Polyurethane foam and its manufacturing method

Abstract

To provide an antibacterial yellowing-resistant polyurethane foam that has antibacterial properties, resists discoloration, and is suitable for hygienic and clean bra pads or the like.SOLUTION: The present invention provides a polyurethane foam suitable for bra pads or the like, which is formed from a polyurethane foam composition containing a polyol, a polyisocyanate, a foamer, a catalyst, and additives. The additives in the polyurethane foam composition include an antioxidant and an antibacterial. The antibacterial is a porous silicate mineral synthesized from metal oxide, silica and alumina.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a polyurethane foam suitable for use in brassiere pads and the like, and a method for producing the same. [Background technology]

[0002] There is a brassiere in which both sides of a cup-shaped pad made of polyurethane foam are covered with a skin material (Patent Document 1).

[0003] Since brassieres come into contact with the body, it is preferable that they are ones that allow less bacterial growth. However, the conventional polyurethane foam used in brassiere pads was not designed to prevent bacterial growth.

[0004] Furthermore, since brassieres are worn directly on the body, they must look clean. However, the conventional polyurethane foam used in brassieres' pads tends to gradually yellow due to exposure to sunlight and nitrogen oxides in the air. If the skin covering the brassier pad is light in color, the yellowed color of the bra pad will show through the skin and become unhygienic. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-112058 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a polyurethane foam which has antibacterial properties and is resistant to discoloration. [Means for solving the problem]

[0007] The first aspect is characterized in that in a polyurethane foam for brassiere pads formed from a polyurethane foam composition containing a polyol, a polyisocyanate, a blowing agent, a catalyst, and additives, an antioxidant and an antibacterial agent are blended as the additives, and the antibacterial agent is a porous silicate mineral synthesized from a metal oxide, silica, and alumina.

[0008] A second aspect is the first aspect, characterized in that an ultraviolet inhibitor, a photodiscoloration inhibitor, and a NOx discoloration inhibitor are blended as the additives.

[0009] In a third aspect, in the first or second aspect, the yellowing is characterized by a ΔYI value of less than 49.

[0010] A fourth aspect is a method for producing a polyurethane foam by foaming a polyurethane foam composition containing a polyol, a polyisocyanate, a blowing agent, a catalyst, and an additive, characterized in that an antioxidant and an antibacterial agent are blended as the additives, and the antibacterial agent is a porous silicate mineral synthesized from a metal oxide, silica, and alumina.

[0011] A fifth aspect is characterized in that in the fifth aspect, an ultraviolet inhibitor, a photodiscoloration inhibitor, and a NOx discoloration inhibitor are blended as the additives. Effect of the Invention

[0012] According to the present invention, a polyurethane foam having antibacterial properties and being resistant to discoloration can be obtained. [Brief description of the drawings]

[0013] [Figure 1] 1 is a table showing the compositions and physical properties of each comparative example and each example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The polyurethane foam of the present invention is formed by foaming a polyurethane foam composition containing a polyol, a polyisocyanate, a blowing agent, a catalyst, and additives.

[0015] The polyol may be any polyol for flexible polyurethane foams, such as polyether polyol, polyester polyol, or polyether ester polyol, and one or more of these may be used.

[0016] Examples of polyether polyols include polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, and sucrose, as well as polyether polyols obtained by adding alkylene oxides such as ethylene oxide (EO) and propylene oxide (PO) to these polyhydric alcohols.

[0017] Examples of polyester polyols include polyester polyols obtained by polycondensation of an aliphatic carboxylic acid such as malonic acid, succinic acid, or adipic acid, or an aromatic carboxylic acid such as phthalic acid, and an aliphatic glycol such as ethylene glycol, diethylene glycol, or propylene glycol. Examples of the polyether ester polyol include those obtained by reacting the above-mentioned polyether polyol with a polybasic acid to form a polyester, and those having both polyether and polyester segments in one molecule.

