JPH01249851A - Acryl elastomer composition - Google Patents

Abstract

PURPOSE:To obtain the present composition consisting of a polymer of alkyl acrylate and/or alkoxyalkyl acrylate and mixture of a salt electrolyte substance comtatible with the above-mentioned polymer with a high polymer acid salt having same monovalent salt as the electrolyte substance and having excellent conductivity. CONSTITUTION:The aimed composition obtained by blending (A) polymer of alkyl acrylate having 1-8C alkyl and/or alkoxyalkyl acrylate having 2-5C alkoxyalkyl with (B) 5-100wt.%, preferably 30-50wt.% (based on the component A) of the mixture of (B1) monovalent salt electrolyte (preferably lithium perchlorate, benzylpyridium chloride, etc.) and (B2) monovalent salt (e.g., lithium salt of polystyrene sulfonic acid) of high polymer having same salt as the component B1 and preferably further (C) 20wt.% (based on the component A) of low- molecular plasticizer (preferably alkylene carbonate) having high dielectric constant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to acrylic elastomer compositions. More specifically, the present invention relates to an acrylic elastomer composition that is excellent in electrical conductivity.

[Conventional technology]

JP-A-59-206,444 describes a conductive polymer material composition in which a water-soluble inorganic salt electrolyte material and a water-soluble polymer material are blended into a base polymer material made of thermoplastic resin or rubber. ing.

However, in this composition, there is insufficient compatibility between the base polymeric substance and the water-soluble polymeric substance, and if the water-soluble polymeric substance is used in a proportion exceeding a certain level, phase separation may occur. , the mechanical strength is reduced, and for these reasons, the amount of electrolyte that can be dissociated is also restricted, and as a result, it is not possible to increase the conductivity as much as expected.

[Problem to be solved by the invention]

Therefore, the present inventors conducted various studies in search of a method for increasing the conductivity of a base polymer material in the coexistence of an electrolyte material and a water-soluble polymer material. Acrylic EX1~ not exemplified in
The acrylic elastomer was selected as the base polymer material and discovered that this acrylic elastomer has strong polarity and good compatibility with water-soluble polymer materials in the coexistence of electrolyte materials or plasticizers. It was previously discovered that this problem could be solved by
No. 904).

By the way, the acrylic elastomer is composed of an electrolyte material and a water-soluble polymer material that are compatible with the acrylic elastomer,
Preferably, the acrylic elastomer composition further contains a plasticizer, and even when the plasticizer is added, the obtained conductivity is 10-'s-em-' (20°C
, 55%R)I). This is due to reasons such as the addition of a water-soluble polymer substance with a high Tg, which increased the Tg of the entire composition, and anions acting as strong traps, which did not significantly increase the degree of dissolution and mobility. it is conceivable that.

The present invention aims to further increase the electrical conductivity of an acrylic elastomer composition, and for this purpose provides a new solid polymer electrolyte that is added to an acrylic elastomer together with an electrolyte substance.

[Means for solving R problem]

Therefore, the object of the present invention is to provide (a) an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and/or (b)
) A polymer of an alkoxyalkyl acrylate having an alkoxyalkyl group having 2 to 8 carbon atoms, and a mixture of the same monovalent salt of a salt electrolyte substance and a polymeric acid salt that are compatible with the polymer, preferably with a lower molecular weight. This is achieved by adding a high dielectric constant plasticizer thereto to form an acrylic elastomer composition.

Forming the acrylic elastomer used in the present invention (
As component a), the alkyl acrylate.

For example, methyl acrylate, ethyl acrylate, Ω-
or iso-propyl acrylate, n- or iso-
Alkyl groups with 1 to 8 carbon atoms (those with substituents such as cyano groups) such as butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, and 2-cyanoethyl acrylate. ), preferably ethyl acrylate or n-butyl acrylate.

Examples of the alkoxyalkyl acrylate of component (b) include methoxymethyl acrylate, ethoxymethyl acrylate, 2-methoxyethyl acrylate, 2-
Alkoxyalkyl acrylates having an alkoxyalkyl method having 2 to 8 carbon atoms, such as ethoxyethyl acrylate and 2-butoxyethyl acrylate, are used, and preferably 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate are used.

These components (a) and (b) are each used as a homopolymer, but generally have a polymer content of about 99.9 to 9
It is copolymerized and used at a ratio of 0 mol%, and when both components (a) and (b) are used, the former has a content of about 1% by mole.
The latter is generally used in a proportion of 0 to 90 mol %, with the latter being about 90 to 10 mol %.

