JP5905380B2 - Manganese dioxide and curable composition containing the same - Google Patents

Description

  The present invention relates to manganese dioxide and a curable composition thereof that are suitably used as a curing agent for a liquid polysulfide polymer.

  Manganese dioxide activated by alkali treatment is used as an oxidizing agent for liquid polysulfide polymers. As manganese dioxide, for example, natural manganese dioxide ore treated with alkali, or manganese dioxide having a sodium birnessite structure described in Patent Document 1 is used, and a paste-like curing agent dispersed in a plasticizer. It is common to make it.

  A rubber-like cured product obtained by curing a liquid polysulfide polymer with a curing agent composed of manganese dioxide contains sulfur in the main chain of the molecule and does not contain double bonds, so it is oil and weather resistant. In addition, it has excellent watertightness and airtightness, and also has good adhesion. Therefore, a cured product of a liquid polysulfide polymer is widely used as a sealing material, an adhesive and a paint. In particular, in multilayer glass applications, it has been used for a long time because of its excellent curability, watertightness and airtightness, which is superior to other base materials such as silicone sealants.

  However, paste-like curing agents in which manganese dioxide is dispersed in a plasticizer have less change in activity after storage and distribution compared to curing agents made of other base materials such as silicone sealants, but more stable handling And in order to obtain workability, a technique for further improving the storage stability has been desired. In addition, as an index of storage stability, a change in curability after the heat accelerated curing test is often evaluated.

JP-A-63-22857

  An object of the present invention is to provide a manganese dioxide capable of curing a liquid polysulfide polymer and suppressing a decrease in curability of the curing agent after heat-accelerated curing when the paste-like curing agent is dispersed in a plasticizer. It is to provide a curable composition.

  The manganese dioxide of the present invention is manganese dioxide used as a curing agent for a liquid polysulfide polymer, and the manganese dioxide is coated on its surface with a liquid organic compound at room temperature, and the organic compound is present in the molecule. It has at least two hydroxyl groups and has a boiling point of 190 ° C. or higher.

  The curable composition of the present invention is characterized by containing the above manganese dioxide and a liquid polysulfide polymer.

  According to the manganese dioxide of the present invention, the surface is coated with a liquid organic compound at room temperature, the organic compound has a boiling point of 190 ° C. or higher, and has at least two hydroxyl groups in the molecule of the organic compound. When heat resistance is improved and a paste-like curing agent dispersed in a plasticizer is used, a decrease in curability after heat accelerated curing can be suppressed. For this reason, the storage stability of a hardening | curing agent can be improved.

  The organic compound is preferably at least one selected from diethylene glycol, ethylene glycol, 1,5-pentanediol, polyethylene glycol, triethanolamine, and diethanolamine, more preferably diethylene glycol and / or triethanolamine. .

As said manganese dioxide, following General formula (1)
Na _0.55 Mn ₂ O ₄ .1.5H ₂ O (1)
It is preferable to consist of monoclinic cation-substituted birnessite-type manganese dioxide in which sodium ions existing between monoclinic sodium birnessite layers represented by formula (1) are substituted with monovalent to trivalent cations. With this monoclinic cation-substituted birnessite-type manganese dioxide, when the cured product of polysulfide polymer is immersed in warm water for a long period of time, the volume swelling and strength reduction of the cured product can be reduced.

  In addition, since the curable composition of the present invention contains the above manganese dioxide and liquid polysulfide polymer, manganese dioxide has excellent heat resistance and storage stability, and suppresses a decrease in curability with respect to the liquid polysulfide polymer. be able to.

  The curable composition can contain at least one selected from a filler, a plasticizer, and a curing accelerator. The filler can be at least one selected from carbon black, calcium carbonate, silica, and microballoons. The plasticizer may be at least one selected from phthalic acid esters, chlorinated paraffins, dipropylene glycol dibenzoates, and halogen-terminated sulfur-containing polymers. Furthermore, the said hardening accelerator can be made into at least one chosen from a thiuram type hardening accelerator and a guanidine type hardening accelerator.

  Hereinafter, the present invention will be described in detail.

