JP2009019300A - Method for fixing fiber onto substrate, and laminated sheet form - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily fixing extrafine fibers onto a substrate while keeping their pores, in the case of needing fixing e.g. a nonwoven fabric comprising such extrafine fibers onto a film, woven fabric or the like, for example, in the case of artificial blood vessels which have enough flexibility and mechanical strength to withstand blood pressure and/or stretch and contraction stemming from body motion and required such the function that substances therein can selectively permeate it. <P>SOLUTION: The method for fixing an extrafine fiber layer on a substrate comprises heating the extrafine fibers each composed of a plurality of components to a temperature higher than the lowest melting point among those of the respective components to melt the component in question. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for fixing fibers to a substrate and a laminated sheet body.

  In some cases, it is necessary to adhere a non-woven fabric made of ultrafine fibers to a film or woven fabric. For example, such as an artificial blood vessel, which has flexibility and strength capable of withstanding expansion and contraction due to blood pressure and body movement, and a function capable of selectively permeating a substance in the blood vessel is required. In such a case, the method of sticking the film body which has a micropore on the strong base material, the method of making an ultrafine fiber entangle with a base material directly, etc. are taken.

For example, in patent document 1, it manufactures by making an ultrafine fiber entangle with a nonwoven fabric. In this case, not only the production is troublesome, but also the fine fiber enters the non-woven fabric of the base material, so that it is difficult to adjust the pore size.
Japanese Patent Application Laid-Open No. 11-164881

  The reason for taking such a laborious method is that it is difficult to bond the ultrafine fibers to the base material with transparency. It has very small pores, and it is very difficult to bond with an adhesive without blocking it.

  In view of this, the present invention provides a method by which an ultrafine fiber can be fixed to a substrate while maintaining its pores.

In view of the current situation, the present inventor has completed the fixing method and the laminated sheet body of the present invention as a result of intensive studies. The feature of the fixing method is that ultrafine fibers are formed on the substrate in the fixing method. It is a method for fixing a layer, which is in that it is heated to the lowest melting point of a fiber composed of a plurality of components and is fixed to a base material by melting the component. An ultrafine fiber layer is fixed to the substrate, and is heated to a temperature higher than the lowest melting point of a fiber composed of a plurality of components, and is fixed to the substrate by melting the components.

The base material here is basically a thin film. Although not limited, the thickness is preferably several tens of μm to several hundreds of μm. This substrate may or may not be air permeable. Examples of the material having transparency include a woven fabric, a nonwoven fabric, and a knitted fabric, and examples of the material having no transparency (not a strict meaning) include a sheet and a flat plate.
Examples of the material include glass, ceramics, metal, plastic, and rubber.

  The ultrafine fiber here refers to a fiber having a diameter of 1 mm or less. This is because the fixing of the present invention becomes difficult when the thickness is 1 mm or more. Among these, several hundred nm to several tens of μm are preferable.

  This fiber is a synthetic fiber and dissolves in a solvent. The method for producing the fiber is arbitrary, but the electrospinning method is convenient. In this method, a polymer is dissolved, put into a syringe, extruded from a narrow hole provided at the tip, the solvent is evaporated to form a fiber, and it is sprayed randomly on the object. At this time, the syringe is charged, the target object is grounded, and the ultrafine fibers are easy to fly. The thickness of the fiber can be adjusted by the diameter of the hole at the tip and the concentration in the solvent.

  Of course, the solvent may be evaporated simply by extruding without applying electric charge, or it may be already in a fibrous form by another method.

The ultrafine fiber layer means that the ultrafine fibers are not simply fixed to several base materials, but are formed into a film having a large number of through-holes by a large number of ultrafine fibers. The thickness of this film is arbitrary, and conversely, by adjusting the thickness, the size of the penetrating material can be limited. An example of the thickness is preferably several tens of μm to several hundreds of μm.
Moreover, although the size of the pores (voids) formed by these fibers is arbitrary, it is preferably several tens of μm to several hundreds of μm.

