1,1-dicyanoethylene-containing composition, cured product, laminate, and method for producing 1,1-dicyanoethylene-containing composition

Abstract

The present invention provides a 1,1-dicyanoethylene-containing composition comprising 1,1-dicyanoethylene, water, and an acidic compound (A), wherein the content of the acidic compound (A) and the content of the water in said composition is expressed by a specific relational expression (Ia): -4.00≤α≤0 (α is expressed by pKa+Log(CH2O / Ca), where pKa is the log acid dissociation constant of the acidic compound (A), CH2O is the molar concentration of the water in said composition, and Ca is the molar concentration of the acidic compound (A) in said composition).

Description

1,1-dicyanoethylene-containing composition, cured product, laminate, and method for producing 1,1-dicyanoethylene-containing composition

[0001] The present invention relates to a 1,1-dicyanoethylene-containing composition, a cured product, a laminate, and a method for producing the 1,1-dicyanoethylene-containing composition.

[0002] 1,1-dicyanoethylene is sometimes used in curable adhesives due to its excellent reactivity.

[0003] However, due to its high reactivity, the use of 1,1-dicyanoethylene requires the use of an acid stabilizer to improve storage stability. Patent Documents 1 and 2 propose the use of benzenesulfonic acid, chlorobenzenesulfonic acid, p-toluenesulfonic acid, or the like as an acid stabilizer.

[0004] Methylenemalonic acid is a compound that has high reactivity similar to 1,1-dicyanoethylene. Patent Document 3 proposes that storage stability can be improved by adding an antioxidant and an acid to methylenemalonic acid. In Patent Document 3, acetic acid is specifically used as the acid in the examples.

[0005] US Patent No. 2,665,298 US Patent No. 2,535,861 Japanese Patent Application Laid-Open No. 2008-174494

[0006] However, as a result of research by the present inventors, it was found that the methods described in Patent Documents 1, 2, and 3 have poor stability, such as generation of solids, due to excessively high acid concentrations. Furthermore, as a result of research by the present inventors, it was found that even when acetic acid described in Patent Document 3 is used, the polymerization of 1,1-dicyanoethylene may not be sufficiently suppressed in some cases.

[0007] Therefore, there remains a need for improving the storage stability of 1,1-dicyanoethylene-containing compositions and for a method for producing 1,1-dicyanoethylene-containing compositions with excellent storage stability. Furthermore, if a 1,1-dicyanoethylene-containing composition with excellent storage stability could be provided, it would be expected that cured products and laminates that do not lose their desired physical properties could be provided.

[0008] An object of the present invention is to provide a 1,1-dicyanoethylene-containing composition having excellent storage stability and a method for producing the same, as well as a cured product using the same components as the 1,1-dicyanoethylene-containing composition and a laminate including the cured product.

[0009] The present inventors conducted extensive research into why the polymerization of 1,1-dicyanoethylene cannot be sufficiently suppressed by simply adding any acidic compound to 1,1-dicyanoethylene, and found that the influence of the amounts of water and acid in a 1,1-dicyanoethylene-containing composition is a factor. The present inventors then discovered that a 1,1-dicyanoethylene-containing composition with excellent storage stability can be obtained by blending water and acid such that the molar concentrations of water and acid satisfy a specific relationship, thereby arriving at the present invention.

[0010] That is, the present invention provides the following items [1] to

[11] . [1] A 1,1-dicyanoethylene-containing composition comprising 1,1-dicyanoethylene, water, and an acidic compound (A), wherein the content of the acidic compound (A) and the content of the water in the composition satisfy the following relational formula (Ia): -4.00≦α≦0 (Ia) (In the above relational formula (Ia), α is represented by the following formula (Ib): α=pKa+Log(C Ｈ２Ｏ / C ａ ) (Ib) In the above formula (Ib), pKa is the logarithmic acid dissociation constant of the acidic compound (A). Ｈ２Ｏ is the molar concentration of the water in the composition. ａis the molar concentration of the acidic compound (A) in the composition.) [2] The 1,1-dicyanoethylene-containing composition according to [1], wherein the acidic compound (A) is selected from acidic compounds having a logarithmic acid dissociation constant pKa of -1.7 or less. [3] The 1,1-dicyanoethylene-containing composition according to [1] or [2], wherein the acidic compound (A) is at least one selected from methanesulfonic acid, sulfuric acid, p-toluenesulfonic acid, and hydrochloric acid. [4] The 1,1-dicyanoethylene-containing composition according to any one of [1] to [3], further comprising a polymerizable monomer (B). [5] The 1,1-dicyanoethylene-containing composition according to [4], wherein the polymerizable monomer (B) is at least one selected from the group consisting of ethylene, propylene, butadiene, isobutylene, isoprene, 1-hexene, 1-octene, vinyl acetate, vinyl propionate, vinyl butyrate, styrene, α-methylstyrene, p-methylstyrene, acrylic acid, methacrylic acid, alkyl acrylate esters, alkyl methacrylate esters, acrylonitrile, vinyl chloride, vinylidene chloride, vinylidene fluoride, alkyl 2-cyanoacrylate esters, alkyl 2-cyanopentadienoate esters, and dialkyl methylidenemalonate esters. [6] The 1,1-dicyanoethylene-containing composition according to [5], wherein the polymerizable monomer (B) comprises an alkyl 2-cyanoacrylate ester. [7] The 1,1-dicyanoethylene-containing composition according to [6], wherein the alkyl 2-cyanoacrylate ester is ethyl 2-cyanoacrylate. [8] The 1,1-dicyanoethylene-containing composition according to any one of [1] to [7], wherein the molar concentration of the acidic compound (A) in the composition is 1,000 mmol / L or less. [9] A cured product obtained by reacting the 1,1-dicyanoethylene-containing composition according to any one of [1] to [8].

[10] A laminate comprising a cured product obtained by reacting the 1,1-dicyanoethylene-containing composition according to any one of [1] to [8], and an adherend adhered to the cured product.

[11] A method for producing a 1,1-dicyanoethylene-containing composition, comprising the step of blending an acidic compound (A) in the composition so that the content of the acidic compound (A) in the composition and the content of water in the composition satisfy the following relational formula (Ia): -4.00≦α≦0 (Ia) (In the above relational formula (Ia), α is represented by the following formula (Ib): α=pKa+Log(C). Ｈ２Ｏ / C ａ ) (Ib) In the above formula (Ib), pKa is the logarithmic acid dissociation constant of the acidic compound (A). Ｈ２Ｏ is the molar concentration of the water in the composition. ａ is the molar concentration of the acidic compound (A) in the composition.

