JP2014201603A - Polyurethane foam for production of electrode material and production method thereof - Google Patents

Abstract

An object of the present invention is to provide a polyurethane foam for producing an electrode material in which generation of VOC under reduced pressure is suppressed, and a method for producing the same. A polyurethane foam for producing an electrode material obtained by foaming and curing a raw material containing a polyol, an isocyanate, a foaming agent, a surfactant having a vapor pressure of less than 1 Pa at 100 ° C., and a metal salt of a hydroxy fatty acid metal salt. A method for producing a polyurethane foam for producing an electrode material, comprising foaming and curing a raw material comprising a polyol, an isocyanate, a foaming agent, a surfactant having a vapor pressure of less than 1 Pa at 100 ° C., and a hydroxy fatty acid metal salt. [Selection figure] None

Description

  The present invention relates to a polyurethane foam for producing an electrode material used as a base material for producing an electrode material, and a method for producing the same.

The polyurethane foam is produced by foam-curing a foam stock solution containing a main raw material composed of polyol and isocyanate, a foaming agent such as water, a catalyst, a surfactant, an antioxidant and the like.
Polyurethane foam is suitably used as various furniture materials such as cushion materials and mats, and vehicle interior materials. In order to suppress the generation amount of volatile organic compounds (VOC) from this polyurethane foam, a technique using a material having a high molecular weight as a raw material in the foaming stock solution has been proposed.
For example, Patent Document 1 describes the use of a polymer compound having a number average molecular weight of a certain level or more as an antioxidant for the purpose of suppressing the amount of VOC generation. Patent Document 2 describes the use of a polymer compound having a molecular weight of a certain level or more as an antioxidant and an ozone degradation inhibitor for the purpose of suppressing the amount of VOC generation. Patent Document 3 discloses a compound containing an isocyanate group-reactive hydrogen atom having a molecular weight of 400 to 15000, water and / or a physical blowing agent, carbon number for the purpose of suppressing the amount of VOC generation and improving aging resistance. A process for producing polyurethane foams by reacting tin salts of 10 to 16 carboxylic acids and diisocyanates or polyisocyanates is described.

In recent years, polyurethane foam has been used as a base material for producing electrode materials such as batteries.
For example, Patent Document 4 discloses a process of conducting a conductive treatment on the surface of a polyurethane foam sheet (conductive treatment step), a step of attaching a metal such as Ni, Cu, Fe, etc. by electroplating (electroplating step), and a polyurethane by heat treatment. It describes that an electrode material made of a metal porous body is produced by performing a process of burning and removing foam (roasting process). Examples of the conductive treatment step include vacuum deposition, chemical plating, and application of a conductive material such as carbon.
Moreover, the electrode material which consists of a metal porous body can also be obtained by burning and removing a polyurethane foam after directly sputtering a metal material on a polyurethane foam sheet under a vacuum.

JP 2004-211032 A Japanese Patent Laid-Open No. 2004-231949 JP 2010-275551 A JP 2010-253901 A

When a polyurethane foam is used as a base material for an electrode material as in Patent Document 4 and a metal is formed on the surface thereof by vacuum vapor deposition or sputtering, it is necessary to reduce the pressure in the vacuum vapor deposition apparatus or the sputtering apparatus. However, under such reduced pressure, VOC is more likely to be generated from the polyurethane foam than under normal pressure. Therefore, even if a material having a large molecular weight is used as a polyurethane foam raw material as in Patent Documents 1 to 3, the reduced pressure is reduced. The amount of VOC generated in can not be sufficiently suppressed. Thus, if the amount of VOC generation under reduced pressure cannot be sufficiently suppressed, the degree of vacuum in the apparatus decreases and the metal film formation efficiency on the polyurethane foam surface deteriorates, and the electrical resistance of the polyurethane foam after metal formation increases. Problems arise.
An object of the present invention is to solve the above-mentioned problems and to provide a polyurethane foam for producing an electrode material in which generation of VOC from the polyurethane foam under reduced pressure is suppressed and a method for producing the same.

