JP7158885B2 - flexible polyurethane foam - Google Patents

Description

The present invention relates to a flexible polyurethane foam that can be thermoformed at low temperatures and a method for producing the same.

Soft polyurethane foam obtained from polyurethane foam raw materials containing polyol, isocyanate, blowing agent, and catalyst is used for pads and cushioning materials for clothing and interior materials for vehicles by thermoforming such as heat press and frame lamination. A material that is formed into a predetermined shape or laminated is used.

Thermoforming of flexible polyurethane foam is desirable from the viewpoint of molding equipment and molding efficiency, and because thermoforming at high temperature for a long time may cause thermal deterioration of the flexible polyurethane foam itself and other laminated members, so thermoforming at low temperature is desirable. It is rare.

As a conventional flexible polyurethane foam that can be thermoformed at a low temperature, a polyol, an isocyanate, and a catalyst are specified (Patent Document 1). There is one that specifies a combination of polyether block copolymer polyols (Patent Document 2) and one that specifies a styrene/acrylonitrile copolymer polyol as at least a part of the polyol (Patent Document 3).

JP 2004-182927 A Japanese Unexamined Patent Application Publication No. 2006-213896 Japanese Unexamined Patent Application Publication No. 2008-201946

However, conventional low-temperature thermoformable flexible polyurethane foams use specific polyurethane foams and isocyanates, and therefore have limited applications and low versatility.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a flexible polyurethane foam that can be thermoformed at a low temperature and has high versatility, and a method for producing the same.

A first aspect is a flexible polyurethane foam obtained from a flexible polyurethane foam raw material containing a polyol, an isocyanate, a blowing agent, a catalyst, and a foam stabilizer, wherein glycidyl ether is blended with the polyurethane foam raw material. and

A second aspect is characterized in that in the first aspect , the blending amount of the glycidyl ether is 0.2 to 1.0 parts by weight with respect to 100 parts by weight of the polyol.

A third aspect is characterized in that, in the first or second aspect , the flexible polyurethane foam has a compressive strain of 1 to 5% at room temperature and can be hot-press molded at 140°C.

A fourth aspect is a method for producing a flexible polyurethane foam by mixing and foaming flexible polyurethane foam raw materials containing a polyol, an isocyanate, a blowing agent, a catalyst, and a foam stabilizer, wherein glycidyl ether is blended with the polyurethane foam raw material. It is characterized by

According to the present invention, by blending glycidyl ether into the flexible polyurethane foam raw material, the resulting flexible polyurethane foam can be thermoformed at a low temperature, and the thermoforming time can be reduced. Further, according to the present invention, since the polyol and isocyanate are not limited to specific ones, the polyol and isocyanate according to the application of the flexible polyurethane foam can be used, and the flexibility (hardness) and Low-temperature thermoforming is possible while maintaining the elongation, and versatility is high.

1 is a table showing measurement results of formulations and physical properties of examples and comparative examples.

The flexible polyurethane foam of the present invention is produced by mixing and foaming flexible polyurethane foam raw materials containing polyol, isocyanate, blowing agent, catalyst, foam stabilizer and glycidyl ether.

Polyols for flexible polyurethane foams can be used as polyols. For example, polyether polyols, polyester polyols and polyether ester polyols may be used, and one or more of them may be used.

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, sucrose, and ethylene oxide (EO ) and polyether polyols to which alkylene oxides such as propylene oxide (PO) are added.

Examples of polyester polyols include polycondensation from aliphatic carboxylic acids such as malonic acid, succinic acid and adipic acid, aromatic carboxylic acids such as phthalic acid, and aliphatic glycols such as ethylene glycol, diethylene glycol and propylene glycol. Polyester polyols obtained by
Examples of polyether ester polyols include those obtained by reacting the above polyether polyols with polybasic acids to form polyesters, and those having both polyether and polyester segments in one molecule.

As for the polyol, it is preferable to use a flexible polyurethane foam that can exhibit flexibility (hardness and elongation). Any of polyether polyol, polyester polyol, and polyether ester polyol should have a hydroxyl value (OHV) of 20 to 80 mgKOH/ g. It is preferable to use one or a plurality of polyols having 2 to 4 functional groups and a weight average molecular weight of 2,000 to 7,000.