[0011] According to the present invention, it is possible to provide a 1,1-dicyanoethylene-containing composition having excellent storage stability and a method for producing the same. Furthermore, according to the present invention, it is possible to provide a cured product using the same components as the 1,1-dicyanoethylene-containing composition, and a laminate including the cured product.

[0012] The following describes an example of a mode for carrying out the present invention (hereinafter, sometimes referred to as "the present embodiment"). However, the embodiment described below is an example for embodying the technical idea of ​​the present invention, and the present invention is not limited to the following description. Furthermore, although preferred modes of the embodiment are shown in this specification, a combination of two or more of the individual preferred modes is also a preferred mode. For matters shown as numerical ranges, when there are several numerical ranges, the lower limit and upper limit can be selectively combined to form a preferred mode. In this specification, when a numerical range is described as "XX to YY," it means "XX or more and YY or less."

[0013] [1,1-dicyanoethylene-containing composition] The 1,1-dicyanoethylene-containing composition according to an embodiment of the present invention is a 1,1-dicyanoethylene-containing composition comprising 1,1-dicyanoethylene, water, and an acidic compound (A), wherein the content of the acidic compound (A) and the content of the water in the composition satisfy the following specific relational formula (Ia): -4.00≦α≦0 (Ia) (In the above relational formula (Ia), α is represented by the following formula (Ib): α=pKa+Log(C Ｈ２Ｏ / C ａ ) (Ib) In the above formula (Ib), pKa is the logarithmic acid dissociation constant of the acidic compound (A). Ｈ２Ｏ is the molar concentration of the water in the composition. ａ is the molar concentration of the acidic compound (A) in the composition.

[0014] In the 1,1-dicyanoethylene-containing composition, when the water content and the content of the acidic compound (A) satisfy the specific relationship (Ia), a 1,1-dicyanoethylene-containing composition having excellent storage stability can be provided. Note that the acidic compound (A) may be one type or multiple types.

[0015] (1,1-Dicyanoethylene) 1,1-dicyanoethylene may be produced according to the production method described in J. Am. Chem. Soc., 1989, 111, 9078-9081 or the production method described in U.S. Pat. No. 2,476,270. 1,1-Dicyanoethylene is preferably produced by the production method described in Production Example 1 described below. The produced 1,1-dicyanoethylene is preferably stored frozen or in the presence of an acidic compound (A) until immediately before use. Furthermore, the produced 1,1-dicyanoethylene may be stored in the presence of, for example, an aromatic solvent such as toluene or xylene; an aliphatic solvent such as hexane or heptane; a naphthenic solvent such as cyclohexane; an ester solvent such as ethyl acetate; or an ether solvent such as tetrahydrofuran or diethyl ether until immediately before use.

[0016] (Purity) The purity of 1,1-dicyanoethylene to be used in the 1,1-dicyanoethylene-containing composition according to an embodiment of the present invention is preferably 95% or more, more preferably 97% or more, even more preferably 98% or more, and still more preferably 99% or more. The purity of 1,1-dicyanoethylene can be determined, for example, by gas chromatography.

[0017] (Water Content of 1,1-Dicyanoethylene) 1,1-dicyanoethylene may contain a trace amount of water depending on its production method or purification method. Needless to say, a small trace amount of water is preferable, and it is, for example, 10,000 mmol / L or less, preferably 1,000 mmol / L or less, more preferably 100 mmol / L or less, even more preferably 50 mmol / L or less, and still more preferably 25 mmol / L or less, relative to the total amount of 1,1-dicyanoethylene. The water content of 1,1-dicyanoethylene can be quantified as the water content of the composition in the co-presence of the acidic compound (A).

[0018] (Water) The 1,1-dicyanoethylene-containing composition according to this embodiment contains water. The amount of water is the total amount of the water content of 1,1-dicyanoethylene, the water content of the acidic compound (A), and the amount of water added. Water may be added, for example, for illustration purposes in the Examples or Comparative Examples described below. Water may also be added so as to satisfy the aforementioned relationship even when the acidic compound (A) is added in excess. The amount of water (total amount) in the 1,1-dicyanoethylene-containing composition can be quantified by the method described in the Examples section described below (specifically, Karl Fischer titration).

[0019] (Acidic Compound (A)) The acidic compound (A) according to this embodiment is not limited as long as it satisfies the above-mentioned specific relational formula (Ia). Preferably, the acidic compound (A) is selected so as to satisfy the relational formula (Ia), and the amount of the selected acidic compound is determined.

[0020] From the viewpoint of satisfying the relational formula (Ia), the acidic compound (A) is preferably selected from acidic compounds having a logarithmic acid dissociation constant pKa of -1.7 or less. The logarithmic acid dissociation constant pKa of the acidic compound (A) is typically the logarithmic acid dissociation constant at room temperature in an aqueous system. For logarithmic acid dissociation constants, see Non-Patent Document 1 (pKa table by D. H. Ripin and D. A. Evans; available at https: / / depts.washington.edu / eooptic / linkfiles / evans_pKa_table.pdf). When the acidic compound (A) undergoes multi-stage dissociation, the logarithmic acid dissociation constant pKa of the first stage is typically used. The logarithmic acid dissociation constant of the acidic compound (A) not described in Non-Patent Document 1 may be determined by a method known to those skilled in the art (e.g., neutralization titration). Although not disclosed in the above Non-Patent Document 1, the pKa of p-toluenesulfonic acid monohydrate is −1.7.

[0021] The acidic compound (A) has a logarithmic acid dissociation constant pKa of −1.7 or less, and thus is capable of dissociating water (H ２ O) to form an oxonium ion (H ３ O ＋ From this viewpoint, the logarithmic acid dissociation constant pKa of the acidic compound (A) is more preferably −1.8 or less, even more preferably −1.9 or less, more preferably −2.0 or less, and even more preferably −2.1 or less.

