JP2009167248A - Polyurethane foam with its film removed, and fluid filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane foam with its film removed exhibiting remarkably improved flame retardancy, and a flame-retardant fluid filter composed of the polyurethane foam with its film removed. <P>SOLUTION: The polyurethane foam with its film removed is obtained by subjecting a polyurethane foam, obtained by expanding a mixture of a polyisocyanate, a polyol, an expanding agent, a catalyst, and other auxiliary agents, to a film-removing treatment. The mixture includes a phosphorous flame-retardant and a melamine-containing polyol. A fluid filter is composed of the polyurethane foam with its film removed. While the use of the phosphorous flame-retardant makes the foam flame-retardant to some extent, combined use of the phosphorous flame-retardant and the melamine-containing polyol makes the skeleton portion of the polyurethane foam further flame-retardant. Therefore, even the polyurethane foam with its film removed having a coarse cell exhibits good flame retardancy. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a membrane-removed polyurethane foam and a fluid filter comprising this membrane-removed polyurethane foam. In particular, the present invention has excellent air permeability, filterability, etc. due to a three-dimensional network skeleton structure formed by membrane removal of a flexible polyurethane foam. The present invention relates to a film removal polyurethane foam having improved flame retardancy and a fluid filter comprising the film removal polyurethane foam.

  Conventionally, there is a fluid filter that uses an internal communication space of a three-dimensional network skeleton structure. As a constituent material of the three-dimensional network skeleton structure, a three-dimensional network skeleton structure formed by film removal of a flexible polyurethane foam is used. Therefore, a film-removed polyurethane foam having excellent air permeability and filterability is widely used (for example, Patent Document 1).

  Since fluid filters are used for dust removal in fields such as home appliances, automobiles, and railways, they are not only filterable and breathable, but also have high flame resistance, especially when used in high-temperature environments. However, if the polyurethane foam is removed to remove the cell membrane at the foamed portion, the air permeability is improved, resulting in a problem that the flame retardancy is lowered. That is, the film removal improves the air flowability during combustion and facilitates the supply of oxygen, so that the film removal polyurethane foam is easy to burn.

  Conventionally, in a conventional polyurethane foam, a flame retardant is blended with a foaming raw material in order to increase the flame retardancy. As a flame retardant, an environment-friendly non-halogen phosphate ester flame retardant is also used. It is used (for example, Patent Document 2).

However, compared with halogen-based flame retardants, non-halogen-based flame retardants that do not contain halogen are not sufficiently effective in improving flame retardancy, but on the other hand, removal of polyurethane foam without cell membranes, especially for coarse cells. As described above, the membrane polyurethane foam easily combusts due to its breathability, and sufficient flame retardancy could not be obtained by blending only the flame retardant.
JP 2004-322027 A JP 2005-029617 A

  The object of the present invention is to solve the above-mentioned conventional problems and to provide a film-removed polyurethane foam with significantly improved flame retardancy.

  Another object of the present invention is to provide a flame retardant fluid filter comprising such a film removal polyurethane foam.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a phosphorus-based flame retardant as a flame retardant, and a polyurethane film-removed by using a melamine-containing polyol as part of the polyol component. It was found that high flame retardancy can be imparted to the foam.
The present invention has been achieved on the basis of such findings, and the gist thereof is as follows.

[1] In a film-removed polyurethane foam obtained by film-removing a polyurethane foam obtained by foaming a mixture containing a polyisocyanate, a polyol, a foaming agent, a catalyst and other auxiliaries, the mixture comprises a phosphorus-based flame retardant and melamine A film-removing polyurethane foam comprising a contained polyol.

[2] The film removal polyurethane foam according to [1], wherein the melamine-containing polyol is obtained by uniformly dispersing a melamine resin in the polyol.

[3] A film removal polyurethane foam according to [1] or [2], wherein the phosphorus flame retardant is a phosphate ester flame retardant containing no halogen.

[4] The film removal polyurethane foam according to any one of [1] to [3], wherein the catalyst includes an amine catalyst and an organometallic catalyst.

