JPS6230098B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a waterproof and breathable laminate. For raincoats and sports clothing, materials are desired that have the property of preventing liquids such as rainwater from penetrating, while allowing moisture vapors such as sweat to easily permeate to the outside. However, it is generally difficult to simultaneously satisfy the contradictory functions of waterproofness and moisture permeability. For example, when a water-repellent resin such as silicone resin or fluororesin is coated on a fabric, it has moisture permeability and repels water droplets, but because the diameter of the pores is too large, rainwater may enter due to wind pressure. On the other hand, by impregnating the fabric with rubber etc., it can be made almost completely waterproof and can withstand considerable water pressure.
It has extremely poor moisture permeability and exhibits a so-called "stuffy" phenomenon. Recently, a laminate in which a first layer of a flexible hydrophobic material and a continuous hydrophilic layer are provided on a fabric has been reported in US Pat. No. 4,194,041 as the above-mentioned material having excellent waterproofness and moisture permeability. However, when the laminate of this US patent is examined in detail, it is found that a hydrophobic layer is provided on the back side of the outer fabric, and a hydrophilic layer is provided on top of that, and both the hydrophobic layer and the hydrophilic layer have waterproof properties. It has moisture permeability. Conventionally, only a hydrophobic layer was provided on the back side of the fabric, but the hydrophobic layer was made of a material with extremely fine pores (for example, NIKKEI PLASTICS 1981
It uses a porous polymer (described as 0.2 microns in the December issue, page 7).
The porous layer does not have a complicated structure in which the bubbles are arranged at different levels from each other, but instead has a simple structure in which the bubbles are arranged in a straight line, so it is difficult to absorb surface tension reducing agents contained in sweat, oil, etc. or dust in the atmosphere. As a result, the pores of the hydrophobic layer were easily clogged, resulting in extremely low moisture permeability, so a hydrophilic layer was provided on top of the hydrophobic layer in order to solve this problem. be. The inventors of the present invention conducted intensive studies to obtain a waterproof and breathable laminate whose structure is fundamentally different from that of the laminate disclosed in the above US patent, and as a result, a hydrophilic urethane layer was directly provided on the back side of the outer fabric. It was discovered that excellent waterproof and moisture permeable effects can be achieved with this alone. However, since a hydrophilic urethane layer alone will swell when it comes into contact with water, a urethane layer with open cells with a complex structure with large pores and pores arranged in different steps is laminated on top of the hydrophilic urethane layer. As a result, it was found that the swelling phenomenon was easily suppressed and the pores were not clogged by components such as oil contained in sweat or dust. That is, in the above-mentioned US patent, a microporous hydrophobic layer is provided on the back side of a fabric that serves as the outer material, and a hydrophilic layer is formed on top of the microporous hydrophobic layer, so that both the hydrophobic layer and the hydrophilic layer have waterproofness and moisture permeability. However, in the present invention, the hydrophilic layer provided on the back side of the outer fabric is made waterproof and moisture permeable, and on top of the hydrophilic layer there is a layer of open cells with large pores that does not have any waterproof properties. By forming a urethane layer, we have succeeded in developing an excellent waterproof and moisture-permeable laminate that does not impair moisture permeability and does not cause swelling or clogging. In the present invention, a first hydrophilic urethane layer having a proportion of hydrophilic groups of about 35% by weight or more is formed on the back side of a fabric serving as the outer material, and on the first urethane layer, a layer with large pores and pores that are mutually connected to each other is formed. The present invention relates to a waterproof and moisture permeable laminate characterized in that a second urethane layer having open cells arranged in different levels is formed. The laminate of the present invention has excellent waterproof and moisture permeability, and since the two layers laminated on each other are both urethane polymer layers, the two layers can be easily bonded due to their good affinity. be.
