JP6559513B2 - Soft polyurethane foam for mattress - Google Patents

Description

  The present invention relates to a flexible polyurethane foam for mattresses, and more particularly, to a flexible polyurethane foam for mattresses that exhibits high air permeability without undergoing film removal treatment and has a small compressive residual strain.

  Conventionally, flexible polyurethane foam is generally used for mattresses and cushions, and various improvements have been made to enhance the physical properties thereof.

  Among them, it is generally known that flexible polyurethane foam is easily stuffy, and in order to improve the stuffiness, those having enhanced air permeability have been studied. (Patent Document 1, Patent Document 2)

JP 11-318646 A JP2011-184487A

  In Patent Document 1, a film-free polyurethane foam is used as a flexible polyurethane foam constituting a mattress in order to eliminate stuffiness. The film-free polyurethane foam is a soft polyurethane foam that has been subjected to a film removal treatment, and the film removal treatment is a treatment for destroying and removing the cell membrane constituting the flexible polyurethane foam, for example, oxygen And the like, and the dissolution treatment with a solvent. The air permeability is improved by removing the cell membrane, and the stuffiness is eliminated by producing a mattress using the non-film polyurethane foam. Further, in Patent Document 1, in addition to using the soft polyurethane foam subjected to the film removal treatment, a plurality of grooves are provided on the surface of the mattress to ensure horizontal air permeability. As a method for ensuring air permeability in the horizontal direction, in addition to the groove processing, formation of an uneven surface by profile processing is also known.

  Patent Document 2 discloses a polyol having an ethylene oxide content of 60% or more for the purpose of providing a polyurethane foam for a mattress that has low density and hardness, high air permeability, and low compression residual strain. A polyurethane foam is produced by using 3 to 22% by mass and another polyol such as a polyol having an ethylene oxide content of 30% or less and using water and carbon dioxide as a blowing agent.

  The filmless polyurethane foam used in Patent Document 1 has a problem that it is easy to sag, although it ensures air permeability. For this reason, mattresses that have been grooved or profiled to further impart acupressure and body pressure dispersibility are easier to sag, and can be sagged not only by long-term use but also by compressed packaging during transportation and storage This has a problem that it is difficult to return to the original thickness and shape. Moreover, the polyurethane foam for mattresses of Patent Document 2 has a low density and hardness, and the elimination of the feeling of bottoming is insufficient.

  The mattress of the present invention provides a flexible polyurethane foam for mattresses that solves the above-described problems, has high air permeability even if it has not been subjected to film removal treatment, is hardly stuffy, and has excellent resilience and durability. Objective.

The invention of claim 1 is a polyurethane foam comprising a polyol component, an isocyanate component, a catalyst, a foaming agent, and a foam stabilizer. The polyol component has a number average molecular weight of 3000 to 5000, an average number of functional groups of 2 to 4, and ethylene. Polyether polyol (I) having an oxide content of 60% or more, polyether polyol (II) having a number average molecular weight of 2000 to 4000, an average number of functional groups of 2 to 4, and an ethylene oxide content of 20% or less; The ratio of the polyether polyol (I) to the polyether polyol (II) is, by weight, polyether polyol (I) / polyether polyol (II) = 60 to 90% / 40 to 10%. Yes, the isocyanate component is diphenylmethane diisocyanate, without film removal treatment Aeration is at 150ml / ^cm 2 / s or more at 75% compression residual strain of 3.0% or less, hardness reduction rate is equal to or less than 20%.

Mattress for flexible polyurethane foams produced by the present invention, a combination of at least two high EO content polyol component Po Li polyether polyol and EO content lower Po Li polyether polyol, a and diphenylmethane diisocyanate as the isocyanate component Because it is used, it has high air permeability without being subjected to film removal treatment, and when it is made into a mattress, in addition to being able to eliminate stuffiness well, it is difficult to sag because it is not film removal treatment, and good restoration It has sex.

The present invention is described in detail below.
As the flexible polyurethane foam for mattress of the present invention, a raw material comprising a polyol component, an isocyanate component, a catalyst, a foaming agent, and a foam stabilizer is reacted, and the air flow rate is 150 ml / cm ² / s without performing film removal treatment. The 75% compression residual strain is 3.0% or less, and the hardness reduction rate is 20% or less.