  As a result of intensive studies to solve the above problems, the present inventor has used VOCs from polyurethane foam even under reduced pressure by using a low vapor pressure surfactant as a surfactant and a hydroxy fatty acid metal salt as a catalyst. The inventors have found that the occurrence of the above can be suppressed, and have completed the present invention.

That is, the present invention includes the following [1] to [4].
[1] A polyurethane foam for producing an electrode material obtained by foaming and curing a raw material containing a polyol, an isocyanate, a foaming agent, a surfactant having a vapor pressure of less than 1 Pa at 100 ° C., and a metal salt of a hydroxy fatty acid metal salt.
[2] The polyurethane foam for producing an electrode material according to [1], wherein the hydroxy fatty acid metal salt is a ricinoleic acid metal salt.
[3] The polyurethane for electrode material production according to [2], wherein the metal ricinoleate is tin ricinoleate, and the content of the tin ricinoleate with respect to 100 parts by mass of polyol is 0.005 to 1.5 parts by mass. Form.
[4] A method for producing a polyurethane foam for producing an electrode material, comprising foaming and curing a raw material comprising a polyol, an isocyanate, a foaming agent, a surfactant having a vapor pressure of less than 1 Pa at 100 ° C., and a hydroxy fatty acid metal salt.
In the present invention, a hydroxy fatty acid metal salt is used as the metal catalyst. This hydroxy fatty acid metal salt is hydrolyzed during production of the polyurethane foam to become metal ions and hydroxy fatty acids. The metal ions serve as a catalyst, and the hydroxyl groups of the hydroxy fatty acids are bonded to the polyurethane resin. This is considered to prevent the hydroxy fatty acid from volatilizing under reduced pressure and lowering the vacuum.
On the other hand, tin 2-ethylhexanoate, which is a typical metal catalyst, liberates 2-ethylhexanoic acid by hydrolysis. Since the vapor pressure of 2-ethylhexanoic acid at 228 ° C. and 20 ° C. is as small as less than 0.01 mmHg, the amount of VOC generated at normal pressure is small, but the generation of VOC under reduced pressure cannot be sufficiently suppressed.

  According to the polyurethane foam for producing an electrode material of the present invention, a surfactant whose vapor pressure at 100 ° C. is less than 1 Pa is used, and a hydroxy fatty acid metal salt is used as a metal catalyst. The amount of VOC generated is suppressed.

[Polyurethane foam for electrode material production]
The polyurethane foam for producing an electrode material of the present invention is obtained by foaming and curing a raw material containing a metal catalyst comprising a polyol, an isocyanate, a foaming agent, a surfactant having a vapor pressure at 100 ° C. of less than 1 Pa, and a hydroxy fatty acid metal salt. Is.
Thus, according to the polyurethane foam for electrode material production of the present invention, since the vapor pressure of the surfactant at 100 ° C. is less than 1 Pa, VOC is generated from the polyurethane foam during vacuum deposition or sputtering, and the degree of vacuum is reduced. The decrease is prevented, and the film formation rate is improved.
Below, each component of a raw material is demonstrated.

<Polyol>
Examples of the polyol component include polyester polyol, polyether polyol, and polymer polyol. These polyols may be used alone or in combination of two or more.
Examples of the polyester polyol include aliphatic dicarboxylic acids having 4 to 20 carbon atoms such as adipic acid, suberic acid, sebacic acid and brassic acid, terephthalic acid and isophthalic acid as acid components, and 1 to 1 carbon atoms such as ethylene glycol. Polyester polyols having an aliphatic glycol diol 6 or ether glycol such as diethylene glycol or dipropylene glycol as a polyol component (alcohol component) can be mentioned.