[5] The film removal polyurethane foam according to any one of [1] to [4], wherein the mixture contains 5 to 50 parts by weight of the melamine-containing polyol in 100 parts by weight of all polyol components.

[6] The film removal polyurethane foam according to any one of [1] to [5], wherein the mixture contains 5 to 30 parts by weight of the phosphorus flame retardant with respect to 100 parts by weight of the total polyol component.

[7] A fluid filter comprising the film-removed polyurethane foam according to any one of [1] to [6].

  The film removal polyurethane foam of the present invention exhibits extremely excellent flame retardancy by the combined use of a phosphorus-based flame retardant and a melamine-containing polyol. In other words, the use of phosphorus-based flame retardants achieves a certain level of flame retardancy, but the combined use of melamine-containing polyols with this phosphorus-based flame retardant makes flame retardant of polyurethane foam even more highly flame retardant. The flame-retardant film-forming polyurethane foam that can exhibit high flame-retardant properties and can meet the level of flame-resistance required in various industrial fields. Can be obtained.

  In the present invention, it is preferable to use a melamine-containing polyol in which a melamine resin is uniformly dispersed as the melamine-containing polyol (Claim 2), and as the phosphorus flame retardant, a phosphate ester flame retardant containing no halogen is used. It is preferable to use (Claim 3).

  As the catalyst, it is preferable to use an amine catalyst and an organometallic catalyst in combination.

  Moreover, it is preferable that the usage-amount of a melamine containing polyol shall be 5-50 weight part in 100 weight part of all polyol components (Claim 5), and a phosphorus flame retardant is 5 with respect to 100 weight part of all polyol components. -30 parts by weight is preferable (claim 6).

  The fluid filter of the present invention is made of a film-removed polyurethane foam excellent in air permeability and filterability, and is also excellent in flame retardancy. Therefore, the fluid filter is industrially extremely useful as a fluid filter in various fields such as home appliances, automobiles and railways. .

  Hereinafter, embodiments of the film removal polyurethane foam and fluid filter of the present invention will be described in detail.

[Film removal polyurethane foam]
The film removal polyurethane foam of the present invention is a polyurethane foam obtained by mixing and foaming a polyisocyanate, a polyol component containing a melamine-containing polyol, a foaming agent, a phosphorus flame retardant as a flame retardant, a catalyst and other auxiliary agents. The film is removed.

{Polyurethane foam raw material}
<Polyol>
In the present invention, a melamine-containing polyol is used as the polyol component of the polyurethane foam raw material.

  The melamine-containing polyol is obtained by mixing and uniformly dispersing a melamine resin in a polyol. Although there is no restriction | limiting in particular in a melamine containing polyol, Commercially available products, such as NMP M-950 (Asahi Glass Co., Ltd. product), can be used conveniently.

  The ratio of the melamine resin and polyol used in the melamine-containing polyol is that the blending ratio of the melamine resin powder to the polyol is too small, the resulting flame retardant of the polyurethane foam is not sufficient, and if it is too much, a stable foam cannot be obtained. Therefore, the melamine resin is preferably 10 to 50 parts by weight with respect to 100 parts by weight of the polyol.

  There is no restriction on the method of adding the melamine resin to the polyol, and a predetermined amount may be added to the polyol component in advance and mixed as a premix. It may be dispersed. A melamine resin may be mix | blended as a synthetic raw material of a polyol component.

  As a polyol component, it is preferable to use together with a melamine-containing polyol, a polyol used in the production of a normal polyurethane foam. In the present invention, as polyols other than the melamine-containing polyol, polyols such as polyether polyol and polyester polyol can be used. These polyols have a molecular weight of 1000 to 6000 and a hydroxyl value of 20 to 250 mg-KOH / g. A degree is preferred.

  If the content of the melamine-containing polyol in the total polyol component is too small, the effect of improving the flame retardancy by using the melamine-containing polyol cannot be sufficiently obtained, and if it is too much, it is difficult to form a stable foam. Therefore, it is preferable to use 5 to 100 parts by weight, particularly 5 to 50 parts by weight, in 100 parts by weight of the total polyol component.

