JPH09180909A - High molecular thermosensitive body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high molecular thermosensitive body having an excellent long-term stability of electric property, by mixing a conductivity supplying agent of graft structure into polyamide resin. SOLUTION: A high molecular thermosensitive body includes a polyamide resin composition which is formed by mixing, into polyamide resin, a conductivity supplying agent made of a high molecular graft body of a structure such that alkylene oxide is graft-polymerized on the main chain of a high molecular compound, and salts. This graft polymer is exemplified by a polyalkylene oxide graft body of sapoinified copolymer of vinyl ester of aliphatic carbonic acid with other polymeric monomers, a polyacrylic polyalkylene oxide graft body having a graft structure using polyalkylene oxide as the side chain with the main chain of acrylic copolymer having a hydroxyl group, or a polyacrylic ether based polyalkylene oxide graft body having a graft structure using polyalkylene oxide as the side chain with the main chain of aryl alcohol copolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymeric temperature sensor used for temperature detection for controlling the temperature of sheet heating elements such as electric blankets and electric carpets.

[0002]

2. Description of the Related Art It is well known in the art that the temperature dependence of the electrical characteristics of a polymer material is used for use as a temperature-sensitive element in a surface heating appliance such as an electric carpet. The temperature control circuit is operated by utilizing the fact that the characteristics such as the dielectric constant, DC resistance, and impedance of the material change with temperature.

The properties required for such a polymer temperature-sensitive material are (1) a large change in the electric properties of the polymer with temperature, and (2) a small change in the electric properties of the polymer over time. , (3) little moisture absorption, little change in electrical characteristics due to moisture absorption, and (4) excellent mechanical properties such as bending resistance.

Polyamide resin is suitable as a heat-sensitive material because it has a large temperature dependency of the above-mentioned electrical characteristics, and also has excellent mechanical characteristics and moldability. In particular, it is a composition of nylon 11 and nylon 12 having low hygroscopicity. Is preferably used.

In addition, JP-A-48-6648 and JP-A-4
No. 8-99691, JP-A-61-2303, etc., these nylons are blended with a phenolic compound,
Alternatively, JP-A-52-27594 and JP-A-58-21
5449, JP-A-60-106101, etc., the temperature dependence of electric characteristics is improved by a method of blending metal salts.

By the method of improving the electric characteristics as described above,
Although the effect of improving the electrical properties is recognized, there is a change in the electrical properties over time due to decomposition and volatilization of the added phenolic compound during long-term use, and variations in sensitivity due to poor compatibility of the added salts with nylon. Due to the polarization phenomenon due to the DC component of the current applied when it is used as a body, there have been drawbacks such as changes in electrical characteristics. Therefore, a material satisfying all the properties required for a polymeric temperature sensitive material such as the initial thermistor characteristics of the temperature sensing element, the stability of characteristics when a direct current or an alternating current is applied, and the stability of characteristics during long-term use have not been obtained so far. It was

Further, Japanese Patent Laid-Open Nos. 6-5175 and 6-
No. 124805 reports a polymer temperature-sensitive material characterized in that a conductivity-imparting agent obtained by dissolving lithium perchlorate in polyethylene oxide is mixed with a polyamide resin. However, the low-molecular-weight polyalkylene oxide used here has low water resistance, easily absorbs water under high humidity, and easily bleeds on the surface of the polyamide. Therefore, such a polymer temperature-sensitive material in which a lithium perchlorate-polyethylene oxide-based conductivity-imparting agent is blended with a polyamide resin is liable to cause a change in electric characteristics with time when used as a heating appliance for a long time. There is a drawback that problems such as deviation of temperature from temperature tend to occur.

[0008]

In view of the above points, the present invention has excellent initial thermistor properties, is free from bleeding of the conductivity-imparting agent, and is excellent in long-term stability of electrical properties.
The object is to provide a high-sensitivity and highly reliable polymer temperature sensor.

[0009]

Means for Solving the Problems As a result of intensive investigations for solving these problems, the present inventors have found that salts are dissolved in a polymer graft body in which a polyalkylene oxide chain is grafted as a side chain of a polymer compound. Hygroscopicity of the conductivity-imparting agent was less compared to the conductivity-imparting agent using a low molecular weight polyalkylene oxide that was conventionally used, and by incorporating this conductivity-imparting agent into a polyamide resin, the initial It was found that a polymer temperature sensitive composition having good long-term stability of the thermistor property and electric property of was obtained. This is because, in the high molecular weight graft polymer used in the present invention, the grafted main chain portion of the polyalkylene oxide chain is hydrophobic, and due to sufficient entanglement of the molecular chains derived from the graft structure, it is difficult to bleed out. It is thought to be because.