[0022] Specific examples of the acidic compound (A) include methanesulfonic acid (pKa: -2.6), sulfuric acid (pKa: -3.0), hydrochloric acid (pKa: -8.0), nitric acid (pKa: -1.3), sulfurous acid (pKa: 1.9), and trifluoroacetic acid (pKa: -0.25). In one aspect of this embodiment, the acidic compound (A) is at least one selected from methanesulfonic acid, sulfuric acid, trifluoroacetic acid, hydrochloric acid, and nitric acid, and is preferably at least one selected from methanesulfonic acid, sulfuric acid, and hydrochloric acid. In another aspect of this embodiment, the acidic compound (A) is at least one selected from methanesulfonic acid, sulfuric acid, p-toluenesulfonic acid, and hydrochloric acid.

[0023] (Specific Relational Expression) In this embodiment, the above-mentioned relational expression is rewritten as follows: −4.00≦α≦0 (Ia) (In the above relational expression (Ia), α is expressed by the following formula (Ib): α=pK ａ + Log(C Ｈ２Ｏ / C ａ ) (Ib) In the above formula (Ib), pKa is the logarithmic acid dissociation constant of the acidic compound (A). Ｈ２Ｏ is the molar concentration of the water in the composition. ａ is the molar concentration of the acidic compound (A) in the composition.

[0024] In order to ensure that the desired effects of the present invention are achieved, α in the above relational formula (Ia) is preferably −3.90 or more, more preferably −3.80 or more, even more preferably −3.70 or more, and still more preferably −3.60 or more.

[0025] When there are two types of acidic compounds (A), the above formula (Ib) is preferably interpreted as the following formula (Ib-2): α = {C ａ１ ×K ａ１ / (K ａ１ +10 α )} + {C ａ２ ×K ａ２ / (K ａ２ +10 α )} (Ib-2) In the above formula (Ib-2), C ａ１ is the molar concentration of the first acidic compound. ａ１ is the acid dissociation constant of the first acidic compound. ａ２ is the molar concentration of the second acidic compound. ａ２ is the acid dissociation constant of the second acidic compound. When three or more types of acidic compounds (A) are used, the sum of the right-hand sides can be calculated in the same manner as in the above formula (Ib-2), taking into consideration the molar concentration and acid dissociation constant of each acidic compound.

[0026] In the present embodiment, the reason why a 1,1-dicyanoethylene-containing composition having excellent storage stability can be obtained by making the content of the acidic compound (A) and the content of the water satisfy the specific relational formula (Ia) is not clear, but the present inventors presume it as follows.

[0027] Water contained in the 1,1-dicyanoethylene-containing composition forms oxonium ions, thereby stabilizing 1,1-dicyanoethylene in the composition. This is thought to inhibit polymerization of 1,1-dicyanoethylene and suppress an increase in viscosity or the formation of precipitates (these phenomena are demonstrated in the Examples section). Here, the oxonium ion-forming ability is possessed by the acidic compound (A) in the 1,1-dicyanoethylene-containing composition. Thus, there is a close relationship between the water content and the acidic compound (A). This fact was first clarified by the examples in the Examples section described below. The higher the water content, the more efficiently water can be converted to oxonium ions by increasing the content of the acidic compound (A), selecting an acidic compound (A) with excellent oxonium ion-forming ability, such as an acidic compound with a smaller pKa value as described above, or by satisfying both of these. On the other hand, if the content of the acidic compound (A) is too high, colored precipitates derived from 1,1-dicyanoethylene tend to form in the 1,1-dicyanoethylene-containing composition. This is thought to be due to the occurrence of a side reaction in which the acidic compound (A) reacts with cyano groups. Since the pKa value of a strongly acidic compound such as sulfuric acid decreases as the amount of water in the composition decreases (the absolute value of the pKa value increases), a low water content relative to the acid results in increased reactivity with cyano groups, presumably accelerating the side reaction. From the above, it can be said that the acidic compound (A) must have a relatively low pKa value, and must be present in an amount appropriate to the water content, i.e., an amount sufficient to convert water to oxonium ions, but not excessive from the perspective of coloration suppression. However, since the amount of precipitates can be minimized as long as 1,1-dicyanoethylene can be stabilized, the issue of coloration suppression can be considered secondary. As a result of such considerations, in this embodiment, the above relationship is expressed using the pKa and molar concentration of the acidic compound (A).

[0028] (Content of Acidic Compound (A)) The content of the acidic compound (A) is not limited as long as the above-mentioned relational formula is satisfied. The mass ratio of the content of the acidic compound (A) to the content of water is, for example, within the range of 1:0.001 to 0.0001:1, preferably within the range of 1:0.01 to 0.01:1, more preferably within the range of 1:0.1 to 0.1:1, and even more preferably within the range of 1:0.1 to 0.1:0.6. From the viewpoint of satisfying the above-mentioned relational formula and converting as much water as possible into oxonium ions, the content of the acidic compound (A) is preferably the same as or greater than the content of water (i.e., (C Ｈ２Ｏ / C ａ ) is preferably 1 or less.

[0029] The molar concentration of the acidic compound (A) in the 1,1-dicyanoethylene-containing composition is not limited as long as the above-mentioned relationship is satisfied. From the viewpoint of suppressing coloration of the 1,1-dicyanoethylene-containing composition, the molar concentration of the acidic compound (A) in the 1,1-dicyanoethylene-containing composition is preferably 1,000 mmol / L or less, more preferably 500 mmol / L or less, even more preferably 150 mmol / L or less, and still more preferably 20 mmol / L or less. On the other hand, from the viewpoint of the storage stability of the 1,1-dicyanoethylene-containing composition, the molar concentration of the acidic compound (A) in the 1,1-dicyanoethylene-containing composition is preferably 0.001 mmol / L or more.

[0030] (Water Content of Acidic Compound (A)) The acidic compound (A) may contain a trace amount of water depending on its production method or purification method. The trace amount of water can be quantified as the water content of the composition in the presence of 1,1-dicyanoethylene.

[0031] (Component (B): Polymerizable Monomer) The 1,1-dicyanoethylene-containing composition according to this embodiment may further contain a polymerizable monomer (B). 1,1-dicyanoethylene is excluded from the polymerizable monomer (B). The polymerizable monomer (B) is preferably reactive with 1,1-dicyanoethylene. The polymerizable monomer (B) may be one type or multiple types. The polymerizable monomer (B) may be a radical polymerizable monomer or an anion polymerizable monomer.