[0018] As for the polyol, it is preferable to use one or more polyols having a hydroxyl value (OHV) of 20 to 80 mgKOH / g, a functionality of 2 to 4, and a weight average molecular weight of 1,000 to 6,000.

[0019] The polyisocyanate may be an aliphatic or aromatic polyisocyanate having two or more isocyanate groups, a mixture thereof, or a modified polyisocyanate obtained by modifying them. Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexamethane diisocyanate, while examples of the aromatic polyisocyanate include toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate, xylylene diisocyanate, and polymeric MDI (crude MDI). Other prepolymers may also be used.

[0020] The isocyanate index (INDEX) is preferably 90 to 120, and more preferably 100 to 115. The isocyanate index is a value obtained by dividing the number of moles of isocyanate groups in an isocyanate by the total number of moles of active hydrogen groups such as hydroxyl groups in a polyol, and multiplying the result by 100, and is calculated as [NCO equivalent of isocyanate / active hydrogen equivalent×100].

[0021] As the blowing agent, water, alternative fluorocarbons, or hydrocarbons such as pentane can be used alone or in combination. In the case of water, carbon dioxide gas is generated during the reaction of polyol with polyisocyanate, and the carbon dioxide gas causes foaming. The amount of water used as the blowing agent is preferably 1.0 to 6.0 parts by weight per 100 parts by weight of polyol.

[0022] As the catalyst, a known urethane catalyst can be used in combination. For example, amine catalysts such as triethylamine, triethylenediamine, diethanolamine, dimethylaminomorpholine, N-ethylmorpholine, and tetramethylguanidine, tin catalysts such as stannous octoate and dibutyltin dilaurate, and metal catalysts such as phenylmercury propionate and lead octenate (also called organometallic catalysts), may be used alone or in combination of the amine catalyst and the metal catalyst. The amount of the amine catalyst is preferably 0.1 to 3 parts by weight relative to 100 parts by weight of the polyol. The amount of the metal catalyst is preferably 0 to 0.4 parts by weight.

[0023] Additives that are used include antioxidants, antibacterial agents, UV absorbers, photodiscoloration inhibitors, and NOx discoloration inhibitors. Examples of antioxidants include BHT and hindered phenols. Adding an antioxidant can prevent discoloration of polyurethane foam. The amount of antioxidant is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 2 parts by weight, per 100 parts by weight of polyol.

[0024] As the antibacterial agent, a porous silicate mineral synthesized from a metal oxide, silica, and alumina is used. As the porous silicate mineral synthesized from a metal oxide, silica, and alumina as the antibacterial agent, an aluminum-containing metal silicate or a hydrate thereof can be exemplified. As the metal oxide, zinc oxide is preferable. A porous silicate mineral (aluminum-containing metal silicate) synthesized from silica, alumina, and a metal oxide can obtain a better antibacterial effect than a silver-based antibacterial agent. In the porous silicate mineral using zinc oxide as the metal oxide, the ratio of the three components is preferably SiO2: 5-80 mol%, ZnO: 5-65 mol%, and Al2O3: 1-60 mol%. As an example of the composition formula of silica, alumina, and zinc oxide in a suitable porous silicate mineral, aSiO2·Al2O3·bZnO can be exemplified. In the above composition formula, a preferably satisfies 7≦a≦10 and b preferably satisfies 3≦b≦7, and more preferably satisfies 8≦a≦9 and b preferably satisfies 4≦b≦6.

[0025] The average particle size of the porous silicate mineral, as measured by the Coulter counter method, is from 1 to 10 μm, and preferably from 2 to 5 μm. From the viewpoint of exhibiting an antibacterial effect, the amount of the antibacterial agent is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, even more preferably 1.0 parts by weight or more, and particularly preferably 1.4 parts by weight or more, relative to 100 parts by weight of the polyol. On the other hand, from the economic viewpoint, the amount of the antibacterial agent is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, even more preferably 4 parts by weight or less, and particularly preferably 3 parts by weight or less.