As a polyelectrolyte containing a high molecular weight base having such a comb-shaped graft structure, a polyelectrolyte using a base in which a polyethylene glycol chain is grafted to polyethylene is disclosed in JP-A-4-359051. It is disclosed. The present inventors focused their attention on this polymer electrolyte,
By adding a polymer electrolyte produced from a base having such a graft structure to a polyamide resin as a conductivity-imparting agent, it has been found that a polymer temperature sensor having excellent long-term stability can be obtained. It has arrived. That is, the present invention, the main chain of various polymer compounds, a polyamide resin composition obtained by blending a polyamide resin with a conductivity-imparting agent consisting of a polymer graft body having a structure in which alkylene oxide is graft-polymerized as a side chain and a salt. It is a high temperature sensor.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The base of the conductivity-imparting agent that can be used in the present invention is not particularly limited as long as it has a graft structure having a polyalkylene oxide as a side chain on the main chain of a polymer compound. However, there is a graft polymer having the following structure, which is convenient from the viewpoint of industrial production.

(A) Polyalkylene oxide graft of saponification product of copolymer of vinyl ester of aliphatic carboxylic acid and other polymerizable monomer (b) In main chain of acrylic copolymer having hydroxyl group, Polyacrylic polyalkylene oxide graft having a graft structure having polyalkylene oxide as a side chain (c) Polyallyl ether-based poly having a graft structure having polyalkylene oxide as a side chain in the main chain of the allyl alcohol copolymer Alkylene oxide graft body There is no particular limitation on the method for producing the base of the conductivity-imparting agent in which polyalkylene oxide is grafted on these side chains,
Known methods can be used.

The polyalkylene oxide graft product of the saponified product of the copolymer of vinyl ester of aliphatic carboxylic acid and other copolymerizable monomer shown in (a) is a vinyl ester of aliphatic carboxylic acid and other polyalkylene oxide graft products. The copolymer obtained by copolymerizing with a copolymerizable monomer is completely or partially hydrolyzed (saponified) to synthesize a polymer having a hydroxyl group, and then a hydroxyl group produced by the hydrolysis It can be produced by adding an alkylene oxide to the moiety.

The vinyl ester of aliphatic carboxylic acid is preferably a vinyl ester of aliphatic carboxylic acid having 2 to 4 carbon atoms, such as vinyl acetate, vinyl propionate,
Vinyl butyrate etc. can be mentioned. Moreover, you may use these 2 or more types in mixture. Among these vinyl esters of aliphatic carboxylic acids, vinyl acetate, which is industrially produced in large quantities, is most preferable.

Other polymerizable monomers that can be copolymerized with the vinyl ester of an aliphatic carboxylic acid include methyl acrylate, ethyl acrylate, butyl acrylate,
Aliphatic acrylates such as hexyl acrylate,
Aliphatic methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, glycidyl acrylate, acrylic acid-
Epoxy acrylates such as 2,3-epoxycyclohexylmethyl, glycidyl methacrylate, epoxymethacrylates such as -2,3-epoxycyclohexylmethyl methacrylate, and the like can be used.

Other than these, ethylene, propylene, styrene, α-methylstyrene, acrylonitrile, methacrylonitrile, maleic acid, succinic acid, succinic anhydride, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl. Acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, polyalkylene oxide-added hydroxyethyl acrylate, polyalkylene oxide-added hydroxyethyl methacrylate, polycaprolactone-added hydroxyethyl acrylate, polycaprolactone-added hydroxyethyl methacrylate, N, N-dimethylamino Ethyl acrylate, N, N-dimethylaminopropyl acryl DOO, acrylamide, methyl vinyl ether, can also be used ethyl vinyl ether, ethylene, propylene, the copolymerizable monomer containing no hydrolyzable ester group, such as styrene, can be suitably used.