[0032] Examples of the polymerizable monomer (B) include ethylene, propylene, butadiene, isobutylene, isoprene, 1-hexene, 1-octene, vinyl acetate, vinyl propionate, vinyl butyrate, styrene, α-methylstyrene, p-methylstyrene, acrylic acid, methacrylic acid, alkyl acrylates such as butyl acrylate, alkyl methacrylates such as methyl methacrylate and dodecyl methacrylate, acrylonitrile, vinyl chloride, vinylidene chloride, vinylidene fluoride, alkyl 2-cyanoacrylates, alkyl 2-cyanopentadienoates, and dialkyl methylidenemalonates. Of these, from the viewpoint of excellent reactivity with 1,1-dicyanoethylene, it is preferable that the polymerizable monomer (B) is an alkyl 2-cyanoacrylate, and it is more preferable that the alkyl 2-cyanoacrylate is ethyl 2-cyanoacrylate.

[0033] The method for producing the polymerizable monomer (B) is not particularly limited, and known methods can be used alone or in combination to produce the polymerizable monomer (B). The polymerizable monomer (B) may be a commercially available product.

[0034] (Other Components) The 1,1-dicyanoethylene-containing composition according to this embodiment may contain one or more other components. Examples of such other components include thickeners, dehydrating agents, radical polymerization inhibitors, plasticizers, pigments, organic solvents, rubber, organic fillers, and inorganic fillers. The other components can be used in amounts that do not impair the intended effects of the present invention. The rubber may function as an organic filler. The inorganic filler may function as a thickener. From the viewpoints of heat resistance and moisture resistance, it is preferable that the 1,1-dicyanoethylene-containing composition according to this embodiment does not contain ethyl 2-cyanoacrylate, butyl 2-cyanoacrylate, or diethyl methylidenemalonate.

[0035] (Content of Each Component) When the entire 1,1-dicyanoethylene-containing composition according to the embodiment is taken as 100% by mass, the total amount of the monomers (1,1-dicyanoethylene and the polymerizable monomer (B) used as needed) is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, from the viewpoint of obtaining desired physical properties. When the polymerizable monomer (B) is used, the mass ratio of 1,1-dicyanoethylene to the polymerizable monomer (B) is not particularly limited, but may be 99:1 to 1:99, 80:20 to 20:80, or 70:30 to 30:70.

[0036] [Method for Producing 1,1-Dicyanoethylene-Containing Composition] A method for producing a 1,1-dicyanoethylene-containing composition according to an embodiment of the present invention is a method for producing a 1,1-dicyanoethylene-containing composition, comprising a step (blending step) of blending an acidic compound (A) in the composition so that the content of the acidic compound (A) in the composition and the content of water in the composition satisfy the following relational formula (Ia): -4.00≦α≦0 (Ia) (In the above relational formula (Ia), α is represented by the following formula (Ib): α=pKa+Log(C Ｈ２Ｏ / C ａ ) (Ib) In the above formula (Ib), pKa is the logarithmic acid dissociation constant of the acidic compound (A). Ｈ２Ｏ is the molar concentration of the water in the composition. ａis the molar concentration of the acidic compound (A) in the composition.

[0037] By employing the above-described production method, it is possible to produce the 1,1-dicyanoethylene-containing composition according to the embodiment described above, i.e., a 1,1-dicyanoethylene-containing composition having excellent storage stability. The blending step may or may not involve stirring. Furthermore, in the blending step, if the content of water is known, it is preferable to determine the type and amount of the acidic compound (A) so as to satisfy the above-described relational formula. If the amount of acidic compound (A) is excessive (or must be excessive) in terms of the above-described relational formula, water is blended so as to satisfy the above-described relational formula. That is, the blending step may be a step of blending water and the acidic compound (A) so that the content of the acidic compound (A) and the content of the water in the composition satisfy the above-described relational formula (Ia).

[0038] (Applications) The 1,1-dicyanoethylene-containing composition according to this embodiment can be used as an (instant) adhesive. Applications of such adhesives include general household adhesives, medical applications, hemostatic adhesives, lamination, bookbinding, shoe assembly, automobile parts, air conditioning systems, components for electrical or electronic devices or other durable consumer goods, assembly of components used in the building industry (e.g., insulating applications, thermal and / or acoustic applications), packaging, die-bonding applications, wound closure, surgical suturing, medical device applications, and all types of labeling, eyelash extension adhesives, cosmetic adhesives, etc. While instant adhesives containing 2-ethyl cyanoacrylate as a primary ingredient are widely known, 2-ethyl cyanoacrylate has the drawback of being poor in heat resistance and moisture resistance, and these instant adhesives suffer from poor heat resistance and moisture resistance. On the other hand, 1,1-dicyanoethylene has excellent heat resistance and moisture resistance, and the adhesive using the 1,1-dicyanoethylene-containing composition according to the present invention has excellent heat resistance and moisture resistance.

[0039] The 1,1-dicyanoethylene-containing composition according to this embodiment can also be used as a coating material. Applications of such coating materials include film capacitors, insulating layers for EL devices, electrostatic induction conversion elements, sensors (e.g., touch sensors, vibration sensors, biosensors, tire sensors (particularly sensors installed on the inner surface of tires)), actuators, touch panels, haptic devices, vibration power generation devices (e.g., vibration power generation floors, vibration power generation tires), speakers, microphones, vibration-damping sheets, hollow fiber membranes for water purification, and resist films. An example of a haptic device is a device that has the function of providing tactile feedback to a user.

[0040] [Cured Product] The cured product according to an embodiment of the present invention is a cured product obtained by reacting the above-described 1,1-dicyanoethylene-containing composition. Specifically, the cured product according to an embodiment of the present invention is a cured product obtained by reacting a composition containing 1,1-dicyanoethylene, water, and an acidic compound (A); or a composition containing 1,1-dicyanoethylene, water, an acidic compound (A), and a polymerizable monomer (B), wherein the content of the acidic compound and the content of the water in the composition satisfy the following relational formula (Ia): -4.00≦α≦0 (Ia) (In the above relational formula (Ia), α is represented by the following formula (Ib): α=pK １ + Log(C Ｈ２Ｏ / C ａ ) (Ib) In the above formula (Ib), pK １ is the logarithmic acid dissociation constant of the acidic compound (A). Ｈ２Ｏ is the molar concentration of the water in the composition. ａ is the molar concentration of the acidic compound (A) in the composition.