Although it does not specifically limit as said polyether polyol, The polyether polyol obtained by ring-opening polymerization of alkylene oxide from a reactive viewpoint is suitable. Examples of such alkylene oxides include propylene oxide (PO) and ethylene oxide (EO). These may be used alone or in combination of two or more.
As the polyether polyol, the PO homopolymer, the EO homopolymer, and the polyether polyol obtained by copolymerization of PO and EO can be used. The copolymerization may be random copolymerization or block copolymerization.
Examples of the polymerization initiator include pentaerythritol, glycerin, ethylenediamine, Mannich, tolylenediamine, and sucrose. These polymerization initiators may be used alone or in combination of two or more.

As a polyol, the hydroxyl value in all polyols is preferably 20 to 1000, more preferably 20 to 100, and the number average in all polyols from the viewpoint of coexistence of the reaction rate of urethane foaming and the mechanical properties of the foam. It is preferable to include a polyol having a molecular weight of 200 to 12000, preferably 200 to 4000, more preferably 500 to 3500, still more preferably 1000 to 3000, and still more preferably 1500 to 2500.
In the present invention, the number average molecular weight is a value calculated as a polystyrene conversion value by the GPC method, and the hydroxyl value is a value measured in accordance with JIS K1557.
Of the above polyols, polyurethane foams produced using polyester polyols often have a reduced degree of vacuum during vacuum deposition or sputtering as compared with polyurethane foams using other polyols. The reason is presumably that a surfactant having a low vapor pressure is used or a non-reactive type catalyst is often used. That is, when polyester polyol is used, the viscosity increases due to ester bonds during foaming. For this reason, in order to prevent the viscosity from becoming excessively high, a surfactant having a relatively low number average molecular weight and a low vapor pressure is often used, and it is assumed that this surfactant volatilizes during sputtering. Is done. In addition, it is assumed that the non-reactive catalyst is easier to volatilize during sputtering than the reactive catalyst. Therefore, the present invention is particularly useful when a polyester polyol is used as the polyol.

<Isocyanate>
As the isocyanate component, various known polyfunctional aliphatic, alicyclic and aromatic isocyanates can be used. For example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate, triphenyl diisocyanate, xylene diisocyanate (XDI), polymethylene polyphenylene polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate (IPDI), orthotoluidine diisocyanate, naphthy Range isocyanate, xylylene diisocyanate, lysine diisocyanate and the like can be mentioned, and these may be used alone or in combination of two or more.

<Foaming agent>
Examples of the foaming agent include water, chlorofluorocarbon, and pentane, but water is preferred. The ratio of water to 100 parts by mass of the polyol is preferably 0.8 to 4.8 parts by mass. When the water content is 0.8 parts by mass or more, the expansion ratio is high, and when it is 4.8 parts by mass or less, the dimensional stability of the polyurethane foam is good. In this respect, the ratio of water is more preferably 3.2 to 4.3. It is also possible to use a low boiling point compound such as methylene chloride or monofluorinated trichloromethane together with water.

<Surfactant>
As the surfactant, those having a vapor pressure at 100 ° C. of less than 1 Pa are used. When the vapor pressure of the surfactant at 100 ° C. is 1 Pa or more, when the metal is sputtered onto the surface of the urethane foam under a vacuum of about 1 Pa, the surfactant in the urethane foam evaporates and the degree of vacuum decreases. However, sputtering cannot be performed satisfactorily. In this respect, the vapor pressure of the surfactant at 100 ° C. is preferably less than 1 Pa, more preferably less than 0.8 Pa, still more preferably less than 0.5, and even more preferably less than 0.4. It is.
The material of the surfactant is not particularly limited as long as the vapor pressure condition is satisfied, and a conventionally known organosilicone surfactant is preferably used. Preferred examples of the organic silicone surfactant include polyether-modified silicone and polyoxyalkylene-modified dimethylpolysiloxane.