As the isocyanate, aliphatic or aromatic polyisocyanates having two or more isocyanate groups, mixtures thereof, and modified polyisocyanates obtained by modifying them can be used. Examples of aliphatic polyisocyanates include hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexamethane diisocyanate. Examples of aromatic polyisocyanates include toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate, xyloxy Examples include diisocyanate, polymeric polyisocyanate (crude MDI), and the like. In addition, other prepolymers can also be used.

The isocyanate index (INDEX) is preferably 90-110. The isocyanate index is a value obtained by dividing the number of moles of isocyanate groups in isocyanate by the total number of moles of active hydrogen groups such as hydroxyl groups in polyol and multiplying it by 100. Calculated.

As blowing agents, water, CFC alternatives, 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 between polyol and isocyanate, and the carbon dioxide gas causes foaming. The blending amount of water as a foaming agent is preferably 2.0 to 5.0 parts by weight per 100 parts by weight of polyol.

As a catalyst, a known urethanization catalyst can be used in combination. For example, amine catalysts such as triethylamine, triethylenediamine, diethanolamine, dimethylaminomorpholine, N-ethylmorpholine and tetramethylguanidine; tin catalysts such as stannus octoate and dibutyltin dilaurate; phenylmercuric propionate and lead octoate. metal catalysts (also called organometallic catalysts) such as amine catalysts and metal catalysts, or both may be used in combination. The amount of the amine catalyst compounded is preferably 0.1 to 1.0 parts by weight with respect to 100 parts by weight of the polyol. The blending amount of the metal catalyst is preferably 0 to 1.0 parts by weight.

As the foam stabilizer, those known for flexible polyurethane foam can be used. Examples thereof include silicone-based foam stabilizers, fluorine-containing compound-based foam stabilizers, and known surfactants. The blending amount of the foam stabilizer is preferably 0.4 to 1.5 parts by weight per 100 parts by weight of the polyol.

A glycidyl ether is an epoxy compound obtained by glycidyl-etherifying an organic acid or/and an alcoholic hydroxyl group. Glycidyl ethers include aliphatic epoxy compounds and aromatic epoxy compounds. Aliphatic epoxy compounds include monofunctional, difunctional and polyfunctional types. Monofunctional types include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol glycidyl ether and the like. Bifunctional types include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol. diglycidyl ether, polypropylene glycol diglycidyl ether and the like. Polyfunctional types include glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether and the like. Aromatic epoxy compounds include phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, dibromophenyl glycidyl ether, resortinol diglycidyl ether and the like.

Examples of commercially available glycidyl ethers that can be used in the present invention include Denacol EX-313, Denacol EX-314, Denacol EX-321, Denacol EX-411, Denacol EX-412 and Denacol EX-512 manufactured by Nagase ChemteX Corporation. , Denacol EX-521, EX-612, Denacol EX-614 and the like. Glycidyl ether is not limited to one, and two or more may be used.

Among the glycidyl ethers, more preferred are bifunctional, polyfunctional, or a mixture of bifunctional and polyfunctional aliphatic epoxy compounds.
The amount of glycidyl ether to be blended is preferably 0.2 to 1.0 parts by weight, more preferably 0.5 to 1.0 parts by weight, based on 100 parts by weight of the polyol, and maintains the physical properties of the flexible polyurethane foam. 0.2 to 0.9 parts by weight is preferable from the viewpoint of If the amount of glycidyl ether is too small, the effect tends to be small, and if it is too large, the physical properties tend to change greatly.

Other substances may be added to the polyurethane foam raw material depending on the application. Other substances to be blended include, for example, colorants and flame retardants. The coloring agent is used according to the application of the flexible polyurethane foam, and the flame retardant is used when the application of the flexible polyurethane foam requires flame retardancy.

Foaming in the method for producing flexible polyurethane foam may be either mold foaming or slab foaming. Mold foaming is a method of injecting a polyurethane foam raw material into a mold and foaming it. Slab foaming is a method in which a mixed composition for flexible polyurethane foam (polyurethane foam raw material) is mixed, discharged onto a belt conveyor, and foamed at room temperature under atmospheric pressure.

The flexible polyurethane foam of the present invention has a compressive strain (based on JIS K6400-4 4.5.2 C method) of 1 to 5% at room temperature. In addition, normal temperature here means 20 degreeC +/-15 degreeC based on JISZ8703. Since the compressive strain at room temperature is as small as 1 to 5%, there is little plastic deformation even after long-term use, and good quality can be maintained.

