JPH0476902A - Macromolecular thermistor material - Google Patents

Abstract

PURPOSE:To reduce hygroscopicity and to improve thermal resistance, electric characteristics and the like by using the specified weight parts of polyvinyl- chloride-based resin, trimellitic-acid-based plasticizer, epoxy-based plasticizer, dibasic lead sulfite and cation-based charge preventing agent. CONSTITUTION:As macromolecular thermistor materials, polyvinyl-chloride-based resin, trimellitic-acid-based plasticizer, epoxy-based plasticizer, dibasic lead sulfite, and cation-based charge preventing agent are used. The adding amount of the trimellitic-acid-based plasicizer is made to be 10-70 weight parts with respect to 100 weight parts of the polyvinyl-based resin, preferably 15-40 weight parts. The adding amount of the epoxy-based plasticizer is made to be 2-10 weight parts with respect to 100 weight parts of the polyvinyl-chloride-based resin, preferably 3-7 weight parts. The adding amount of dibasic lead sulfite, is made to be 3-15 weight parts with respect to 100 weight parts of the polyvinyl-chloride-based resin, preferably 5-10 weight parts. In this way, the electric characteristics (thermistor B constant) can be made large, and thermal resistance can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polymer thermistor material used in heating appliances such as electric carpets and electric blankets.

(Prior Art) Thermistor materials used in heating appliances such as electric carpets and electric blankets include polyamide resins (for example, Japanese Patent Application Laid-Open No. 60-248774) and vinyl chloride resins (
For example, Japanese Patent Publication No. 48-37787) is known.

Polyamide resins are widely used because they have excellent heat resistance and mechanical properties, and their electrical properties can be easily designed, but they have the disadvantage that they are highly hygroscopic and their electrical properties vary greatly depending on the moisture absorption rate.

In addition, vinyl chloride resins have poor heat resistance, are limited to use at low temperatures, and have poor electrical properties, particularly the electrical properties change due to plasticizer migration.

(Problem B to be Solved by the Invention) In view of the above drawbacks, an object of the present invention is to provide a polymer thermistor material with low hygroscopicity (excellent heat resistance, electrical properties, etc.).

(Means for Solving the Problems) The vinyl chloride resin (a) used in the present invention includes a homopolymer of vinyl chloride as well as a copolymer of a polymerizable monomer copolymerizable with vinyl chloride. . Examples of the polymerizable polymer include ethylene, propylene,
α-olefins such as 1-butylene, vinyl monomers such as vinyl acetate and vinyl stearate, styrene, α-
Styrenic monomer butyl (meth) such as methylstyrene
Examples include (meth)acrylate monomers such as acrylate, 2-ethylhexyl (meth)acrylate, and methyl methacrylate, rl-i1m maleimide monomers such as cyclohexylmaleimide and phenylmaleimide, cecyl vinyl ether, and vinylidene chloride.

If the amount of the monomer increases, the electrical properties and heat resistance necessary for a thermistor material will deteriorate, so it is preferable to copolymerize the monomer in an amount of 5% by weight or less.

Also, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate-carbon oxide copolymer, ethylene-ethyl acrylate-carbon oxide copolymer, polyurethane It may also be a graft polymer obtained by graft-polymerizing vinyl chloride or the like.

Furthermore, a chlorinated vinyl chloride resin obtained by chlorinating the above resin may also be used. These vinyl chloride resins may be used alone or in combination.
More than one species is used in combination.

As the trimellitic acid plasticizer (b) used in the present invention, any conventionally known trimellitic acid plasticizer can be used, such as tri-2-ethylhexyl trimellitate, tri-n-octyl Examples include trimellitate.

If the amount of trimellitic acid plasticizer (b) added decreases, the electrical properties (thermistor B characteristics) will decrease, and if it increases, the heat resistance will decrease.
The amount is 10 to 70 parts by weight, preferably 15 to 40 parts by weight, per 100 parts by weight.

The epoxy plasticizer (c) used in the present invention includes:
Any conventionally known epoxy plasticizer can be used,
Examples include a reaction product of epichlorohydrin and bisphenol A, epoxidized soybean oil, epoxidized linseed oil, etc., and epoxidized soybean oil is preferably used.

If the amount of epoxy plasticizer (c) added is small, the electrical properties (thermistor B characteristics) will deteriorate, and if it is too large, the electrical properties will not improve and the processing performance will deteriorate. (a) It is 2 to 10 parts by weight, preferably 3 to 7 parts by weight, per 100 parts by weight.