The expression “consisting of a plurality of components” is used in the present application in two meanings.
One is when one fiber is a mixture of multiple components rather than a single component. For example, it is like two polymers making a sea-island structure. At least one component must be a polymer, but the other can be an oligomer. It is not limited to two components, and may be three or more components.

  It is essential that the plurality of components have different melting points. Although the degree of difference is not limited, in practice, it is preferable that there is a difference of 30 ° C. or more. Considering the ease of temperature management and the like, it is more preferable if there is a difference of about 50 to 100 ° C. In the case of three or more components, there is no need for all differences. There should be at least one difference.

  The melting point in the present application is not only the melting point in the sense that the crystal melts, but also the softening point of the amorphous substance, which can be fixed to other things if it is higher than the softening point, and keeps its state if it is lower than that temperature It also includes the meaning of temperature that can be used.

  Any solvent may be used as long as it dissolves the polymer or the like. The concentration in the solvent also varies depending on the viscosity of the polymer, the thickness of the fiber to be produced, the solvent used, etc., but is usually about 1 to 50% by weight.

Examples of such fibers are as follows when a combination of two kinds of polymers and oligomers and a solvent at that time are exemplified. The last is a solvent.
1 Polylactic acid Polycaprolactone Dichloromethane 2 Polylactic acid Polybutylene succinate Dichloromethane 3 Polyacrylonitrile Polylactic acid N, N-dimethylformamide 4 Polyamide Polymethyl methacrylate Formic acid 5 Polyamide Polyoxymethylene Hexafluoroisopropanol 6 Polyamide Polyethylene terephthalate Hexafluoroisopropanol 7 Polyethylene oxide Polycarbonate Chloroform 8 Polyaniline Polystyrene Chloroform 9 Polyurethane Polylactic acid N, N-dimethylformamide 10 Polystyrene Polyvinyl chloride Chloroform 11 Polycaprolactone Polymethyl methacrylate Chloroform 12 Polycarbonate Polycarbonate oligomer Chloroform

  Another meaning of the expression “consisting of a plurality of components” is a method using a plurality of fibers composed of different components. This is like a non-woven fabric or the like in which polylactic acid fibers and polycaprolactone fibers are separately present.

  The fiber is heated above the lowest melting point of such a plurality of components. That is, a component having a low melting point of the fiber is heated and melted (including softening, the same applies hereinafter), and thereby fixed to the substrate. For example, in the case where the above-described polylactic acid (melting point: about 160 ° C.) and polycaprolactone (melting point: about 60 ° C.) have a sea-island structure, the fiber is heated to 60 ° C. or higher. However, strictly in the case of a sea-island structure, it does not always melt at its melting point, so it may have to be higher. In short, it is the temperature at which one component melts and adheres to the substrate.

  By this heating, a part of the fiber (low melting point portion) melts and adheres to the base material and other fibers. No adhesive is required.

  Further, when a plurality of components constitute separate fibers, the low melting point fiber is melted as a whole, and the unmelted fiber and the base material are fixed. In this case, the substrate preferably has no permeability.

  The heating method may be any method as long as the fiber is heated, such as heating a table or roller (metal or the like) on which the substrate is placed with an electric heater, or sending hot air to the fiber.

  In order to easily and reliably fix the fiber and the substrate, the substrate and the fiber may be pressed. This is possible with a press, a pressing roller, or the like.

  The present invention is a method for fixing ultrafine fibers to a substrate as described above, and the use of the fixed fibers is not limited. To the last, it is a novel method of dissolving and fixing one component of the fiber without using an adhesive. Unlike conventional mere fusion, the entire fiber does not melt or soften.

  Examples of uses of the present invention include clothing, medical devices (such as wound tape), artificial organs (such as artificial blood vessels), and various separation membranes. Various materials may be selected for the base material and may be made suitable for the application depending on the material and thickness of the fiber to be fixed.

