-mentioned common porous fibre, and the outward appearance and the feel that make this fiber have better feel and dyeability (particularly coloring effect) and this fiber is had be similar to animal wool.

About accompanying drawing:

Fig. 1 is the electron scanning micrograph that shows the cross section of embodiments of the invention 1 resulting fiber;

Fig. 2 is the electron scanning micrograph that shows the cross section of embodiments of the invention 2 resulting fibers;

Fig. 3 is the electron scanning micrograph that shows the cross section of embodiments of the invention 3 resulting fibers;

Fig. 4 is the electron scanning micrograph that shows the cross section of embodiments of the invention 4 resulting fibers;

Fig. 5 is the electron scanning micrograph of demonstration as the general fibre cross section of the contrast of embodiment 1;

Fig. 6, A, B and C are the schematic diagrames that shows common porous fibre cross section; With

Fig. 7 and 8 is the electron micrographs in the animal wool cross section of quoting as a reference herein.

At first, the polymer that consists of fiber of the present invention can be any thermoplastic polymer, for example take acrylonitrile, polyvinyl chloride and vinylidene chloride, olefin polymer as the polyvinyl of representative and the polymer of other polyamide, polyester and polyurethane type. As poromeric be polyvinyl, the polymer that wherein preferably contains acrylonitrile, this kind polymer is preferably and contains 25%(weight) above acrylonitrile, be more preferably and contain 35-85%(weight), and best be to contain 40-60%(weight) acrylonitrile. Certainly these polymer can use with straight chain polymer, copolymer or its form to the admixture of polymer.

Secondly, description is basic conception about the spinning process of using a kind of low-boiling compound. Usually, when obtaining porous fibre in order to use a kind of low-boiling compound, before the solvent solution with thermoplastic polymer is transported to spinning-nozzle, with a kind of liquid low boiling polymer (hereinafter to be referred as blowing agent), under normal pressure, add in the thermoplasticity solvent solution and prepare spinning solution earlier. After spinning solution being carried out spinning or spraying into coagulating bath, in forming the process of fiber, blowing agent contained in the fiber is heated to above the temperature of its boiling point, and the expansive force of the gas that produces just is used for obtaining above-mentioned fibre structure (bubble structure). The present invention there is no other differences at aspects such as stretching and heat treatments. Following explanation is undertaken by the order of this kind basic skills.

Can adopt any common wet spinning process process to carry out spinning. Half-dried wet the technical process that when needed, also can adopt publication application number 30934/79 to narrate.

The blowing agent that blowing agent preferably can evaporate rapidly in a kind of temperature range used in normal spinning technique process. Under normal pressure, be liquid, and its boiling temperature requires to be not more than 120 ℃, and be more preferably in 10-100 ℃ of scope. This class blowing agent is the lower aliphatic hydrocarbon, for example, pentane, hexane, heptane and benzinum, rudimentary alicyclic, for example, pentamethylene and cyclohexane, alcohol Class, for example methyl alcohol and ethanol, fontanel be for hydrocarbon, for example, bromoethane, iodomethane and carrene, ethers, ether for example, chlorine fluoro-hydro carbons, for example, 1,1,2-, three chloro-1,2, the single fluoromethane of 2-HFC-143a and trichlorine, ketone, aldehydes and ester class etc. These blowing agents are added in the solvent solution of polymer, namely in the spinning solution. When using solvent, the kind of its kind and blowing agent all must be selected carefully. Think by the saying that behind meticulous selective solvent and the blowing agent the present invention is achieved success it is at all not excessive. According to general method, a existing patent about the acrylic acid series porous fibre for example, a kind of requirement of necessity is that blowing agent is non-solvent for polymer, is insoluble to or is dissolved in hardly polymer solvent solution or solidification liquid. The example is inorganic solvent, for example nitric acid and thiocyanic acid sodium, see number of patent application 210/76 and patent publication No. 38527/83, polar organic solvent, for example dimethyl formamide (DMF), dimethyl sulfoxide (DMSO) (DMSO) and dimethylacetylamide (DMA) are seen patent publication No. 6297/66 and 21300/67. But, use these methods, these blowing agents are only to be dispersed in the solution all the time, and under this state, just exist the danger that a kind of blowing agent is adhered together in leading to the pipeline of spinning-nozzle, stop up spinning-nozzle (especially under fiber is flat and situation fiber breakage), reduce blowing agent efficient, reduce these normally serious consequences of mechanical strength of porous fibre thereby produce. According to the present invention, requiring blowing agent is non-solvent for polymer, dissolves in the solution of the solvent of polymer or polymer, and is insoluble to again or is dissolved in hardly in the solidification liquid or water that carries out in the wet spinning technology process. Requiring blowing agent is that polymer has a kind of interface for the reason that polymer does not have solvability, and this expansive force for the gas that produces by the blowing agent evaporation forms foaming structure and is absolutely necessary. Requiring this kind blowing agent to dissolve in the solution of the solvent of polymer and polymer to be in order to prevent the impact of above-mentioned peptizaiton, also is to be to carry out in the whole inside of fiber in order to make foaming effect. In the wet spinning technology process, require blowing agent insoluble or be dissolved in hardly in coagulating bath or the water, yes wishes highly effectively to make the effusion of blowing agent from system be reduced to minimum degree.