[0026] Examples of the ultraviolet absorbing agent include a benzotriazole-based ultraviolet absorbing agent, a benzophenone-based ultraviolet absorbing agent, a benzoate-based ultraviolet absorbing agent, and a cyanoacrylate-based ultraviolet absorbing agent.

[0027] Examples of benzotriazole-based ultraviolet absorbers include 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole, 2-(2-hydroxy-5-(1,1,3,3-tetraethylbutyl)phenyl)benzotriazole, 2,2'-methylenebis(6-(2H-benzotriazol-2-yl)-4-1,1,3,3-(tetramethylbutyl)phenol), 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, and 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(t-butyl)phenol.

[0028] Benzophenone-based ultraviolet absorbers include 2-hydroxy-4-methoxybenzophenone, 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid, 2-hydroxy-4-n-octyloxybenzophenone, and 2,4-dihydroxybenzophenone. Benzoate-based ultraviolet absorbents include 2,4-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate. Examples of the cyanoacrylate ultraviolet absorber include ethyl-2-cyano-3,3-diphenylacrylate, and 2-ethylhexyl-2-cyano-3,3-diphenylacrylate.

[0029] By blending an ultraviolet absorbing agent, the effect of suppressing discoloration of the polyurethane foam caused by ultraviolet rays can be enhanced. The amount of the ultraviolet absorbing agent is preferably 0.05 to 2.0 parts by weight, more preferably 0.1 to 0.5 parts by weight, based on 100 parts by weight of the polyol.

[0030] Examples of photodiscoloration inhibitors include hindered amines, etc. By incorporating a photodiscoloration inhibitor, the effect of suppressing discoloration of the polyurethane foam caused by sunlight and ultraviolet rays can be enhanced.

[0031] Examples of hindered amine-based photodiscoloration inhibitors include bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidylsebacate, bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate, poly((6-((1,1,3,3-tetramethylbutyl)amino)-s-tetrazine-2,4-dyl)(2,2,6,6-tetramethyl-4-piperidyl)imino)hexamethylene(2,2,6,6-tetramethyl-4-piperidyl)imino)), bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, and the like.

[0032] The amount of the photodiscoloration inhibitor is preferably 0.01 to 2.0 parts by weight, and more preferably 0.05 to 0.5 parts by weight, based on 100 parts by weight of the polyol.

[0033] Examples of NOx discoloration inhibitors include phosphorus-based antioxidants and sulfur-based antioxidants. By adding a NOx discoloration inhibitor, it is possible to suppress discoloration of polyurethane foam caused by NOx in the air. Examples of the phosphorus-based antioxidant include pentaerythritol diphosphate and diisodecylpentaerythritol diphosphite. Examples of the sulfur-based antioxidant include bis{2-methyl-4-[3-n-alkyl (C12 or C14)thiopropionyloxy]-5-t-butylphenyl}sulfide. The amount of the NOx discoloration inhibitor is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 2.0 parts by weight, and further preferably 0.7 to 1.5 parts by weight, based on 100 parts by weight of the polyol.

[0034] The polyurethane foam composition may contain other auxiliaries, such as a foam stabilizer and a colorant. As the foam stabilizer, any of those known for flexible polyurethane foams can be used, such as silicone-based foam stabilizers, fluorine-containing compound-based foam stabilizers, and known surfactants. Colorants are appropriately blended to suit the user's color preferences.