The molecular weight of the copolymer of these copolymerizable monomers and the above-mentioned vinyl ester of aliphatic carboxylic acid is not particularly limited, and from low molecular weight liquid state to high molecular weight solid state are used. You can However, the preferable molecular weight is 300 to 100,000.
The range of 0, more preferably 1000 to 50,000 is desirable. At a low molecular weight of 300 or less, the effect of using a high molecular weight graft polymer is not exhibited, and at a molecular weight of 1,000,000 or more, compatibility with nylon is extremely poor even if polyalkylene oxide is grafted, which is preferable. Absent.

The copolymerization composition ratio of the vinyl ester of aliphatic carboxylic acid and the other copolymerizable monomer is preferably in the range of 5: 1 to 1:30 in terms of molar ratio. When used as a conductivity-imparting agent, the glass transition point of the base graft polymer is preferably room temperature or lower, and from this point, the molar ratio is from 2: 1 to 1:20, more preferably from 1: 1. The range is 1:10.

Next, the method for graft-polymerizing alkylene oxide onto the saponified product of a vinyl ester copolymer of an aliphatic carboxylic acid is not particularly limited, but the saponified product of a vinyl ester copolymer of an aliphatic carboxylic acid is not particularly limited. In addition, it is common to react the alkylene oxide in a gaseous state. As the alkylene oxide, those having 2 to 4 carbon atoms are preferable, and in particular, from the viewpoint that the oxygen atom in the polyalkylene oxide side chain obtained by grafting is easily coordinated to the cation and high ionic conductivity is exhibited, ethylene oxide and propylene oxide are shown. Are most preferred. Also,
The alkylene oxide used may be a single type, or two or more types of alkylene oxide may be used in combination.

In the base of these conductivity-imparting agents, the amount of the alkylene oxide to be graft-polymerized is 1: 1 in a molar ratio with respect to the vinyl alcohol moiety in the copolymer.
It is 300: 1, preferably 3: 1 to 50: 1 from the viewpoint of obtaining high ionic conductivity, and 3: 3 from the viewpoint of preventing the formation of alkylene oxide homopolymer.
1-15: 1 is preferred.

It is generally considered that the cation moves in the helical structure formed by the polyalkylene oxide polymer while changing the coordination position by molecular motion. However, when the graft chain is short, the polyalkylene oxide is effective for the cation transfer. The conductivity is reduced without forming a spiral structure. On the other hand, when the crystallinity of the graft polymer is high, the migration of cations due to molecular motion tends to be hindered. Therefore, the molecular weight of the polyalkylene oxide to be graft polymerized is preferably in the range of 50 to 10,000, and particularly preferably 1
The range is from 00 to 3000.

The polyacrylic polyalkylene oxide graft having a graft structure having a polyalkylene oxide as a side chain on the main chain of the acrylic polymer having a hydroxyl group shown in (b) is hydroxyethyl acrylate or hydroxypropyl acrylate. , Hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, polycaprolactone-added hydroxyethyl acrylate, polycaprolactone-added hydroxyethyl methacrylate, etc. to an acrylic resin containing an acrylic or methacrylic monomer having a hydroxyl group as a constituent component, It can be prepared by adding an alkylene oxide to the portion of the hydroxyl group, or polyalkylene It can be prepared by polymerizing acrylic or methacrylic monomers having oxide adduct of hydroxyethyl acrylate, a polyalkylene oxide chain, such as polyalkylene oxide addition hydroxyethyl methacrylate.

The acrylic polymer having a hydroxyl group as the main chain may be a copolymer. In addition to the above-mentioned acrylic or methacrylic monomer having a hydroxyl group, α, β-unsaturated monomers that can be used as a copolymerization monomer include various α, β-unsaturated monomers used in the production of ordinary acrylic resins. Examples include monomers. As such an α, β-unsaturated monomer,
Hydroxyl group-containing monomers such as allyl alcohol and methallyl alcohol, amino group-containing monomers such as dimethylaminoethyl acrylate and dimethylaminoethyl methacrylate, amide group-containing monomers such as acrylic acid amide and methacrylic acid amide, acrylonitrile and methacrylonitrile, etc. Nitrile group-containing monomer, γ-
A silyl group-containing monomer such as trimethoxysilylpropyl methacrylate, an alkyl group-containing monomer such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, acrylic acid, methacryl Carboxylic group-containing monomers such as acids, crotonic acid, itaconic acid, maleic acid and fumaric acid, polymerizable aromatic compounds such as styrene and α-methylstyrene, ethylene, propylene, vinyl chloride, vinylidene chloride, vinyl fluoride, fluorine It is possible to use polymerizable monomers such as vinylidene chloride, vinyl acetate, butadiene and isoprene. These monomers may be used alone or in combination of two or more. The method for producing an acrylic polymer having a hydroxyl group is not particularly limited, and bulk polymerization, solution polymerization,
Known methods such as aqueous suspension polymerization and emulsion polymerization can be used. As a polymerization initiator, an organic peroxide such as benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, an organic azo compound such as azoisobisisobutyronitrile, azobis (2,4-dimethyl) valeronitrile Inorganic water-soluble radical initiators such as potassium persulfate, ammonium persulfate, sodium persulfate and hydrogen peroxide, and redox type initiators are preferably used.