[0041] (Monomer Mixture) 1,1-dicyanoethylene may or may not constitute a monomer mixture together with the polymerizable monomer (B). In the case of a monomer mixture, the 1,1-dicyanoethylene and the polymerizable monomer (B) are the same as the 1,1-dicyanoethylene and the polymerizable monomer (B), respectively, that may be contained in the 1,1-dicyanoethylene-containing composition according to the present embodiment described above. The monomer mixture may contain one or more other components. Such other components are also the same as the other components that may be contained in the 1,1-dicyanoethylene-containing composition described above.

[0042] (Lewis Basic Compound) In addition to water, a Lewis basic compound other than water may or may not be used. The Lewis basic compound usually functions as a polymerization catalyst for 1,1-dicyanoethylene or the above-mentioned monomer mixture. Examples of the Lewis basic compound include alcohols and alkylamines.

[0043] Examples of alcohols include methanol, ethanol, and propanol.

[0044] Examples of alkylamines include tertiary amines such as trimethylamine, triethylamine, tripropylamine, triisopropylamine, N,N-dimethylethylamine, N,N-dimethylpropylamine, and N,N-dimethylisopropylamine.

[0045] (Other Additives) The cured product according to this embodiment may contain at least one additive selected from the group consisting of thickeners (e.g., organic thickeners, inorganic thickeners such as silica), dehydrating agents (e.g., carboxylic acid anhydrides such as acetic anhydride, cyclic sulfonic acid esters such as propane sultone, and phosphoric acid anhydrides such as diphosphorus pentaoxide), radical polymerization inhibitors (e.g., phenolic compounds, quinone compounds, stable radical compounds, metal salts), plasticizers (e.g., ester compounds such as phthalates and adipates), rubbers (e.g., natural rubber, styrene-butadiene rubber, hydrogenated styrene-butadiene rubber, acrylic rubber, nitrile rubber, hydrogenated nitrile rubber, etc.), pigments, and fillers (e.g., inorganic fillers, organic fillers), in an amount that does not excessively impair the intended effects of the present invention. Specific examples of organic thickeners include polymeric compounds such as ethylene-vinyl acetate copolymers, (meth)methyl acrylate resins, polystyrene resins, (modified) cellulose resins, and acrylonitrile resins. Specific examples of phenolic compounds include BHT (dibutylhydroxytoluene). An example of a quinone compound is hydroquinone. Specific examples of stable radical compounds include DPPH (2,2-diphenyl-1-picrylhydrazyl) and TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl). The inorganic thickener may function as an inorganic filler. The radical polymerization inhibitors mentioned above exclude the phenolic compounds. The rubber may function as an organic filler. Furthermore, curing accelerators such as polyethylene glycol derivatives, crown ethers, and calixarene may be added to improve adhesion speed. Furthermore, fillers, elastomers, thixotropy-imparting agents, adhesion-imparting agents, crosslinking agents, fragrances, and the like may be added depending on the purpose.

[0046] (Method for Producing Cured Product) The method for producing the cured product is not particularly limited. For example, the cured product can be obtained by mixing the above-mentioned monomer mixture and a Lewis basic compound at room temperature (23°C).

[0047] The amount of the Lewis basic compound is not particularly limited, but is preferably 0.001 to 1.0 part by mass, and more preferably 0.01 to 0.5 part by mass, relative to 100 parts by mass of the monomer mixture. When the content of the Lewis basic compound is within this range, the monomer mixture reacts quickly.

[0048] (Uses) The cured product according to this embodiment may be a cured product of an (instant) adhesive. Uses of the adhesive are as described above.

[0049] The cured product according to this embodiment may be a coating material, the uses of which are as described above.

[0050] [Laminate] A laminate according to an embodiment of the present invention is a laminate comprising a cured product obtained by reacting the 1,1-dicyanoethylene-containing composition described above, and an adherend adhered to the cured product. The laminate according to an embodiment of the present invention may be a laminate comprising the cured product according to the embodiment described above and an adherend adhered to the cured product. There are no particular restrictions on the layer structure, but the cured product may be formed on one adherend, or the cured product may be located between two adherends. By having the cured product between the two adherends, the adherends can be firmly bonded to each other.

[0051] The adherend used in the laminate of the present invention is not particularly limited, and examples thereof include synthetic resins, metals, ceramics, and fabrics. Examples of synthetic resins include polyolefin resins such as polyethylene, polypropylene, copolymers of ethylene and one or more α-olefins having 3 to 20 carbon atoms (e.g., propylene, 1-butene, 1-pentene, 1-hexene), ethylene-propylene-diene copolymers (EPDM), ethylene-vinyl acetate copolymers, and ethylene-acrylic acid copolymers, polyurethane resins, polyamide resins, polyester resins, polycarbonate resins, vinyl chloride resins, acrylonitrile butadiene styrene rubber, natural rubber, butadiene rubber, styrene butadiene rubber, and acrylonitrile butadiene rubber. Examples of metals include steel plates such as stainless steel plates, cold-rolled steel plates, and galvanized steel plates, copper, aluminum, and magnesium alloys.

[0052] There is no particular limitation on the thickness of the adherends constituting the laminate. On the other hand, from the viewpoint of firmly bonding the adherends together, the thickness of the layer containing the cured product is preferably 0.01 to 2.0 mm, more preferably 0.015 to 1.5 mm, and even more preferably 0.02 to 1.2 mm.

[0053] Although there are no particular limitations on the method for producing the laminate, it is preferable to produce the laminate by the laminate production method of the present invention, which includes a bonding step of bonding a first adherend and a second adherend via the cured product. There are no particular limitations on the method for bonding the first adherend and the second adherend with the 1,1-dicyanoethylene-containing composition, but for example, the first adherend and the second adherend can be bonded by applying the 1,1-dicyanoethylene-containing composition to one adherend, placing the other adherend on top of it, and curing the composition.

[0054] The method for applying the 1,1-dicyanoethylene-containing composition to an adherend is not particularly limited, and examples thereof include spin coating, spray coating, bar coating, knife coating, roll coating, roll knife coating, blade coating, die coating, and gravure coating.