  Furthermore, as one aspect of the present invention, there is one manufactured by the above method, that is, one in which ultrafine fibers are fixed to a substrate by the above fixing method. This is referred to herein as a laminated sheet body.

The present invention has the following advantages.
(1) Even very thin fibers can be fixed to a substrate without using an adhesive and almost without blocking the space formed by the thin fibers.
(2) Since very thin fibers can be fixed to the base material, an artificial organ of a human body such as an artificial blood vessel can be manufactured by selecting an appropriate base material.
(3) The size of the particles passing through the fiber layer can be freely adjusted depending on the thickness and amount of the ultrafine fibers.
(4) Particularly, if the fiber is produced by the electrospinning method, the ultrafine fiber can be easily obtained and is more preferable.

  Hereinafter, the present invention will be described in more detail with reference to examples.

FIG. 1 is a schematic sectional view showing an example of the fixing method of the present invention. This is an application of the electrospinning method. A substrate 2 is placed on a metal roll 1, and a liquid 4 in which a polymer is dissolved is placed in a syringe 3. The syringe 3 is charged and the metal roll 1 is grounded.
When the piston 5 is pushed in this state, the dissolved liquid 4 is ejected from the tip opening 6 toward the grounded roll 1. In the middle, the solvent is volatilized, the liquid is solidified, and placed in a solid state (thin fibrous form) on the base material 2 on the roll 1 like a nonwoven fabric. Then, the roll 1 is heated, a part of the fiber is melted, and the unwound part (part of the fiber) is fixed (fused) to the base material 2 so that the whole fiber is fixed to the base material. The

  Here, a press roll 7 is provided in the information of the metal roll 1 in order to make the fixation more reliable. Then, when both rolls are rotated as indicated by the arrows, a pressed and fixed 8 (laminated sheet body) can be obtained.

  As the substrate 2, a woven fabric made of PET (polyethylene terephthalate) was used. The thickness of the yarn is about 50 μm and is woven with a space of about 10 μm.

The liquid used in this example will be described.
First, the following two equal weight mixtures of A and B were used as fiber components.
Component A: polylactic acid (melting point: about 60 ° C., average molecular weight: about 80,000)
Component B: polycaprolactone (melting point: about 160 ° C., average molecular weight: about 300,000)
This was dissolved in a mixed solvent of 60% by weight of DCM (dichloromethane) and 40% by weight of pyridine. The concentration was about 6% by weight.

  The charged voltage is 10 kV. The distance between the opening 6 of the nozzle and the substrate 2 was 150 mm, the liquid feeding amount of the piston was 0.1 to 1 ml / Hr, and the diameter of the opening 6 was 120 μm.

  The heating temperature of the metal roll 1 was 80 ° C. and an electric heater (not shown) was incorporated.

  As a result, a structure in which a very fine thin nonwoven fabric was stuck on a PET woven fabric was obtained.

It is a schematic sectional drawing which shows an example of this invention method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal roll 2 Base material 3 Syringe 4 Liquid 5 Piston 6 Opening 7 Pressing roll 8 What was fixed

Claims (6)

 A method for fixing an ultrafine fiber layer on a base material, wherein the fiber is fixed to the base material by heating above the lowest melting point of the fiber composed of a plurality of components and melting the components. Fiber fixing method.   The method for fixing fibers to a substrate according to claim 1, wherein the plurality of components are contained in one fiber as a sea-island structure.   The method for fixing fibers to a substrate according to claim 1, wherein the plurality of components are configured as separate fibers.   The fiber fixing method according to claim 1, wherein the substrate is a permeable membrane.   The method for fixing fibers to a substrate according to claim 1, wherein the substrate is a non-permeable film. An ultrafine fiber layer is fixed on a substrate, and is heated to the lowest melting point of a fiber composed of a plurality of components and fixed to the substrate by melting the components. Laminated sheet body.