  As said polyol component, at least 2 sort (s) of polyether polyol (I) and polyether polyol (II) is included.

When the total amount of alkylene oxide units is 100 % , the polyether polyol (I) has an ethylene oxide unit content (hereinafter referred to as EO content) of 60% or more and a number average molecular weight of 3000 to 3000. 5000, the average number of functional groups is 2-4. The EO content is preferably 70% or more.

  Next, the polyether polyol (II) has a number average molecular weight of 2000 to 4000, an average number of functional groups of 2 to 4, and an EO content of 20% or less.

The blending ratio of the polyether polyol (I) and the polyether polyol (II) is such that when the total amount of the polyether polyol (I) and the polyether polyol (II) is 100% by weight, the polyether polyol (I) / Polyether polyol (II) is 60 to 90% by weight / 40 to 10% by weight.
Moreover, it is preferable when EO content rate in the whole polyol component shall be 45-68%. If the EO content is too high, collapse is likely to occur during foaming, whereas if it is too low, shrinkage is likely to occur.

  In addition, as said polyol component, if it is a grade which does not impair the effect of this invention, you may use together the well-known polyol generally used for the flexible polyurethane foam. For example, a low molecular weight polyol that can be used as a cross-linking agent.

Diphenylmethane diisocyanate (MDI) is used as the isocyanate component.
In addition, it is preferable to set it as 90-105 by an isocyanate index as a compounding ratio of a polyol component and an isocyanate component. When the isocyanate index is low, the elasticity of the foam tends to be low, while when too high, the foam tends to shrink during foaming. If it is in the range of 90 to 105, foaming of the flexible polyurethane foam is good, and physical properties such as hardness useful as a mattress can be obtained, which is preferable.

In addition, as long as it is a grade which does not impair the effect of this invention, you may use together the well-known isocyanate currently used for the flexible polyurethane foam as said isocyanate component.
Known isocyanates include aromatic polyisocyanates such as tolylene diisocyanate (TDI), 1,5-naphthalene diisocyanate, paraphenylene diisocyanate, and aliphatic polyisocyanates such as hexamethylene diisocyanate, hydrogenated MDI, and isophorone diisocyanate. Can also be used. In addition to these, a prepolymer type polyisocyanate can also be used.

  As a foaming agent, the well-known thing used for manufacture of a flexible polyurethane foam can be used. For example, water, acid amides, nitroalkanes, etc., which decomposes by heat, such as trichlorofluoromethane and chlorodifluoromethane as low-boiling inert solvents, methylene chloride, water, acid amide, nitroalkane etc. Examples of those that generate water include sodium bicarbonate and ammonium carbonate. These foaming agents may be used alone or in combination of two or more. Preferably, water and methylene chloride are used in combination. Use of water and methylene chloride is preferable because the flexible polyurethane foam can be foamed well.

  Moreover, when using water as said foaming agent, it is preferable to make it contain 1.5 to 5 weight% with respect to 100 weight% of polyol components. Further, when methylene chloride is used in combination, it is preferably contained at 11% by weight or less. By using methylene chloride in the above range, it is easy to obtain hardness suitable as a mattress.

  As a foam stabilizer, a well-known thing used for manufacture of a flexible polyurethane foam can be used. For example, various siloxane-polyether block copolymer silicone foam stabilizers and the like can be used.

  The blending amount of the foam stabilizer is preferably 0.5 to 3% by weight with respect to 100% by weight of the polyol component. If the amount is too small, it is difficult to obtain a foam regulating effect, while if it is too much, the air flow rate and compression residual strain may be deteriorated.

  As a catalyst, the well-known thing used for manufacture of a flexible polyurethane foam can be used. For example, amine-based catalysts such as tertiary amine compounds such as triethylamine, triethylenediamine, bis (2-dimethylaminoethyl) ether, N-methylmorpholine, dimethylaminomethylphenol, and imidazole can be used. In addition, a metal catalyst such as an organic tin compound such as stannous octoate or an organic nickel compound such as nickel acetylacetonate may be used. These catalysts may be used alone or in combination of two or more. In addition, the compounding quantity of a catalyst can be 0.1-1.5 weight%, when the said polyol component is 100 weight%.