[0055] The amount of the 1,1-dicyanoethylene-containing composition to be applied to the adherend is not particularly limited, but is preferably 0.01 to 3.0 μL / mm ２ It is preferable that the concentration is 0.05 to 2.5 μL / mm ２ More preferably, it is 0.1 to 2.0 μL / mm ２ When the coating amount is equal to or greater than the lower limit, the adherends can be firmly bonded to each other, whereas when the coating amount is equal to or less than the upper limit, the two can be bonded with an appropriate amount.

[0056] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. [1,1-dicyanoethylene-containing composition] [Components] The components used in the examples and comparative examples are as follows.

[0057] <1,1-dicyanoethylene> 1,1-dicyanoethylene: 1,1-dicyanoethylene (purity 99%) produced according to Production Example 1 below.

[0058] (Production Example 1: Production of 1,1-dicyanoethylene) 1,1-dicyanoethylene was produced as follows. 1,1,3,3-tetracyanopropane was synthesized from malononitrile in a yield of 73% by the production method described in J. Am. Chem. Soc., 1989, 111, 9078-9081. The resulting crystalline 1,1,3,3-tetracyanopropane was mixed with diphosphorus pentoxide and subjected to thermal decomposition at 180°C to obtain a crude product of 1,1-dicyanoethylene (yield: 60%). The crude product was purified by distillation under reduced pressure (480 Pa) to obtain 1,1-dicyanoethylene with a purity of 99%.

[0059] <Water> Water: Ion-exchanged water

[0060] <Acidic Compounds (A)> (A1): methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd. (purity >99.0%)) (pKa = -2.6) (A2): sulfuric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. (purity: 96 to 98%)) (pKa = -3.0) (A3): acetic acid (manufactured by Kanto Chemical Co., Ltd. (purity >99.0%)) (pKa = 4.8) (A4): trifluoroacetic acid (manufactured by Tokyo Chemical Industry Co., Ltd. (purity >99.0%)) (pKa = -0.25) (A5): p-toluenesulfonic acid (p-toluenesulfonic acid monohydrate) (derived from Tokyo Chemical Industry Co., Ltd. (purity >98.0%)) (pKa = -2.8)

[0061] <Polymerizable Monomers> (B1) Ethyl 2-cyanoacrylate (manufactured by Sigma-Aldrich (purity > 99.9%)) (B2) Methyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd. (purity > 99.8%)) (B3) Styrene (manufactured by Tokyo Chemical Industry Co., Ltd. (purity > 99.0%)) (B4) Vinyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd. (purity > 99.0%))

[0062] [Evaluation Method] The liquid 1,1-dicyanoethylene-containing compositions obtained in the Examples and Comparative Examples were used as samples and evaluated as follows.

[0063] <Storage Stability> (Storage Test) Three 1 mL samples were placed in 10 mL high-density polyethylene containers, which were then sealed. A mark was attached to the side of each container at a position corresponding to the sample liquid level. The state of the sample in each container was visually observed immediately before the start of the storage test. The three containers were then left to stand in a 50% humidity environment for 6 hours at 70°C, 24 hours at 70°C, and 48 hours at 70°C, respectively. The storage test was conducted in this manner.

[0064] (Observation) Then, each container was inverted, and 5 seconds after the inversion was completed, the state of the sample in the container was visually observed. The observation results were divided into the following three scores. Score "1": 90% or more by volume of the sample in the container exceeded the mark when viewed from the side. This meant that the sample maintained sufficient fluidity, similar to that immediately before the start of the storage test (0 minutes). Score "2": Although 10% or more by volume of the sample in the container exceeded the mark when viewed from the side, 90% or more by volume did not exceed the mark when viewed from the side. This meant that the fluidity of the sample had decreased (thickened) compared to immediately before the start of the storage test (0 minutes). Score "3": Only less than 10% by volume of the sample in the container exceeded the mark when viewed from the side. This meant that the polymerization of 1,1-dicyanoethylene had progressed, and solidification of the sample had progressed.

[0065] (Evaluation) Subsequently, the samples in the three containers were subjected to a 70°C storage test and evaluated based on the three observation results according to the following criteria: "A": The total score was 3. "B": The total score was 4 to 7. "C": The total score was 8 to 9.

[0066] <Colorability> (Observation) In the <Storage Test>, the color of the sample in the container subjected to the storage test at 70°C for 48 hours was visually observed. The observed color of the sample was classified into four grades: "transparent," "light yellow," "yellow," and "yellowish brown." Note that "yellow" means that the color was darker than "light yellow" and lighter than "yellowish brown."

[0067] (Evaluation) Subsequently, based on the observation results, evaluation was performed according to the following criteria: "A": "Transparent" "B": "Light yellow" "C": "Yellow" "D": "Yellowish brown"

[0068] <Overall Evaluation of Storage Stability and Colorability> The evaluation results of the above <Storage Stability> and the evaluation results of the above <Colorability> were comprehensively evaluated according to the following criteria. "A": The evaluation result of storage stability was "A" or "B", and the evaluation result of colorability was "A". "B": The evaluation result of storage stability was "A" or "B", and the evaluation result of colorability was "B" or "C". "C": The evaluation result of storage stability was "C", or the evaluation result of colorability was "D".

[0069] (molar concentration C of the acidic compound (A) in the composition ａ The molar concentration of the acidic compound (A) used in the examples and comparative examples was determined by ion chromatography (IC) according to the following method. This method can also be used to determine the molar concentration of two types of acidic compound (A).

[0070] First, 0.1 g of the 1,1-dicyanoethylene-containing composition was added to 99.9 g of an ion chromatography eluent (a mixed aqueous solution of 0.6 mmol / L sodium carbonate and 12 mmol / L sodium bicarbonate) to obtain a solution. The obtained solution was stirred for one day. It was then filtered through a filter (0.22 μm, made of PTFE). This yielded a measurement sample solution. The measurement sample solution was measured using the following ion chromatography measurement apparatus under the following measurement conditions. The molar concentration of the acidic compound (A) contained in the 1,1-dicyanoethylene-containing composition was quantified from a calibration curve prepared using the acidic compound (A).

