JPS62269053A - Polymer humidity sensor - Google Patents

Abstract

PURPOSE:To obtain a high sensitivity humidity sensor, by a method wherein a copolymer of N, N-dimethylaminoethylacrylamide or N, N- dimethylaminopropylacrylamide and a vinyl monomer is quaternized and perchlorate is added to the quaternized one to make the same hydrophobic and the obtained hydrophobic copolymer is applied to an Al2O3 substrate to form a film. CONSTITUTION:About 50-90mol%, pref., about 70-80mol% of N, N- dimethylaminoethylacrylamide or N, N-dimethylaminopropylacrylamide is mixed with a vinyl monomer and the resulting mixture is copolymerized in the presence of benzene and AIBN being a polymerization initiator while the bubbling of N2-gas is applied to said mixture and, subsequently, alkyl halide, for example, methyl iodide, a nitromethane solvent and benzene are added to the reaction solution to quaternize the formed copolymer at 60 deg.C. The quaternized copolymer is precipitated and purified using diethyl ether and made hydrophobic by the addition of LiClO4. The obtained copolymer is applied to an Al2O3 substrate using a Pt/Pd paste to form a film and aging of AC4V, 13hr is applied to the film. A humidity-resistance characteristic can be freely changed by the kind of perchlorate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field) The present invention relates to N-dimethylaminoethyl acrylamide or N,N-dimethylaminopropylacrylamide and vinyl nanano! This invention relates to a polymer humidity sensor formed by quaternizing a copolymer with - and adding perchlorate to make it hydrophobic and coating it on an alumina substrate in a Vcv shape.

(Prior art and its problems) Humidity control is air conditioning in the living environment (40-704
Not only is R, H, ) required for humidity control in addition to temperature control, but ceramic humidity sensors have already been commercialized as humidity sensors. However, no one has been obtained that has satisfactory moisture sensitivity characteristics, especially in a high temperature range.

(Object of the invention) The present inventors have solved the problems of the prior art described above, and
-dimethylaminoethyl acrylamide or N,N-
Excellent moisture sensitivity properties can be obtained by quaternizing a copolymer of dimethylaminopropylacrylamide and a vinyl monomer by adding an alkyl halogen and a sulfate ester, and making it hydrophobic by adding a perchlorate. They discovered this and arrived at the present invention.

(Structure of the Invention) That is, according to the present invention, a copolymer of N,N-dimethylamineethylacrylamide or N,N-dimethylaminopropylacrylamide and a vinyl monomer is quaternized by adding an alkyl halogen and an ether sulfate. ,
A polymer humidity sensor is obtained by adding perchlorate to make it hydrophobic, coating it in the form of a film on an alumina substrate, and then aging it.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a 70-chart created by an embodiment of the humidity sensor of the present invention.

As described above, the sensor substance of the present invention is N-dimethylaminoethyl acrylamide or N.

Copolymerization of N-dimethylamine propylacrylamide with vinyl monomers (styrene, EMA, etc.) with reduced EE distillation (40°C r 1rxHg) was carried out in the presence of benzene and AIBN as a polymerization initiator. Next, methyl iodide and the solvents nitromethane and benzene were added to quaternize at 60°C. This was purified by precipitation using diethyl ether, and then perchlorate (L i C -130+, KC
-/304. Cs C-eo+ etc.) to make it hydrophobic was coated in a film form with a bar coater on an alumina substrate printed with platinum baladium paste, and further coated with AC4V.
Acing was performed for 13 hours to produce the sensor element of the present invention.

As perchlorate, as mentioned above, L i CJ30
4.

KC-gO The mixing ratio of aminoethyl acrylamide or N,N-dimethylaminopropylacrylamide to the vinyl monomer is 50 to 90 mo1%,
Preferably 70 to 80 mo! − is.

The process of producing the sensor material of the present invention is shown in chemical formulas as follows.

HH! 1icAO+N Illustrated by diagram.

Figure 2 shows EMA:N,N-dimethylaminopropylacrylamide (hereinafter referred to as DMAPAA) (2:8), 2
This is the case of 5°C and two frequencies I K F (z I7).

Figure 3 goes to E fA: DMAPAA (3: 7)
This is the case of 2-station wave number IKE (z) at 25°C.

FIG. 4 shows the combination of EMA: DMAPAA (5:5), temperature 25° C., two frequencies IKFfzLT)'III.

Figure 5 is still/: DMAPAA (2: 8).

This is a case where the temperature is 25° C. and the frequency is IKHz (r).

(Effects of the Invention) By adopting the above configuration, the present invention can exhibit the following effects.

(II) Can be used over a wide temperature range and exhibits excellent moisture sensitivity properties.

(2) Since it is heat resistant, it can withstand being exposed to heat in a high temperature range.

[Brief explanation of the drawing]

Figure 1 is a flowchart for creating an embodiment of the present invention;
The figure shows EMA: DMAPAA (2:8). Electrical resistance-relative humidity characteristic diagram in the case of 1 degree 25 degrees Celsius 2 frequency IKHz, Figure 3 is EMA: DMAPAA (3 near), @1f electric resistance-relative humidity characteristic diagram in the case of 25 degrees Celsius 1 frequency IKHz, Figure 3 Figure 4 shows EMA:DMAPAA (5
: 5), Electrical resistance-relative humidity characteristic diagram at a temperature of 25°C and a frequency of IK Hz, Figure 5 is 7: DMA
PAA (2:8), 1m degree 25℃ 9 frequency IKHz
It is an electrical resistance-relative humidity characteristic diagram in the case of.

Claims (1)

[Claims] (1) A copolymer of N,N-dimethylaminoethyl acrylamide or N,N-dimethylaminopropylacrylamide and a vinyl monomer is quaternized by adding a halogen alkyl and a sulfuric ester, and a perchlorate is added to this. A polymer humidity sensor characterized by coating a hydrophobic material on an alumina substrate in the form of a film and then subjecting it to aging.