In addition, the polyurethane foam of the present invention can be heat-press molded at a low temperature of 140° C., and the heat-pressing can be performed at a low temperature.

The following raw materials were mixed according to the formulation shown in FIG. 1, reacted and foamed to prepare flexible polyurethane foams of Comparative Example 1 and each example.
Polyol: polyether polyol, molecular weight (Mw) 3000, number of functional groups 3, hydroxyl value 56 mgKOH / g, product number; GP3050, manufactured by Sanyo Chemical Industries, Ltd. Blowing agent: water Amine catalyst: N,N-dimethylaminohexanol, Product name: Kaorizer No. 25, manufactured by Kao Corporation Foam stabilizer: silicone surfactant, product name; B-8110, manufactured by Evonik Metal catalyst: stannous octylate, product number; MRH110, Johoku Chemical Industry Co., Ltd. Isocyanate: TDI : A mixture of 80% 2,4-TDI and 20% 2,6-TDI, product number; Coronate T-80, manufactured by Toso Corporation Glycidyl ether-1: glycerol polyglycidyl ether, product number; Denacol EX-313, Nagasechem Tex Co., Ltd. Glycidyl ether-2: Trimethylolpropane polyglycidyl ether, product number; Denacol EX-321, manufactured by Nagase ChemteX Co., Ltd.

Cream time and rise time were measured in order to determine the reactivity of the polyurethane foam raw materials of Comparative Example 1 and each example. The cream time is the time required for the polyurethane foam raw material to change from a liquid state during mixing and discharging to a resin state. On the other hand, the rise time is the time from the time of mixing/discharging until the maximum foaming height is reached. Furthermore, the appearance of the polyurethane foams of Comparative Example 1 and each example was visually evaluated, and "⊚" was given when the appearance was good, and "×" was given when there was a poor appearance due to poor foaming.

Regarding the polyurethane foam of Comparative Example 1 and each example, density (JIS K7222), hardness (JIS K6400-2 6.7 D method), tensile strength (JIS K6400-5 5), elongation (JIS K6400-5 5) , Tear strength (JIS K6400-5 6 B method), compressive strain at 70 ° C (JIS K6400-4 4.5.2 A method), normal temperature compressive strain (JIS K6400-4 4.5.2 C method) It was measured. The test conditions for compressive strain at room temperature were 23° C., 22 hours, and 50% compression.

Further, the polyurethane foams of Comparative Example 1 and each example were evaluated for heat pressability as follows. From the polyurethane foams of Comparative Example 1 and each example, the required number of test samples (6 each) of 50 mm length x 50 mm width x 10 mm thickness were prepared, and the heat press temperature and heat press time were varied to obtain 550 mm length x width. The test sample was hot-pressed (70% compression) to 3 mm with a 500-mm hot plate, the thickness was measured 24 hours after hot-pressing, and the restoration rate after 24 hours with respect to the thickness (10 mm) before hot-pressing was calculated. . The recovery rate is calculated by the formula [thickness after 24 hours/thickness before hot pressing (10 mm)]×100 (%). The smaller the recovery rate, the better the hot press moldability. The evaluation of hot pressability is as follows: “◎”: 0% ≤ recovery rate < 5%, “◯”: 5% ≤ recovery rate < 20%, “△”: 20% ≤ recovery rate < 50%, “×”: 50 %≦restoration ratio≦100%. In addition, "130 ° C. x 180 seconds" in Fig. 1 indicates hot pressing at 130 ° C. for 180 seconds, "130 ° C. x 540 seconds" indicates hot pressing at 130 ° C. for 540 seconds, and "140 ° C. x 540 seconds". indicates hot pressing at 140°C for 540 seconds, "150°C x 180 seconds" indicates hot pressing at 150°C for 180 seconds, "180°C x 55 seconds" indicates hot pressing at 180°C for 55 seconds, "180°C x 120 seconds" indicates heat pressing at 180°C for 120 seconds.

Comparative Example 1 is an example in which no glycidyl ether is blended. Comparative Example 1 has a cream time of 14 seconds, a rise time of 102 seconds, an appearance of "A", a density of 27.2 kg/m ³ , a hardness of 167 N, a tensile strength of 93.7 kPa, an elongation of 120%, a tear strength of 4.7 N/cm, Compressive strain at 70 ° C. 3.2%, compressive strain at room temperature 2.2%, hot press evaluation: 130 ° C. x 180 seconds "x", 130 ° C. x 540 seconds "x", 140 ° C. x 540 seconds 150° C.×180 seconds is “x”, 180° C.×55 seconds is “Δ”, and 180° C.×120 seconds is “⊚”. In Comparative Example 1, since glycidyl ether was not blended, the thermoforming evaluation was "x" up to 150 ° C. x 180 seconds, finally became "△" at 180 ° C. x 55 seconds, and "" at 180 ° C. x 120 seconds. ⊚”, indicating poor thermoformability.

