JPS62179541A - Electroconductive polyurethane foam - Google Patents

Abstract

PURPOSE:To eliminate a risk of, e.g., a fire and increase the adhesion of electroconductive particles to a polyurethane foam, by impregnating a polyurethane foam with a water-based polyurethane resin containing electroconductive particles and drying the foam. CONSTITUTION:An electroconductive polyurethane foam obtained by impregnating a polyurethane foam with a water-based polyurethane resin containing electroconductive particles and drying it. As the water-based polyurethane resin, an aqueous dispersion of a cationic polyurethane having quat. ammonium groups in the molecule is particulraly desirable. Examples of the electroconductive particles include carbon black, graphite, fine metal powders and powders of metal oxides. By suitably using compounds of various colors as the electroconductive particles, it is possible to obtain electroconductive polyurethane foams which can be discriminated by their colors.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to conductive polyurethane foams.

(VT rice technology) Conventionally, as a patent for conductive 7 ohm, for example,
-70473, No. 50-98978, etc. are publicly known.

However, the former uses furfur such as methyl alfur and ethyl alcohol to improve dispersibility and cause temporary swelling of the base material.
Because it is used for industrial purposes, it has serious disadvantages such as fire danger due to its low boiling point and deterioration of the working environment. Furthermore, acrylic emulsion, rubber latex, polyethylene, vinylidene chloride resin, etc. are exemplified as bindu resins that can be used, but these 01 resins have a weak adhesion force of conductive particles to urethane 7 ohm, so the obtained 7 ohm When bent or rubbed, conductive particles fall off.
It also has the problem of α.

The latter also uses acrylic acid ester-based, acrylic-styrene copolymer-based, and acetic acid-acrylic copolymer-based acrylic gums (fats) as water-dispersible binders. It has the disadvantage of weak adhesion.Furthermore, carbon black and graphite are used as conductive particles for the latter, but these particles only provide a black 7 ohm, making it difficult to identify them by color, for example. is not possible.

(Problems to be Solved by the Invention) The purpose of the present invention is to provide a 7-ohm conductive polytalethane that can be manufactured by a method that does not pose a risk of fire or deterioration of the working environment. be.

Another object of the present invention is to provide a conductive polyurethane foam that has excellent adhesion of conductive particles to 7 ohm urethane.

A further object of the present invention is to provide conductive polyurethane foams that can be identified by various colors.

(Means for Solving the Problems) The present invention is a polyurethane aqueous solution containing conductive particles? 31
It relates to conductive polyurethane foam obtained by impregnating polyurethane foam with fat and drying it.

In the present invention, by using a polyurethane aqueous resin that has not been used conventionally as a baingu resin, and by appropriately using compounds with various colors as conductive particles, there is no risk of fire, etc., and the adhesive strength is excellent. Moreover, it has become possible to obtain conductive polyurethane foam that can be identified by color.

In the present invention, the aqueous polyurethane resin is obtained, for example, by reacting a polyol, a polyisocyanate, and, if necessary, a chain extender. Further, as an example of the polyurethane aqueous resin, an aqueous dispersion of a cationic polyurethane having an fjS quaternary ammonium group in the molecular chain is particularly suitable. It can be obtained by reacting a tertiary amine 7 group with two or more chain extenders and quaternizing agents having Tzelevitinoff activity.

In the present invention, various polyester polyols, polyether polyols, and other polyols can be used as the polyol. Examples of polyester polyols include aliphatic dicarboxylic acids having 4 to 20 carbon atoms such as heptanopic acid, superic acid, sebacic acid, and brassylic acid, terephthalic acid, and isophthalic acid as acid components, and ethylene glycol, propylene glycol, and neopentyl glycol. , aliphatic nols having 1 to 6 carbon atoms such as hexamethylene glycol, ether glycols such as noethylene glycol and dipropylene glycol, spiroglycols, and N-furkyl dialkanolamines such as N-methylnoethanolamine. Polyester polyols or polycaprolactone polyols can be used as polyol components, and specific examples include adipate polyols such as polyethylene anovate polyol, polybutylene adipate polyol, and polyethylene propylene adipate polyol, terephthalic acid polyols (e.g., Examples include Toyobo Co., Ltd., trade name Byron 1'?UX, Byron RV-2001), polycaprolactone polyols (eg, Gwisselkaji, trade names Plaxel 212, Plaxel 220), and the like.