As the chain transfer agent, mercaptans such as ethyl mercaptan and methyl mercaptan, α-methylstyrene dimer, or halogenated carbons such as carbon tetrachloride and carbon tetrabromide can be used.

When an alkylene oxide is added to the hydroxyl group of the main chain acrylic polymer to produce a graft product, the alkylene oxide can be grafted in the same manner as in the case of a).

A preferred molecular weight of the acrylic polymer having a droxyl group as a main chain is 300 to 1,000,000,
More preferably, the range of 1000 to 50,000 is desirable. At a low molecular weight of 300 or less, the effect of using a high molecular weight graft polymer is not exhibited, and the molecular weight is 1
When it is, 000,000 or more, even if polyalkylene oxide is grafted, the compatibility with the polyamide resin becomes extremely poor, which is not preferable.

An acrylic monomer having polyalkylene oxide, or a monomer having a hydroxyl group for adding polyalkylene oxide,
The copolymerization composition ratio with other copolymerizable monomers is 5: in molar ratio.
1 to 1:30 is preferred. In the base of these conductivity-imparting agents, the amount of the alkylene oxide used is 1: 1 to a molar ratio with respect to the hydroxyl group portion in the copolymer.
It is 300: 1, preferably 3: 1 to 50: 1 from the viewpoint of obtaining high ionic conductivity, and 3: 3 from the viewpoint of preventing the formation of alkylene oxide homopolymer.
1-15: 1 is preferred.

As in the case of a), the molecular weight of the grafted polyalkylene oxide is 50 to 1000.
The range of 0 is desirable, and particularly preferably 100 to 3000.
Range.

A polyallyl ether-based polyalkylene oxide graft product having a graft structure having a side chain of polyalkylene oxide on the main chain of the copolymer of allyl alcohol and another copolymerizable monomer shown in (c). Can be produced by copolymerizing a polyalkylene oxide having an allyl ether group only at one end with another copolymerizable monomer.

It can also be produced by polymerizing allyl alcohol with another copolymerizable monomer and then adding a polyalkylene oxide to the trunk of this copolymer having a hydroxyl group in the same manner as in the case of a). It is possible.

In the base of these conductivity-imparting agents, the amount of alkylene oxide to be graft-polymerized as a side chain is 1: 1 to 100: 1 in a molar ratio with respect to the hydroxyl group in the main chain copolymer. Therefore, 3: 1 to 50: 1 is preferable from the viewpoint of obtaining high ionic conductivity, and 3: 1 to 15: 1 is preferable from the viewpoint of preventing the formation of alkylene oxide homopolymer. Further, similarly to the case of a), the molecular weight of the polyalkylene oxide to be grafted is preferably in the range of 50 to 10,000, and particularly preferably in the range of 100 to 3,000.

As for the method for producing the copolymer and the copolymerization monomer in c), the production method and the copolymerization monomer described in b) can be used.

The type of salt that can be used in the conductivity-imparting agent of the present invention is not particularly limited as long as it can generate an ion in the conductivity-imparting agent and transport an electric charge as a carrier, and an alkali metal salt. , Alkaline earth metal salts, organic ammonium salts, and heavy metal salts such as zinc and copper can be preferably used, but alkali metal salts such as lithium salt, sodium salt and potassium salt are preferable.

The anion species of these salts include perchlorate ion, borofluoride ion, hexafluorophosphate ion, arsenic hexafluoride ion, tetrafluoroborate ion, periodate ion, sulfate ion and halogen. Ion, nitrate ion, boron ion, p-toluenesulfonate ion, metasulfonate ion, trifluoromethanesulfonate ion, trifluoroacetate ion, thiocyanate ion, hydroxide ion, carbonate ion, bicarbonate ion and the like. it can.