Example 1 is an example in which 0.25 parts by weight of glycidyl ether-1 was blended. Example 1 has a cream time of 15 seconds, a rise time of 104 seconds, an appearance of "A", a density of 28.2 kg/m ³ , a hardness of 156 N, a tensile strength of 97.6 kPa, an elongation of 130%, a tear strength of 4.9 N/cm, Compressive strain at 70 ° C. 8.4%, compressive strain at normal temperature 2.7%, hot press evaluation: 130 ° C. x 180 seconds is "x", 130 ° C. x 540 seconds is "x", 140 ° C. x 540 seconds 150° C.×180 seconds was “◯”, 180° C.×55 seconds was “◯”, and 180° C.×120 seconds was “⊚”. In Example 1, 0.25 parts by weight of glycidyl ether-1 was blended, so the thermoforming evaluation was "○" at 140 ° C. × 540 seconds, "○" at 150 ° C. × 180 seconds, and 180 ° C. × 55 seconds. "O" at 180 ° C for 120 seconds, and "◎" at 180 ° C for 120 seconds. Good moldability.

Example 2 is an example in which 0.5 parts by weight of glycidyl ether-1 was blended. Example 2 has a cream time of 15 seconds, a rise time of 103 seconds, an appearance of "A", a density of 26.8 kg/m ³ , a hardness of 159 N, a tensile strength of 99.1 kPa, an elongation of 121%, a tear strength of 4.3 N/cm, Compressive strain at 70 ° C. 29.5%, compressive strain at room temperature 3.7%, hot press evaluation: 130 ° C. x 180 seconds is "x", 130 ° C. x 540 seconds is "△", 140 ° C. x 540 seconds 150° C.×180 seconds was “◯”, 180° C.×55 seconds was “◯”, and 180° C.×120 seconds was “⊚”. In Example 2, since 0.5 parts by weight of glycidyl ether-1 is blended, the thermoforming evaluation is "○" at 140 ° C. × 540 seconds, "○" at 150 ° C. × 180 seconds, and 180 ° C. × 55 seconds. and "⊚" at 180°C for 120 seconds.

Example 3 is an example in which 1 part by weight of glycidyl ether-1 was blended. Example 3 has a cream time of 16 seconds, a rise time of 105 seconds, an appearance of "A", a density of 26.8 kg/m ³ , a hardness of 153 N, a tensile strength of 95 kPa, an elongation of 114%, a tear strength of 4.6 N/cm, and 70°C. Compressive strain of 31.3%, compressive strain of normal temperature 3.6%, evaluation of hot pressability is "x" for 130 ° C. x 180 seconds, "△" for 130 ° C. x 540 seconds, and "△" for 140 ° C. x 540 seconds. ◯”, 150° C.×180 sec. is “◯”, 180° C.×55 sec. In Example 3, since 1 part by weight of glycidyl ether-1 was blended, the thermoforming evaluation was "○" at 140 ° C. × 540 seconds, "○" at 150 ° C. × 180 seconds, and "○" at 180 ° C. × 55 seconds. ⊚” and ⊚ at 180°C for 120 seconds.

Example 4 is an example in which 0.25 parts by weight of glycidyl ether-2 was blended. Example 4 has a cream time of 15 seconds, a rise time of 100 seconds, an appearance of "A", a density of 26.6 kg/m ³ , a hardness of 171 N, a tensile strength of 93.4 kPa, an elongation of 115%, a tear strength of 4.5 N/cm, Compressive strain at 70°C: 24.8%, compressive strain at room temperature: 3.4%, hot pressability evaluation: 130°C x 180 seconds is "x", 130°C x 540 seconds is "△", 140°C x 540 seconds 150° C.×180 seconds was “◯”, 180° C.×55 seconds was “◯”, and 180° C.×120 seconds was “⊚”. In Example 4, 0.25 parts by weight of glycidyl ether-2 was blended, so the thermoforming evaluation was "Good" at 140 ° C. x 540 seconds, "Good" at 150 ° C. x 180 seconds, and 180 ° C. x 55 seconds. and "⊚" at 180°C for 120 seconds.