According to above-mentioned definition, solvent-blowing agent combination can be DMF and 1,1,2-three chloro-1,2, and the combination of 2-HFC-143a and acetone and 1,1, the combination of 2-HFC-143a, pentane, hexane etc. is closed.Spinning solution is extruded and enters the coagulating bath (gas of water, solvent or heating) from spinning-nozzle, in coagulating bath, carry out a series of fibroplastic so-called freezing actions, for example solvent is diffused into the coagulating bath beyond the fiber (under the wet spinning situation) from fiber surface, in this coagulating bath, will take place water intrusion, with respect to the solvent strength of polymer descend, polymer separates or be precipitated out.This solidifying process process is repeatedly being carried out a kind of cyclic process, and promptly solvent is diffused into beyond the fiber and solidification liquid is invaded fibrous inside from fiber surface, promptly from fiber surface gradually to its diffusion inside, just form so-called not solidified elastomer subsequently.So just form the shell of the crust shape of a kind of being commonly referred to as " cortex " at the fiber surface of close solidifying phase.

The effect of this kind " cortex " is to prevent from that fibrous inside from solidifying rapidly also to prevent simultaneously blowing agent stripping fiber outer surface.This kind cortex also prevents to foam at fiber surface.Simultaneously, because blowing agent is a non-solvent for polymer, and is dissolved in the solvent in the spinning solution, therefore, in the solidifying process process, demonstrate a kind of diffusion that is similar to solvent.But,,, and be most blowing agent is still stayed fiber with the state that forms stable mixture with solvent inside at least so it can or can not be dissolved out from fiber hardly because blowing agent is insoluble to or is dissolved in hardly in coagulating bath or the water.Show that by contrast in the general technology process, solvent and blowing agent have diverse performance.Particularly be dispersed in the blowing agent in the spinning solution, further segregation comes out from polymer and solvent, consequently in fiber be usually with simply with segregation or adhesion brokenly demonstrating the effect of analysing mutually clearly, thereby cause partial foaming during the heat treatment of carrying out afterwards.

The consumption of blowing agent is 3 to 100%(weight), 5 to 50%(weight even more preferably), but, this depends on kind and its solvability in thermoplastic-polymer solution of blowing agent.Except that the kind of blowing agent with the state of the spinning solution after adding blowing agent, suitable consumption is to select according to the state of formed fiber after spinning and the situation of fiber cross sections.The method that adds blowing agent can be blowing agent directly to be added in the spinning solution jar or before carrying out spinning by spinning-nozzle individually or with the mixture of organic solvent mix with this spinning solution immediately.

In case of necessity, judge, can add nucleator in the spinning solution according to the foamed state of fiber or from relevant production reason.

Nucleator can be used inorganic powder, and particle mean size can be up to 10 μ m, is preferably 5 μ m or less than 5 μ m, and is more preferably 2 μ m or less than 2 μ m.This kind inorganic compound can be, nonmetal oxide for example, for example, boron oxide, silica, metal oxide, for example aluminium oxide, antimony oxide, zirconia, titanium oxide, zinc oxide and tin oxide, water-soluble hardly or water-fast metal hydroxides or slaine, silicon compound, for example kaolin, talcum and bentonite still, are not limited thereto and available above-mentioned more than one mixture.In addition, organic nucleating agent is known a cellulose esters, for example acetyl cellulose, cellulose propionate ester, and they can also mix use with inorganic particulate, and there is no particular restriction for the consumption of this type of nucleator.