Specific examples of polyether polyols include polyoxyethylene polyol, polyoxypropylene polyol,
and polyoxytetramethylene polyol.

Other polyols include polycarbonate polyols (e.g., Bayer AG, West Germany, trade name Desmoreene 2020E), polybutanoene polyols (e.g., Nippon Soda, trade names G-1000, G-2000, G-300).
0, Idemitsu Petrochemical, trade name PolybdR-451-I
T), polypentadiene polyol, castor oil polyol, and the like. These polyols can be used alone or in combination of 2M1 or more.

Various polyisocyanates can be used in the present invention, such as diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TD).
r), toridine diisocyanate (TOr)T), xylylene noisocyanate (MDI), na7tylene noisocyanate (NDI),
IPDI), hexamethylene diisocyanate (MDI)
), nocyclohexylmethane diisocyanate (HMD
I), diisocyanates such as lysine di-incine (LDI), triphenylmethane triisocyanate, polymethylene polyphenylisocyanate (PA
PI), carposiimide-modified MDI, and other polyisocyanates, and these can be used alone or in combination of two or more. It is also possible to use a product in which part of these incyanates is blocked with a blocking agent.

Preferred examples of chain extenders in the present invention include the following formula: %<R' is a linear or branched fullkylene group having 2 to 10 carbon atoms, and may be connected through an oxygen atom.

R2 is a linear or branched fullkylene group having 2 to 10 carbon atoms or a 1m ring group. A and B are groups having an aromatic ring. ), aliphatic diols, aliphatic diamines, aromatic diols, aromatic diamines, etc. can be mentioned.

Preferred examples of the aliphatic diol include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, etc., and specific examples of the aliphatic diamine include ethylene diamine, 1,6- Examples include xamethylene diamine and isophorone diamine.

Examples of the aromatic diol A include the following, and examples of the aromatic diamine B include the following.

The polyurethane aqueous IJf resin of the present invention uses the above-mentioned components, and the chemical equivalent ratio of the active hydrogen groups contained in the polyol and chain extender to the NGO groups of the polyincyanate is preferably 0.9 to 1.4. It is preferable to react within a range of 0.95 to 1.1.

Next, the case of manufacturing the above-mentioned cationic polyurethane according to the present invention will be explained. The same polyols and polyisocyanates as mentioned above can be used.

Examples of chain extenders having at least one tertiary amine 7 group and two or more Tzelevitinoff activities in the molecule include N
Examples include -methylgetanolamine, N-ethylgetanolamine, N-butyldiet-7-lamine, bis-hydroxyethylpiperazine, and N-phenyldiethanolamine.

Examples of quaternary cutting include difurkyl sulfate such as trimethyl sulfate and diethyl sulfate, halogenated hydrocarbons such as chloride/chill, methyl iodide, ethyl bromide, and benol chloride, organic acids such as acetic acid, propionic acid, and monochloroacetic acid, Various 4a-forming agents can be used, such as hydroiodic acid, hydrobromic acid, hydrochloric acid, non-chlorinated acids such as perchloric acid, and the like.

The above-mentioned cationic polyurethane is prepared by adding in advance a chain extender having at least one tertiary amine 7 group and two or more having Zerevitinoff activity in the molecule that can be converted into an ionic group, and then grading the cationic polyurethane with a grading agent. It can be obtained by copolymerizing the above-mentioned chain extender into polyurethane and then quaternizing it with a quaternizing agent. In this case, the usual chain extenders mentioned above can be used in combination. Each of the above components may be appropriately determined from a wide range depending on the desired aqueous dispersion, but for example, the chemical equivalent ratio of the active hydrogen groups contained in the polyol and chain extender to the NCO groups of the polyisocyanate is 0. 9-1.4, preferably 0.95-1
．． It is best to react within a range where the value is 1.