  The manganese dioxide of the present invention is activated manganese dioxide capable of curing a liquid polysulfide polymer, and its surface is coated with a liquid organic compound at room temperature, thereby improving heat resistance and dispersing it in a plasticizer. When a hardener paste is used, it is possible to suppress a decrease in curability after heating accelerated curing. As a result, the change in activity after storage and distribution can be further reduced, the storage stability can be improved, and more stable handling and workability can be obtained.

  The organic compound which is liquid at room temperature is an organic compound having at least two hydroxyl groups in the molecule and having a boiling point of 190 ° C. or higher. By coating the surface of manganese dioxide with such an organic compound, the heat resistance is improved, and even if it is subjected to a heat history such as heat accelerated curing after being made into a hardener paste, the decrease in activity as a hardener is greatly suppressed. can do. The organic compound has at least 2 hydroxyl groups, preferably 2 or 3 hydroxyl groups in the molecule. When the organic compound has two or more hydroxyl groups in the molecule, the oxidation action of manganese dioxide can be appropriately maintained and the storage stability can be increased.

  The boiling point of the organic compound is 190 ° C. or higher, preferably 190 ° C. or higher and 380 ° C. or lower. By setting the boiling point of the organic compound to 190 ° C. or higher, the surface of manganese dioxide can be reliably protected and the heat resistance can be improved.

  Furthermore, since the organic compound is liquid at room temperature, it can be easily coated on the surface of manganese dioxide. Here, room temperature means 20 ° C. The viscosity of the organic compound is preferably 1 to 500 mPa · s, more preferably 20 to 400 mPa · s. By making the viscosity of the organic compound within such a range, the surface of manganese dioxide can be uniformly and easily coated. In this specification, the viscosity of an organic compound shall be measured on condition of 20 degreeC and rotation speed 50rpm using an E-type viscosity meter.

  Examples of the organic compound in the present invention include diethylene glycol, ethylene glycol, 1,5-pentanediol, polyethylene glycol, triethanolamine, and diethanolamine. Of these, diethylene glycol and triethanolamine are more preferred because of their good workability. These organic compounds can be used alone or in combination of two or more.

  The amount of the organic compound added is preferably 0.1 to 20% by weight, more preferably 0.5 to 4% by weight, and further preferably 1 to 2% by weight with respect to dry manganese dioxide. Good.

  In the present invention, the method for coating manganese dioxide with an organic compound is not particularly limited. For example, it is preferable to add an organic compound when pulverizing manganese dioxide. As a result, an organic compound can be coated on the surface of manganese dioxide, and at the same time, the organic compound can act as a dispersion aid to suppress agglomeration of the manganese dioxide powder, and appropriately control the particle size of manganese dioxide. Can do.

  When manganese dioxide of the present invention is used, in the state of a hardener paste dispersed in a plasticizer, a decrease in curability of the hardener after heating accelerated curing at 70 ° C. for 3 days is suppressed and mixed with a main agent containing a liquid polysulfide polymer. The A hardness of the curable composition after 6 hours can be preferably 9 or more, more preferably 20 or more. In the present invention, the A hardness of the curable composition is the hardness of the curable composition determined by a type A durometer based on JIS K6253.

As the manganese dioxide of the present invention, manganese dioxide having an action of curing a polysulfide polymer can be used. For example, orthorhombic sodium birnessite-type manganese dioxide (Na ₄ Mn ₁₄ O ₂₇ · 9H ₂ O), simple Oblique-type sodium banesite-type manganese dioxide (Na _0.55 Mn ₂ O ₄ .1.5H ₂ O), manganese dioxide activated by alkali treatment and having a banesite structure or bucerite structure, monoclinic cation-substituted banesite-type Manganese dioxide can be exemplified. Monoclinic cation-substituted birnessite-type manganese dioxide is preferable.

  Manganese dioxide having a benesite structure has an interlayer distance of about 7 angstroms, preferably 6.70-7.50 angstroms, more preferably 6.90-7.25 angstroms. As the birnessite-type manganese dioxide, it is possible to preferably use monoclinic sodium birnessite activated by alkali treatment using natural birnessite ore, or burntite by chemical synthesis. Examples of banesite by chemical synthesis include those obtained by the precipitation method, that is, products obtained by dropping an alkaline aqueous solution such as caustic soda into an aqueous solution of manganese chloride, manganese sulfate, manganese nitrate, etc. in the presence of oxygen. .