Specific examples thereof include lithium perchlorate, sodium perchlorate, sodium thiocyanate, lithium trifluoromethanesulfonate, sodium borofluoride and sodium trifluoromethanesulfonate.

The production of the conductivity-imparting agent of the present invention, that is, the dissolution of the above-mentioned salts in the base, is carried out by heating at 50 ° C. to 150 ° C., melting the solid base, and melting the liquid base. Reduce its viscosity. Then, it can be obtained by gradually adding and dissolving salts such as metal thiocyanate and metal halide while stirring.

The conductivity-imparting agent can also be prepared by dissolving salts and a base in water or an organic solvent and then removing the solvent by distillation or the like. As the solvent, water, methanol, ethanol, isopropyl alcohol, tetrahydrofuran, methyl ethyl ketone, toluene, xylene or the like can be used.

The amount of the salt dissolved in the base is not particularly limited as long as it does not cause precipitation of the salt upon standing, but is usually 0.5% by weight to 50% by weight, preferably 3% by weight.
A range of 30% by weight is suitable.

In order to improve the electrical characteristics of the present conductivity-imparting agent when it is produced and used, the polyamide resin composition does not have problems such as deterioration of mechanical properties and bleeding.
You may use together well-known bases, such as polyalkylene glycol and polyethyleneimine.

The amount of the conductivity-imparting agent to be kneaded with the polyamide resin is preferably 0.01 to 20% by weight. 0.
If the amount is less than 01% by weight, the performance as an ionic conductor is extremely low. On the other hand, if the amount is more than 20% by weight, strands are likely to break during kneading and extrusion with a polyamide resin, which makes production difficult. Further, the blended polyamide resin is inferior in mechanical properties and the thermistor properties are also poor because the conductive component is too much. In addition, the polarization effect when a direct current is continuously applied becomes strong, and it is not suitable as a polymer temperature sensitive material.

The polyamide resin which can be used in the polymer temperature-sensitive material of the present invention is not particularly limited, but from the viewpoint of water absorption and electric characteristics, a polyamide resin having an amide group concentration of 14 or less per 100 carbon atoms. Can be preferably used. As such a polyamide resin, (a) polyundecane amined (nylon 11), (b) polydodecane amide (nylon 12), (c) N-alkyl substituted polyamide, (d) polyether amide, polyether ester Examples thereof include amides, polyamides such as (e) dimer acid-containing and / or hydrogenated dimer acid-containing polyamides, and copolymers thereof.

Various additives may be added to the polyamide resin composition of the present invention for the purpose of improving electric characteristics. As such an additive, a known phenol compound, a phenol resin, and a phenol resin oligomer or polymer having an alicyclic skeleton from the viewpoint of lowering water absorption and preventing change in electrical properties with time are desirable. ) DPP series, PP series, and the like manufactured by () can be preferably used.

Further, in the polyamide resin composition of the present invention, various antioxidants, heat stabilizers, hydrogen chloride gas generated from the vinyl chloride resin used for coating, etc. for the purpose of improving heat resistance and weather resistance. In order to prevent the deterioration of the polyamide resin due to the above, a known vinyl chloride stabilizer such as a phosphite, an epoxy compound, a compound of zinc, cadmium, or lead can be used in combination.

[0044]

EXAMPLES The present invention will be specifically described below, but the present invention is not limited thereto. All parts mean parts by weight.

The conductivity-imparting agent base in Synthesis Example 1 the conductive material bases (an acrylic resin A) a condenser, a nitrogen inlet tube was connected with a stirrer, taking 120 parts of xylene separable flask 3-neck, 100
The temperature was raised to ° C. Then, a mixture of the following acrylic monomers, styrene and an initiator was added dropwise to 120 parts of xylene at 100 ° C. for 4 hours, and the temperature was raised to 120 ° C., followed by aging for 3 hours.

Blemmer AE350 60 parts (Nippon Oil & Fats: Polyethylene glycol monoacrylate, molecular weight about 380) Butyl methacrylate 20 parts Methyl methacrylate 10 parts Styrene 10 parts Perhexyl O (Nippon Yushi Oil: radical polymerization initiator) 2.5 parts Polymerization end After that, the solvent and low-boiling components were removed to obtain a highly viscous acrylic resin.

