JPS5825345B2 - Coloring method for porous fluororesin material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for coloring a fluororesin open-pore porous material with dyes while retaining its properties such as breathability and flexibility. The purpose is to provide

Fluororesin, represented by polytetrafluoroethylene (hereinafter referred to as PTFE), is a plastic with excellent properties such as heat resistance, chemical resistance, and slipperiness, and can be manufactured into various shapes and structures by various processing methods. It is processed into products and widely used in various industrial fields.

In particular, continuous pore porous materials made of fluororesin have excellent flexibility, lightness, texture, texture, breathability, etc., in addition to the excellent properties inherent to fluororesin, so they can be used, for example, as clothing materials and artificial leather materials. It is attracting attention as

The method for producing porous fluororesin material is described in, for example, Japanese Patent Publication No. 1973-
Porous fluororesin materials are known from JP-A No. 44664, JP-A-46-7284, JP-A-50-2281, etc., and are available in various forms such as sheets, tubes, fibers, threads, rods, etc. can be manufactured.

However, the excellent chemical resistance of fluororesin is a disadvantage, and both full-sized fluororesin products and porous products are dyed using water as a solvent, and organic solvent dyeing using perchloroethyl L/7 etc. as a solvent. It is extremely difficult to directly color the surface or the interior of the product clearly and without color fading even by dyeing with oil dyes, printing, etc., and this is one of the reasons why fluororesin products are being used more widely. It's becoming a bottleneck.

The conventionally commonly used method for obtaining colored fluororesin products is to add a coloring agent to the fluororesin powder or pellets that serve as the raw material for the product (for example, coloring the coating resin of a fluororesin-coated electric wire). ).

However, in this resin coloring method, the coloring agents used are generally higher in processing temperature than general resins (for example, the melting point of PTFB is about 327°C), so there is a lack of color variety and color tones. Inorganic pigments are dull, and they are limited to those with good heat resistance.Dye and other organic colorants, which come in an extremely wide variety of colors and have vivid tones, have the disadvantage that they can hardly be used.

When coloring with the above-mentioned inorganic facial pigment mixture, a satisfactory coloring effect cannot be obtained unless the amount of the inorganic pigment is increased considerably.

Therefore, there is also the drawback that the physical properties of fluororesin products are impaired due to an increase in the amount added.

In particular, when producing porous fluororesin products, if a large amount of inorganic pigment is blended into the raw material powder, it becomes difficult to produce the porous product itself.

Another method is to apply a pigment resin paint for coloring, but if the product is a fluororesin-rich product, the coating layer does not adhere firmly to the product surface and is easily peeled off afterwards.

In addition, in the case of a porous product, the characteristics such as flexibility, texture, and feel of a porous product are impaired.

In addition, the present inventors have developed a method that has been conventionally adopted as a means for improving the dyeability of resins that similarly have poor dyeability, such as polypropylene, in which organic metal compounds such as Ni and At are mixed into the resin as a dyeing seat to modify the resin. In accordance with the method described above, an inorganic metal compound such as At203 is used as a dyeing seat for the dye in the fluororesin (organometallic compounds cannot be used because the processing temperature of the fluororesin is high), and fluorine-based surfactants are added as other auxiliary agents. Attempts have been made to improve the dyeing properties of fluororesin by mixing it with fluororesin, but even if it is colored to a certain degree in both fluororesin-filled products and porous products, the color fades easily and the washing resistance or dry cleaning resistance is poor. It was extremely bad.

Moreover, it has the disadvantage that the water repellency, which is a characteristic of fluororesin, is significantly reduced.

As a result of further research into methods for coloring fluororesin products with dyes, the inventors of the present invention have found that they do not substantially impair the characteristics of open-pore porous fluororesin products, such as breathability and flexibility. We have developed a method that allows for vivid and strong coloring without fading.