On the other hand, according to the above-mentioned U.S. patent, a hydrophobic layer made of a hydrocarbon such as polytetrafluoroethylene or polypropylene, and a hydrophilic layer such as a chemically dissimilar polyether-polyurethane or perfluorosulfonic acid polymer. layers are used. Further, the second urethane layer of the laminate of the present invention also has an excellent texture and feel unique to urethane. When water vapor comes into contact with one side of the hydrophilic urethane film of the present invention, the water vapor is diffused into the film by the action of the hydrophilic groups in the urethane molecules, moves to the other side of the film, and exits the system. be discharged. As described above, the hydrophilic urethane coating is an excellent coating that is non-porous and has moisture permeability without having any voids. However, the non-porous hydrophilic urethane layer has the disadvantage that it easily swells when it comes into contact with moisture. Therefore, by laminating an open-cell layer of urethane coating having good affinity on this hydrophilic urethane coating, swelling that occurs when the hydrophilic urethane coating comes into contact with water droplets can be prevented. In this case, it is not clear why swelling is prevented, but one reason is that the stress of the swelling force is alleviated by the sandwich structure of the urethane coating, which is structurally centered on the hydrophilic urethane coating, and has fabric and open cells. It is thought that this is because of this. The waterproof and breathable laminate of the present invention has excellent waterproofness and breathability, and generally has a waterproofness of 2500 mmaq.
It is said that if it can withstand water pressure of 3000 to 7500 mmaq., it will be completely waterproof and will not leak even when riding a motorcycle in heavy rain, but the waterproofness of the present invention is extremely excellent at about 3000 to 7500 mmaq. or more. Also, the moisture permeability of raincoats is 500-600g/ ^m2 . It is said that the feeling of stuffiness will be reduced if it lasts for 24 hours or more, but in the case of the present invention, about 24 hours or more
1000g/ ^m2 . Shows sufficient moisture permeability for 24 hours or more. In the present invention, the fabric serving as the outer material is not particularly limited, and for example, all natural and synthetic fibers can be used. Specific examples include cotton, cotton, nylon, ester, acrylic, or a blend of two or more of these, and any of plain woven fabrics, twill woven fabrics, tricot fabrics, nonwoven fabrics, etc. may be used. These fabrics may also be treated with water repellent treatment such as silicone resin or fluororesin, in which case the moisture permeability is generally 2000 g/m ² . Preferably for 24 hours or more. The hydrophilic first urethane layer of the present invention can be obtained by introducing a hydrophilic group into the polyol used. Examples of hydrophilic groups include hydroxyl groups, amino groups, oxyethylene groups, quaternary ammonium bases, etc. Among these, hydroxyl groups react with isocyanate to form urethane groups, so they do not contribute significantly to hydrophilicity, and amino A group, an oxyethylene group, a quaternary ammonium base, etc. are effective. The first urethane layer is formed by coating the polyol, isocyanate, chain extender, etc. as necessary on the fabric by a one-shot method, semi-prepolymer method, or prepolymer method, and curing it by heating as necessary, or almost completely. It is formed by drying a urethane solution on a cloth. Examples of hydrophilic polyols include the following. (a) Those with oxyethylene groups Low molecular weight hydroxy compounds such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butadiene diol, neopentyl glycol, glycerin, etc.
(b) Amino and oxyethylene group MW500-4000 made by addition polymerizing EO to monoamines such as ethylamine and propylamine
Polymers of MW 500 to 4,000 made by co-addition polymerizing EO and PO to the above monoamines Polymers of MW 700 to 4,000 made by addition polymerizing EO or EO and PO to diamines such as ethylene diamine and propylene diamine Amino alcohols such as aminoethyl alcohol A polymer having a MW of 500 to 4,000 obtained by addition polymerizing EO or EO and PO. Examples of chain extenders include the following. (a) Hydrophilic chain extender ethylene glycol, diethylene glycol, N・N・N′・N′-tetrakis(2-hydroxypropyl)ethylenediamine, methyldiethanolamine, triethanolamine, methyldiethanolamine, quaternary triethanolamine Ammonium salts, etc. (b) Non-hydrophilic chain extenders Propylene glycol, dipropylene glycol, 1,4-butanediol, neopentyl glycol, glycerin, etc. Isocyanates include aliphatic and aromatic isocyanates used in the production of ordinary urethanes. and alicyclic diisocyanates, triisocyanates, etc. are used.