The number average molecular weight by GPC analysis is 2900.
Met.

Synthesis Example 2 Conductivity-Giving Agent Base (Acrylic Resin B) Instead of the Bremmer AE350 of Synthesis Example 1, Bremmer PME450 (Nippon Yushi Co., Ltd .: methoxypolyethylene glycol monomethacrylate, molecular weight about 500)
Acrylic resin B was prepared in the same manner as in Synthesis Example 1 except that was used. The number average molecular weight by GPC analysis was 3,200.

Synthesis Example 3 Conductivity-Giving Agent Base (Acrylic Resin C) Instead of the Bremmer AE350 of Synthesis Example 1, Bremmer 70PEP370B (Nippon Yushi Co., Ltd .: polypropylene glycol monomethacrylate, molecular weight about 60) was used.
Acrylic resin C was prepared in the same manner as in Synthesis Example 1 except that 0) was used. The number average molecular weight by GPC analysis was 3,600.

Synthesis Example 4 Conductivity-Giving Agent Base (Copolymer D) 120 parts of xylene and UNIOX PKA5005 (manufactured by NOF CORPORATION: allylated polyethylene) were placed in a three-neck separable flask connected with a condenser, a nitrogen introducing tube and a stirrer. Oxide, molecular weight about 1500) 60 parts, 100 parts
The temperature was raised to ° C. Then, a mixture of the following acrylic monomers, styrene and an initiator was dropped into 120 parts of xylene at 100 ° C. for 4 hours, heated to 140 ° C. and aged for 3 hours.

Butyl Methacrylate 20 parts Methyl Methacrylate 10 parts Styrene 10 parts Perbutyl O (Nippon Oil & Fats: Radical Polymerization Initiator) 3.5 parts After the polymerization is completed, the solvent and low boiling components are removed to obtain a high viscosity polymer. Obtained. Number average molecular weight by GPC analysis is 3100
Met.

Preparation of conductivity-imparting agent Conductivity-imparting agent NO. 1 (NaI / Sumied 300
G) Polyethylene oxide graft polyethylene (Sumitomo Chemical; Sumiade 300G, number average molecular weight about 4000,
81.5 parts of hydroxyl value 80 mgKOH / g) was placed in a beaker and heated at 80 ° C. to melt. Then, 18.5 parts of sodium iodide was added and stirred, and then mixed at high speed with a homomixer at about 2500 rpm, and continued for about 3 hours until completely transparent. The product was a waxy solid at room temperature.

Similarly, the conductivity-imparting agent NO. 2 to NO. 4 was prepared.

[Table 1] Conductivity imparting agent NO. 5 (LiClO ₄ / acrylic resin A) 81.5 parts of the acrylic resin A synthesized in Synthesis Example 1 was placed in a beaker and heated at 80 ° C. Then, 13.1 parts of lithium perchlorate was added and stirred, and after mixing, the mixture was stirred at high speed with a homomixer at about 1500 rpm, and continued for about 5 hours until completely transparent. The product is a paste at room temperature ~
It was waxy.

Similarly, the conductivity-imparting agent NO. 6 to NO. 12 was prepared.

[0055]

[Table 2]

[Table 3] Examples 1 to 12 Nylon 12, nylon 12 elastomer and hydrogenated dimer acid-modified nylon 12 manufactured by Daicel Hüls were used as the polyamide resin, and the conductivity imparting agent NO. 1 to NO.
12 and the additives were blended in the proportions (parts by weight) shown in Tables 4 and 5, melt-kneaded at 210 ° C. by an extruder, and pelletized by a pelletizer.

These pellets at 210 ° C. and a thickness of about 0.
A 5 mm film was formed, and then a tin electrode was attached, and the impedance at each temperature was measured with an LCR meter manufactured by Yokogawa-Hewlett-Packard. Figure 1 shows the evaluation results
3 is shown.

The films of Examples 2 and 5 were dried in an oven at 100 ° C. for 2 hours, and
When the humidity was controlled with a thermo-hygrostat at 60 ° C. for 20 hours, the impedance at each temperature was measured by the same measurement method. The results are shown in FIGS. 4 and 5.

The films of Examples 2 and 9 were left in an oven at 80 ° C. for a long period of time, and the change in impedance (measurement temperature 60 ° C.) with time was measured. The results are shown in FIG.