The number average molecular weight of this surfactant is preferably 3000 to 9000. When it is 3000 or more, it is further prevented that the surfactant evaporates during the sputtering and the degree of vacuum is lowered, and the sputtering can be performed satisfactorily. If it is 9000 or less, the urethane foam film becomes strong and is difficult to communicate. In this respect, the number average molecular weight of the surfactant is more preferably 4000 to 8000, and further preferably 5000 to 8000.
It is preferable that the compounding quantity of the said surfactant is 0.2-4 mass parts with respect to 100 mass parts of polyols. When the amount is 0.2 parts by mass or more, sufficient foam regulating power and compatibilization can be obtained, and a low-density polyurethane foam can be obtained. When the amount is 4 parts by mass or less, the degree of vacuum due to the evaporation of the surfactant is further prevented, and the proportion of the surfactant with respect to other components does not increase so much, and the reactivity when forming the polyurethane foam is increased. Can be prevented. In this respect, the surfactant is preferably in the range of 0.2 to 4 parts by mass, more preferably in the range of 0.5 to 2 parts by mass with respect to 100 parts by mass of the polyol.

<Metal catalyst>
As the metal catalyst, a hydroxy fatty acid metal salt is used.
The hydroxy fatty acid metal salt is not particularly limited, and may be a saturated fatty acid or an unsaturated fatty acid.
The hydroxy fatty acid metal salt is preferably a hydroxy fatty acid metal salt having 12 to 20 carbon atoms, more preferably a hydroxy fatty acid metal salt having 16 to 20 carbon atoms, from the viewpoint of suppressing volatilization under reduced pressure and improving catalytic activity, and ricinol. Acid metal salts and hydroxystearic acid metal salts are more preferred.
As the metal constituting the hydroxy fatty acid metal salt, tin, zinc, lead, cobalt, iron, nickel, calcium, and potassium are preferable, tin and zinc are more preferable, and tin is further preferable. The hydroxy fatty acid metal salt is more preferably tin ricinoleate and tin hydroxystearate.
These hydroxy fatty acid metal salts may be used alone or in combination of two or more.
The content of the hydroxy fatty acid metal salt with respect to 100 parts by mass of the polyol is preferably 0.005 to 1.5 parts by mass, more preferably 0.01 from the viewpoint of improving the reaction activity and suppressing the volatilization amount under reduced pressure. It is -1.0 mass part, More preferably, it is 0.05-0.7 mass part, More preferably, it is 0.5-0.7. In addition, the content of the hydroxy fatty acid metal salt with respect to 100 parts by mass of the polyol is preferably 0.001 to 1.0 part by mass, more preferably 0.005 to 0.1 part by mass, in terms of metal. Preferably it is 0.05-0.07 mass part.

In addition to the above hydroxy fatty acid metal salt, other catalysts may be used, but from the viewpoint of suppressing volatilization under reduced pressure, it is preferable not to use other catalysts.
When another catalyst is used, the content of the other catalyst in the total amount of the catalyst is preferably 50% by mass or less.
The content of the hydroxy fatty acid metal salt in the total amount of the catalyst is preferably 50% by mass or more.
Examples of other metal catalysts include fatty acid metal salts that do not have a hydroxyl group and amine-based catalysts. Specific examples include those described in Patent Document 1.

<Other optional components>
The raw material may contain an antioxidant as described in Patent Document 1 as necessary, but from the viewpoint of suppressing the amount of VOC generation under reduced pressure, 100 parts by mass of an optional polyol The content of is preferably 10 parts by mass or less, more preferably 1 part by mass or less, and still more preferably not contained.
In addition, the raw material may appropriately contain a crosslinking agent, a filler and the like as necessary.
The content of the essential component in the raw material is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and still more preferably 99% by mass or more.

[Production method of polyurethane foam for electrode material production]
The method for producing a polyurethane foam for producing an electrode material according to the present invention foams a raw material containing a metal catalyst comprising a polyol, an isocyanate, a foaming agent, a surfactant having a vapor pressure at 100 ° C. of less than 1 Pa, and a hydroxy fatty acid metal salt. It cures.
The method of blending each component is not particularly limited, and for example, it is produced by first preparing a polyol composition comprising each component other than isocyanate and then mixing with isocyanate.
The polyol composition is prepared by first blending the metal catalyst with the polyol and then blending the surfactant and other components from the viewpoint of bringing the blowing agent and the metal catalyst into contact as much as possible. It is preferable to blend a foaming agent.