The proportion of quaternized amide 7 groups in the polyurethane is usually preferably 0.1 milliequivalent of 7 g or more per polymer.

In the present invention, inert solvents that do not react with NGO groups can be used, and can be recovered by distillation if necessary. Furthermore, in order to suppress foaming during emulsification, a known urethanization catalyst, aqueous T-pore J'III (e.g., Toray Silicone, 5M-5512, San Nopco, SN), is used.
It is also optional to use deformers 113, 432, etc.).

Examples of the above-mentioned solvents include acetone, ketones such as methyl ethyl ketone, esters such as ethyl acetate and methyl propionate, ethers such as dioxane, tetrahydro7rane, cellosolve acetate, dinotylformamide, trimethylacetamide, dimethyl sulfoxide, etc. Examples include hexamethylphosphoric triamide and N-methylpyrrolidone, and these solvents may be used at any stage of the reaction of the present invention.

The aqueous polyurethane resin of the present invention can be produced by various methods, such as a one-shot method or a prepolymer method. The prepolymerization reaction is generally preferably carried out at a temperature of 60 to 130°C. In addition, the quaternization reaction is usually carried out at a temperature of 40 to 100℃.
It is preferable to do so.

In the present invention, a pond emulsion can also be blended with the obtained polyurethane water-based resin. An example of a pond emulsion is a vinyl acetate/vinyl chloride copolymer emulsion (e.g. Denki Kagaku Kogyo, trade name Denkatex AC-20).
), ethylene/vinyl acetate copolymer emulsion (e.g. 7I
For example, hydroxyethyl cellulose, methyl cellulose, polyethylene glycols, etc. can be used for stability and viscosity adjustment.
Polyvinyl alcohol, polyvinylpyrrolidone, water-soluble polyurethane, etc. can also be used.

The conductive polyurethane foam of the present invention can be obtained by impregnating one polyurethane foam with the above-mentioned aqueous polyurethane (M fat) containing conductive particles and drying.

As the conductive particles, for example, carbon black, graphite, gold powder, metal oxide powder, and other materials can be used. Preferred specific examples of car pump racks include Ketjen black, acetylene black, and the like. For example, product names include Ketjen Black EC and ECDJ-6 manufactured by Lion Corporation.
00, Vulcan XC-72 manufactured by CaboL, Toka Black #4500 manufactured by Tokai Carbon Co., Ltd. 51,
Examples include @5500. Fine metal powders include powders of gold, silver, so-called nickel, etc., and powders of gold IfGm compounds include zinc oxide (Hakusui Kagaku Kogyo, 23K).
, titanium oxide type (Kosei Shokai, AE-75, etc.), tin oxide, antimony type (Sumitomo Aluminum, FF-202),
Tin oxide type (Mitsubishi Metals, Elcom T1-20.1-22
), zinc oxide, aluminum-based (Sumitomo aluminum, F
WIOI, 102) etc., use mica as a material for the pond.
Examples include conductive powder fillers made by coating non-conductive particles such as fine powder, glass particles, and alumina with tin oxide, metal, etc., conductive dots such as chopped stainless fiber strands, and soybeans. The conductive particles are usually about 2 to 300 parts, preferably about 5 to 20 parts, based on 100 parts (by weight, the same applies hereinafter) of the solid content of polyurethane aqueous υ (fat).
0 It is better to mix them together.

In the present invention, the aqueous polyurethane resin and the conductive particles can be mixed using various known stirring and mixing devices.

In the present invention, the polyurethane foam is a well-known 3F! I
It is preferable to use an impregnation roll, spray, etc. to impregnate the polyurethane foam with the aqueous resin, and it is preferable to adjust the degree of impregnation according to the 7 ohm density. The amount of impregnation is usually 0.2 to 5 kg7m2・elm when wet for 7 ohm, preferably about 0.4
~3 kg/+++2・Cl11 is preferable.

