JPS5920793B2 - Durable water-resistant, moisture-permeable, breathable, and anti-melt processing method for synthetic fiber knitted fabrics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves dispersing or dissolving a vapor permeable filler, a sublimable substance, a hardening agent for silicone rubber, an adhesion imparting agent composed of a silane coupling agent, and a pigment in silicone rubber. A durable water-resistant, moisture-permeable, breathable material, characterized by applying the mixed solution to a synthetic fiber knitted fabric and post-heating treatment to form a silicone rubber layer with fine voids on the surface of the fabric.
Regarding a melt-proofing method.

The demand for synthetic fibers is not limited to clothing, but is also used for various industrial materials, but the melting point of synthetic fibers such as polyamide and polyester is generally 200 to 300°C, so the demand for clothing and industrial materials made from these synthetic fibers is In the process of use, material products melt and open pores due to heat compared to natural fiber materials, and encounter various problems caused by heat.

In other words, when products made from synthetic fibers such as polyamide and polyester fibers come into contact with high-temperature objects such as cigarettes, torches, and welding sparks, or due to sudden contact friction heat, the contact area may melt and open holes, which can be fatal to the product. give a flaw.

In addition, general waterproof products such as coats and awnings do not allow rain to pass through, but they also do not allow air or water vapor to pass through, and there is a problem that they become stuffy when worn or used.

For this reason, ■ a method in which a microporous 4-fluoroethylene film is laminated on a fabric, or ■ a method in which fillers and solvents that are very easily eluted in water or special solvents are added to a resin solution mainly composed of polyurethane elastomer, which is generally called the wet method. After applying it on the fabric, it is passed through a special solvent tank and hot water washing tank in an undried state.The filler and solvent are eluted and a microporous resin film is created. moisture,
Waterproof fabrics are manufactured.

However, the disadvantages of products produced by these methods are that if emphasis is placed on film performance, the peel strength of the film will be weak; if emphasis is placed on peel strength, the adhesive will inhibit air permeability and moisture permeability, and the product's texture will be rough and hard. In case (2), the shape of the pores in the resin film generated when the filler solvent is eluted tends to have a columnar structure with respect to the film layer, such as vertically elongated or vertically cracked pores, which tends to cause defects in its waterproof performance.

In addition, moisture permeability is achieved using a so-called dry method, which uses a resin mainly composed of polyurethane elastomer that has moderate moisture absorption.
Although waterproof fabrics have been manufactured, there is an upper limit to the thickness of the resin coating in order to maintain its performance, which naturally results in the disadvantage that the surface coating becomes weak.

Furthermore, when the above-mentioned processing method is applied to synthetic fiber fabrics, they do not have melt-proofing properties, and when they come in contact with a cigarette or the like, they melt and open holes, causing fatal defects in the product.

Particularly in clothing made of horse hair, fluff may come out from the melted pores, which can be fatal to the product.

The present inventors have completed the present invention as a result of intensive research to solve the above problems, and have created a synthetic fiber knitted fabric that has a flexible texture and is durable under simple and easy-to-manage conditions. This makes it possible to provide a water-resistant, moisture-permeable, breathable, and melt-proof processing method.

In melt-proof processing of synthetic fibers, there are methods to prevent or reduce damage caused by heat-induced melting or decomposition of fibers using physical or chemical methods.

That is, by coating the surface of the fibers with a heat-resistant insoluble resin, the fibers are protected from heat, and even if the fibers are melted, flow is suppressed and the original shape of the fabric is maintained.

Melt-proof resins commonly used in these melt-proofing processes include silicone resins, crosslinkable acrylic resins, mixtures of silicone resins and modified alkyd resins, and compositions in which acrylic resins are blended with metal salts such as zinc sulfate.

However, all of them still have problems such as poor wash resistance and hardened texture after imparting anti-melt properties.

Among these, the above-mentioned silicone resin is entirely crosslinked by steric bonding, so after the resin film is formed, the film is hardened strongly due to the steric crosslinking, resulting in a lack of flexibility in the processed fabric.

Therefore, two-component room temperature curing silicone rubber (hereinafter referred to as RTV type silicone rubber), which has properties very similar to the silicone, is used.
Two-component low-temperature curing silicone rubber (hereinafter referred to as LTV silicone rubber) has good gas permeability and water vapor permeability due to the low molecular attraction caused by the linear bond crosslinking property and the amorphous structure; We also focused on the thermal stability of the polymer (depending on the size of the siloxane bond).

