JPS58144156A - Production of armatic polyamide nonwoven fabric - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for producing aromatic polyamide nonwoven fabric.

More specifically, we will discuss 9 aromatic polyamides with excellent heat resistance, flame retardancy, impregnability, 2 surface smoothness, and 41 kK.

Conventionally, it has been widely used to manufacture non-woven fabrics by combining or entangling polyester and nylon fibers using complex methods as base materials, but these products have poor heat resistance and flame retardancy. Building materials and interior materials that require heat resistance and SL flammability due to poor roundness.

Electric I! 3 Edge material stI [It is difficult to use in the field of composite materials.

It is known that a paper-like material made of aromatic polyamide and polymetaphenylene isophthalamide (41) can be effectively used to meet such requirements for heat resistance and II flammability.

For example, it is disclosed that a polymetaphenylene ino-7 thalamide solution is dispersed in an aqueous solution to prepare a pulp of a specific shape, and the pulp and fibers are soaked in water for 11 seconds, dried, and then heated and pressurized.

(1% Public 1835-1111! It No. 1 Publication jl).

However, although this method yields a paper-like material with a dense surface structure, it has the disadvantage of having voids inside. Insulating varnish also has poor impregnation properties.

When used for insulating materials that require the use of insulating oil, etc., the dielectric strength may decrease due to the need for impregnation, and mechanical strength may be reduced.
It's not a good idea to see the drop in et life.

On the other hand, as a method for obtaining a highly impregnable aromatic polyamide nonwoven fabric, as a binder: (1) a hot dusting polymer (polyamide, polyester, etc.);

(ii) Epoxy polymer (-) Aromatic polyamide powder.

(:V) Aromatic polyamide low orientation low crystallization fiber.

A method using .

However, the nonwoven fabric obtained in (1) and (it) above has insufficient heat resistance. Also, the above (Iiii), (+v
) has sufficient heat resistance, but K requires extremely high temperatures and pressures in order to exhibit satisfactory mechanical properties. To make matters worse, the surface density and smoothness of the obtained nonwoven fabric is insufficient, and it is difficult to use for applications that require surface density and smoothness, such as applying adhesives to nonwoven fabrics or surface coating processing. A problem arises.

The present inventors have conducted intensive studies to obtain an aromatic polyamide nonwoven fabric with excellent impregnability, surface density, and smoothness without impairing the heat resistance and flammability of the aromatic polyamide material. It's a good thing to have arrived.

That is, the present invention is characterized by attaching a plating agent (such as a polar amide solvent and/or water) to a web consisting of aromatic polyamide ridges that are substantially oriented and crystallized, and then subjecting the web to hot-pressure processing. This is a method for producing aromatic polyamide nonwoven fabric.

The aromatic polyand referred to in the present invention is the following (1).

00- Ar 1-00- ・・・・・・・・・・・・
......(1)s Here, R1*% + island may be the same or different and represents a hydrogen atom or an alkyl group having 3 or less carbon atoms.

Substantive K(1) and (2) are the current molar Jl 1 ,
(3) does not necessarily include (1) and 0 at the same time.

M9ArHtAJpmr1 is an aromatic residue and may be the same or different. Typical examples of Arl+Arl+Mrs are ha57xnylene, metaphenylene, biphenylene, or a residue represented by the following formula (4).

indicates -N-, %14 is hydrogen atom, and good is 3 or more carbon atoms. It is a residue derived from the alkyl group below.

Preferred aromatic polyamides are: Ar1+ Arl+
Arc selected from hippo-phenylene or meta-phenylene.

More preferably 0 is the case where the mushroom is metaphenylene or paraphenylene consisting of (1) and O). Most preferably, it is a shim r1+ Ar meaning- This is the case with metaphenylene O.

There are several known methods for producing aromatic polyamide fibers for use in real estate @KsI. For example, one method for producing polymetaphenylene isophthalamide Iam involves dissolving polymetaphenylene isophthalamide. The raw fibers are spun using a dry method, a wet method, or a semi-dry and semi-wet method, then washed with water, subjected to boiling water abrasive stretching, dried, and then subjected to stretching heat at a temperature higher than the glass transition temperature. Take the chicken processing process.