  Manganese dioxide having a bcelite structure has a larger amount of water of crystallization and a longer interlayer distance than the banesite structure. The interlayer distance is about 10 angstroms, preferably 7.50-11.50 angstroms. As bucerite-type manganese dioxide, natural bcelite ore and bucelite by chemical synthesis can be used. Examples of the bucelite obtained by chemical synthesis include a product obtained by a precipitation method, that is, a product obtained by dropping an alkaline aqueous solution such as caustic soda into an aqueous solution such as manganese chloride, manganese sulfate and manganese nitrate in the presence of oxygen.

Monoclinic cation-substituted birnessite-type manganese dioxide is a cation-substituted birnessite in which sodium ions existing between monoclinic sodium birnessite represented by the following general formula (1) are replaced with monovalent to trivalent cations. Type manganese dioxide.
Na _0.55 Mn ₂ O ₄ .1.5H ₂ O (1)

  Monoclinic cation-substituted birnessite-type manganese dioxide, in which sodium ions existing between monoclinic sodium birnessite layers are replaced with monovalent to trivalent cations, has high water-absorbing sodium ions. By substituting with a low monovalent to trivalent cation, the water absorption of manganese dioxide can be reduced. By using this manganese dioxide as a curing agent, the water absorption of the cured product of the polysulfide polymer is greatly reduced, so that the volume swelling and strength reduction of the cured product can be reduced even when immersed in warm water for a long period of time.

  The monovalent to trivalent cation replacing the sodium ion has an ionic radius that falls between the layers of the monoclinic birnessite structure, and is not particularly limited as long as it is a cation with low water absorption. Preferable examples include metal ions such as calcium ion, magnesium ion, strontium ion, nickel ion, iron (III) ion, lanthanum ion, zinc ion, barium ion, proton, ammonium ion and the like.

  The replacement of sodium ions with monovalent to trivalent cations means that at least the content of monovalent to trivalent cations is made higher than the content of sodium ions. In order to suppress the volume swelling rate of the cured product of polysulfide polymer during long-term warm water immersion, it is preferable that the substitution rate of the low water-absorbing cation is high, that is, the amount of remaining sodium ions is small. The content of sodium ions in the cation-substituted manganese dioxide is preferably 0.40% by weight or less, more preferably 0.15% by weight or less.

  The method for replacing sodium ions between monoclinic sodium birnessite with monovalent to trivalent cations is, for example, treating monoclinic sodium birnessite with an aqueous solution containing monovalent to trivalent cations. Then, after the sodium ion is replaced with a monovalent to trivalent cation, the product is washed with water and dried, or a commonly performed ion replacement method can be used.

  In the treatment method with an aqueous solution containing monovalent to trivalent cations, the aqueous solution containing monovalent to trivalent cations is not particularly limited as long as it contains a water-soluble metal salt. The metal salt is preferably a chloride, sulfate, nitrate, carbonate, or organic acid salt. The concentration of the metal salt in the aqueous solution is preferably 0.5 to 50% by weight, more preferably 2 to 30% by weight.

  The treatment method with an aqueous solution containing monovalent to trivalent cations is not particularly limited. For example, manganese dioxide may be added to these aqueous solutions and stirred. The amount of manganese dioxide added to the aqueous solution is preferably 0.1 to 200 g, more preferably 0.5 to 150 g, per liter of the aqueous solution containing cations. The treatment conditions are such that the temperature of the aqueous solution is preferably 10 to 80 ° C., more preferably 20 to 50 ° C., and the treatment time is preferably 1 to 72 hours, more preferably about 5 to 24 hours. Further, when drying the cation-substituted manganese dioxide, it is preferably dried at 20 to 180 ° C, more preferably 60 to 150 ° C, and preferably 1 to 150 hours.

  The curable composition of the present invention contains the above-described manganese dioxide and a liquid polysulfide polymer. When manganese dioxide whose surface is coated with a liquid organic compound at room temperature having a boiling point of 190 ° C. or more and having at least two hydroxyl groups in the molecule is used as a curing agent, a decrease in curability is suppressed even when the curing agent is heated and cured. Therefore, the storage stability can be greatly improved. In particular, after curing the curing agent at 70 ° C. for 3 days, the A hardness of the curable composition after 6 hours of mixing with the main agent containing the liquid polysulfide polymer can be 9 or more. Further, when monoclinic cation-substituted birnessite-type manganese dioxide is used as manganese dioxide, swelling and strength reduction of the cured product made of polysulfide polymer when immersed in warm water can be reduced, and after immersion in warm water at 80 ° C. for 10 days. The volume swelling ratio can be less than 10%.