Drying may be carried out at room temperature, but it is usually preferable to dry at about 60 to 150°C for about 3 to 30 minutes.

(Effects of the Invention) In the present invention, it is possible to obtain a conductive polyurethane foam with excellent adhesion of conductive particles to 7 ohm urethane without causing any risk of fire or deterioration of the working environment. By appropriately using conductive particles, when using conductive polyurethane foam for packaging, for example, it becomes possible to identify parts by grade by packaging them using foams of different colors.

(Example) The invention will be explained below with reference examples, working examples, and comparative examples. Note that "part" and "%" indicate ffz1 part and double base percentage, respectively.

Reference Example 1 Conductive carbon black dispersion (A) was produced by adding Aiden H:T-109 (Daiichi Kogyo Seiyaku Co., Ltd., H
LB = 10, 8 parts of /ionic surfactant) and 2 parts of Futamine 24P (Kao Atlas Co., Ltd., cationic surfactant) were dissolved, and 10 parts of carbon black (Ketjenblack EC) was added while stirring with a homogenizer. Stir for 30 minutes. The concentration of carbon black is approximately 10111L
A dispersion liquid with excellent storage stability of % was obtained.

Reference Example 2 Production of polyurethane water-based resin (1) (,)
= Tuboran 4009 150g (
Polybutylene anovate diol molecule, 1looo, manufactured by Nippon Polyurethane Co., Ltd.) (b) M
D I 75g (c
) N-methyljetanolamine 10.7g (
tJ) 1.4-butanediol 5.
4g(e) trimethyl sulfate 11.
(a) and (b) in a 1 liter separable flask equipped with a 3g stirrer, thermometer, condenser, and nitrogen inlet tube.
) ingredients and react at 80°C for 1 hour. Next, add 504g of methyl ethyl ketone (M E K ) and (c)
and component (d) are added, and the mixture is allowed to react in a nitrogen atmosphere under MEK reflux until no absorption of NGO is detected in an infrared absorption spectrum. Next, after cooling to 70°C, component (e) was added and stirred for 30 minutes, then 379g of water was added and MEK was distilled off. Solid content was 40wL%, viscosity was 120cpr, 72
A milky white aqueous resin (1) at 5°C was obtained.

Examples 1 to 6 The conductive particles listed in Table 1 were mixed with the aqueous polyurethane resin (I) of Reference Example 2 so as to have the solid content percentages listed in the table, and this was mixed to a thickness of 1cIIl1width and length 1+a. Impregnate the cut flexible polyurethane foam using an impregnation roll,
The amount of impregnation was 1.5 kg per 7 ohms. Next, it was dried at 120° C. for 30 minutes to produce a conductive polyurethane foam designated as L1. The conductive carbon black was used in the form of the dispersion (A) of Reference Example 1, and the conductive particles of the same were directly added in powder form to the aqueous polyurethane side JJff(+>).

Table 1 also shows the results of investigating the surface resistance value of the obtained conductive 7 ohm and powder falling off by rubbing (dropping off of conductive particles).

The surface resistance value was determined by pressing two square body foil electrodes with a side of 25 re 8tsu Denshi, SC-
7403). Also, in the powder drop test, ◎ is 7
A case where no powder was observed to fall off when the ohm was rubbed by hand, and an x indicates a case where powder fall was clearly observed.

Comparative Examples 1 to 3 Acrylic emulsion (Hoechst Synthesis, Movinyl 966
,ratio? Polyurethane foams were obtained in the same manner as in Examples 1 to G, except that EVA emulsion (Electrochemistry, Denka EVA Tex #80, Comparative Example 3) was used. Show the results to the first person as well.

Table 1

Claims (2)

[Claims] (1) A conductive polyurethane foam obtained by impregnating a polyurethane foam with a polyurethane aqueous resin containing conductive particles and drying it. (2) The polyurethane foam according to claim 1, wherein the aqueous polyurethane resin is an aqueous dispersion of a cationic polyurethane having a quaternary ammonium group in its molecular chain.