<Polyisocyanate>
In the present invention, the polyisocyanate of the polyurethane foam raw material is not particularly limited, and diphenylmethane diisocyanate (MDI) or modified MDI, xylylene diisocyanate (XDI), isophorone diisocyanate (PDI) regardless of whether it is toluene diisocyanate (TDI) or pure or crude type. IPDI), hexamethylene diisocyanate (HMDI), prepolymer types of these isocyanates, carbodiimide-modified types, and the like can be used. Furthermore, a mixture of crude MDI and TDI can be used.

  The polyisocyanate is preferably used so that the isocyanate index of the polyurethane foam raw material is about 80 to 120.

<Catalyst>
As the catalyst, a known one for polyurethane foam is used. For example, amine catalysts such as monoethanolamine, dimethylethylethanolamine, N-ethylmorpholine, bis (2-dimethylaminoethyl) ether, triethylamine, triethylenediamine, tetramethylguanidine, stannous 2-ethylhexylate, dibutyltin Examples thereof include tin catalysts such as dilaurate and stannous octoate, and metal catalysts (also referred to as organometallic catalysts) such as nickel naphthenate and lead octenoate.

  These catalysts may be used individually by 1 type, and may mix and use 2 or more types.

  In particular, the organometallic catalyst is 0.1 to 1.0 part by weight with respect to 100 parts by weight of the total polyol component, and the amine catalyst is 0.1 to 6.0 part by weight with respect to 100 parts by weight of the total polyol component. It is preferable to use 0.2 to 7.0 parts by weight with respect to 100 parts by weight of all polyol components.

<Flame Retardant>
In the present invention, a phosphorus-based flame retardant is used as the flame retardant. As the phosphorus-based flame retardant, those containing no halogen are preferable from the viewpoint of the environment, and phosphate ester-based flame retardant containing no halogen is particularly preferable. Specifically, one or two or more of condensed phosphate ester, triethyl phosphate, tributyl phosphate and the like are used, and the condensed phosphate ester is preferable.

  Such phosphorus flame retardant is preferably used in an amount of 3 to 40 parts by weight, particularly preferably 5 to 30 parts by weight, based on 100 parts by weight of the total polyol component. If the amount of the phosphorus-based flame retardant used is less than this range, sufficient flame retardancy cannot be obtained, and if it is too large, it is difficult to form a stable foam, and the physical properties of the resulting foam become unstable.

<Foam stabilizer>
As the foam stabilizer, a known silicone foam stabilizer for polyurethane foams may be used alone or in combination of two or more.
It is preferable to use 0.3 to 3.0 parts by weight of the foam stabilizer based on 100 parts by weight of the total polyol component.

<Foaming agent>
As the foaming agent, conventionally known general foaming agents such as water and methylene chloride can be used, but water is preferably used.
The amount of foaming agent used is usually about 1.0 to 5.0 parts by weight per 100 parts by weight of the total polyol component.

<Other additives>
The polyurethane foam raw material which concerns on this invention may contain the various additives normally used for manufacture of a polyurethane foam other than the said polyol, polyisocyanate, a catalyst, a foam stabilizer, a flame retardant, and a foaming agent. Examples of such additives include colorants such as pigments, fillers such as calcium carbonate, antioxidants, ultraviolet absorbers, light stabilizers, conductive materials such as carbon black, and antibacterial agents.

{Production method}
The film removal polyurethane foam of the present invention can be produced according to a conventional method using the above-mentioned polyurethane foam raw material.

  As a method of mixing the polyurethane foam raw material, a commonly used method such as a one-shot method or a prepolymer method can be used, and a polyurethane foam can be obtained by stirring and mixing and foaming.

  The method of removing the cell membrane (bubble membrane) by removing the film from the obtained polyurethane foam is not particularly limited, and examples thereof include post-treatment with heat, ozone, alkali and the like. By removing the membrane, most of the cell membrane is removed from the polyurethane foam, and a three-dimensional network skeleton structure having 8 to 60 cells per 25 mm is obtained.

{Physical properties}
The film removal polyurethane foam of the present invention is a three-dimensional network skeleton structure having 8 to 60 cells per 25 mm.
Moreover, the film removal polyurethane foam of this invention has the high air permeability whose air permeability measured by JISK6400 is 150cc / cm < ² > / sec or more.

