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(11) | EP 0 423 621 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A clothing pad |
| (57) A clothing pad which consists of a polyurethane foam pad core (1) and a film (2)
of a nonyellowing urethane resin coated formed on at least the surface of the pad
core to be made in contact with the outside cloth of an article of clothing has no
possibility that the outside cloth appears discolored, the intrinsic feel and form-maintaining
property of a polyurethane foam, can be easily produced and is highly economical. |
[0001] This invention relates to a clothing pad such as a shoulder pad, a brassiere pad, a knee pad, an elbow pad, a buttock pad and the like.
[0002] Conventionally known clothing pads such as shoulder pads include those consisting of polyurethane foam, those consisting of a polyurethane foam pad core covered with a non-woven fabric and those obtained by shaping non-woven fabrics into pads. The above clothing pads consisting of polyurethane foam can be obtained by cutting polyurethane foam into pads or by cutting polyurethane foam into shapes similar to those of final products and then shaping the intermediate products into pads by thermal pressing.
[0004] Specifically, the pads consisting of polyurethane foam have inferior antiweatherability since the foam gradually yellows during use, resulting in that the outside clothing of an article of clothing touching the pads come to appear discolored. The inventors have considered the use of a nonyellowing polyurethane foam for pads as a countermeasure. However, a nonyellowing polyurethane foam is not suitable as a pad material because it is very expensive and it is difficult to regulate its foam properties such as hardness. For pad material, polyether polyurethane foams are not suitable for dry cleaning because they have inferior solvent resistance and their dry cleaning results in their significant swelling and reduced strength. It is necessary to use expensive polyester polyurethane foams as pad materials when dry cleaning is necessary.
[0005] The pads consisting of a polyurethane foam pad core covered with a non-woven fabric are disadvantageous because they are not economical because many processes are required for processing and the non-woven fabric deteriorates the intrinsic feel and form-maintaining property of the polyurethane foam.
[0006] The pads consisting of non-woven fabrics alone are disadvantageous because it is more difficult to produce their proper shapes as compared to polyurethane foam pads, they have inferior form-maintaining property and they are too soft. Moreover, as they are formed by laminating pieces of non-woven fabric, it takes a long time to produce the pads, resulting in high costs.
[0007] An object of this invention is to provide a novel clothing pad which is free from any disadvantages of the conventional clothing pads in their yellowing, form-maintaining property, dry cleaning suitability, production costs and feels during use.
[0008] According to the present invention, there is provided a clothing pad consisting of a polyurethane foam pad core and a film of a nonyellowing urethane resin coating formed on at least the surface of the pad core to be made in contact with the outside cloth of an article of clothing.
[0009] The above and other objects, features, and advantages of the present invention will be better understood from the following description taken in conjunction with the accompanying drawing, in which:
Fig. 1 is a cross-sectional view of one embodiment of this invention, and
Fig. 2 is a cross-sectional view of another embodiment of this invention.
[0010] The clothing pad according to the present invention consists of a polyurethane foam pad core and a film of a nonyellowing urethane resin coating formed thereon.
[0011] In this invention, although there is no restriction to the type of polyurethane foam used to form a pad core, any one of flexible, semi-rigid or rigid polyurethane foams can be used, flexible or semi-rigid polyurethane foams being preferred.
[0012] Although the properties of a polyurethane foam used to form a pad core are not specially restricted and they can be properly selected according to the purpose of use, it is usually suitable to use a polyurethane foam having a density of 0.014 to 0.050 g/cm³, a hardness (JIS-K-6401) of 4 to 25 kgf and a cell number of 20 to 60/inch.
[0013] As the polyurethan foam, a polyester polyurethane foam or a polyether polyurethane foam can be used. A polyether polyurethane foam is used for a pad core without the problem of dry cleaning suitability by coating the entire surface of the pad core with a polyester polyurethane nonyellowing urethane resin coating which is excellently solvent resistant. When a coating film is formed only on the surface of a pad core to be made in contact with the outside cloth of an article of clothing, it is desirable to use a polyester polyurethane foam in terms of dry cleaning suitability. In the present invention, it is possible to use a nonyellowing polyurethane foam, although it is preferable to use a usual polyurethane foam because of physical properties of the foam and its price.
[0014] The nonyellowing urethane resin coating has excellent antiweatherability and dose not easily yellow. As the nonyellowing urethane resin, one produced from a polyol and an aliphatic isocyanate can favorably be used. Examples of the polyols include polyester polyols having a molecular weight of 1000 to 4000 obtained by condensation polymerization of dicarboxylic acid such as phthalic acid, adipic acid, succinic acid, azelaic acid, sebacic acid, ricinoleic acid and the like and a glycol such as ethylene glycol, propylene glycol, butane diol, hexane diol, neopentyl glycol, diethylene glycol, 1,4-butanediol, triethylene glycol, pentane diol, cyclohexane dimethanol and the like, and polyester polyols having a molecular weight of 1000 to 4000 by addition polymerization of propylene oxide and/or ethylene oxide. Among them, polyester polyols having a molecular weight of 1000 to 4000, preferably 1500 to 3000 are preferred. Particularly, a polyester polyol having a molecular weight of about 1800 obtained from phthalic acid and diethylene glycol and a polyester polyol having a molecular weight of about 2000 obtained from adipic acid and 1,4-butanediol can be used.