The effect of this type of nucleator is known, can be used to prevent the partial foaming in the technical process that forms fiber, improves the stability in the process for making and reduces because the danger of the fiber breakage that partial foaming caused.Except that above-mentioned effect, when cellulose esters was used to make fleece, cellulose esters can improve the overall performance of porous fibre.

With prepared spinning solution, spray in the coagulating bath then, make porous fibre with half-dried or wet spinning technology process.Can use the additive that other made porous fibre has the needed character of specific use, for example stabilizing agent, organic or inorganic colouring agent, Optical Bleaching Agent, flatting agent and fire retardant be not if they disturb purpose of the present invention.

For spinning process, the spinning solution for preparing is sprayed in the water coagulating bath by nozzle.Many alternative gap nozzles are arranged, for example circular, square or other shapes, can select the nozzle of other any shapes according to the concrete purposes of fiber.

A kind of aqueous solution of organic solvent of polymer is preferably adopted in coagulating bath.Determine arbitrarily in the boiling spread of blowing agent that temperature and concentration can be under curing conditions.The blowing agent that is adopted in coagulating bath solubility and the transverse shape of the fiber of manufacturing also should take in.The meaning of " considering the solubility of used blowing agent " is that the requirement blowing agent is dissolved in hardly or is insoluble in the aqueous solution of organic solvent.Specifically, the solubility of blowing agent in coagulating bath should reach 10%(weight), and preferably reach 5%(weight).If the solubility of used blowing agent in coagulating bath surpasses 10%(weight) time, the concentration of blowing agent in polymer just reduces significantly, the result just can not fully foam in foam process process subsequently, when if the temperature of coagulating bath surpasses the boiling point of blowing agent, fiber begins foaming, but the bubble of this kind porous fibre can be broken or connect together, and so just makes the foaming failure.

In case of necessity, before the rinsing, the fiber of the polymer that will solidify stretches in the bath of the aqueous solution of the organic solvent of polymer or in air in water-bath.The rinsing temperature can be determined arbitrarily and needn't consider the boiling point of blowing agent, but in order successfully to form fiber, preferably from fiber, remove the solvent of polymer and make blowing agent still stay in the fiber, and in order to promote the desolventizing effect, then preferably keep high rinsing temperature, in case of necessity, can in rinse cycle, stretch.Also may reach partial foaming with the rinsing temperature that is higher than blowing temperature.But in rinse cycle, excessive foaming rapidly is problematic for fibre forming.Therefore, preferably suitably consider the type of used blowing agent and from fiber, remove solvent and determine the rinsing temperature.

When as method in, use a kind of in solvent undissolved blowing agent, realize admixture of the present invention be very the difficulty.Therefore, available fibre structure is the air pocket that what is called that the isolated sticking action caused partial foaming of blowing agent in polymer caused is disperseed.Think that the last foaming condition of fiber is to depend on that blowing agent and solvent are not excessive at all in the character of fibrous inside and the saying of the performance in distribution and their heating process in the back.

Resulting porous fibre is with lubricator handled and carried out drying, with the shaping of further promotion fiber.In dry run, if the amount of the solvent of polymer in rinsing is bathed is higher than a certain limited amount, then can cause welding between the fiber, thereby cause " perforate degree " to reduce, therefore preferably handle fiber, so that make the danger of static disorder be reduced to minimum degree with suitable lubricant with antistatic property.When the consumption of blowing agent was high, the solvent with fiber rinsing that spun was also inevitable high, and this just causes increasing single fiber and welds together danger.In order to prevent this point, preferably use the lubricant of high score from effect.What effect was good especially in this respect is silicone lubricant.The general silicone lubricant that uses is a dimethyl polysiloxane, and methylhydrogenpolysi,oxane and alkoxyl polysiloxanes, and the polysiloxanes of sex change for example, contain the polysiloxanes of epoxy radicals and contain amino polysiloxanes.These siloxanes generally are to use with the form of emulsion.In order to improve the feel of foamed fibre, particularly preferredly be to use the epoxy radicals sex change and silicone lubricant amino sex change.