[0071] (Ion Chromatography Measurement Apparatus and Measurement Conditions) Apparatus name: Shimadzu Corporation Liquid Chromatograph / 10A Series Column: Shim-pack IC-SA2 (inner diameter 4.0 mm, length 250 mm) Measurement temperature: 40°C Eluent: the above eluent

[0072] Example 1 A 1,1-dicyanoethylene-containing composition X1 was prepared by mixing 100 g (corresponding to 100 parts by mass) of the 1,1-dicyanoethylene produced in Production Example 1 with 0.00010 parts by mass of sulfuric acid (component (A2)) under nitrogen. The water content of the prepared 1,1-dicyanoethylene-containing composition X1 was determined to be 0.055 mmol / L by a water content measurement method in accordance with JIS K0068:2001, specifically, by coulometric titration of the Karl Fischer titration method. The molar concentration of component (A2) in the 1,1-dicyanoethylene-containing composition was quantified by the above-mentioned method (IC method), and was found to be 0.010 mmol / L. The prepared 1,1-dicyanoethylene-containing composition was sealed in a high-density polyethylene container and stored in an environment with a water concentration of 0.3 ppm. The stored 1,1-dicyanoethylene-containing composition X1 was subjected to the above-described evaluations of storage stability and coloration, as well as an overall evaluation. The results are shown in Table 1.

[0073] Example 2 A first 1,1-dicyanoethylene-containing composition was prepared by mixing 0.10 parts by mass of methanesulfonic acid (component (A1)) with 100 g (corresponding to 100 parts by mass) of the 1,1-dicyanoethylene produced in Production Example 1 under nitrogen. The water content and molar concentration of the component (A1) of the first 1,1-dicyanoethylene-containing composition were determined in the same manner as in Example 1. Next, ion-exchanged water was mixed with the first 1,1-dicyanoethylene-containing composition to obtain a second 1,1-dicyanoethylene-containing composition 2. As a result, the water content (parts by mass and molar concentration) and molar concentration of the component (A1) of the second 1,1-dicyanoethylene-containing composition were as shown in Table 1. The prepared second 1,1-dicyanoethylene-containing composition X2 was sealed in a high-density polyethylene container and stored in an environment with a water concentration of 0.3 ppm. The stored second 1,1-dicyanoethylene-containing composition X2 was used to evaluate storage stability and coloration, as well as to perform an overall evaluation, in the same manner as in Example 1. The results are shown in Table 1.

[0074] Example 3, Examples 5 to 11, Examples 14 to 15, Comparative Examples 1 to 6 Second 1,1-dicyanoethylene-containing compositions X3, X5 to X11, X14, X15, and Y1 to Y6 were prepared in the same manner as in Example 2 so as to have the formulations shown in Tables 1 and 2. The prepared second 1,1-dicyanoethylene-containing compositions X3, X5 to X11, X14 to X15, and Y1 to Y6 were stored in the same manner as in Example 2. The stored second 1,1-dicyanoethylene-containing compositions X3, X5 to X11, X14 to X15, and Y1 to Y6 were used to evaluate storage stability and colorability, as well as to perform an overall evaluation, in the same manner as in Example 2. The results are shown in Tables 1 and 2.

[0075] Examples 4, 12, and 13 1,1-dicyanoethylene-containing compositions X4, X12, and X13 were prepared in the same manner as in Example 1 so as to have the formulations shown in Tables 1 and 2. The prepared 1,1-dicyanoethylene-containing compositions were stored in the same manner as in Example 1. The stored 1,1-dicyanoethylene-containing compositions X4, X12, and X13 were used to evaluate storage stability and colorability, as well as to perform an overall evaluation, in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[0076] Example 16 A first 1,1-dicyanoethylene-containing composition was prepared by mixing, under nitrogen, 100 g (corresponding to 100 parts by mass) of the 1,1-dicyanoethylene produced in Production Example 1 with p-toluenesulfonic acid monohydrate so that the p-toluenesulfonic acid component (A4) was 0.001 parts by mass. The water content and molar concentration of the (A4) component of the first 1,1-dicyanoethylene-containing composition were determined in the same manner as in Example 1. Next, ion-exchanged water was mixed with the first 1,1-dicyanoethylene-containing composition to obtain a second 1,1-dicyanoethylene-containing composition X16. As a result, the water content (parts by mass and molar concentration) and molar concentration of the (A4) component of the second 1,1-dicyanoethylene-containing composition were as shown in Table 2. The prepared second 1,1-dicyanoethylene-containing composition X16 was sealed and stored in a high-density polyethylene container in an environment with a moisture concentration of 0.3 ppm. The stored second 1,1-dicyanoethylene-containing composition X16 was used to evaluate storage stability and colorability, as well as to perform an overall evaluation, in the same manner as in Example 1. The results are shown in Table 2.

[0077] Example 17, Comparative Example 7 1,1-dicyanoethylene-containing compositions X17 and Y7 were prepared in the same manner as in Example 12 so as to have the formulations shown in Table 2. The prepared 1,1-dicyanoethylene-containing compositions X17 and Y7 were stored in the same manner as in Example 1. Using the stored 1,1-dicyanoethylene-containing compositions X17 and Y7, evaluations of storage stability and colorability, as well as an overall evaluation, were carried out in the same manner as in Example 1. The results are shown in Table 2.

[0078] Examples 18 to 35, Comparative Examples 8 to 19 Second 1,1-dicyanoethylene-containing compositions X18 to 35 and Y8 to 19 were prepared in the same manner as in Example 2 so as to have the formulations shown in Tables 3 and 4. The prepared second 1,1-dicyanoethylene-containing compositions X18 to 35 and Y8 to 19 were stored in the same manner as in Example 2. The stored second 1,1-dicyanoethylene-containing compositions X18 to 35 and Y8 to 19 were used to evaluate storage stability and colorability, as well as to perform an overall evaluation, in the same manner as in Example 2. The results are shown in Tables 3 and 4.

[0079] Reference Examples 1 to 4 Second ethyl 2-cyanoacrylate-containing compositions Z1 to Z4 were prepared in the same manner as in Example 2 so as to have the formulations shown in Table 5. The prepared second ethyl 2-cyanoacrylate compositions Z1 to Z4 were stored in the same manner as in Example 2. Using the stored second ethyl 2-cyanoacrylate-containing compositions Z1 to Z4, evaluations of storage stability and colorability, as well as an overall evaluation, were performed in the same manner as in Example 2. The results are shown in Table 5.