[0015] Examples of the aliphatic isocyanates include 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylene diisocyanate (XDI), 2,2,4(2,4,4)-trimethylhexamethylene diisocyanate (TMDI), 4,4-dicyclohexylmethane diisocyanate (HMDI), tetramethylene diisocyanate (TMXDI), 1,4-cyclohexyl diisocynate (CHDI) and lysine diisocyanate. The nonyellowing urethane resin is prepared by reacting the polyol with the aliphatic isocyante. If required, a chain-lengthening agent such as a diol including 1,4-butanediol, trimethylene glycol, ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol, a triol including glycerin and trimethylolpropane, a diamine including hexamethylene diamine, 4,4′-diaminodiphenylmethane, m-phenylenediamine, diethylated toluenediamine, 3,3′-dichloro-4,4′-diaminodiphenylmethane, mixed mono and dichloro (3,3′ and 5,5′-) isomers of 4,4′-diamino diphenylmethane, hydrazine, 1,4-butaneamine, hexamethylenediamine and isophoronediamine, and an amino alcohol including diethanolamine, triethanolamine, aminoethylethanolamine and 2-amino-2-methylpropanol may be added.
[0016] The molar ratio of the total of OH and NH₂ per 1 mol of NCO may be in the range of 0.9 to 1.3, preferably 1.0 to 1.2. The resin terminated with a OH group is preferably used. The molecular weight of the resin may be 50000 to 300000, preferably 100000 to 200000 as number-average molecular weight. In case of using a low molecular-weight resin terminated with a OH group, a hardner may be used in an effective amount for hardening the resin. As the hardner, aliphatic diisocyanates explained above and prepolymers terminated with NCO group obtained by lengthening the chain of the aliphatic diisocyanate.
[0017] It is desirable that the color of a nonyellowing urethane resin coating should be similar to that of the outside cloth of an article of clothing to which the pad is to be attached in order to prevent it from being conspicuously seen through the outside cloth even when it is thin.
[0018] There is no restriction to the method for producing the clothing pad of this invention and it is possible to adopt the method of shaping a polyurethane foam into the form of a final product either by cutting or by cutting followed by thermal pressing and then applying the shaped polyurethane foam with a nonyellowing urethane resin coating, or the method of shaping a polyurethane foam into a shape similar to a final one by cutting, applying the shaped polyurethane foam with a nonyellowing urethane resin coating and then shaping the coated shaped polyurethane foam into a final shape by thermal pressing.
[0019] As the method of applying a nonyellowing urethane resin coating to a pad core, brush coating, dip coating, roller coating or spray coating may be adopted. Among them, spray coating is preferred from the point of coating efficiency. In performing spray coating, it is preferably to use a coating composition prepared by dissolving a nonyellowing urethane resin in a volatile solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, cyclohexane, isopropyl acetate and the like. The solvent may be used singly or in combination. This coating composition for spraying is sprayed from a position apart from a pad core so that most of the volatile solvent evaporates before reaching the pad core which is a porous body and it is coated with entangled filaments as thin as spider's threads of the solid component. A film of said coating is favorably formed on a pad core by properly adjusting the distance for spraying so that the solid component partially encroaches upon holes of the pad core and closes them.
[0020] A clothing pad having excellent antiweatherability and solvent resistance can be obtained by applying an underlayer coating to the surface of a pad core by spray coating to form an underlayer and then applying a nonyellowing urethane resin coating to the underlayer. As the underlayer coating, a coating composition prepared by dissolving a film-forming solid component composed of a nonyellowing urethane resin or a usual urethane rein in a volatile solvent can be used.
[0021] The total thickness of the underlayer and the nonyellowing urethane resin coating may be 20 to 200µm, prefedrably 40 to 120µm. More specifically, the thickness of the nonyellowing urethane resin coating may be 20 to 200µm, preferably 40 to 120µm when an underlayer is not formed and 10 to 140µm, preferably 20 to 80µm when an underlayer is formed. If the total thickness is less than 20µm, the coating effect is hardly exerted. If the total thickness is more than 200µm, the feel of a pad core formed by polyurethane foam may be worsened.
[0022] A clothing pad should have a margin to sew up when an article of clothing and said pad are joined by stitching before its use. In such a case, making a cloth such as a non-woven fabric having a size larger than a pad core by a margin to sew up in close contact with one surface of the pad core and then forming a film of a nonyellowing urethane resin coating over the pad core and the cloth in close contact with each other enables the margin to sew up to be ensured while maintaining the pad core and the cloth in completely close contact with each other.