A part of these components (a) and/or (b), specifically up to about 10 moles, may be substituted with other copolymerizable monomers and copolymerized. Examples of such copolymerizable monomers include vinyl chloride, vinylidene chloride, acrylonitrile, styrene, vinyl acetate, ethyl vinyl ether, butyl vinyl ether, alkyl methacrylate,
Examples include alkoxyalkyl methacrylate.

Depending on the use of the acrylic elastomer, crosslinkable groups may be introduced therein. The following crosslinking agents are used depending on the type of component forming the crosslinking point and its reactive group.

(a) Epoxy group-containing vinyl monomer allyl glycidyl ether, glycidyl acrylate,
Glycidyl methacrylate is exemplified, and examples of these crosslinking agents include polyamines such as diethylenetriamine and metaphenylenediamine, polycarboxylic acids such as adipic acid, acid anhydrides such as pyromellitic anhydride and maleic anhydride, and polyamides. and sulfonamides are used.

(b) Carboxyl group-containing vinyl monomers such as acrylic acid, methacrylic acid, and itaconic acid are exemplified, and examples of crosslinking agents for these include polyepoxides such as ethylene glycol diglycidyl ether and 1,6-hexanesiol diglycidyl ether. , 1,4-butanediol,
Polyols such as 1,1,1-trimethylolpropane are used. Instead of using these crosslinking agents, crosslinking may be performed only by heating.

(c) Reactive halogen-containing vinyl monomers 2-chloroethyl vinyl ether, monochloroacetic acid, etc. are exemplified, and crosslinking agents for these include, for example, diethylenetriamine,
Polyamines such as triethylenetetramine, polycarbamates such as hexamethylene diamine carbamate, etc. are used.

(d) Diene monomers divinylbenzene, piperylene, isoprene, pentadiene, vinylcyclohexene, chloroprene, butadiene, methylbutadiene, cyclopentadiene, methylpentadiene, ethylene glycol diacrylate, propylene glycol diacrylate, ethylene glycol dimethacrylate , propylene glycol dimethacrylate, etc. Examples of crosslinking agents include sulfur, organic peroxides such as benzoyl peroxide and dicumyl peroxide, azo compounds such as azobisisobutyronitrile, and divinylbenzene. , triallyl cyanurate, triallyl isocyanurate, etc. are used. Instead of using these crosslinking agents, crosslinking may be performed only by heating.

(e) Hydroxyl group-containing vinyl monomers Examples include hydroxyalkyl methacrylate, hydroxyalkoxy acrylate, and N-methylol acrylamide. Examples of crosslinking agents for these include polyisocyanates such as hexamethylene diisocyanate and tolylene diisocyanate, and adipine. Polycarboxylic acids such as acids, alkoxymethylmelamines such as methoxymethylmelamine, and the like are used.

(f) Amide group-containing vinyl monomers such as acrylamide and methacrylamide are exemplified, and as a crosslinking agent for these, aminoformaldehyde and the like are used, for example. Alternatively, crosslinking may be effected only by heating.

To explain the polymerization reaction of the above polymerizable monomers in terms of copolymerization reactions, the copolymerization reactions include bulk polymerization method, emulsion polymerization method, Ken 4
This may be carried out by any method such as a polymerization method or a solution polymerization method, but specifically, for example, it may be carried out as follows. In a flask equipped with a reflux condenser, a dropping funnel, and a stirrer, 100 parts by weight of solvent (approximately 5 to
98% by weight) and maintained at a predetermined temperature. In the dropping funnel, a monomer mixture of about 10 to 900
Add a solution of about 1 to 10 parts by weight of a polymerization initiator to each part by weight, and dropwise add the solution over about 0.5 to 5 hours.
Continue the reaction for ~5 hours. Under such reaction conditions, the polymerization rate is about 80 to 95%. In order to further increase the polymerization rate, add about 1 to 5 liters of polymerization initiator after dropping the monomer mixture.
By adding part by weight, the polymerization rate can be increased to 992 or more.

When such a dropwise polymerization method is adopted, there is an advantage that the copolymerization ratio of monomers having different reactivities is not much different between the start and end of polymerization, and a copolymer elastomer with a uniform composition can be obtained. In addition, when copolymerizing monomers with extremely different reactivities, it is recommended to increase the concentration of the monomer with low reactivity at the beginning of the dropwise addition and lower the concentration at the later stage of the dropwise addition to achieve a relatively uniform composition. A copolymer elastomer is obtained.