Specific examples include tolylene diisocyanate (TDI), xylene diisocyanate (XDI),
4,4'-diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI),
Use of 1,6-hexamethylene diisocyanate (HDI), purified products, crude products, and modified products thereof, as well as prepolymers having isocyanate groups at the ends and products in which part or all of the isocyanate groups are blocked. I can do it. The proportion of hydrophilic groups in the hydrophilic urethane molecule of the present invention is generally preferably about 35% by weight or more,
In this range, the moisture permeability is 1000g/m ² . Can be 24 hours. The hydrophilic urethane layer contains antioxidants, ultraviolet absorbers, foam breakers, anti-stick agents,
Various compounding agents known in the urethane field, such as pigments, can also be added. The coating amount of the hydrophilic urethane layer may vary depending on the thickness of the fabric, the weaving method, etc., but it is usually preferable to have a solid content of about 10 g/m ² or more, and the thicker the urethane layer, the more
Since waterproofness and durability are improved, it is preferable to determine the amount of application depending on the application. The second urethane layer having open cells of the present invention is
First, the hydrophilic urethane layer should have negligible swelling even when water droplets come into contact with it, and it should not impede the moisture permeability of the hydrophilic urethane layer, and it should also have excellent texture and feel, and if necessary, it should have heat retention properties. have Therefore, in terms of shape, they are open cells, and the average cell diameter is not very small, usually about 10 microns or more, about 30 to 500 microns.
Micron diameter is preferable, and the material is required not to swell with water. When the average cell diameter is within the above range, it is preferable because it has good moisture permeability and does not become clogged with components such as oil contained in sweat and dust during wear. The second urethane layer can be formed by applying a solution obtained by a one-shot method, semi-prepolymer method, prepolymer method, etc. on the hydrophilic urethane layer and curing it by heating, or by forming the second urethane layer in advance by forming a foam.
The urethane layer can be formed by a method in which the hydrophilic layer is bonded and cured before the hydrophilic urethane layer is cured. The second urethane layer having open cells is made of the same isocyanate as used in producing the first urethane layer, a chain extender if necessary, various known compounding agents, except that the following polyol and blowing agent are used.
Manufactured using bubble stabilizers, etc. (a) Polyol PO is added and polymerized to low molecular weight hydroxy compounds such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, neopentyl glycol, and glycerin.
Polyol with a functional group number (f) of 2 to 3 in MW700 to 8000 Polytetramethylene glycol (MW700
Polyol of MW 700 to 5,000) A condensed polyester obtained from adipic acid and ethylene glycol, propylene glycol, 1,4-butanediol, or a mixture of these diols Polyol of MW 700 to 5,000 Addition polymerization of ε-caprolactone to the above low molecular weight hydroxy compound Sesame MW700~5000
The polyol used in the formation of the second urethane layer should be used in the first hydrophilic urethane layer, provided that the proportion of hydrophilic groups in the first hydrophilic urethane layer is approximately 35 wt% or more.
It can also be used in combination with the polyol used for forming the urethane layer. (b) Foaming agent Gas: air, N ₂ , CO ₂ , etc. Liquid: water, low-boiling point inert hydrocarbons (e.g. freon, methylene chloride, etc.) In addition, the second urethane layer of the present invention may have moisture permeability and texture. For the purpose of improving the composition, finely powdered inorganic fillers such as carboxymethyl cellulose, fiber flock (powdered fiber), silica, calcium carbonate, and titanium white may be blended. The second urethane layer of the present invention can be made into open cells by a commonly known method. The first function of the second urethane layer is to prevent swelling of the hydrophilic urethane layer, so its thickness is important, but a thickness of about 0.1 mm or more is usually particularly preferable. There is no particular limit to the maximum thickness, but it is usually 5 mm if cold protection is taken into consideration.
You can also use some. The laminate of the present invention is usually produced by applying a hydrophilic first urethane solution to the back side of the fabric and curing it by heating.