[Method for producing metal-coated polyurethane foam]
A metal-coated polyurethane foam can be produced by coating the surface of the above-mentioned polyurethane foam for electrode material production with a metal.
This metal-coated polyurethane foam is preferably produced by a process of conducting a conductive treatment on the surface of the above-mentioned polyurethane foam for electrode material production (a conductive treatment process), and a process of further depositing a metal on the surface by electroplating (plating process). can do. In this conductive treatment step, vacuum deposition or sputtering under reduced pressure is performed. In the conductive treatment step, the polyurethane foam for producing the electrode material is placed under reduced pressure, but since the amount of VOC generation is suppressed because the surfactant and the metal catalyst are used, the degree of vacuum is increased. Therefore, the deposition efficiency of the metal film is improved. Electroplating can be satisfactorily performed by performing electroplating (plating process) after improving the surface conductivity by this conductive treatment process.
The metal-coated polyurethane foam can also be preferably produced by directly sputtering a metal material on the above-mentioned polyurethane foam for electrode material production under reduced pressure.
The metal to be coated includes Ti, Sb, Te, Ge, Sn, Se, Bi, In, Co
Cr, W, Gd, Tb, Ag, Pt, Au, Si, Ru, or an alloy containing these is preferable, and AL, Ni, Cu, and Fe are more preferable.
[Method for producing electrode material]
By heat-treating the metal-coated polyurethane foam and removing the polyurethane foam by burning (roasting step), an electrode material made of a metal porous body can be suitably produced.
After the roasting step, a step of further reducing and annealing the metal may be performed. These steps can be performed using a known method.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
In addition, the following were used as a raw material.
<Raw material>
(Polyol)
Polyester polyol “Ediform E521” (manufactured by Kao Corporation), number average molecular weight 2200, hydroxyl value 60
(Isocyanate)
TDI-based isocyanate (2,4-TDI: 2,6-TDI = 80: 20 (mass ratio)) “T80” (manufactured by Mitsui Chemicals Polyurethanes), number average molecular weight 174.2
(Foaming agent)
Water (surfactant)
A-1:
Polyether-modified dimethylpolysiloxane having a number average molecular weight of 6000 “trade name SILBYK9100” (manufactured by BYKCHEMIE),
Number average molecular weight 6000, vapor pressure at 100 ° C. 0.3 Pa
A-2
Polyether-modified dimethylpolysiloxane "trade name L-530"
(Momentive Performance Materials Japan GK)
Number average molecular weight 2000, vapor pressure over 1 Pa at 100 ° C (metal catalyst)
B-1:
Tin ricinoleate "Product name Cosmos EF" (Evonik Degussa Japan Co., Ltd.)
B-2:
2-ethylhexylate "trade name Cosmos 29" (Evonik Degussa Japan Co., Ltd.)
(Amine catalyst)
C-1:
Dimethylaminohexanol “Caoraiser No.25” (manufactured by Kao Corporation)
C-2:
N-Ethylmorpholine “Caorizer No.22” (manufactured by Kao Corporation)

<Example 1>
(Manufacture of polyurethane foam for electrode material manufacturing)
For 100 parts by mass of polyester polyol, 51.9 parts by mass of TDI isocyanate, 4.0 parts by mass of water, 1.5 parts by mass of polyether-modified dimethylpolysiloxane A-1, 0.5 parts by mass of ricinoleic acid B-1, Then, 0.4 parts by mass of dimethylaminohexanol C-1 was added and foam-cured to produce a block-like polyurethane foam 700 (H) × 700 (W) × 1100 (L) (mm).
The obtained urethane foam was subjected to an explosion treatment to remove the foamed film, and then peeled to a thickness of 1.8 mm to produce a polyurethane foam for production of a roll electrode material having a thickness of more than 100 m.

(Thermogravimetric analysis under reduced pressure)
The obtained polyurethane foam for electrode material production was used as a sample, and loss on heating (% by mass) was measured by thermogravimetric analysis (TGA). A 20 mg sample was heated to 210 ° C. at a heating rate of 30 ° C./min under a reduced pressure of 3.5 Pa, and the heat loss from 25 ° C. to 200 ° C. was integrated and calculated. The results are shown in Table 1.