When the copolymerization reaction is carried out using a mercapto compound as a chain transfer agent in the polymerization reaction carried out in this manner, the resulting copolymer elastomer provides a crosslinked product with excellent vulcanization properties.

As the mercapto compound, ω-mercaptoalkanol, alkylmercaptan, allylmercaptan, mercaptocarbonol, dithioglycerin, trithioglycerin, etc. are used, but preferably 2-mercaptoethanol,
ω-mercaptoalkanols such as 3-mercaptopropanol and 4-mercaptobutanol are used. These mercapto compounds have approximately 0
．． It is used in a proportion of 1 to 3 molar pairs, preferably about 0.15 to 1 molar pair.

Another advantage of using these mercapto compounds is that the copolymerization ratio of the crosslinkable group-containing monomer can be increased. In general, increasing this copolymerization ratio makes gelation easier, but by using this chain transfer agent,
Even when a relatively large amount of the crosslinking group-containing monomer, about 0.1 to 10 moles, is copolymerized, the copolymerization can be achieved without gelation.

Monovalent salt electrolyte substances that are compatible with the acrylic elastomer and are added to the acrylic elastomer thus polymerized together with the polymeric acid salt include hydrohalic acid, perhalogenated oxyacid, halogenated oxyacid, Alkali metal salts and ammonium salts of primary halogenated oxyacids, tetrahalogenated boric acids, hexahalogenated phosphoric acids, trihalogenated metasulfonic acids, thiocyanic acid, nitric acid, sulfuric acid, phosphoric acid, carbonic acid, etc. Furthermore, organic carboxylates, organic sulfonates, various onium salts, quaternary ammonium salts, etc. are used, preferably perchlorates such as lithium perchlorate, quaternary ammonium salts such as benzylpyridinium chloride, and thiocyanate. Thiocyanate salts such as sodium thiocyanate and lithium thiocyanate are used.

These monovalent salt electrolyte substances are used as a mixture of this electrolyte substance and a monovalent salt of a polymeric acid having the same type of salt. The polymeric acids forming such monovalent salts include homopolymers consisting of monomer units represented by the formula % (in the formula, R1 is hydrogen or an alkyl group having 1 to 5 carbon atoms), or the above-mentioned Monomer units and any monomer unit represented by the general formula (% formula %) (wherein R2 is hydrogen, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms, or an aralkyl group) Contains a proportion of copolymers.

Examples of polymeric acids include polystyrene sulfonic acid, polymethacrylic acid, polyethylene sulfonic acid, polyacrylic acid, and the like. The degree of polymerization of the polymeric acid is 102 to 10s, preferably 103 to 10'. These polymeric acids are used as monovalent salts such as alkali metal salts such as sodium salts and lithium salts, or ammonium salts, and are preferably used as lithium salts.

The electrolyte material and the polymeric acid salt are added to the acrylic elastomer as a mixture. Polymer acid salts.

Usually stored in the form of an aqueous solution of sodium salt,
When monovalent salts other than sodium salts are used, this aqueous solution is passed through an ion exchange resin in acid form to return to the acid form, and then an aqueous solution having the same monovalent cation as the electrolyte substance to be mixed is prepared. The mixture is neutralized with water, an electrolyte is added thereto, and water is evaporated and solidified using a spray drying method or the like to form a mixture. In the case of the mixture obtained in this way, it is dried and then pulverized to form fine particles with a particle size of approximately 5 μm or less before use. When mixing the two, a water-soluble organic solvent is used and the fine particles are re-precipitated in water. You can also do it.

The electrolyte material-polymer acid salt mixture obtained in this way has a total weight range of about 1
~70 weight 2. The mixture is preferably about 10 to 50% by weight, and is used in a proportion of about 5 to 100% by weight, preferably about 30 to 50% by weight of the acrylic elastomer.

In addition to this mixture, a low molecular weight high dielectric constant plasticizer is added to the acrylic elastomer at about 20 parts by weight, preferably about 5 to 1 part by weight.
It may also be added in a proportion of 5% by weight. As such a plasticizer, any plasticizer can be used as long as it has a polarity that dissociates the electrolyte, is nonvolatile, and is compatible with the acrylic elastomer 1-mer.
Although valent or polyvalent carboxylic acid esters, triesters of phosphine oxide, sulfamide compounds, alkylene glycols or alkyl etherified products thereof may also be used, alkylene carbonate compounds such as ethylene carbonate and propylene carbonate are preferably used.