It is obtained by forming a second urethane layer having open cells on top of the urethane layer, but the fabric, the first
The urethane layer and the second urethane layer can also be laminated by sewing or bonding with an adhesive or the like. The waterproof and breathable laminate of the present invention is suitable for use in clothing such as raincoats and jumpers for leisure sports, sleeping bags, tent materials, diaper covers, and the like. In addition, when the laminate obtained by the present invention is further sewn, for example, when sewing with a sewing machine, the surface of the open cell layer is dusted with inorganic powder or spray coated with a lubricant to improve slipperiness. It is also possible to attach waterproof tape to the needle of the sewing machine where raincoats and the like are sewn. It is also optional to use a lining when making a raincoat. The present invention will be described below with reference to Examples, but the present invention does not depart from the purpose and gist thereof.
The present invention is not limited to such embodiments. Note that parts or % indicate parts by weight or % by weight. Example 1 (a) Formation of hydrophilic urethane layer The following components were added in the order of solvent, polyol, and isocyanate to a flask equipped with a stirrer, thermometer, and cooling tube, and reacted at 70°C for 4 hours to reduce the solid content.
A 50% amber, viscous solution containing 70.1% (calculated value) of hydrophilic groups was obtained. Polyethylene ether glycol (MW1000,
f = 2) 1400 parts 1,4-butanediol 45 MDI 500 Dimethylformamide (DMF) 950 Toluene 445 Methyl ethyl ketone (MEK) 550 The above solution was mixed with 70 denier nylon 6 thread, 100 threads per inch and 90 threads per inch for warp and weft, respectively. Solid content of 10g, 20g and 30g per m ² for book plain woven fabric
It was applied uniformly at a ratio of 1.5 g and heated at 140° C. for 10 minutes to form a hydrophilic urethane layer. For reference, when one drop of water was dropped on the hydrophilic urethane layer, it immediately swelled and left a trace of the water drop, and it took 2 to 3 hours for it to return to its original state. In addition, when the hydrophilic urethane layer was coated on a clean glass plate, heated and dried, and then peeled off from the glass plate and immersed in distilled water at room temperature, the initial weight was 3.3 g.
It absorbed up to 7.2g of water, and its volume increased by about 50%. (b) Formation of open-cell urethane layer Part A Polypropylene ether glycol (MW2200, f=2) 100 Ethylene glycol 6 Silicone surfactant (Toray Silicon, SH-
193) 8 Nickel acetylacetonate 2 B liquid part isonate 143-L (Kasei Upjiyon Co., Ltd.)
(MDI modified product) 100 Polypropylene ether glycol (MW2200, f=2) 43.3 Mix liquid B in advance at room temperature to form a prepolymer. Mix 120 parts of liquid B with 209 parts of liquid A, and mix air with a whisk to double the volume of the liquid. m ² of this to the hydrophilic urethane layer obtained in (a).
Apply evenly at a rate of 40g or 80g per 140g
Cure for 5 minutes to form a uniform open-cell urethane layer. When the bubble diameter was observed using a microscope, it was 80 to 130 microns. The waterproofness and moisture permeability of the laminate of the present invention obtained above were measured according to JIS K6328-1977, and the results are shown in Table 1. In addition, in order to investigate the swelling property due to water, the surface condition of the outer fabric side of the part (100 mmφ) where the sample came into contact with water immediately after the waterproof test was observed with the naked eye, and the results were marked with ○ (no change) and △ mark (swelling). (some irregularities due to swelling are observed) and x marks (unevenness due to swelling is observed).
For comparison, measurements were also performed on samples with only the base fabric and without the open-cell urethane layer, and the results are also described.

[Table] Example 2 (a) Synthesis of hydrophilic urethane solution 119 parts of methyldiethanolamine was added to a three-necked flask equipped with a stirrer, a thermometer, and a dropping funnel, and the flask was cooled in an ice-water cooling bath to cool the liquid. While stirring, 126 parts of dimethyl sulfuric acid was added dropwise from the dropping funnel while adjusting the amount so as to maintain the liquid temperature at 30-35°C. After dropping, remove the cooling tank, raise the liquid temperature to 70°C, react for 1 hour, and then cool to room temperature. A pale yellow transparent viscous chain extender containing a quaternary ammonium salt was obtained. Next, add the ingredients shown below at 70°C in the same manner as in Example 1.