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] It is clear from Tables 1 and 2 that the 1,1-dicyanoethylene-containing compositions of Examples 1 to 17 had superior storage stability compared to the 1,1-dicyanoethylene-containing compositions of Comparative Examples 1 to 7. It is also clear from Comparative Examples 3, 4, 5, and 6 that it is difficult to obtain a 1,1-dicyanoethylene-containing composition with excellent storage stability when α exceeds 0. Furthermore, it is clear that when the molar concentration of the acidic compound is high relative to the molar concentration of water, as in Examples 10, 13, and 14, the evaluation of colorability tended to be slightly inferior to that of Examples 1 to 9.

[0086] It can be seen from Tables 3 and 4 that the 1,1-dicyanoethylene-containing compositions of Examples 18 to 35 were superior in storage stability and colorability even when containing polymerizable monomer (B) compared to the 1,1-dicyanoethylene-containing compositions of Comparative Examples 8 to 19. Furthermore, as shown in Reference Examples 1 to 4 (Table 5), compositions not containing 1,1-dicyanoethylene were superior in storage stability and colorability compared to compositions containing 1,1-dicyanoethylene such as Comparative Examples 1 to 3 and Example 10, demonstrating that these properties are unique to 1,1-dicyanoethylene-containing compositions.

[0087] [Laminate] [Adherend] Steel plate (manufactured by Standard Test Piece Co., Ltd., length 25 mm, width 100 mm, thickness 1.6 mm) Aluminum plate (manufactured by Standard Test Piece Co., Ltd., length 25 mm, width 100 mm, thickness 1.6 mm) Polyvinyl chloride (PVC) plate (manufactured by Nippon Test Panel Co., Ltd., length 25 mm, width 100 mm, thickness 2.0 mm)

[0088] [Measurement Method] Using the laminates obtained in the Examples and Comparative Examples as samples, the tensile shear adhesive strength was measured as follows.

[0089] <Evaluation of Tensile Shear Adhesive Strength> The tensile shear adhesive strength of the laminate was measured at 25° C. and 25% RH using a universal material testing machine Model 5969 (manufactured by Instron) at a pulling rate of 20 mm / min.

[0090] Examples 36 to 44, Comparative Examples 20 to 22 100 μL of a 1,1-dicyanoethylene-containing composition shown in Table 6 was applied to an area of ​​12.5 mm x 25 mm of an adherend (1) shown in Table 6, and an adherend (2) shown in Table 6 was placed on the applied surface. The 1,1-dicyanoethylene-containing composition was then allowed to stand for one day in an environment of room temperature (23°C) and humidity (50%) to cure, thereby bonding adherends (1) and (2) to obtain a laminate. Tensile shear adhesive strength was measured using the resulting laminate. The results are shown in Table 6.

[0091]

[0092] Table 6 shows that the laminates obtained by curing the 1,1-dicyanoethylene-containing compositions of Examples 36 to 44 had superior tensile shear adhesive strength compared to the laminates obtained by curing the 1,1-dicyanoethylene-containing compositions of Comparative Examples 20 to 22.

[0093] Furthermore, according to the present examples, a 1,1-dicyanoethylene-containing composition having excellent storage stability and a method for producing the same can be provided, and it has been found that it is expected that the deterioration of physical properties resulting from the loss of storage stability of the 1,1-dicyanoethylene-containing composition can also be suppressed in cured products and laminates thereof.

Claims

1. A 1,1-dicyanoethylene-containing composition comprising 1,1-dicyanoethylene, water, and an acidic compound (A), wherein the content of the acidic compound (A) and the content of the water in the composition satisfy the following relational formula (Ia): -4.00≦α≦0 ... (Ia) (In the above relational formula (Ia), α is represented by the following formula (Ib): α=pKa+Log(C Ｈ２Ｏ / C ａ In the above formula (Ib), pKa is the logarithmic acid dissociation constant of the acidic compound (A). Ｈ２Ｏ is the molar concentration of the water in the composition. ａ is the molar concentration of the acidic compound (A) in the composition.

2. The 1,1-dicyanoethylene-containing composition according to claim 1, wherein the acidic compound (A) is selected from acidic compounds having a logarithmic acid dissociation constant pKa of -1.7 or less.

3. The 1,1-dicyanoethylene-containing composition according to claim 1, wherein the acidic compound (A) is at least one selected from the group consisting of methanesulfonic acid, sulfuric acid, p-toluenesulfonic acid, and hydrochloric acid.

4. The 1,1-dicyanoethylene-containing composition according to claim 1, further comprising a polymerizable monomer (B).

5. The 1,1-dicyanoethylene-containing composition according to claim 4, wherein the polymerizable monomer (B) is one or more selected from the group consisting of ethylene, propylene, butadiene, isobutylene, isoprene, 1-hexene, 1-octene, vinyl acetate, vinyl propionate, vinyl butyrate, styrene, α-methylstyrene, p-methylstyrene, acrylic acid, methacrylic acid, alkyl acrylates, alkyl methacrylates, acrylonitrile, vinyl chloride, vinylidene chloride, vinylidene fluoride, alkyl 2-cyanoacrylates, alkyl 2-cyanopentadienoates, and dialkyl methylidenemalonates.

6. The 1,1-dicyanoethylene-containing composition of claim 5, wherein the polymerizable monomer (B) comprises a 2-cyanoacrylic acid alkyl ester.

7. The 1,1-dicyanoethylene-containing composition of claim 6, wherein the 2-cyanoacrylic acid alkyl ester is ethyl 2-cyanoacrylate.

8. The 1,1-dicyanoethylene-containing composition according to claim 1, wherein the molar concentration of the acidic compound (A) in the composition is 1,000 mmol / L or less.

9. A cured product obtained by reacting the 1,1-dicyanoethylene-containing composition according to any one of claims 1 to 8.

10. A laminate comprising a cured product obtained by reacting the 1,1-dicyanoethylene-containing composition according to any one of claims 1 to 8, and an adherend bonded to the cured product.

11. A method for producing a 1,1-dicyanoethylene-containing composition, comprising a step of blending an acidic compound (A) in the composition so that the content of the acidic compound (A) in the composition and the content of water in the composition satisfy the following relational formula (Ia): -4.00≦α≦0 ... (Ia) (In the above relational formula (Ia), α is represented by the following formula (Ib): α=pKa+Log(C Ｈ２Ｏ / C ａ In the above formula (Ib), pKa is the logarithmic acid dissociation constant of the acidic compound (A). Ｈ２Ｏ is the molar concentration of the water in the composition. ａ is the molar concentration of the acidic compound (A) in the composition.

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