The preparation of the composition involves adding an electrolyte to the acrylic elastomer.
The polymeric acid salt mixture is added and kneaded using a roll, kneader, mixer, etc. If a plasticizer is further added, the plasticizer is added from the beginning or at this stage and kneaded.

At this time, when considering applications such as batteries and ECD elements, it is desirable to operate in a dry state to avoid moisture absorption.

However, for purposes of simply preventing static electricity, this is not necessary. Further, in the case of batteries, ECD elements, etc. that are used in a sealed state, there is no need for crosslinking.

〔Effect of the invention〕

The acrylic elastomer composition according to the present invention can have a low molecular weight high dielectric constant plasticizer added thereto, but even when it is not added, it has a good J of the order of IF5s-cm-'.
It has pentaelectricity.

〔Example〕

Next, the present invention will be described in detail with reference to examples.

Example 1 A 10% aqueous solution of poly(sodium ρ-styrene sulfonate) was passed through an ion exchange resin, Na' was replaced with 114, and then neutralized with an equivalent amount of lithium hydroxide.

After dividing this aqueous solution into three equal parts and dissolving a predetermined amount of lithium thiocyanate, fine particles having a particle size of about 3 μm or less were obtained by spray drying. These microparticles were prepared such that thiocyanic acid accounted for 1.0%, 30%, or 50% of the total weight of the polymeric acid salt solids.

The thus obtained fine particles were added to the acrylic elastomer (degree of polymerization 700) obtained by polymerizing ethyl acrylate in the presence of 2-mercaptoethanol and azobisisobutyronitrile at 30% by weight or 5% by weight.
It was added in an amount of 0% by weight and kneaded with a roll to prepare a composition. Each of these compositions was divided into three equal parts, propylene carbonate as a plasticizer was added thereto in an amount of 0% by weight, 10% by weight or 20% by weight based on the acrylic elastomer, and the mixture was kneaded with a roll to plasticize it. An agent-added composition was prepared.

The above operations were carried out carefully to avoid moisture absorption, and after drying at 50°C, 10-" Torr, for 6 hours, the conductivity was adjusted in a dry nitrogen atmosphere (20°C, frequency 5-13X The values obtained from the complex impedance plot at 10'Hz) were measured.The obtained results are based on the amount of fine particles added to the acrylic elastomer (wt%), the proportion of Li5CN in the fine particles (wt%), and the addition of plasticizer. The amounts (weight X) are shown in Table 1 below.

(Margins below) Table 1 1 30 10 0 3.2X10"'
2 10 7, I X 10-
'3 20 7.2x 10-
'4 50 0 9.2X10-'
5 10 1.8X 10-5
6 20 2.2X to-'
7 30 30 0 ], 1X10
"8 10 3, lX10-'
9 20 3, OX to-'
10 50 0 4, OXl, O-
'11, 10 4.3X10
”12 20 4.9XlO-
'13 30 50 0 2.8XIO
-'14 10 3.2xlO
-51,5203,7X 10-' 1.6 50 0 3.8XIO-
'17 1.0 7.8X],
0-518 20 8.5X1
0-' Example 2 In Example 1, lithium polyacrylate was used instead of poly(P-lithium styrene sulfonate), lithium perchlorate was used instead of lithium thiocyanate, and lithium perchlorate was used instead of ethyl acrylate homopolymer. n-butyl acrylate-2-hydroxyethyl acrylate (weight ratio 1oo
: 3) Using a copolymer (degree of polymerization: 600), the results shown in Table 2 below were obtained.

Table 2

Claims (1)

[Scope of Claims] 1. A polymer of (a) an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and/or (b) an alkoxyalkyl acrylate having an alkoxyalkyl group having 2 to 8 carbon atoms, and the polymer An acrylic elastomer composition comprising a mixture of the same monovalent salt of a salt electrolyte material and a polymeric acid salt which are compatible with each other. 2. Polymers of (a) alkyl acrylates having an alkyl group having 1 to 8 carbon atoms and/or (b) alkoxyalkyl acrylates having an alkoxyalkyl group having 2 to 8 carbon atoms, low molecular weight high dielectric constant plasticizers, and these. An acrylic elastomer composition comprising a mixture of the same monovalent salt of a salt electrolyte material and a polymeric acid salt which are compatible with at least one of the following.