[0035] The polyurethane foam composition is preferably foamed by slab foaming, which is a method in which the polyurethane foam composition is mixed, discharged onto a belt conveyer, and foamed at atmospheric pressure and room temperature. The foamed polyurethane foam can be used to form a brassiere pad as follows. The polyurethane foam is cut into a sheet having a thickness of, for example, about 10 mm by a skiving process, and the resulting sheet-like polyurethane foam is sandwiched between a male mold and a female mold having mold surfaces of a predetermined cup (bowl) shape, etc., and heat-pressed at 150 to 260° C. The mold surface distance between the male and female molds is narrower by a predetermined amount than the thickness of the polyurethane foam before heat pressing. After heat pressing, unnecessary parts are removed by trimming to obtain a pad. Both sides of the resulting pad are covered with a brassiere skin material, and necessary members such as shoulder straps are further attached to form a brassiere. EXAMPLES

[0036] Polyurethane foam compositions were prepared from the following components according to the formulations shown in FIG. 1 for each of the comparative examples and examples. The prepared polyurethane foam compositions were mixed and foamed to produce polyurethane foams.

[0037] Polyol: Polyether polyol, molecular weight: 3000, functionality: 3, hydroxyl value: 56.1 mg KOH / g, product name: Sannix GP-3050NS, manufactured by Sanyo Chemical Industries, Ltd. Amine catalyst: Triethylenediamine 33%, Product name: 33LSI, Air Products Japan Foam stabilizer: Silicone foam stabilizer, product name: L-595, manufactured by Momentive Tin catalyst: Stannous octylate, product name: MRH-110, manufactured by Johoku Chemical Industry Co., Ltd. Foaming agent: water Antioxidant; benzenepropanoic acid, 3,5-bis(1,1-methyl-ethyl)-4 hydroxy-, C7-C9 side chain alkyl ester, product name: I-1135, manufactured by Chiba Specialty Chemicals, UV absorber: Benzotriazole type, product name: T-571, manufactured by BASF Photodiscoloration inhibitor; hindered amine type, product name: T-765, manufactured by BASF NOx discoloration inhibitor; phosphorus type, product name: CS-22LF, manufactured by Momentive Performance Materials Japan LLC Antibacterial agent A: Silver-based, Product name: Zeomic AW10N, manufactured by Sinanen Zeomic Co., Ltd. Antibacterial agent B: Zinc oxide / silicon dioxide / aluminum oxide porous silicate mineral, product name: Laonite SF, manufactured by Lion Specialty Chemicals Isocyanate; T-80, 2,4-TDI / 2,6-TDI=80 / 20

[0038] The foaming property of the polyurethane foam was evaluated. The foaming property was evaluated as "Good" when there was no puncture, no down, no shrinkage, and the foaming property was good, and as "Poor" when the foaming property was not good. The evaluation results are shown in Figure 1.

[0039] The physical properties of the polyurethane foam produced were measured, including density (JIS K 7222), ILD hardness (JIS K 6400-2), tensile strength (JIS K 6400-5), elongation (JIS K 6400-5), tear strength (JIS K6400-5), compression set (JIS K 6400-4), and air permeability (JIS K 6400-7), and the physical properties of the polyurethane foam were evaluated based on the measurement results. The physical properties were evaluated as "Good" if they were equivalent to the current product, and "Poor" if they showed a significant decrease. The measurement results are shown in Figure 1.

[0040] The antibacterial properties of polyurethane foam were measured and evaluated. The antibacterial activity value for Staphylococcus aureus was measured based on JIS K6400-9:2019. The common logarithm of the viable cell count after 24 hours of shaking culture in the control group (air shaking) was 5.60. The greater the antibacterial activity value against Staphylococcus aureus, the greater the antibacterial effect, and from the viewpoint of antibacterial effect, an antibacterial activity value of 1.2 or more is preferable, 1.4 or more is more preferable, 2.0 or more is even more preferable, and 2.4 or more is particularly preferable. The measurement results are shown in FIG.

[0041] The yellowing resistance of polyurethane foam was measured and evaluated. For the measurement of yellowing resistance, a polyurethane foam test piece (t10mm x 50mm x 150mm) was irradiated with a fadeometer at 63°C for 10 hours, and the color difference ΔYI before and after irradiation was measured. The yellowing resistance was evaluated as follows: ΔYI value less than 35 was marked "◎", 35 to less than 40 was marked "◯", 40 to less than 49 was marked "△", and 49 or more was marked "X". The measurement results are shown in Figure 1.