The aromatic polyamide fiber used in Honjitsu 91 is one that has been substantially oriented and crystallized, and for 631, 11, the aromatic polyamide fiber obtained through the abrasive heat treatment process as described above is used. It gets cloudy.

In the present invention, it is also possible to use a small proportion of III heat-resistant fibers in combination with the aromatic boriyad fibers, for example, aromatic polyester fibers.

Carbon fiber-1 can include inorganic fibers, glass fibers, metal fibers, and the like.

The web referred to in the present invention refers to a round article made into a sheet shape obtained by the conventional method of making paper, such as a crimped staple (flat card or roller car).
#Method of opening the fibers using a card machine and making them into a sheet, a method of laminating long fiber O tow and planting needles on it)
The so-called long fiber tow spreading method, in which a sheet-like product is obtained by stretching in the middle direction using a belt, or 5 to 20% 1
A sheet-like product obtained by dispersing short fibers of i1 in water or air to obtain a sheet-like product.

As a polar amide solvent in KsP of the present invention, N-methyl-
Snow-Pyrridone, N,N-dimethylformamide, N,
N-dimethylacetamide, dimethyl sulfoxide, hemethylenephosphoramide, tetramethylurea, N-
Examples include methyl caprolactam, N-methyl piperidine, and mixtures thereof.

When the polar amide solvent alone or its aqueous solution is applied to a web made of aromatic boramide fibers, the amount of adhesion is preferably 1 to 160% by weight of the polar amide solvent relative to the web.

In the case of polar aqueous IIO, it should be selected appropriately depending on its concentration, but it is generally preferable to reduce the amount of attached aqueous solution 1, which has a high concentration.

If the amount deposited on the tip is less than 1 weight after changing to a polar adduct solvent,
Hot pressure processing 11O mechanical properties and surface smoothness are insufficient
On the other hand, if it exceeds 100% by weight, the nonwoven fabric will deteriorate during hot press processing, which is not preferable.

Similarly, when the plasticizer is water, the amount of the plasticizer applied is preferably 10 to 150 wt.

If the amount of water attached is less than 10% by weight, the mechanical properties and Kll
! If the smooth surface is insufficient, it will deteriorate, while if it exceeds 150% by weight, the energy loss during hot press processing will be large.

As a method for attaching the polar amide solvent and/or water to the web, a method commonly used in industry that can uniformly attach the polar amide solvent to the web can be used, such as a spray method or an impregnation method. .

In the present invention, the hot-pressing processing conditions are influenced by the amount of polar amide solvent and/or water adhering to the web, so it is best to select them appropriately, and the temperature is usually 150 to 400°C.

The processing is carried out under conditions of a pressure of 10 to 10,001 f/aaG and a processing speed (paper passing speed) of 1 ml- or higher.

If the temperature is lower than 150°C, the material is aromatic polyamide fiber, so the fusion properties are low and sufficient mechanical properties cannot be obtained. On the other hand, if the temperature is higher than 400°C, the paper passing speed is However, since the good solvent that adheres to the web tends to scatter before pressing, the fusion becomes uneven and the resulting nonwoven fabric yellows and deteriorates.

If the pressure is too low, the fusion will be insufficient), whereas if it is too high, it does not matter how high it is, but it is wasteful in terms of energy, so it is usually preferably up to 1000 Q/-.

If the paper feeding speed is slower than 3 V, the good solvent adhering to the web will scatter or become uneven before being pressurized, which is undesirable as it will result in a decrease in fusion properties and non-uniformity.

The hot pressing method is preferably carried out using two or more hot pressing rolls.

In the flat press method, the surface smoothness of the obtained nonwoven fabric is not lacking compared to that using a hot pressure roll.

Since the nonwoven fabric obtained by Honjitsu flK is composed of fibers, it is essentially voidless and has a significantly different impregnating property from synthetic paper obtained using Top pulp.