(Manufacture of metal-coated polyurethane foam)
A metal-coated polyurethane foam was produced by continuously performing nickel sputtering on the surface of a roll-form polyurethane foam for electrode material production using a magnetron sputtering apparatus. That is, the roll-form polyurethane foam for electrode material production is set in the apparatus, the flow rate is adjusted so that the Ar partial pressure is 0.0003 Pa in a state where the pressure is reduced to less than 1 Pa, and the roll-form polyurethane foam for electrode material production Was sputtered at a feed rate of 1.0 m / s.
As a result, a decrease in the degree of vacuum and blackening of the target surface were not confirmed, and stable sputtering could be performed. Resistance was measured by a four-probe method in accordance with JIS K7194. In addition, the measurement result of resistance was displayed as an index with the measured value of resistance in Comparative Example 1 described later as 100. The results are shown in Table 1.

<Example 2>
The same operation as in Example 1 was performed except that 46.6 parts by mass of TDI-based isocyanate, 3.5 parts by mass of water, and 1.2 parts by mass of polyether-modified dimethylpolysiloxane A-1 were used. The results are shown in Table 1.
In sputtering, a decrease in the degree of vacuum and blackening of the target surface were not confirmed, and stable sputtering could be performed.

<Comparative Example 1>
As a surfactant, 1.5 parts by mass of polyether-modified dimethylpolysiloxane A-1 was used instead of 1.5 parts by mass of polyether-modified dimethylpolysiloxane A-1, and as a catalyst, tin ricinoleate B- 1 Instead of 0.5 parts by mass (0.065 parts by mass in terms of tin), 0.15 parts by mass of tin 2-ethylhexylate B-2 (0.042 parts by mass in terms of tin) and dimethylaminohexanol C-1 The same operation as in Example 1 was performed except that 1.0 part by mass of N-ethylmorpholine was used instead of 4 parts by mass. The results are shown in Table 1.
In sputtering, the degree of vacuum decreased to about 0.95 Pa, so it was necessary to readjust the degree of vacuum and Ar partial pressure and to reduce the delivery speed, and the target surface was contaminated with volatile substances, resulting in a deterioration in sputtering efficiency. .

<Comparative example 2>
As a catalyst, instead of 0.5 parts by mass of tin ricinoleate B-1 (0.065 parts by mass in terms of tin), 0.15 parts by mass of tin 2-ethylhexylate B-2 (0.042 parts by mass in terms of tin), and The same operation as in Example 2 was performed except that 1.0 part by mass of N-ethylmorpholine was used instead of 0.4 part by mass of dimethylaminohexanol C-1. The results are shown in Table 1.
In sputtering, the degree of vacuum decreased to about 0.93 Pa. Therefore, it was necessary to readjust the degree of vacuum and Ar partial pressure, and to reduce the feed rate, and the target surface was contaminated with volatile substances, and the sputtering efficiency deteriorated. .

Claims (4)

  A polyurethane foam for producing an electrode material obtained by foaming and curing a raw material containing a polyol, an isocyanate, a foaming agent, a surfactant having a vapor pressure of less than 1 Pa at 100 ° C., and a hydroxy fatty acid metal salt.   The polyurethane foam for electrode material production according to claim 1, wherein the hydroxy fatty acid metal salt is a ricinoleic acid metal salt.   The polyurethane foam for electrode material production according to claim 2, wherein the ricinoleic acid metal salt is tin ricinoleate, and the content of the tin ricinoleate with respect to 100 parts by mass of polyol is 0.005 to 1.5 parts by mass.   A method for producing a polyurethane foam for producing an electrode material, comprising foaming and curing a raw material comprising a polyol, an isocyanate, a foaming agent, a surfactant having a vapor pressure of less than 1 Pa at 100 ° C., and a hydroxy fatty acid metal salt.