From the above measurement results, the temperature-sensitive material of the present invention showed a large change in volume specific impedance with respect to a change in temperature, and excellent detection sensitivity for temperature change was obtained.
Also, there is little change in impedance between moisture absorption and drying,
There is little fluctuation in the set temperature during actual use under various humidity conditions. Furthermore, even in the high temperature long-term aging test at 80 ° C, there is little change in impedance,
It showed stable temperature sensing characteristics over a long period of time.

[0060]

[Table 4]

[Table 5] Comparative Examples 1 to 3 Polyethylene glycol 600 (reagent: molecular weight 600)
90 parts and 10 parts of lithium perchlorate and 1 part of methyl alcohol
After stirring and dissolving in 50 parts, methyl alcohol was distilled off under reduced pressure by an evaporator, and then at 50 ° C. for 10 tons.
It was dried at rr for 3 hours to prepare a conductivity-imparting agent.

As the polyamide resin, Nylon 12, Nylon 12 elastomer and hydrogenated dimer acid-modified Nylon 12 manufactured by Daicel Hüls were used, and the above-mentioned conductivity-imparting agent and additives were blended in the proportions (parts by weight) shown in Table 6. The mixture was melt-kneaded at 210 ° C. by an extruder and pelletized by a pelletizer.

Each of these pellets and nylon 12 alone (Comparative Example 3) was formed into a film having a thickness of about 0.5 mm at 210 ° C., and then a tin electrode was attached, and the impedance at each temperature was measured by an Yokogawa-Hewlett-Packard LCR meter. It was measured at. The evaluation results are shown in FIGS.

[0063]

[Table 6]

[0064]

By adding the conductivity-imparting agent having the graft structure described in the present invention to the polyamide resin, good thermistor characteristics which cannot be obtained by the conventional metal salt alone or the polyalkylene glycol solution of the metal salt are obtained. In addition, it is possible to obtain a high-sensitivity and highly reliable polymer temperature sensitive body, which can prevent the electric characteristics from changing with time due to long-term use at high temperature.

Further, the polyamide resin composition obtained by the present invention has an appropriate melting point and also has a function as a thermal fuse, and satisfies the mechanical characteristics required for a temperature sensitive body for a heater wire. ing.

[Brief description of the drawings]

FIG. 1 is a polymer temperature sensor of Examples 1 to 4 and nylon 1.
It is a graph which shows the measurement result of the initial impedance in each temperature of 2 (comparative example 3).

FIG. 2 Polymer temperature sensitive bodies and Nylon 1 of Examples 5-8
It is a graph which shows the measurement result of the initial impedance in each temperature of 2 (comparative example 3).

FIG. 3 is a graph showing the measurement results of the initial impedance of each of the polymer temperature sensor of Examples 9 to 12 and nylon 12 (Comparative Example 3) at each temperature.

FIG. 4 is a graph showing the measurement results of the initial impedance at each temperature during drying and moisture absorption of the polymer temperature sensitive bodies of Example 2 and Comparative Example 1.

FIG. 5 is a graph showing the measurement results of the initial impedance at each temperature during drying and moisture absorption of the polymer temperature sensitive bodies of Example 5 and Comparative Example 2.

FIG. 6 is a result of measuring a change in impedance (measurement temperature 60 ° C.) with time in a long-term aging test in which the polymer temperature sensitive bodies of Example 2 and Example 9 are left to stand in an oven at 80 ° C. for a long time. It is a graph which shows.

Claims (4)

[Claims] 1. A polymer temperature-sensitive polymer comprising a polyamide resin composition in which a conductivity-imparting agent comprising a polymer having a structure obtained by graft-polymerizing an alkylene oxide in the main chain of a polymer compound and a salt is blended with a polyamide resin. body. 2. The polymer graft product has a structure in which an alkylene oxide is graft-polymerized on a main chain of a saponified product of a copolymer of an aliphatic carboxylic acid vinyl ester and another polymerizable monomer. Polymer temperature sensor. 3. The polymer according to claim 1, wherein the polymer graft has a structure in which an alkylene oxide is graft-polymerized on the main chain of a copolymer of an acrylic monomer having a hydroxyl group and another polymerizable monomer. Temperature sensitive body. 4. The polymer graft has a structure in which alkylene oxide is graft-polymerized on the main chain of a copolymer of allyl alcohol and another polymerizable monomer.
The polymer thermosensitive body according to the above.