In addition, dry run must be to be to be higher than the boiling point of blowing agent and to be not less than under 100 ℃ the condition to carry out in dry air, temperature.If baking temperature is lower than 100 ℃, the inside of fiber remains wet, and this can disturb the physical property of fiber, but also makes troubles for fiber process step afterwards.If in rinsing or dry run, do not reach the boiling point of blowing agent, this will cause foaming insufficient, and needless to say, this is not wish the phenomenon that exists.

Will be through the fiber of supersolidification and heating (foaming) process, before it becomes the end product fiber, through the needed a plurality of steps of process, just pass through stretching for the first time, rinsing, drying, stretching for the second time, heat treatment and curly course, but the step with general fibre is identical basically for these processes.Also can with heating (foaming) with solidify, process such as first time stretching, rinsing carries out simultaneously.Use spinning character, antistatic behaviour, water proofing property, grease proofness, the character of depolluting that various auxiliary agents improve fiber, feel etc. do not belong to scope of the present invention, when needed, can use wherein any auxiliary agent.And for processes such as drying, printing and dyeing, coating, lamination, shaping processing, its situation also is like this.

The meaning of spongiform foaming part of the present invention is, independent or mutually continuous bubble or its mixed form randomly be distributed in fibrous inside or the polymer composition.Bubble can also be by membranaceous structure, be similar to the culture propagation structure in the complexion room or form island structure and seal.But, needless to say, require these bubbles not disturb bare bones of the present invention, that is to say, do not disturb the effect of the present invention based on foaming structure.In this respect, the bubble that arrives fiber surface should be avoided in strictness, and this that is to say that the bubble that arrives fiber surface can produce crackle or hole that dyeability (particularly color effects) to fiber or spinnability have adverse effect.

Wish that expansion ratio is 3% or higher.If be lower than 3%, porous fibre does not have such enough performances of original hope.If expansion ratio is higher than 100%, it is unpractical so, because it had not only influenced the mechanical performance of fiber but also influence its physical property.Preferred range is 5-90%, can realize purpose of the present invention effectively in this scope.If physical property, the apparent thickness when shade or thin shade are especially dyed in stock-dye, soft gloss and transparency of visual sense etc. all added go in the technical conditions, then can make evaluation stricter and exactly.

The cross section of porous fibre is clearly determined bubble core with numerous air-bubble and the structure cortex that is different from the former significantly (being designated hereinafter simply as " double-layer porous fiber ") in spongelike structure, the bulkiness of this kind porous fibre, heat-insulating property, mechanical performance and physical property and all further be improved as the colour rendering of animal wool.

In spongelike structure of the present invention, the bubble core that is formed by dividing wall is a part by the cortex sealing, this part does not comprise following described bubble in fact, this kind bubble core has a kind of many independent or continuous bubble of random dispersion, a kind of bubble structure that has by the hollow space of its inner thin membranous wall segmentation, a kind of round yeast-leavened composition of resembling of this center, cross section or island structure.But the position of this core is also unrestricted, as long as it is surrounded just passable by cortex.

The cortex meaning different with the bubble core is that the compactedness of this cortex part is similar to non-porous fiber, but and do not require that it is not have bubble structure fully.As long as this part has the compactedness that is different from the bubble core, promptly meet the requirements.But needless to say, it should not influence the double-deck effect of representative bare bones of the present invention.Foregoing loose structure is different from common hollow fibre, and hollow fibre is owing to being heated or outer mechanical force makes its cross-sectional deformability, and the effect that is more or less the same with the present invention can not be provided.Thereby at those fibers that have a small amount of bubble on the cross section or the bubble that all distributing can not identify cortex on whole cross section is not within the scope of the invention.Fig. 6 shows the typical cross section of general fibre.Fig. 6 (a) is an example with a kind of fiber of chemical foam blowing agent, Fig. 6 (b) is with the example of the caused phase separation of method that mixes incompatible polymers, and Fig. 6 (c) is a kind of porous fibre of the inner hollow made from low-boiling foaming agent.