In other words, two-component RT used for electrical insulation.
By using V,LTV silicone rubber for fiber processing,
The flexibility of the resin film due to linear bonding and the heat resistance of the silicone resin itself give the processed fabric a flexible texture and durable melt-proofing properties that are not found in conventional melt-proof fabrics, and it is also filled with water vapor permeability. By adding agents and sublimation substances, we succeeded in further improving air permeability and permeability without reducing water resistance.

To explain the present invention item by item, 1) The silicone rubber is preferably RTV type or LTV type silicone rubber from the viewpoint of processing, and the main body is diorganopolysiloxane and the curing agent is acetoxysilane, oxime silane, silicone resin, or alkyl silicate. The mold and main body are vinyl-containing diorganopolysiloxane and the curing agent is 5i.
-H-containing diorganopolysiloxane, which is a silicone rubber having an addition type crosslinking mechanism.

Note that the present invention does not limit the use of silicone rubber, fluorinated silicone rubber, or phenylated silicone rubber having a vinyl group, hydroxyl group, or hydrogen group in the side chain of siloxane, but these silicone rubbers If,
There are some problems in terms of heat resistance and stability.

2) Vapor-permeable fillers include synthetic silica made by fume or wet methods, silica earth, quartz powder, siliceous sandstone, silicone silicate, silicates such as clay, calcium carbonate, or carboxyl vinyl polymers. It is a filler with hygroscopic and water-retaining functions, and its particle size is 0.
．． 0.007 to 100 μm can be used.

The type and particle size of the filler have a large effect on moisture permeability, air permeability, water resistance, anti-melt performance, texture, resin film surface quality and strength, and processing conditions such as uniform dispersion and application of the resin solution should also be considered. A filler having a particle size of 0.007 to 30 μm is preferable.

3) The sublimable substance has a boiling point of 60 to 300°C, preferably 10
Known substances that have a temperature of 0 to 250°C, such as α-trioxane, DL-malic acid, maleic acid, dimethyl oxalate, valadichlorobenzene, oxalic acid, phthalic acid, naphthalene, benzoic acid, etc., are dissolved and dispersed in the resin. do.

This substance has a larger molecular weight than the solvent in the resin, and is thought to form a random microporous shape in the resin film due to the difference in vaporization temperature during heat treatment.

4) Synthetic fiber knitted fabric is a well-known synthetic fiber knitted fabric composed of polyamide/polyester fibers, and is subjected to ordinary scouring,
It is a knitted fabric that has been dyed.

In addition, among polyamide, polyester fiber, cotton, rayon, cupro, etc., polyamide,
It can also be applied to knitted fabrics containing 50% or more of polyester fibers.

5) The adhesion imparting agent is, for example, a silane coupling agent having an organic functional group such as a vinyl group, an amino group, an epoxy group, or a mercapto group, and an organic metal salt such as butyl titanate or a peroxide such as benzoyl peroxide or the like as a catalyst. Platinums such as platinic acid are used.

6) The organic solvent may be any solvent as long as it dissolves and decomposes the resin, curing agent, adhesive agent, filler, etc. used in the present invention. Specifically, organic solvents such as trichlorethylene, perchlorethylene, toluene, and xylene are used. Polar solvents, hydrocarbon solvents, and alcohol solvents are preferable.

7) The coating method may be essentially any method as long as it can coat the resin mixed solution of the present invention, but preferably an air knife coater, floating knife coater, knife over roll coater, reverse roll coater, or gravure coater. , a dip coater is better for working.

8) This product, for example, the film made from a mixed solution of silicone rubber mainly composed of dimethylpolysiloxane, fumed silica, and resin such as a hardening agent, is almost colorless and requires coloring to improve aesthetics. .

Heat-resistant and weather-resistant organic pigments such as quinacrid red, polyazo and monoazo red, disazo yellow, cyanine green, cyanine blue, etc. can be used to make this possible, but preferably mainly inorganic pigments and To take advantage of the properties of silicone rubber, we use pigments with excellent acid, alkali, chemical, and heat resistance, such as titanium oxide (white), iron oxide (red, yellow, black), carbon black (black), and aluminum powder ( In terms of moisture permeability, air permeability, water resistance, etc., particles with a particle size of 100 μm or less are preferable.

Note that the purpose of coloring using these pigments is to improve aesthetics, and if coloring is not required, the pigments do not need to be mixed.