  The film-removed polyurethane foam of the present invention exhibits excellent flame retardancy superior to that of HBF in the UL94 combustion test in the above cell size range.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

  The polyurethane foam raw materials used in the following examples and comparative examples are as follows.

<Melamine-containing polyol>
“NMP M-950” manufactured by Asahi Glass Co., Ltd.
(Hydroxyl value 35.5 mg-KOH / g)

<Polyether polyol>
"Accor 3P-56D" manufactured by Mitsui Takeda Chemical Co., Ltd.
(Molecular weight 3000, hydroxyl value 56 mg-KOH / g)

<Polyisocyanate>
"Cosmonate T-65" manufactured by Mitsui Takeda Chemical Co., Ltd.
(Mixture of 2,4-TDI: 2,6-TDI = 65: 35)

<Foaming agent>
Water <foam stabilizer>
Momentive Performance Material Japan (L) “L-650” (silicone foam stabilizer)
<Flame Retardant>
"SH-0880" manufactured by Daihachi Chemical Industry Co., Ltd.
(Non-halogen flame retardant: Fatty acid condensed phosphate ester)

<Catalyst>
Amine catalyst 1: “DOBCO CS-90” manufactured by Air Products Japan Co., Ltd.
(Mixture of diethylene glycol of triethylene dian and tertiary amines)
Amine catalyst 2: “NIAX CATALYST A-133” manufactured by Momentive Performance Material Japan
(Dipropylene glycol mixture of bis (2-dimethylaminoethyl) ether (active ingredient amount 23% by weight)
Organometallic catalyst: “Nikka Octix Tin” manufactured by Nippon Kagaku Sangyo Co., Ltd. (stannous 2-ethylhexylate (active ingredient amount 28% by weight))

Moreover, the evaluation method of the obtained polyurethane foam is as follows.
<Number of cells>
The test piece horizontally cut according to the growth direction of the block was observed with a stereomicroscope, and the number of cells per 25 mm was measured.
<Density>
Evaluation was made in accordance with JIS K 6400.
<Breathability>
Evaluation was made in accordance with JIS K 6400.
<Flame retardance>
The UL94 combustion test was conducted. (Sample thickness 13.0 mm)

<Examples 1-3, Comparative Examples 1 and 2>
The polyurethane foam raw material composition shown in Table 1 was mixed and foamed by a one-shot method, and the resulting polyurethane foam was subjected to film removal treatment by heat treatment.
The obtained film removal polyurethane foam was evaluated, and the results are shown in Table 1.

  From Table 1, it can be seen that the film-removed polyurethane foam of the present invention is excellent in flame retardancy, and particularly exhibits excellent flame retardancy even in the case of a high-breathed film-removed polyurethane foam having a large cell.

Claims (7)

In the film-removed polyurethane foam formed by film-removing a polyurethane foam obtained by foaming a mixture containing polyisocyanate, polyol, foaming agent, catalyst and other auxiliary agents
A film-removing polyurethane foam, wherein the mixture contains a phosphorus-based flame retardant and a melamine-containing polyol.   2. The film removal polyurethane foam according to claim 1, wherein the melamine-containing polyol is obtained by uniformly dispersing a melamine resin in the polyol.   3. The film removal polyurethane foam according to claim 1, wherein the phosphorus flame retardant is a phosphoric ester flame retardant containing no halogen.   4. The film removal polyurethane foam according to any one of claims 1 to 3, wherein the catalyst includes an amine catalyst and an organometallic catalyst.   5. The film removal polyurethane foam according to claim 1, wherein the mixture contains 5 to 50 parts by weight of the melamine-containing polyol in 100 parts by weight of the total polyol component.   6. The film removal polyurethane foam according to any one of claims 1 to 5, wherein the mixture contains 5 to 30 parts by weight of the phosphorus-based flame retardant with respect to 100 parts by weight of the total polyol component.   A fluid filter comprising the film-removed polyurethane foam according to any one of claims 1 to 6.