Furthermore, since the hot-pressure processing is performed with the adhesion of m-type amide solvent and/or water, the hot-pressure processing conditions are relaxed, and the denseness and image smoothness of the resulting nonwoven fabric are greatly improved. In addition, the heat-pressure-processed nonwoven fabric has an extremely low residual rate of adhesion and good solvents in the nonwoven fabric, and does not impair the heat resistance of the material at all.

The nonwoven fabric obtained in this way can be used as an electrical insulation material, a building material,
It is expected to be used in O-heat composite materials such as inner pocket materials, release sheets, and even honeycombs.

Examples of the present invention will be described below.

The oil impregnation properties in the examples were as follows: After drying a 5 m square sample in vacuum at 2°C under atmospheric pressure, the insulating oil was poured onto the surface of the sample using insulation oil No. 1 (JI8 standard). The time taken by the town is measured and carried out by friends.

In addition, the scale representing the WiO flatness of the table is JI8B...01-1
Center line average roughness B, which is specified in 176 and indicates nine surface roughness.
1).

Fruit 11-3. Comparative Examples 1 to 3 Commercially available polymetaphenylene isophthalamide fabric (trade name: Cornenox) subjected to stretching heat treatment.

After pre-opening the thread yarn [1,5 de, cut length 51 kaku] with a single scatcher, flat car)
A cross-laid uniform was used to form a cube on a belt conveyor, and then a needle machine was used with a 9-barb needle at a needle density of 84 needles/- to obtain an intertwined web with a fabric weight of zsot/kame.

Using a spray device on both sides of this web, N-methyl-
2-pyrrolidone 5 parts 1% aqueous solution to the web 100%
The weight was attached. Next, the mixture was pressed using a hot press roll at various temperatures, a linear pressure of aooQ/cIK, and a speed of 8 ml, and continuously wound up while applying tension.

The physical properties of the obtained nonwoven fabric are shown in Table 1.

The strength elongation was measured using an Instron measuring machine with a chuck spacing of 201. Sample width 1.5clL, head contact [1021
Measured under the conditions of m/-9.

Comparative Example 2 shows the physical properties of a needle web, and Comparative Example 3 shows the properties of a needle web without a plasticizer at a temperature of 250°C.

Table 1 shows the physical properties of the nonwoven fabric, which was pressed under the conditions of a linear pressure of 4 o o k/- and a speed of f 8 */-.

First Table 11-S1 Comparative Example 4 For 9 webs obtained in the same manner as in Example 1, 5 weight 9
1N-Methyl-2-pyrrolidone water droplets were sprayed at various adhesion amounts (based on aqueous solution) shown in Table 2, and then heated to a temperature of ysso℃.
Press under the conditions of , linear pressure of 400 i/a and speed of 81 g@/ah, and roll it continuously while applying tension. The physical properties of the obtained nonwoven fabric are shown in Table 2.

Happy 2nd table

Claims (1)

[Scope of Claims] L A lubrication agent consisting of polar adsorbent*S and/or water is adhered to a cube made of aromatic polyamide fiber that is substantially finely crystallized, and then subjected to hot pressure processing. A method for producing an aromatic boria nonwoven fabric characterized by a 1d1 web.
9 metaphenylene iso7 tarazudo) Kameru Patent - Search for Amm 1st Note 110 Aromatic Polyand Nonwoven Fabric OII Manufacturing Method 1 The aromatic boria (de fibers) constituting Kuep are Patent, Purchasing No. 01111, Paragraph 1 describes the manufacture of aromatic boria 2-doped nonwoven fabric og4. Also, the lubricant is water and the amount of O adhesion is l compared to Kuep.
・The method for preparing the faO aromatic polyamide nonwoven fabric described in Patent-In-vehicle Item 11 which has a weight of ~150.翫 The air absorbent is a polar adosolvent or its aqueous solution,
The adhesion amount converted to polarity ad 11#& is 1 to the web.
-1. The method for producing an aromatic polyamide nonwoven fabric according to claim 11, which is heavy. Tortoise Heat pressure processing using a heat pressure roll at a temperature of 150 to 4...℃
, Positive pressure 0~1@@O Immediate/am Q, Processing interruption'IIL
Claim I performed under O condition at ssI/min or more! 1. O aromatic polyamide nonwoven fabric OII manufacturing method.