The liquid polysulfide polymer used in the present invention is preferably represented by the following general formula (2).
HS- (R- _Sx ) _n- R-SH (2)
(However, R is a divalent or trivalent organic group containing a —O—CH ₂ —O— bond, n is an integer of 1 to 200, and preferably an integer of 1 to 50. x is 1 to 5) And the average value of x is 1 to 2.5.)

In the formula (2), R is preferably an organic group containing a —O—CH ₂ —O— bond and a linear alkylene group or a branched alkylene group. R is more preferably an organic group containing a —O—CH ₂ —O— bond and a branched alkylene group. The linear or branched alkylene group is preferably 0 to 70 mol% with respect to the number of moles of the —O—CH ₂ —O— bond.

R is preferably
—C ₂ H ₄ —O—CH ₂ —O—C ₂ H ₄ —
Is contained in an amount of 50 mol% or more. More preferably,
—C ₂ H ₄ —O—CH ₂ —O—C ₂ H ₄ —
70 mol% or more.

The branched alkylene group is preferably a polyfunctional component derived from a trihalo organic compound and is an organic group represented by the following general formula (3).

  Preferred as the branched trihalo organic compound is a trihaloalkyl compound, and more preferred is trihalopropane. Preferred halogen atoms of trihalopropane are chlorine, bromine, and iodine, and more preferred halogen atoms are chlorine atoms.

  In the liquid polysulfide polymer used in the present invention, n in the formula (2) is an integer of 1 to 200, preferably an integer of 1 to 50. The liquid polysulfide polymer is liquid at room temperature, and the number average molecular weight is preferably 500 to 50,000, more preferably 1,000 to 10,000.

  Furthermore, x in the formula (2) is an integer of 1 to 5, preferably an integer of 1 to 3, and the average value of x is 1 to 2.5. In particular, when the average value of x is less than 2, there are effects of low viscosity, low glass transition temperature, and high heat resistance.

  The liquid polysulfide polymer used in the present invention can be obtained by a conventional production method via formation of solid polysulfide and a production method described in Japanese Patent No. 4227787 which does not include formation of solid polysulfide using a phase transfer catalyst. The method is not limited to any method.

  When using manganese dioxide as a curing agent for a liquid polysulfide polymer, the curable composition of the present invention is a plasticizer, a filler, a curing accelerator, if necessary, for the purpose of improving workability and physical properties after curing. Further, additives such as adhesion promoters and pigments can be contained. Preferably, at least one selected from fillers, plasticizers, and curing accelerators may be contained.

Examples of the plasticizer include phthalic acid esters such as dibutyl phthalate, butyl benzyl phthalate, and alkyl (C ₇ -C ₉ ) benzyl phthalate, chlorinated paraffin, dipropylene glycol dibenzoate, diethylene glycol dibenzoate, and triethylene glycol diester. Examples thereof include benzoate, dipropylene glycol monobenzoate, hydrogenated terphenyl, hydrocarbon plasticizer described in JP-A-2004-51918, and halogen-terminated sulfur-containing polymer described in Japanese Patent Application No. 2011-167330. A preferable plasticizer is at least one selected from phthalic acid esters, chlorinated paraffins, dipropylene glycol dibenzoates, and halogen-terminated sulfur-containing polymers.

  The addition amount of the plasticizer is set by the hardness, strength and elongation of the cured product, and further by the design of the viscosity of the curable composition before curing, but is 1 to 100 parts by weight with respect to 100 parts by weight of the liquid polysulfide polymer Preferably there is. When the addition amount of the plasticizer exceeds 100 parts by weight, the amount of non-reactive liquid increases and the hardness of the cured product may not be maintained. More preferably, it is 1-50 weight part, More preferably, it is 1-30 weight part.