Double-decker of the present invention can compare according to the cross-sectional configuration of the ratio of bubble core area and total cross sectional area and Fig. 7 and 8 shown true animal wools and estimate.With the foaming core of formula calculating described below and the area ratio in cross section, preferably between 5 to 90%.If be lower than 50%, porous fibre is enough performances of expection not, if be higher than 90% then be unpractical, not only influenced the mechanical performance of fiber but also have influenced its physical property.Preferred scope is 10-60%, in this scope, can reach purpose of the present invention effectively.If with physical property, when with stock-dye, especially dye the apparent thickness of shade or thin shade, soft gloss and transparency of visual sense etc. and all add and go in the technical conditions, then can estimate stricter and exactly.

For the form in the basic cross section of porous fibre of the present invention and unrestricted, it can be a kind of shape in the following different shape, for example, and annular, U-shaped, eyebrow shape, potato shape, rectangle, triangle, Y shape, 11 shapes and star.

In above-mentioned shape, cited herein is a kind of rectangle cross section (hereinafter referred is " flat ").Adopt " flat " or slit shape cross section commercial be the common practice, owing to apparent thickness that it had makes fiber have a kind of very soft feel, and owing to increase that it had its reflective surface area and orientation etc. produce very good color effects.From the microscope cross section photo of Fig. 7 (true fur) and Fig. 8 (true fox skin) as can be seen, animal wool has flat bubble, still, they neither single be not again uniform, but having a kind of spongiform outward appearance, its inner hollow part is separated by many film shape walls.The inventor thinks, this kind difference structurally is exactly the reason of animal wool and the huge difference of common porous fibre on performance, and this is very important main points for the value of improving " flat fiber ".

The basic transverse shape of this kind cited herein is not limited in rectangle, and it can also be " Eight characters " shape, avette, dumb-bell shape, rhombus, sweet potato shape or or even annular.

About basic structure of the present invention, the transverse shape of the animal wool in Fig. 7 or Fig. 8 can be used as the case of comparative examples by length/minor axis ratio and expansion ratio (being measured by the proportion of measuring fiber) expression.The sponge structure of this expansion ratio and fiber is closely related.Length/minor axis ratio preferably between 2.0 to 15.0, when it is lower than 2.0, can not reach desirable thick visual sense.

Needless to say, resulting porous fibre has the feature of general fibre, in addition, because its loose structure, and makes it have many outstanding features, promptly in light weight, bulk, heat-insulating property and heat-proof quality.Double-deck maximum characteristics are the mechanical strengths that keep porous fibre, and this porous fibre can stand many preprocessings well, for example painted, spinning, knitting and braiding.Further be pointed out that its soft hand feeling and fabulous dyeability (special color effect).In addition, unexpectedly be the very approaching true animal wool of the gloss of porous fibre of the present invention, feel and colour rendering.Hereinafter further narration again.

When their color dyes and whens dyeing with itself, the characteristics of true animal wool are just more obvious.When accurately checking true animal wool, the apparent thickness that can see so-called " pin hair " depends on the degree of depth of its tone greatly.

That is to say that when they presented thin shade, for example when ecru and grey, they were with regard to seeming thick and matt, when they presented shade, for example when brown or black, they just seemed very thin, transparent and have gloss.In addition, the degree of depth of tone even variation continuously with different single hairs, this has a kind of very interesting effect.The inventor supposes that its reason is the optical property of the core segment of animal, and obtains following results after further studying.Though former carrying on as before do not know,, inventor's suggestion is that top result is because the multipath reflection and the scattering of the light on the incident sponge structure cause.When hair was light color, the major part of incident light was carried out multipath reflection and is presented a kind of lacklustre outward appearance that adds under a kind of inorganic matter situations such as (fillers) that is similar at the sponge core.On the other hand, when hair is dark color, goes into the dyestuff that the time just existed in a large number and absorb, and above-mentioned above-mentioned reflecting effect at the sponge core just has been cancelled, the result does not have obvious effects.

Therefore, the degree of depth of color influences the apparent thickness of animal wool sensitively.

Observe double-layer porous fiber, when it was light color, incident light then saw through on the interface of cortex/core that the cortex part almost directly is mapped to fiber, and it was contained in small amounts of pigment and transparency height at that time.But wherein a part of incident light is by random scatters, and remaining incident light so it is such just to obtain being similar to the situation that adds inorganic matter (filler), produces a kind of lacklustre effect then through repeatedly reflection.When this fiber was dark color, wide pigment that is existed in a large number of incident absorbed, and the phenomenon that those take place on the interface does not just have significant effect.Because the character of cortex part is closely knit, so when this kind character and so-called " mirror effect " when combining, the gloss of fiber surface will be given a kind of charming visual sense of people.