After reacting for 2 hours and cooling to room temperature,
MDI (250 parts) was added and the reaction was carried out again at 70°C for 3 hours to obtain an amber colored, viscous solution containing 86.0% (calculated value) of hydrophilic groups with a solid content of 50%. Polyethylene ether glycol (MW2000,
f=2) 2800 The above chain extender 123 TDI-80 174 DMF 1147 Toluene 1100 MEK 1100 (b) Production of laminate The above hydrophilic urethane solution was applied per m ² to the same plain woven fabric as used in Example 1. Apply it evenly at a rate of 40g in solid content, and apply a thick layer on top of this when uncured.
A commercially available polyether-based soft urethane foam with a size of 5.0 mm and a bulk specific gravity of 0.018 (the number of cells measured according to JIS K6402 was 45) was pasted, and 100
The hydrophilic layer was cured by heating at .degree. C. for 18 minutes, and the open-cell soft urethane foam layer was adhered to obtain a laminate of the present invention. The resulting laminate has a waterproof property of 5500 mmaq. and a moisture permeability of 1730 g/m ² . It was hot in 24 hours. Example 3 (a) Formation of hydrophilic urethane layer A urethane solution was obtained in the same manner as in Example 1 using the following components. Polyethylene ether glycol (MW1000,
f=2) 900 Polypropylene ether glycol (MW1000, f=2) 600 1,4-butanediol 45 MDI 500 DMF 745 Toluene 700 MEK 700 To 4190 parts of the obtained above solution, MDI (blocked 100 parts of isocyanate) was added to the same plain woven fabric used in Example 1 at a concentration of ⁴⁰ g/m2 (solid content: 20 g/m2).
g) and heated at 150° C. for 10 minutes to obtain a hydrophilic urethane layer containing 41.0% (calculated value) of hydrophilic groups. (b) Formation of open-cell urethane layer 1000 parts of polypropylene ether glycol (MW1000, f=2) and 261 parts of MDI
React at 70°C for 2 hours to obtain an NCO-terminated prepolymer, add 50 (parts) of trichloromonofluoromethane to this prepolymer, and silicone foam stabilizer (Toray Silicon, SH-193).
30 Methylene chloride 25 Antioxidant (Ciba Geigy, Irganox
10-10) 5 A solution obtained by adding ultraviolet absorber (Ciba Geigy, Tinuvin #328) 5 was uniformly applied to the above hydrophilic urethane layer at a rate of 60 g/m ² and heated at 70°C at 95°C.
%RH for 4 minutes and immediately at 130°C.
The mixture was heated for 10 minutes to form an open-cell urethane layer with a thickness of 0.13 mm and a cell diameter of 60 to 80 microns. The waterproofness of the laminate of the present invention obtained above is
6500mmaq., moisture permeability 1153g/m ² . It was hot in 24 hours. As described above, the waterproof and moisture-permeable laminate obtained by the present invention is excellent in its waterproofness and moisture permeability, and since the two layers to be laminated are both urethane layers, their good affinity allows for easy joining and lamination. Furthermore, by using urethane, the finished assembly has an excellent texture and feel.

Claims (1)

[Claims] 1. The proportion of hydrophilic groups on the back side of the outer fabric is approximately
A first urethane layer having a hydrophilic content of 35% by weight or more is formed, and a second urethane layer having open cells having a large pore diameter and arranged at different levels from each other is further formed on the first urethane layer. A waterproof and breathable laminate featuring: 2 The average cell diameter of the open cells in the second urethane layer is approximately
The waterproof and moisture permeable laminate according to claim 1, which has a thickness of 10 microns or more. 3. The waterproof and moisture-permeable laminate according to claim 2, which has an average cell size of about 30 to 500 microns. 4. The waterproof and breathable laminate according to claim 1, wherein the second urethane layer has a thickness of about 0.1 mm or more.