  Examples of the filler include inorganic fillers such as calcium carbonate, aluminum oxide, aluminum hydroxide, silica, silicate, sulfate, and carbon black. In addition, lightweight polymer fillers such as polyamide and polyethylene, thermoplastic balloons (thermal expansion microcapsules) such as silica, acrylonitrile, methacrylonitrile and vinylidene chloride, thermosetting balloons such as phenol and epoxy, shirasu and fly ash Examples thereof include hollow fillers such as inorganic balloons such as glass and alumina. A preferred filler is at least one selected from carbon black, calcium carbonate, silica, and microballoons. Two or more kinds of fillers may be used, and any of the fillers may have a surface treated with a fatty acid, a resin acid, a surfactant, a silane coupling agent, paraffin, or the like.

  The calcium carbonate is preferably heavy calcium carbonate or colloidal calcium carbonate. Generally, heavy calcium carbonate is calcium carbonate obtained by mechanically crushing and classifying raw limestone to obtain a desired particle size. In addition, colloidal calcium carbonate is obtained by co-firing raw limestone with coke, etc., once producing calcium oxide (quick lime), reacting it with water to form calcium hydroxide (slaked lime), and reacting with carbon dioxide gas generated during firing, Calcium carbonate obtained to have a desired particle size and particle shape.

  The amount of filler added is preferably 0.1 to 500 parts by weight with respect to 100 parts by weight of the liquid polysulfide polymer. When the addition amount of the filler is less than 0.1 parts by weight, sufficient reinforcement and curing cannot be obtained. More preferably, it is 1-300 weight part, More preferably, it is 10-200 weight part, More preferably, it is 30-60 weight part.

  Examples of the curing accelerator include aldehyde / ammonia and aldehyde / amine-based, thiourea-based, guanidine-based, thiazole-based, sulfenamide-based, thiuram-based, dithiocarbamate-based, and xanthate-based curing accelerators. Specific examples include tris (dimethylaminomethyl) phenol, diphenylguanidine, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, hexamethylenetetramine and the like. A preferable curing accelerator is at least one selected from a thiuram curing accelerator and a guanidine curing accelerator. Two or more curing accelerators may be used.

  Although the addition amount of a hardening accelerator is set with the hardening rate of a curable composition, and also use temperature, it is preferable that it is 1-10 weight part with respect to 100 weight part of liquid polysulfide polymers. When the addition amount of the curing accelerator exceeds 10 parts by weight, the remaining accelerator that is not involved in the reaction may deteriorate the performance of the cured product. More preferably, it is 1-5 weight part, More preferably, it is 1-3 weight part.

  Examples of the adhesion promoter include a silane coupling agent containing a hydrolyzable silyl group and a reactive organic functional group. Specifically, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyl Triethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (amino Ethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl- Examples include 3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and bis (triethoxysilylpropyl) tetrasulfide. Further, a terminal trimethoxysilane-modified polysulfide polymer synthesized by reacting polysulfide polymer “thiocol LP-3” and 3-gridoxypropyltrimethoxysilane described in JP-A-6-271833 is also used as a silane coupling agent. Can do. Two or more of these silane coupling agents may be used.

  The cured product obtained by the curable composition of the present invention has characteristics excellent in oil resistance, weather resistance, water tightness, air tightness and adhesiveness. Further, by using monoclinic cation-substituted birnessite-type manganese dioxide as manganese dioxide, the volume swelling of the cured product when immersed in warm water can be extremely reduced. These characteristics are suitable for sealing materials, adhesives, paints and the like. In particular, since the surface of manganese dioxide is coated with a specific organic compound, the storage stability of the curing agent constituting the curable composition can be further improved.

  Moreover, the feature that the volume swelling of the cured product when immersed in warm water is extremely small is optimal for a sealing material for double-glazed glass that requires durability against water accumulated in a sash. The conventional polysulfide-based multi-layer glass sealing material using manganese dioxide as a curing agent, which has the largest market share in the world market, has a swelling of 20% or more in 10 days of hot water immersion at 80 ° C. Therefore, in order to improve durability in the polysulfide-based sealing material, it is preferable to suppress the volume swelling rate after 10 days of 80 ° C. hot water immersion to less than 20%. More preferably, the volume swelling rate after 10 days of 80 ° C. hot water immersion is less than 10%.

  There are various methods for measuring the volume swelling rate, but the method of obtaining the volume from the weight in air and the weight in water and obtaining the volume change rate (%) before and after immersion in warm water is simple and accurate. The thickness of the sample needs to be adjusted to be thin so that it is more susceptible to immersion. However, from the reproducibility of the data, it is preferable to use a sheet having a thickness of 2 mm or less and an area of 30 × 30 mm or more.