The unique hand feeling of fiber of the present invention is considered to by the apparent thickness of the fiber in flat cross section (major axis on one side area effect), soft hand feeling characteristic (minor axis curvature effect on one side) and has that elastomeric sponge structure causes.In addition, when the sponge core is considered to multilayer, produce the pearl effect gloss that seems when using flake pigment probably, this Another reason that the chances are this " charming effect ".

Hereinafter explain the present invention, but these only are some embodiment, and must not be used for limiting the present invention with embodiment.

The area ratio of being mentioned in the embodiment of this paper, length/minor axis ratio, apparent thickness and expansion ratio are measured by following method.

(a) area ratio:

Application scanning electron microscope (the board Works ' Model s-510 of Hitachi) under fixedly multiplication factor and fixed range, is taken the cross section of single fiber from the upper right side, after definite cortex/cored structure, measure total cross sectional area.Measure the cross sectional area of cortex part then, the ratio of core segment and the cross section gross area then is with the mean value calculation of 25 samples with following formula.

Area is than (%)=((S _s-S _b)/S _s) * 100

In the formula: S _s: total cross section of porous fibre

S _b: total cross section of porous fibre cortex part

(b) length/minor axis ratio:

Application scanning electron microscope (the board Work ' s Model S-510 of Hitachi) under fixedly multiplication factor and fixed range, is taken the cross section of single fiber from the upper right side.Get 25 samples then at random, measure their major axis and minor axis, the major axis of measuring each sample is with the ratio of minor axis and average.

The length of the length/minor axis of length/minor axis ratio=major axis

(c) expansion ratio

Sample (particle) accurately weighing in air with about 0.5 gram, under the speed that is no more than the fiber wetting speed, it is immersed in automatic opacimeter, and (Toyo Seiki Sei Sakusho measures the proportion of fiber by the substituted water yield in top ltd) and the water receptacle of bottom.For preventing on specimen surface, to form air bubble, in water, add the agent for capturing of Trace Fluoride surfactant as bubble.Then, calculate expansion ratio with following formula by proportion.

Expansion factor (%)=(B/S-1) * 100

In the formula: B is the proportion (blank) of non-porous fiber

S is the proportion of porous fibre

Embodiment 1

Will be by 50%(weight) acrylonitrile, 49%(weight) vinyl chloride and 1%(weight) the copolymer formed of Sodium styrene sulfonate be dissolved in the acetone, the polymer that adds per unit weight again be 40% 1,1,2-three chloro-1,2,2-HFC-143a and 0.2% titanium dioxide, this polymer concentration is adjusted to 25%(weight), and in closed container, stirred 30 minutes down at 40 ℃.

With the spinnerets of resulting spinning solution by 0.18 millimeter aperture * 200 holes, spray in 25 ℃ 21% aqueous acetone solution, and under 4.5 meters/minute coiling speed, in bathing, this flooded for 9 seconds, then, this fiber was flooded for 6 seconds and stretches 1.8 times in the bath with same composition and temperature, make it subsequently under tension force, in 75 ℃ of hot baths, stop about 1 minute to finish foaming process.Fiber with resulting rinsing, in 120 ℃ hot flue gases drying machine, be dried to remaining water content and be up to 1%, and then this kind fiber stretched 2.75 times for the second time, and under tension force, at 145 ℃, heat treatment 5 minutes is that 15 dawn, area ratio are 43% so just obtain a kind of filamentary fiber number, and apparent density is 0.86 and the porous fibre of expansion ratio 50%.With this kind fiber, use method commonly used, when being organized into pluse cloth, this kind fiber is different from common artificial wool fully, but extremely light, and tone, gloss and feel are all fabulous and very beautiful simultaneously.Fig. 1 shows the electron scanning micrograph of prepared fiber cross section.