Dibasic lead sulfite (d) used in the present invention is added in a small amount (if the amount is added, the heat resistance will decrease, and if it is added in a large amount, the processing performance will be decreased, so it should be added to 100 parts by weight of the vinyl chloride resin (a)). , 3 to 15 parts by weight, preferably 5 to 10 parts by weight.

Examples of the cationic antistatic agent (e) used in the present invention include cyclohexylamine butyrate, cyclohexylamine wasylinate, cyclohexylamine borate, tributylamine phosphate, and cyclohexylamine phosphoric acid. Amine-based antistatic agents such as salt, monoethanolamine/butyrate, butylamine/butyrate, 1-
Hydroxyethyl-2-alkylimidazurin, 2-guanidinohenzimidazurin, 2-alkylimidazurin.
Imidacillin-based IF antistatic agents such as phosphates, 2-alkylimidapurine-ethylene oxide adducts and phosphates, ethylenediamine-propylene oxide adducts, ethylenediamine-ethylene oxide adducts, polyalkylene polyamines.
Ethylene oxide or propylene oxide adduct system antistatic iJ such as propylene oxide adduct, polyalkylene polyamine-ethylene oxide adduct, isopropanolamine-ethylene oxide adduct, didodecyldipropylammonium bromide, octylcyclohexyldimethylammonium , quaternary ammonium-based antistatic agents such as quaternary ammonium salts represented by general formula (1), and general formula (I
) are preferably used.

In the formula, R' represents an alkyl group having 4 to 10 carbon atoms;
2, R3 and R4 represent an alkyl group or a hydroxyalkyl group having 1 to 4 carbon atoms, and may be the same or different.

The amount of antistatic agent (e) to be added is 1 to 5 parts by weight per 100 parts by weight of the vinyl chloride resin (a), because if the amount is too small, the electrical properties will deteriorate, and if it is too large, the heat resistance will be reduced. Preferably it is 1.5 to 4.5 parts by weight.

The polymer thermistor material of the present invention includes the vinyl chloride resin (a), a trimellitic acid plasticizer (with), an epoxy plasticizer (c), a dibasic acid lead sulfite (d), and a cationic antistatic agent. (e), but when used as a thermistor, it is formed into a wire shape, film shape, etc. To form into a wire shape, film shape, etc., the above-mentioned vinyl chloride resin (a), trimellitic acid plasticizer (b), epoxy plasticizer (c), dibasic acid lead sulfite (d) and cationic charge are used. The composition comprising the inhibitor (e) may be molded by a molding method such as extrusion molding, calendar molding, press molding, or casting molding.

In the present invention, the above composition may further contain di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate, di-2-ethylhexyl maleate, di-2-ethylhexyl phosphate, etc. Plasticizers, lead-based stabilizers such as tribasic lead sulfate and lead stearate, tin-based stabilizers such as dialkyltin malate and dialkyltin laurate, composite stabilizers such as calcium-zinc type and barium-zinc type, lubricants, Antioxidants, fillers, processing aids, etc. may be added.

(Example) Next, the present invention will be explained in detail.

The thermistor B constant R was calculated by measuring the insulation resistance of the sample at 60°C and 80°C using the following formula.

In the formula, R is the insulation resistance value at 60°C, RO is 80°
The insulation resistance value at C, T is 333 ('K=60''C
), To indicates 353 ("K=80°C).

Heat resistance was determined by supplying the sample to a gear oven at 120°C.
Processed for 300 hours.

Examples 1 to 5, Comparative Examples 1 to 8 Predetermined amounts of vinyl chloride resin (a), trimellitic acid plasticizer ('b), and epoxy plasticizer (c) shown in Table 1
, after roll kneading a blend consisting of dibasic acid lead sulfite and cationic antistatic agent (e) at 170°C for 3 minutes,
Pressed at 175°C and 175kg/d for 7 minutes to a thickness of 1m.
m samples were obtained. After the thermistor B constant and heat resistance test of the obtained sample, the thermistor B constant was measured and shown in Table 1.

(The following is a blank space) (Effects of the Invention) Since the structure of the polymer thermistor material of the present invention is as described above, it has a large thermistor B constant and excellent heat resistance, and can be suitably used as a thermistor.

Claims (1)

[Claims] 1. (a) 100 parts by weight of vinyl chloride resin, (b) 10 to 70 parts by weight of trimellitic acid plasticizer, (c) 2 to 10 parts by weight of epoxy plasticizer; (d) 3 to 15 parts by weight of dibasic lead sulfite; and (e) 1 to 5 parts by weight of cationic antistatic agent Polymer thermistor material made of