  If necessary, other additives can be used in combination as long as the effects of the present invention are not impaired. For example, an antioxidant, a UV absorber, a colorant, and a diluent for reducing the viscosity of the urethane foam raw material to facilitate stirring and mixing.

The flexible polyurethane foam for mattresses of the present invention has an air permeability of 150 ml / cm ² / s or more without performing film removal treatment, and a compressive residual strain of 3.0% or less. It is difficult to drip because no film removal treatment is applied. In addition, since the air flow rate is 150 ml / cm ² / s or higher and the air permeability is high and the compressive residual strain is 3.0% or less, the surrounding air can be easily taken in when the pressure is released. High resiliency such as quick return to the state. Furthermore, since the air permeability is high as described above, the stuffiness during use can be eliminated well, and it is very suitable for bedding-related applications such as mattresses. In addition, since the said ventilation | gas_flowing amount is 200 ml / cm < ² > / s or more, the cancellation | restoration of the said resilience | restoration and stuffiness improves more, and it is preferable.

  Moreover, the soft polyurethane foam for mattresses of the present invention has a hardness reduction rate of 20% or less. For this reason, even if it is repeatedly used or exposed to compressed packaging during transportation and storage, the physical properties are low and it can be used comfortably for a long time.

Furthermore, the flexible polyurethane foam for mattresses of the present invention preferably has a density of 30 to 60 kg / m ³ . When the density is less than 30 kg / m ³ , the polyurethane foam may be sag easily. On the other hand, when the density exceeds 60 kg / m ³ , the weight increases when the mattress is used, and thus the burden on the user when moving, etc. May increase.

  Moreover, it is preferable that the hardness at the time of 40% compression of the flexible polyurethane foam for mattresses of this invention is 40-70N. When the hardness is too soft, there is a risk of feeling a bottom when used as a mattress. On the other hand, when it is too hard, the feel and body pressure dispersibility may be deteriorated.

  As a manufacturing method of the flexible polyurethane foam for mattresses of this invention, it manufactures by a conventionally well-known method. For example, it can be obtained by a method of mixing a polyol component with a component excluding an isocyanate component such as a foaming agent, a foam stabilizer, a catalyst, and other auxiliary agents, and then mixing and foaming with the isocyanate component.

The flexible polyurethane foam for mattress of the present invention may be used as it is, or may be laminated on other members. For example, by laminating the flexible polyurethane foam for mattresses of the present invention on a flexible polyurethane foam having high impact resilience and high hardness, it can be used as a mattress that has good body pressure dispersibility and can suppress stuffiness. it can.
If necessary, the surface can be provided with an uneven shape using a conventionally known method such as profile processing or two-dimensional processing.

  In addition, when using as a mattress, it covers and uses with a side material. A conventionally known material can be used as the side material, but it is preferable to use a material made of a material having high air permeability in order to exhibit the characteristics of the flexible polyurethane foam for mattresses of the present invention.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example.
Examples 1 to 7, Comparative Examples 1 and 2, Reference Examples 1 and 2
[sample]
<Polyol component>
Polyol A: polyether polyol (Accor EP-505S, manufactured by Mitsui Chemicals, Inc.) having a number average molecular weight of 3360, a functional group number of 3, and an EO content of 75%
Polyol B: Polyether polyol having a number average molecular weight of 3,000, a functional group number of 3, and an EO content of 0% (Asahi Glass Co., Ltd., EXCENOL3030)
<Isocyanate component>
Isocyanate A: Polymeric MDI having an NCO content of 31.5% (manufactured by Tosoh Corporation, MR-200)
Isocyanate B: TDI with an NCO content of 42.8% (Mitsui Chemicals Cosmonate T-80)
<Foaming agent>
Foaming agent A: water (ion exchange water)
Foaming agent B: methylene chloride <foam stabilizer>
Foam stabilizer: Silicone surfactant (manufactured by Dow Corning Toray, SH-192)
<Catalyst>
Catalyst A: tertiary amine catalyst, triethylenediamine 33% dipropylene glycol solution (TODA Corporation, TEDA-L33)
Catalyst B: Stanas octoate (Nitto Chemical Co., Ltd., Neostan U-28)