[0042] The results of each comparative example and each example are shown below. Comparative Example 1 Comparative Example 1 is an example in which the polyurethane foam composition consists of 100 parts by weight of polyol, 0.85 parts by weight of amine catalyst, 1.00 part by weight of foam stabilizer, 0.035 part by weight of tin catalyst, 3.15 parts by weight of blowing agent, 0.50 parts by weight of antioxidant, and isocyanate index 105.0, and does not contain any ultraviolet absorber, photodiscoloration inhibitor, NOx discoloration inhibitor, or antibacterial agent.

[0043] Comparative Example 1 has a density of 29.6 kg / m 3 , ILD hardness 98N, tensile strength 87kPa, elongation 161%, tear strength 4.7N / cm, compression set 2.6%, breathability 38ml / cm 2 The viscosity was 0.01 / s, foaming property was 0.01, and physical properties were 0.01. In addition, antibacterial property was not measured because it does not contain an antibacterial agent. The yellowing resistance was 0.01, with a ΔYI of 45.3 and an evaluation of 0.01.

[0044] Comparative Example 2 Comparative Example 2 has the same composition as Comparative Example 1, except that 0.20 parts by weight of a silver-based antibacterial agent A was used as the antibacterial agent in Comparative Example 1. Comparative Example 2 has a density of 28.8 kg / m 3 , ILD hardness 82N, tensile strength 83kPa, elongation 150%, tear strength 4.5N / cm, compression set 2.7%, breathability 38ml / cm 2 The antibacterial properties were not measured, but the yellowing resistance was rated x with a ΔYI of 49.9. Comparative Example 2 was inferior in yellowing resistance to Comparative Example 1 due to the incorporation of a silver-based antibacterial agent.

[0045] Example 1 Example 1 has the same formulation as Comparative Example 2, except that instead of the 0.20 parts by weight of the silver-based antibacterial agent A in Comparative Example 2, 0.50 parts by weight of antibacterial agent B consisting of a porous silicate mineral of zinc oxide / silicon dioxide / aluminum oxide was used. Example 1 has a density of 29.7 kg / m 3 , ILD hardness 84N, tensile strength 76kPa, elongation 148%, tear strength 4.5N / cm, compression set 2.9%, breathability 34ml / cm 2The foaming property was "good", and the physical properties were "good". The antibacterial property was not measured, but the yellowing resistance was 47.2, and the evaluation was "△". Compared to Comparative Example 2, Example 1 had stronger antibacterial properties due to the incorporation of an antibacterial agent made of a porous silicate mineral of zinc oxide / silicon dioxide / aluminum oxide instead of a silver-based antibacterial agent, and the evaluation of yellowing resistance was improved from "X" in Comparative Example 2 to "△".

[0046] Example 2 Example 2 has the same composition as Example 1, except that 0.11 parts by weight of an ultraviolet absorber, 0.05 parts by weight of a photodiscoloration inhibitor, and 0.49 parts by weight of a NOx discoloration inhibitor are added to the composition of Example 1. Example 2 has a density of 29.4 kg / m 3 , ILD hardness 81N, tensile strength 74kPa, elongation 132%, tear strength 4.4N / cm, compression set 4.4%, breathability 21ml / cm 2 The antibacterial properties were not measured, but the yellowing resistance was rated as "good" with a ΔYI of 35.4. In comparison with Example 1, Example 2 was evaluated as being resistant to yellowing from "△" in Example 1 to "◯" due to the inclusion of an ultraviolet absorber, a photodiscoloration inhibitor, and a NOx discoloration inhibitor.