[0023] According to the present invention, a small number of processes are required for processing and the pad is very economical. Since the clothing pad of this invention consists of a polyurethane foam pad core and a film of a nonyellowing urethane resin coating formed thereon, which has excellent antiweatherability, there is no possibility that a part of the pad core coated with the film is discolored and therefore there is no possibility that a part of the outside cloth of the article of clothing touching the pad appears discolored. Further, since a pad core consists of a polyurethane foam, there are no inconveniences that a proper pad shape can not be produced, that the pad easily gets out of shape and is too soft, and that shaping takes a long time, as in the case of a pad consisting of a non-woven fabric alone. Since a coating film is formed on a pad core, the intrinsic feel and form-maintaining property of a polyurethane foam are not deteriorated as compared with a pad consisting of a pad core covered with non-woven fabric. Furthermore, when the entire surface of a pad core is coated with a polyester polyurethane nonyellowing urethane resin coating which is excellently solvent resistant, the pad core is completely protected by a film of said coating and there are no problems of dry cleaning suitability even when a cheap polyeter polyurethane foam is used for the pad core, resulting in cheaper cost.
EXAMPLE
[0024] Examples of the invention are given below by way of illustration and not by way of limitation.
[Example 1]
[0025] A polyurethane foam having a density of 21 kg/m³ and a hardness of 13 kgf was cut in a similar shape of the final product and set in a mold and pressed at 220°C for two minutes to obtain a shoulder pad core having the shape of a final product. A nonyellowing urethane resin coating prepared by dissolving 100 parts by weight of a nonyellowing urethane resin in 350 parts by weight of cyclohexane and 650 parts by weight of isopropyl acetate was applied to either the entire surface of the above shoulder pad core or only its surface to be made in contact with the outside cloth of an article of clothing in a thickness of 50 µm by spray coating to obtain a shoulder pad, as shown in Figs. 1 and 2. In the drawings, the reference number 1 represents a shoulder pad core and 2 represents a coating film.
[0026] The nonyellowing urethane resin had a molecular weight of 170,000 and was produced by allowing ethylene glycol and trimethylene glycol to react with a prepolyer having NCO terminal groups which was obtained by allowing HDI (hexamethylene diisocyanate) and a polyester polyol (condensation polymerization product of adipic acid and 1,4-butanediol) to react with each other.
[Example 2]
[0027] An underlayer urethane resin coating prepared by dissolving 100 parts by weight of a polyurethan resin in 300 parts by weight of cyclohexane and 600 parts by weight of isopropyl acetate was applied to either the entire surface of the same shoulder pad core as that used in Example 1 or only its surface to be made in contact with the outside cloth of an article of clothing in a thickness of 40 µm by spray coating to form an underlayer. The above polyurethane resin had a molecular weight of 150,000, which was produced by allowing ethylene glycol to react with a prepolymer having NCO terminal groups which was produced by allowing pure MDI (4,4′-diphenylmethan diisocyanate) and a polyester polyol (condensation polymerization product of adipic acid and 1,4-butanediol) to react with each other.
[0028] Thereafter, a nonyellowing urethane resin coating having the following composition was applied to the above underlayer in a thickness of 50 µm by spray coating to obtain a shoulder pad, as shown in Figs. 1 and 2.
Nonyellowing urethane resin coating
[0029]
(A) Polyol solution
[1] Polyester polyol (Polymerization product of phthalic acid and diethylene glycol,
Molecular weight ≒ 1,800)
[2] Dilution solvent
Xylene: Toluene: Cellosolve acetate = 15:25:60 (ratio by weight)
[1] : [2] = 1:1 (ratio by weight)
Viscosity: about 300 cps
(B) Isocyanate solution
[3] Nonyellowing polyisocyanate (HDI)
Molecular weight ≒ 750
[4] Dilution solvent
Xylene: Toluene: Cellosolve acetate = 15:25:60 (ratio by weight)
[3] : [4] = 1:9 (ratio by weight)
Viscosity: about 100 cps
(3) : (4) = 7:1 (ratio by weight)
[0030] The antiweatherability of the above shoulder pads was investigated by a fade meter at 63°C for 200 hours. As the result, the surface of a shoulder pad consisting of a polyurethane foam alone was significantly discolored under the same condition, whereas the coating films of the shoulder pads of this invention were not discolored entirely.
[0031] The form-maintaining property of the shoulder pads was investigated by 500 times of repeated 90% compression. As the result, a shoulder pad consisting of a non-woven fabric alone significantly got out of shape under the same condition, whereas the shoulder pads of this invention did not get out of shape.
[0032] In addition, each of the shoulder pad of this invention and a polyether polyurethane foam was washed by dry cleaning. As the result, the polyether polyurethane foam was significantly swollen, whereas the shoulder pad of this invention was not swollen.
[0033] Although some preferred embodiments have been described, many modifications and variations may be made thereto in the right of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
1. A clothing pad consisting of a polyurethane foam pad core and a film of a nonyellowing
urethane resin coating formed on at least the surface of the pad core to be made in
contact with the outside cloth of an article of clothing.
2. The clothing pad of claim 1 wherein the thickness of said film of the nonyellowing
urethane resin coating is 20 to 200 µm
3. The clothing pad of claim 1 wherein said polyurethane foam used to form a pad core
has a density of 0.014 to 0.050 g/cm³, a hardness of 4 to 25 kgf and a cell number
of 20 to 60/inch.
4. The clothing pad of claim 1 wherein said nonyellowing urethane resin is one produced
from a polyol and an aliphatic isocyanate.