Embodiment 2

To form identical polymer with embodiment 1 is dissolved in the acetone, the polymer that adds per unit weight again is the sulfoacid calcium powder of 20% pentane and 2%, the final concentration of this polymer is adjusted to 25%(weight), and in closed container, stirred 30 minutes down at 33 ℃.Resulting spinning solution sprayed into by an identical spinnerets in one 10 ℃ 50% aqueous acetone solution, and under 4.5 meters/minute coiling speed, in bathing, this flooded for 9 seconds, then this fiber is flooded 18 kinds of clocks and stretches 3.06 times in 40% aqueous acetone solution, in 50 ℃ of water-baths, proceed for the first time 12 seconds of foaming process subsequently, make it in 70 ℃ of hot baths, stop 13 kinds of clocks then, to finish foaming process.The fiber of rinsing is dried to residual moisture content is up to 1% in 120 ℃ of hot flue gases drying machines, and then this kind fiber stretched 2.65 times for the second time, and at 145 ℃, under tension force, heat treatment 5 minutes, so just obtaining a kind of filamentary fiber number was 15 dawn, area shows the porous fibre of density 0.95 and expansion ratio 35.8% than 16%.When this kind fiber was used to make the Wilden woven carpet, it was bulk and of good quality, and is graceful unique in the cross section and the edge tone variations of fiber.Fig. 2 shows the electron scanning micrograph of this fiber cross section.

Embodiment 3

Will the spinning solution identical with example 1 having 100 by one is being 0.60 millimeter on the major axis and is being the spinnerets of 0.08 millimeter rectangle narrow slit on minor axis, spray in 25 ℃ 30% aqueous acetone solution, resulting fiber under 4.5 meters/minute coiling speed, in bathing, this was flooded for 9 seconds.Then, in 30 ℃ 25% aqueous acetone solution, flooded for 6 seconds and stretch 1.8 times, make it subsequently under tension force, in 75 ℃ of hot baths, stopped about 1 minute, to finish foaming process.The fiber of resulting rinsing is dried to residual moisture content is up to 1% in 120 ℃ hot flue gases drying machine, and then this kind fiber stretched 2.75 times for the second time, and under tension force, at 145 ℃, heat treatment 5 minutes was 20 dawn so just obtain a kind of filamentary fiber number, and the ratio of length/minor axis is 4,5, expansion ratio is 15% flat porous fibre.With this kind fiber, during the pluse cloth that is organized into method commonly used, this fiber is different from common artificial wool fully, but extremely light, and good, gloss of tone and feel are all fabulous and very beautiful simultaneously.Fig. 3 shows the electron scanning micrograph of prepared fiber cross section.

Embodiment 4

In the polymer identical with embodiment 1, add 12% pentane and 2% calcium carbonate powder, obtain a kind of spinning solution of 25% polymer.This spinning solution is had 100 by one to be 0.55 millimeter on the major axis and to be the spinnerets of 0.13 millimeter oval narrow slit on minor axis, spray in 25 ℃ 21% aqueous acetone solution, resulting fiber under 4.5 meters/minute coiling speed, in bathing, this is flooded 9 kinds of clocks.Then, this fiber was stopped for 18 seconds and stretches 1.8 times in the bath with same composition and temperature, subsequently, make it under tension force, in 75 ℃ of hot baths, stop 45 kinds of clocks, to finish foaming process.

With resulting fiber use with the foregoing description 3 in described identical method handle, thereby obtain the fiber of elliptic cross-section, its filamentary fiber number was 15 dawn, length/minor axis ratio is 5.4, expansion ratio is 12%.When this kind fiber is organized into a kind of pluse cloth with method commonly used, prove its performance resemble described in the foregoing description 3 good.Fig. 4 shows the electron scanning micrograph of prepared fiber cross section.

Reference examples 1

Except using blowing agent and nucleator,, make fibre number and be 20 dawn and length/minor axis than the flat fiber (general fibre) that is 6.3 with the same method described in the foregoing description 4.Fig. 5 shows its electron scanning micrograph.