[0047] Example 3 Example 3 has the same formulation as Example 2, except that the amount of ultraviolet absorber in the formulation of Example 2 was increased from 0.11 parts by weight to 0.21 parts by weight, the amount of photodiscoloration inhibitor was increased from 0.05 parts by weight to 0.11 parts by weight, and the amount of NOx discoloration inhibitor was increased from 0.49 parts by weight to 0.98 parts by weight. Example 3 has a density of 29.5 kg / m 3 , ILD hardness 84N, tensile strength 79kPa, elongation 153%, tear strength 3.6N / cm, compression set 4.0%, breathability 37ml / cm 2 The antibacterial activity value was 1.3, indicating antibacterial action, and the yellowing resistance ΔYI was 30.3, resulting in an evaluation of '◎'. In Example 3, the amounts of the ultraviolet absorber, photodiscoloration inhibitor, and NOx discoloration inhibitor were increased compared to Example 2, and as a result, the yellowing resistance was improved from "good" in Example 2 to "Excellent".

[0048] Example 4 Example 4 is similar to Example 3, except that the amount of antibacterial agent B in the formulation of Example 3 was increased from 0.50 parts by weight to 1.00 parts by weight. Example 4 has a density of 29.5 kg / m 3 , ILD hardness 81N, tensile strength 83kPa, elongation 150%, tear strength 2.8N / cm, compression set 4.3%, breathability 38ml / cm 2 The antibacterial activity value was 1.5, indicating antibacterial action, and the yellowing resistance ΔYI was 33.3, resulting in an evaluation of '◎'. In Example 4, compared to Example 3, the amount of antibacterial agent added was increased, and as a result, the yellowing resistance was slightly decreased.

[0049] Example 5 Example 5 is similar to Example 3, except that the amount of antibacterial agent B in the formulation of Example 3 was increased from 0.50 parts by weight to 2.00 parts by weight. Example 5 has a density of 28.6 kg / m 3 , ILD hardness 82N, tensile strength 76kPa, elongation 148%, tear strength 3.8N / cm, compression set 5.0%, breathability 35ml / cm 2 The antibacterial activity value was 2.7, indicating antibacterial action, and the yellowing resistance ΔYI was 36.4, resulting in an evaluation of "good." In Example 5, the amount of antibacterial agent added was increased compared to Examples 3 and 4, and as a result, the yellowing resistance was reduced. However, compared to Comparative Examples 1 and 2, the yellowing resistance was high.

[0050] As described above, the polyurethane foam of the present invention contains an antioxidant and an antibacterial agent consisting of a porous silicate mineral of zinc oxide / silicon dioxide / aluminum oxide, and therefore has antibacterial properties and is resistant to discoloration, giving it a hygienic and clean feel and making it suitable for use as brassiere pads, clothing pads such as shoulder pads, masks, etc.

Claims

1. In a polyurethane foam formed from a polyurethane foam composition containing a polyol, a polyisocyanate, a blowing agent, a catalyst, and an additive, The additives are made up of five components: an antioxidant, an ultraviolet absorber, a photodiscoloration inhibitor, a NOx discoloration inhibitor, and an antibacterial agent. A polyurethane foam, characterized in that the antibacterial agent is a porous silicate mineral synthesized from zinc oxide, silica and alumina.

2. In the polyurethane foam composition as a raw material, The antibacterial agent is blended in an amount of 0.1 parts by mass or more relative to 100 parts by weight of the polyol, The antioxidant is mixed in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the polyol, The ultraviolet absorber is blended in an amount of 0.05 to 2.0 parts by weight based on 100 parts by weight of the polyol, The photodiscoloration inhibitor is blended in an amount of 0.01 to 2.0 parts by weight based on 100 parts by weight of the polyol, 2. The polyurethane foam according to claim 1, wherein the NOx discoloration inhibitor is blended in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the polyol.

3. 3. The polyurethane foam according to claim 1, wherein the yellowing is such that the ΔYI value is less than 40.

4. A clothing pad comprising the polyurethane foam according to any one of claims 1 to 3.

5. A method for producing a polyurethane foam described in any one of claims 1 to 3, comprising producing a polyurethane foam by foaming the polyurethane foam composition.

Images