The manufacturing method of the porous fluororesin material itself is already known in the above-mentioned publications, but to give an overview, it consists of a fluororesin powder such as PTFE and a liquid lubricant (for example, hydrocarbons such as solvent naphtha and white oil, petroleum ether, etc.) or a mixture with a small amount of organic or inorganic additives is preformed, and the preform is extruded into a sheet, tube, rod, etc. by ram extrusion, etc. Alternatively, it is further rolled to create a molded product with an arbitrary cross-sectional shape.

Next, with or without removing the liquid lubricant from this molded product, the molded product is subjected to 1.
Uniaxial or multiaxial stretching is carried out in the range of 2 to 50 times.

As a result of this stretching, the entire body of the molded product becomes a so-called fibril structure (a type of fine network structure in which many fine fibers are interconnected by many fine nodules), resulting in a continuous micropore porous structure.

Next, the porous structure is manufactured by heat-setting the porous structure at a temperature below or above the sintering temperature (for example, 200 to 380°C) while maintaining the stretched state.

The porous fluororesin material obtained in this way has excellent properties such as heat resistance, corrosion resistance, water repellency, and flexibility, as well as excellent texture and texture, and can be used not only as an industrial material but also as a clothing material.
As mentioned above, it is also effective as an artificial leather material.

By adjusting various manufacturing conditions such as stretching ratio, the porosity, average pore diameter, Gurley number, etc. of the porous product can be adjusted to 20 to 90, 0.1 to 30 μ-0,
It can be adjusted in a wide range from 01 to 5000 seconds,
Materials suitable for the purpose can be easily obtained.

In addition, the Gurley number is 12
．． It represents the time required for air to pass through LOOce under a pressure of 7rItIrLH20.

In coloring the above-mentioned porous fluororesin material by dyeing, the present invention provides a coating that forms a thin coating film on the surface of each fine fiber or fine nodule in the porous structure of the material when the material is impregnated and dried. A resin solvent solution is prepared by dissolving the resin (resin with good dyeing properties) that will serve as a dyeing seat at a low concentration such that it remains, and after impregnating the porous material with this solution and drying it, it is dyed according to a conventional method. Then, excess and unfixed dye is washed off and dried to obtain a colored product.

Alternatively, the above resin solvent solution is further prepared by dissolving and containing an amount of dye to obtain the desired dark color density, impregnating a porous material with the resin dye solvent solution, and drying it → washing → drying. A colored product is obtained.

The resin to be used as the dyeing sheet can be selected and used as appropriate from various conventionally known resins, and several examples are summarized in the table below, along with examples of solvents that are suitable for the resin, and examples of dyeing materials that are suitable for the resin. .

The resin concentration of the dyed sheet resin solution or the dyed sheet resin solution to which dye has been added may be adjusted while taking into consideration the dyeing effect in order not to impair the flexibility, texture, feel, etc. of the porous material after dyeing. It is possible to reduce the concentration as low as possible, for example 1 to
Prepare in a range of 15 inches.

Further, when a dye is added to the resin solution in advance, the amount added can be increased or decreased as appropriate depending on the concentration to be colored, and the standard is usually 0.1 to 3 grams per 100 liters of the resin solution.

The porous fluororesin material is impregnated with the resin liquid or resin + dye solution by dipping, but other methods such as spraying or brushing can also be used to impregnate the entire wall thickness or surface layer of the porous material. Impregnate only.

Drying may be done by natural drying or forced drying by heating, and in the case of forced drying by heating, care must be taken to prevent the porous material from shrinking due to heat.

As a result of this drying, the solvent in the resin liquid evaporates, and the resin solids form a thin, continuous coating on the individual circumferential surfaces of each microfiber or micronodule in the complex fibrillar structure that constitutes each micropore in the porous material. Even if there is no mutual adhesion between the residual resin and the fluororesin that is the matrix of the porous material, the residual resin will adhere to each fine fiber and fine nodule of the porous material's fibrillar structure, as described above. Since each of the particles is covered with a thin, continuous coating, it will not fall off easily.

Further, since the resin coating is thin and does not cover the porous structure, it does not impair the characteristics of the porous structure itself.