Example 5 is an example in which 0.5 parts by weight of glycidyl ether-2 was blended. Example 5 has a cream time of 15 seconds, a rise time of 101 seconds, an appearance of "A", a density of 27.3 kg/m ³ , a hardness of 172 N, a tensile strength of 96.9 kPa, an elongation of 110%, a tear strength of 4.5 N/cm, Compressive strain at 70 ° C. 35.6%, compressive strain at room temperature 3.1%, hot press evaluation: 130 ° C. x 180 seconds is "x", 130 ° C. x 540 seconds is "○", 140 ° C. x 540 seconds 150° C.×180 seconds was “◯”, 180° C.×55 seconds was “⊚”, and 180° C.×120 seconds was “⊚”. In Example 5, 0.5 parts by weight of glycidyl ether-2 was blended, so the thermoforming evaluation was "○" at 130 ° C. x 540 seconds, "○" at 140 ° C. x 540 seconds, and 150 ° C. x 180 seconds. "○" at 180°C x 55 seconds, "⊚" at 180°C x 120 seconds.

Example 6 is an example in which 1 part by weight of glycidyl ether-2 was blended. Example 6 has a cream time of 16 seconds, a rise time of 107 seconds, an appearance of "A", a density of 28.4 kg/m ³ , a hardness of 167 N, a tensile strength of 88 kPa, an elongation of 112%, a tear strength of 4.5 N/cm, and 70°C. Compressive strain of 34%, compressive strain of normal temperature 2.6%, evaluation of hot pressability is "x" at 130 ° C. x 180 seconds, "○" at 130 ° C. x 540 seconds, and "○" at 140 ° C. x 540 seconds. , 150° C.×180 seconds was “◯”, 180° C.×55 seconds was “⊚”, and 180° C.×120 seconds was “⊚”. In Example 6, 1 part by weight of glycidyl ether-2 was blended, so the thermoforming evaluation was "○" at 130 ° C. x 540 seconds, "○" at 140 ° C. x 540 seconds, and "" at 150 ° C. x 180 seconds. "A" at 180°C for 55 seconds and "A" at 180°C for 120 seconds.

As described above, the flexible polyurethane foam of the present invention can be thermoformed at a lower temperature than before, and has a recovery rate of less than 20% after 24 hours, making it excellent in thermoforming at a low temperature. In addition, since the flexible polyurethane foam of the present invention is not limited to specific polyols and isocyanates, it is possible to use polyols and isocyanates suitable for the application of the flexible polyurethane foam while maintaining the hardness and elongation of the flexible polyurethane foam. It is highly versatile.

Claims (5)

In a flexible polyurethane foam obtained from a flexible polyurethane foam raw material containing a polyol, an isocyanate, a blowing agent, a catalyst, and a foam stabilizer,
The polyol includes those having 3 to 4 functional groups,
(1) Glycidyl ether is blended with the polyurethane foam raw material, and the glycidyl ether is either a bifunctional or polyfunctional aliphatic epoxy compound, or a mixture thereof; or
(2) glycidyl ether (excluding silicone copolymers containing glycidyl ether and brominated phenylglycidyl ether) is added to the polyurethane foam raw material ;
A flexible polyurethane foam , wherein the glycidyl ether is added in an amount of 0.2 to 1.0 parts by weight per 100 parts by weight of the polyol . In a flexible polyurethane foam obtained from a flexible polyurethane foam raw material containing a polyol, an isocyanate, a blowing agent, a catalyst, and a foam stabilizer,
Glycidyl ether is blended with the polyurethane foam raw material, and the glycidyl ether is glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether. A flexible polyurethane foam characterized by being any of 3. The flexible polyurethane foam according to claim 2, wherein the amount of the glycidyl ether compounded is 0.2 to 1.0 parts by weight per 100 parts by weight of the polyol . The flexible polyurethane foam according to any one of claims 1 to 3, wherein the flexible polyurethane foam has a compressive strain of 1 to 5% at room temperature and can be hot-press molded at 140°C. Density (JIS K7222) is 26.6-28.4kg/m ³ and/or a hardness (JIS K6400-2 6.7 D method) of 153 to 172N, the flexible polyurethane foam according to any one of claims 1 to 4.

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