The processing method according to the present invention will be described in detail below. 100 parts by weight (hereinafter simply referred to as "parts") of two-component RTV or LTV silicone rubber, 5 to 20 parts of a curing agent, and 0.5 to 10 parts of a silane coupling agent containing a catalyst. , 5 to 10 parts of a hygroscopic and water-retaining filler, 10 to 40 parts of a sublimable substance, and 0 to 30 parts of a colorant that is an organic or inorganic pigment, and an organic solvent to an appropriate viscosity and concentration. Add and stir as adjusted to create a resin solution in which the additives are dispersed and mixed.

The resin liquid is uniformly applied to the surface of a polyamide or polyester knitted fabric which has been scoured and dyed in a conventional manner by the previously described coating method, such as the floating knife coating method, and then dried.

This is further heat-treated at 140-200°C for 30-120 seconds to harden the silicone rubber and form a resin film on the fabric.

In general, silicone rubber films have potential gas permeability and moisture permeability, but this is further enhanced by the discontinuous arrangement of fillers with hygroscopic and water-retaining functions in the resin film. Due to the stepwise and continuous vaporization effect caused by the temperature difference between the organic solvent and the sublimable substance that vaporize from the film, micropores with various shapes such as columnar, spherical, and elliptical shapes are formed in the silicone rubber film layer. It is thought that each of these contact holes has a microscopic contact point.

Another factor is that silicone rubber undergoes a dehydrogenation condensation reaction due to heat treatment=Si-OH+H-8i=→=St
One of the reasons for this is thought to be that continuous micropores are formed in the film using hydrogen gas generated by OSt'=+H2↑ as a foaming agent.

The above micropores have an average particle diameter of 100 to 500 for drizzle, small rain, and rain.
smaller than μ, and the average particle of water vapor is 0.0004μ
Since it is larger, it can exhibit water-resistant breathability and moisture permeability functions.

The resulting product has a soft texture, excellent water resistance, air permeability, and does not easily melt and open holes even when exposed to a cigarette.

This exhibits performance suitable for cold-resistant clothing and the like.

Examples of the present invention will be described below.

Note that the comparative test characteristic values in the examples were measured and evaluated based on the following measurement method.

■) Evaluation method for melt-proofing performance Time until the contact area melts and opens using the 75 degree cigarette smoke method (
2) Water resistance JIS-L-1092 (low water pressure method) Unit: 1L11L2
0 3) Air permeability JIS-L-1006 Gurley method Unit: seconds/100cc 4) Place the fabric in a moisture-permeable cup filled with moisture-permeable calcium chloride for about 8 minutes, and place in a constant temperature and humidity chamber at 40°C and 90% RH. Leave it for 1
After a period of time, it is taken out and its weight (Wl) is measured.

Leave it in a constant temperature and humidity chamber for another 4 hours, then take it out and weigh it (W2)
Measure.

The moisture permeability Vp is calculated using the following formula.

However, S: moisture permeable area (m') 5) Washing resistance JIS-L-0217-104 6) Dry cleaning resistance Petroleum solvent (Drysol) and chlorine solvent (Perchlorethylene) at 30° After treatment in a wash cylinder for 10 minutes at a C1 ratio of 1:9, the mixture was deliquified and air-dried.

Example 1 Two-component WRTV of vinyl-containing diorganopolysiloxane
Silicone rubber (for example, product name ``Roadsil RTV147''
AJ Dainippon Ink Chemical Co., Ltd.) 100 parts, 5i-H-containing diorganopolysiloxane (for example, trade name [Rhodesil R
TV147BJ manufactured by Dainippon Ink Co., Ltd.) 10 parts, adhesion agent (for example, trade name [AP-2J manufactured by Shin-Etsu Chemical Co., Ltd.) 2 parts, vapor permeable filler (for example, trade name "Aerosil 2004"),
A resin solution prepared by dissolving or dispersing 5 parts (manufactured by Nippon Aerosil Co., Ltd.), 10 parts of a sublimable substance (for example, Naphthalene (trade name), and 60 parts of toluene) was used to dye nylon tack (warp 70/68, weft 70) by a conventional method. /68, density: 125 threads/inch long, 94 threads/inch long) by floating knife coating method on one side with dry weight of 10 g/inch.
lri” applied uniformly to the surface of the fabric and dried at 190°C for 30 minutes.
This product was obtained by heat treatment for 0 seconds.