Therefore, if the porous fluororesin impregnated with the resin solution and dried, which will become the dyed seat, is then dyed in accordance with the conventional method, the dyed seat resin will be easily and vividly dyed. It is vividly colored without losing its properties such as flexibility and flexibility, and without fading.

After this dyeing, excess or unfixed dye is washed off and dried to obtain a final colored product.

In the case of a resin liquid to which a dye has been added in advance, a porous fluororesin material is impregnated with the resin liquid and then dried to obtain a porous product that is colored vividly and without fading.

In this case as well, the final colored product is obtained by washing and drying.

As described above, according to the method of the present invention, among fluororesin materials that are difficult to color by conventional dyeing, especially porous fluororesin materials, the coloring becomes clear without impairing the properties such as air permeability and flexibility of the porous material. It can be dyed and colored without fading and is extremely effective and suitable as a method for coloring porous fluororesin materials by dyeing, and can dramatically expand the field of use of this type of material.

Examples will be described below.

Example 1 Methoxymethylated nylon (
A 5% methanol solution of Torezin M-20 (trade name, Teikoku Kagaku Sangyo) was prepared, and 5 parts of citric acid was added to the solid content of the resin solution.

A porous PTFE sheet material was impregnated with the resin solution, and then the sheet material was fixed to a frame so as not to shrink due to heat.
It was dried at 0°C for 30 minutes.

The dry sheet material is once dipped in methanol to impregnate it with methanol, and then dipped in water to replace the impregnated methanol with water.

Next, the water-impregnated sheet material was placed in a dye bath having the following composition at 90°C.
- Soaked for about 1 hour.

Mitsu, 'Acid Mil Red 3
B) 3j' glacial acetic acid
51 water 1
0007111 Next, the sheet material is taken out from the dye bath, washed with water, soaped with water, and washed with water (repeated as necessary).

The same applies to Examples 2 to 4), and the unfixed dye is sufficiently washed out and then dried to improve breathability, flexibility,
Porous P that maintains the original characteristics of porous PTFE sheet material such as texture, and is vividly and strongly colored (red).
A TFE sheet material was obtained.

Example 2 Modacrylic fiber (trade name
Kanekalon S (Kanebuchi Kagaku Kogyo) is dissolved in a 7:3 mixed solvent of dimethylformamide and acetone as a solution.

A porous PTFE sheet material was impregnated with the resin solution, and then the sheet was fixed to a frame so as not to shrink due to heat.
It was dried at ℃ for 5 minutes.

The dried sheet material was impregnated with water in the same manner as in Example 1, and then immersed in a dye bath having the composition shown below at 120° C. for 30 minutes.

Dye (AihiIon Red GTLHconc,)
3? Glacial acetic acid 5g water 1000772
#Next, the sheet material was taken out from the dye bath, washed with water → leaped → washed with water to wash out the unfixed dye, and dried to obtain a porous PTFE colored sheet material similar to Example 1 (
red color) was obtained.

Example 3 The methoxymethylated nylon used as the dyed sheet resin in Example 1 was dissolved in a 7:3 mixed solvent of methanol and acetone as a 5% solution, and in addition, 5% of citric acid was added to the solid content of the resin solution. Add.

Next, a dye (metallic dye, kayakal on Bro.
wnOL, Nippon Kayaku] and stirred and mixed well to prepare a solution of dyed seat resin treatment material.

Next, a porous PTFE sheet material is immersed in the above solution to impregnate the sheet material with the solution, then pulled up, fixed to a frame to prevent heat shrinkage, and dried at 130° C. for 30 minutes.

Next, a porous PTFB colored sheet material (brown color) similar to that of Example 1 was obtained by washing with water, soaping, and washing with water to sufficiently wash out unfixed dye, and then drying.

Example 4 As a dyed sheet resin solution, acrylic fiber (trade name: Toleron, Toshi) was dissolved as a 5% solution in a 7:3 mixed solvent of dimethylformamide and acetone, and this solution
Dye (cationic dye, Ser B
ER (manufactured by Duponv) was added thereto and thoroughly stirred and mixed to prepare a solution of dyed sheet resin + dye.