  The invention is illustrated in more detail by the following examples. In the following text, “parts” means “parts by weight” based on weight unless otherwise specified.

  For identification of the crystal structure of manganese dioxide and calculation of the interlayer distance, powder X-ray diffraction measurement (X'Pert PRO MRD manufactured by Spectris Co., Ltd.) was performed to obtain an X-ray diffraction chart. The crystal structure was identified by comparing the peak with the standard diffraction chart, and the interlayer distance was calculated assuming that the interplanar spacing of the peak indexed to the 001 reflection corresponds to the interlayer distance of the burntite structure.

  For calculation of the chemical composition ratio, quantification was performed using atomic absorption method for Na, oxidation-reduction titration method for Mn, and ICP emission spectroscopic analysis method (ICP-AES method) for other metals. In addition, the chemical analysis result described in Table 1 represents the content (% by weight) of each metal in manganese dioxide.

Synthesis Example 1
Commercially available product 1 (Honeywell Manganese Dioxide Type-FA, Monoclinic Sodium Bahnesite Manganese Dioxide) 100 parts diethylene glycol (Wako Pure Chemical Industries, Ltd., hydroxyl number 2, boiling point 245 ° C., E-type viscometer Manganese dioxide of Synthesis Example 1 was obtained by adding 2.0 parts of a viscosity of 25.4 mPa · s) at 20 ° C. measured in step 1 and grinding in an automatic mortar for 1 hour. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Example 1. Manganese dioxide of Synthesis Example 1 is a surface-treated powder coated with 2.0% by weight of diethylene glycol with respect to monoclinic sodium banesite type manganese dioxide.

Synthesis Example 2
100 parts of commercial product 1 2.0 parts triethanolamine (manufactured by Wako Pure Chemical Industries, Ltd., 3 hydroxyl groups, boiling point 360 ° C., viscosity at 20 ° C. measured by E-type viscometer 370.1 mPa · s) And pulverized in an automatic mortar for 1 hour to obtain manganese dioxide of Synthesis Example 2. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Example 2. Manganese dioxide of Synthesis Example 2 is a surface-treated powder coated with 2.0% by weight of triethanolamine with respect to monoclinic sodium birnessite-type manganese dioxide.

Synthesis Comparative Example 1
An aqueous solution (A) prepared by adding 188.7 parts of manganese chloride dihydrate to 3000 parts of distilled water and an aqueous solution (B) comprising 825 parts of caustic soda, 216.2 parts of hydrogen peroxide, and 3750 parts of distilled water were prepared. . Both aqueous solutions (A) and (B) were kept at 10 ° C. or lower, and then the aqueous solution (B) was added to the aqueous solution (A) over 120 minutes while stirring at a rotation speed of 800 rpm. After the addition was completed, the mixture was further stirred for 5 hours. Thereafter, the suspension was filtered and washed with water until the electric conductivity of the filtrate reached 100 microsiemens (μS / cm) to obtain a filtrate (1). 400 parts of the filtered product (1) was added to an aqueous solution consisting of 370 parts of acetic acid and 14700 parts of distilled water, and stirred for 12 hours. Next, the obtained suspension is filtered, washed with water until the electric conductivity of the filtrate reaches 100 microsiemens (μS / cm), and then the filtrate is recovered and dried at 150 ° C. for 12 hours. (1) was obtained. The obtained dried product (1) was pulverized in a mortar to obtain manganese dioxide of Synthesis Comparative Example 1. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Comparative Example 1. From these results, the manganese dioxide of Synthesis Comparative Example 1 is a monoclinic birnessite having a sodium content of 0.07% by weight and having protons introduced between layers.

Synthesis Example 3
Manganese dioxide of Synthesis Example 3 was obtained by adding 1.0 part of diethylene glycol to 100 parts of the dried product (1) obtained in the same manner as in Synthetic Comparative Example 1, and grinding it in an automatic mortar for 1 hour. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Example 3.

  From these results, the manganese dioxide of Synthesis Example 3 has a sodium content of 0.07% by weight and a surface coated with 1.0% by weight of diethylene glycol with respect to monoclinic birnessite with protons introduced between the layers. Processed powder.