Example 2 A resin solution similar to that in Example 1 was prepared using 50 parts of toluene, and a polyester tack (warp 50/24, weft 75/36, density warp 157/
A coating of 12 g/m (dry weight) was applied uniformly to one side of the fabric using a floating knife coating method, and after drying, heat treatment was performed at 190° C. for 60 seconds to obtain this product.

Comparative Example 1 A resin solution prepared by dissolving and preparing 100 parts of Loadsil RTV147AJ, 10 parts of Loadsil RTV147BJ, 2 parts of AP-2, and 30 parts of toluene was floating on one side of a nylon tack (the same product used in Example 1). 1 part gin by dry weight by knife coating method?
After uniformly coating and drying, the product was heat-treated at 190° C. for 30 seconds.

Comparative Example 2 100 parts of a hygroscopic polyurethane elastomer (for example, trade name ``Honey Top 8259EJ'' manufactured by Honey Kasei Co., Ltd.), 10 parts of a crosslinking agent (for example, ``Crysbon NXJ'' manufactured by Dainippon Ink Chemical Co., Ltd.), 30 parts of DMF, acetic acid. A resin solution in which 10 parts of ethyl was dissolved was applied uniformly to one side of polyester taffeta (the same product used in Example 2) by a dry weight of 597 m by the knife-over roll coating method, and after drying, a transparent layer was further applied on the same side. 100 parts of wet polyurethane elastomer (for example, trade name [Honey Top 8252EJ manufactured by Honey Kasei Co., Ltd.), crosslinking agent (for example, Crisbon NXJ)
A resin solution containing 5 parts of ethyl acetate, 30 parts of ethyl acetate, and 10 parts of DMF was applied evenly by knife-over-roll coating method to a dry weight of 7 ji/m.
This product was obtained by heat treatment at ℃ for 30 seconds.

Comparative Example 3 As a general soft coating agent, 100 parts of acrylic resin (for example, trade name "Curikoat S20" manufactured by Inu Nippon Ink Chemical Co., Ltd.) and a crosslinking agent (for example, trade name "Polynate 70") were used.
A resin solution in which 2 parts (manufactured by Toyo Polymer Co., Ltd.) and 30 parts of toluene were dissolved was uniformly applied to one side of a nylon tack (the same product used in Example 1) at a dry weight of 109/rrl, and after drying was heated at 180°C. This product was obtained by heat treatment for 30 seconds.

Next, Examples 1 and 2 according to this explanation and Comparative Example 1 which is a conventional product
, 2.3 shows the comparative test results.

Claims (1)

[Scope of Claims] 1 Silicone rubber with a vapor-permeable filler, a sublimable substance,
A mixed solution in which a silicone rubber curing agent, an adhesion imparting agent composed of a silane coupling agent, and a pigment are dispersed or dissolved is applied to a synthetic fiber knitted fabric and then heat-treated to form porous surfaces on the fabric surface. Durable water resistance, moisture permeability, breathability, characterized by forming a high quality silicone rubber layer.
Anti-melt processing method. 2. Claims in which the silicone rubber is a room-temperature curing type or a low-temperature curing type rubber, and the main body of the crosslinking mechanism is a diorganopolysiloxane diol, a vinyl-containing diorganopolysiloxane, a hydrogen polysiloxane, or a copolymer thereof. The method described in paragraph 1. 3 Vapor permeable fillers are synthetic silica made by fume method or wet method, silica, quartz powder, siliceous sandstone, silicates such as zirconium silicate, clay, calcium carbonate, or carboxyl vinyl polymers. The method according to claim 1, which is a filler having hygroscopic, hygroscopic and water-retaining functions. 4 The sublimable substance has a boiling point of 60 to 300°C, preferably 100°C.
~250°C known sublimable substances such as α-trioxane, DL-malic acid, maleic acid, dimethyl oxalate,
The method according to claim 1, which is parachlorobenzene, oxalic acid, phthalic acid, naphthalene, benzoic acid, etc. 5. The method according to claim 1, wherein the synthetic fiber knitted fabric is composed of polyamide or polyester fibers. 6 Claims 1 and 2 in which the curing agent for silicone rubber is a condensation type curing agent such as acetoxysilane, oxime silane, silicone resin, or alkyl silicate, or an addition type curing agent using a 5i-H-containing diorganopolysiloxane. Method described. 7. Claims 1 and 2, wherein the adhesion-imparting agent composed of a silane coupling agent is an adhesion-imparting agent that uses an organic metal as a catalyst for a silane coupling agent having an organic functional group. The method described in Section 3.