Embodiment 5

(1) with 48%(weight) acrylonitrile, 51%(weight) vinyl chloride and 1% pair-Sodium styrene sulfonate are dissolved in (stoste A) in the acetone, adding the per unit weight polymer again is 40%1,1,2-three chloro-1,2, the 2-HFC-143a, 0.2% titanium dioxide and 2% poly (glycidyl methacrylate) are adjusted to 22.7%(weight with this polymer concentration), and under 45 ℃, stir 3 hours with the preparation spinning solution.With this spinning solution by one have the aperture be 0.15 millimeter 10, the spinnerets in 000 hole, spray in 25 ℃ the first bath of 2.0% aqueous acetone solution, resulting fiber is stretched 1.2 times in second bath with uniform temp and concentration, bathe (65 ℃), the 4th the 3rd and bathe (75 ℃), with rinsing in the 5th bath (80 ℃), and simultaneously with its total stretching 2.1 times, dipping is removed these auxiliary agents in the bath of this fiber being equipped with non-ionic antistatic agent and amino sex change polysiloxanes emulsion then.Then with fiber 110 ℃ of dryings, by 1: 2.5 draw ratio, in 130 ℃ air, stretch, under 145 ℃ of conditions, heat-treat subsequently, draw ratio is reduced to 1: 0.9, makes the porous fibre at 7 dawn, and using then that rod formula crimping machine curls this fiber and be cut into length is 51 millimeters.(artificial fibre A)

(2) in the polymer of stoste A, add 45% 1,1,2-three chloro-1,2,2-HFC-143a, 0.2% titanium dioxide and 2% poly (glycidyl methacrylate), and the ultimate density of polymer regulated most 22.5%(weight).Then, prepared original solution is had the spinnerets that the aperture is 13,333 holes of 0.11 millimeter by one, spray in 23 ℃ the first bath of 20% aqueous acetone solution.In second of uniform temp and concentration is bathed, stretch 1.2 times then, and bathe (80 ℃) and the 4th rinsing bath (84 ℃), this fiber is further stretched 2.1 times by the 3rd rinsing.After this use above-mentioned (artificial fibre A) identical method with this fibre finish, and to be cut into length after curling be 38 millimeters.(artificial dimension dimension B)

(3) in the polymer of stoste A, add 18%1,1,2-three chloro-1,2,2-HFC-143a, 0.2% titanium dioxide and 1.7% poly (glycidyl methacrylate), and the ultimate density of polymer is adjusted to 23%(weight), stirred 3 hours down at 45 ℃ then, it is dissolved fully.Then with prepared stoste by a spinnerets with 3,333 holes of 0.08 millimeter of long 0.60 mm wide, spray in 30 ℃ the first bath of 20% aqueous acetone solution.Then this fiber is stretched 1.2 times in second of uniform temp and concentration is bathed, and bathe 80 ℃ by the 3rd rinsing, 85 ℃ of the 4th rinsing baths and the 5th rinsing are bathed 90 ℃, further stretch 2.1 times.Put this fiber in order with above-mentioned identical method then, and to be cut into length after curling be 51 millimeters.(artificial fibre C)

Table 1

Fibre number intensity percentage elongation Young's modulus amount of crimp expansion ratio

(d) (g/d) (%) (kilogram/millimeter ²) (per 1 inch)

S.F.A 7.6 2.6 27 280 7.2 11

S.F.B 3.1 2.9 27 310 8.2 12

S.F.C 20.0 2.2 25 350 6.0 7

Porous fibre of the present invention has the favorable mechanical performance, and actual use is satisfactory.

Claims (2)

1, a kind of porous synthetic fiber, it is characterized in that a kind of bubble structure (loose structure) being arranged at the fibrous inside that acrylonitrile polymer or its copolymer are made, described fiber is flat, and the length on its cross section/minor axis ratio is 3.2 to 8.8, and has 3 to 50% expansion ratio.

2, be manufactured on the method that this fibrous inside has the porous synthetic fiber of bubble structure (loose structure), this method comprises the following steps:

(a) by acrylonitrile polymer or its copolymer are dissolved in a kind of organic solvent, prepare a kind of spinning solution;

(b) in described polymer, add a kind of described polymer calculating of pressing, its quantity be 5 to 45% be selected from pentane, hexane, heptane, benzinum, pentamethylene, 1,1,2-three chloro-1,2, the blowing agent of 2-HFC-143a, this type of blowing agent dissolve in the organic solvent of polymer or the solution of polymer, and are dissolved in hardly or are insoluble in the water coagulating bath of carrying out wet spinning;

(c) the described spinning solution that will contain described blowing agent sprays in the described water coagulating bath;

(d) the resulting fiber of rinsing; With

(e) in dry air, under 50 to 145 ℃ of temperature and condition, finish foaming process in 3 to 50% expansion ratio.

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