At the blending ratio shown in Table 1, various foaming agents, foam stabilizers and catalysts are mixed with the polyol component, then mixed with the isocyanate component, foamed and cured to produce a polyurethane foam, and the method described below Various evaluations were performed.
[density]
It measured based on JISK7222.
[40% compression hardness]
Measured based on JIS K 6400-2 A method.
[Air flow rate]
Measured based on JIS K 6400-7 B method (fragile aeration rate).
[75% compression residual strain]
It measured based on JIS K 6400-4 A method.
[Hardness reduction rate]
Based on JIS K 6400-4 (repetitive compression residual strain test, constant load method), it was calculated from the difference between 40% compression hardness before measurement and 40% compression hardness after measurement.
[Drying performance]
Install a φ90mm filter paper soaked in water at the center of the upper surface of the flexible urethane foam that is cut into a block shape with a width of 150mm, a length of 150mm, and a thickness of 50mm. The whole weight was measured by covering a glass plate of 100 mm × 100 mm so as to cover, and the weight was measured again after being left at room temperature (24 ° C.) for 5 hours. From the measurement results, the weight of the soft urethane foam block and the filter paper not containing water and the weight of the glass plate are subtracted, and the weight change rate due to the change in the amount of water evaporated through the flexible urethane foam is calculated and evaluated according to the following criteria: Went.
○: Weight reduction exceeding 80% was confirmed.
(Triangle | delta): The weight fall of 60 to 80% was confirmed.
X: Weight reduction of less than 60% was confirmed.

Examples 1-7
The flexible polyurethane foam for mattresses of the present invention has a high air flow rate of 150 ml / cm ² / s or more, and moisture can be released through the urethane foam, so that the feeling of stuffiness can be satisfactorily eliminated. Further, since the 75% compression residual strain is 3% or less and the hardness reduction rate is 20% or less, it is difficult to sag and can be used over a long period of time.

<Comparative Example 1>
TDI was used as the isocyanate component.
As a result, the foam volume was low at 100 ml / cm ² / s and it was difficult to eliminate stuffiness. Further, the 75% compression residual strain was as high as 4.0%, and it was easy to sag.
<Comparative Example 2>
As the polyol component, only polyol B having an EO content of 0% was used.
As a result, shrinkage occurred during foaming, and a good polyurethane foam could not be obtained.
<Comparative Example 3>
As the polyol component, only polyol A having an EO content of 75% was used.
As a result, collapse occurred during foaming and a good polyurethane foam could not be obtained.
<Reference Example 1>
The conventional flexible polyurethane foam was examined. Although the hardness and the like can be freely changed, the air flow rate is as low as 60 ml / cm ² / s and it is easy to feel stuffiness. In addition, since the hardness reduction rate was as high as 23%, the hardness decreased due to long-term use and the like, and it was easy to sag.
<Reference Example 2>
In order to improve the air permeability, a film-free polyurethane foam obtained by subjecting the flexible polyurethane foam obtained in Reference Example 1 to a film removal treatment was examined. Since the film removal treatment has been performed, the air flow rate is as high as 350 ml / cm ² / s. On the other hand, the 75% compression residual strain is 4.7% and the hardness reduction rate is as high as 41%. The hardness decreased due to the use of and so on.

The flexible polyurethane foam for mattresses of the present invention has high air permeability despite not being subjected to film removal treatment, and at the same time has a low compressive residual strain and hardness reduction rate. It was difficult for sag to occur in compressed packaging during storage. The flexible polyurethane foam can be applied not only to mattresses and other bedding, but also to conventionally known articles in which the flexible polyurethane foam is used.

Claims (1)

It is a flexible polyurethane foam consisting of polyol component, isocyanate component, catalyst, foaming agent, foam stabilizer,
The polyol component has a polyether polyol (I) having a number average molecular weight of 3000 to 5000, an average functional group number of 2 to 4, an ethylene oxide content of 60% or more, a number average molecular weight of 2000 to 4000, and an average functional group number. 2 to 4 and a polyether polyol (II) having an ethylene oxide content of 20% or less,
The ratio of the polyether polyol (I) and the polyether polyol (II) is, by weight ratio, polyether polyol (I) / polyether polyol (II) = 60 to 90% / 40 to 10%,
The isocyanate component is diphenylmethane diisocyanate;
The air flow rate is 150 ml / cm ² / s or more without film removal treatment,
75% compression residual strain is 3.0% or less,
A flexible polyurethane foam for mattresses having a hardness reduction rate of 20% or less.