Next, a porous PTFB sheet material is immersed in the above solution to impregnate the sheet material with the solution, then pulled up, fixed in a Q-frame to prevent heat shrinkage, and dried at 160° C. for 5 minutes.

Next, a porous PTFE colored sheet material (blue) similar to that of Example 1 was obtained by washing with water, soaping, and washing with water to sufficiently wash out unfixed dye, and then drying.

Example 5 Sublimation transfer printing paper (
Disperse dye) was applied for 30 seconds in a temperature atmosphere of 200° C. to perform transfer printing.

The transfer-printed surface of the sheet material was clearly and strongly colored to the extent that it did not interfere with practical use.

Example 6 In Example 2, sublimation transfer printing paper (
Transfer printing was performed by overlapping oil dye) for 30 seconds in a temperature atmosphere of 200°C.

The transfer-printed surface of the sheet material was clearly and strongly colored to the extent that it did not interfere with practical use.

Comparative Example 1 A porous PTFE sheet material containing an anionic heat-resistant fluorine surfactant was directly dyed in a dye bath in Example 2 without being treated with a dye sheet resin. Stained according to procedure.

Comparative Example 2 An oil-based dye (Aizen HCBlue I, Hodogaya Chemical) was dissolved in a 7:3 mixed solvent of toluene and methyl ethyl ketone, and a porous PTFE sheet material was added to the 0.5% solution, which was treated with a dye sheet resin. It was immersed and dyed without rubbing.

Comparative Example 3 A porous PTFE sheet material containing γ alumina powder was dyed with dye (Kaya Kalon Brown) 3 without being subjected to dye sheet resin treatment.
S' glacial acetic acid 51 water
Dyeing treatment was carried out in the same manner as in Example 1 using a dye bath consisting of ioooml.

Comparative Example 4 A porous PTFE sheet material is immersed in methanol to impregnate it with methanol without being subjected to dye sheet resin treatment, and then immersed in water to replace the impregnated methanol with water.

This water-impregnated sheet material was dyed with disperse dye (Dispersol Blue B-R3).
? Grains, I.C.I.) It was immersed in a dye bath consisting of 100mg of water at 120°C for 90 minutes, then washed with water and then dried for dyeing.

As described above, each of the sheet materials of Comparative Examples 1 to 4 was colored to a certain extent, but not clearly colored, and the coloring had poor fastness in dry cleaning.

Table A shows the dye fastness test (J
This figure shows the results of staining tests on various fibers such as IS-LO844-73, B-1) and cotton yarn.

Bunjin B also shows the results of a dye fastness test (JIS-LO860-74) for dry cleaning and a staining test for various fibers such as cotton yarn.

In addition, each philtral mark - does not change color or fade when washed or dry cleaned (dye fastness, 9 or does not stain other fibers).

The symbol 10 is slightly discolored and faded (same, middle).

Or it may slightly contaminate other fibers.

Symbol ++! Very discolored (same, small).

or contaminate other fibers.

represents something.

Claims (1)

[Claims] 1. A continuous porous material made of fluororesin that improves the air permeability of the material.
When dyeing while maintaining flexibility, dyeing is done at such a low concentration that when the material is impregnated and dried, it remains as a thin coating on the surface of each fine fiber or nodule in the porous structure of the material. A resin solvent solution is prepared by dissolving the resin that will become the seat, and a continuous porous fluororesin material is impregnated with the solution, dried, and then dyed. A method for coloring a porous fluororesin material. 2. The continuous pore porous material of fluororesin is
When dyeing while maintaining flexibility, dyeing is done at such a low concentration that when the material is impregnated and dried, it remains as a thin coating on the surface of each fine fiber or nodule in the porous structure of the material. A resin and dye solvent solution is prepared by dissolving the resin that will become the seat and containing an amount of dye dissolved to obtain the desired dyeing density, and a continuous porous fluororesin material ζ is impregnated with the above solution. A method for coloring a porous fluororesin material, characterized by: drying.