Synthesis Example 4
Manganese dioxide of Synthesis Example 4 was obtained by adding 2.0 parts of diethylene glycol to 100 parts of the dried product (1) obtained in the same manner as in Synthetic Comparative Example 1, and grinding it in an automatic mortar for 1 hour. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Example 4.

  From these results, the manganese dioxide of Synthesis Example 4 has a sodium content of 0.07% by weight and a surface coated with 2.0% by weight of diethylene glycol with respect to monoclinic birnessite with protons introduced between the layers. Processed powder.

Synthesis Example 5
Manganese dioxide of Synthesis Example 5 was obtained by adding 1.0 part of triethanolamine to 100 parts of the dried product (1) obtained in the same manner as in Synthetic Comparative Example 1, and grinding it in an automatic mortar for 1 hour. . Table 1 shows the interlayer distance and chemical composition ratio of manganese dioxide of Synthesis Example 5.

  From these results, manganese dioxide of Synthesis Example 5 was coated with 1.0% by weight of triethanolamine with respect to monoclinic birnessite having a sodium content of 0.07% by weight and protons introduced between the layers. Surface-treated powder.

Synthesis Example 6
Manganese dioxide of Synthesis Example 6 was obtained by adding 2.0 parts of triethanolamine to 100 parts of the dried product (1) obtained in the same manner as in Synthetic Comparative Example 1, and grinding it in an automatic mortar for 1 hour. . Table 1 shows the interlayer distance and chemical composition ratio of manganese dioxide of Synthesis Example 6.

  From these results, manganese dioxide of Synthesis Example 6 was coated with 2.0% by weight of triethanolamine with respect to monoclinic birnessite having a sodium content of 0.07% by weight and protons introduced between the layers. Surface-treated powder.

Synthesis Comparative Example 2
Dodecane (Wako Pure Chemical Industries) with respect to 100 parts of the manganese dioxide obtained in Synthesis Comparative Example 1 (interlayer distance: 7.19 mm, sodium content: 0.07 wt%, monoclinic banesite with protons introduced between layers) By adding 2 parts of Kogyo Co., Ltd., no hydroxyl group, boiling point of 215 ° C., viscosity of 20 ° C. measured by E-type viscometer is 1.4 mPa · s), and grinding in an automatic mortar for 1 hour, Manganese dioxide was obtained. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Comparative Example 2.

  Manganese dioxide of Synthesis Comparative Example 2 is a surface-treated powder coated with 2.0% by weight of dodecane with respect to monoclinic birnessite having a sodium content of 0.07% by weight and protons introduced between layers. .

Synthesis Comparative Example 3
Ethanol (Wako Pure Chemical Industries) with respect to 100 parts of the manganese dioxide obtained in Synthesis Comparative Example 1 (interlayer distance: 7.19 mm, sodium content: 0.07% by weight, monoclinic banesite with protons introduced between layers) Synthetic Comparative Example 3 by adding 2 parts by Kogyo Co., Ltd., having 1 hydroxyl group, boiling point of 78 ° C., and 20 ° C. viscosity measured by an E-type viscometer of 1.2 mPa · s) and grinding in an automatic mortar for 1 hour. Of manganese dioxide was obtained. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Comparative Example 3.

  Manganese dioxide of Synthetic Comparative Example 3 is a surface-treated powder coated with 2.0% by weight of ethanol on monoclinic birnessite having a sodium content of 0.07% by weight and protons introduced between the layers. .

Synthesis Comparative Example 4
To 100 parts of the manganese dioxide obtained in Synthesis Comparative Example 1 (interlayer distance: 7.19 mm, sodium content: 0.07 wt%, monoclinic banesite with protons introduced between layers), 1-hexanol (sum A synthetic comparison was made by adding 2 parts of Kojunyaku Kogyo Kogyo Co., Ltd., having a hydroxyl number of 1, a boiling point of 158 ° C., a viscosity at 20 ° C. measured by an E-type viscometer of 4.4 mPa · s), and grinding in an automatic mortar for 1 hour. The manganese dioxide of Example 4 was obtained. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Comparative Example 4.

  Manganese dioxide of Synthesis Comparative Example 4 is a surface-treated powder coated with 2.0% by weight of 1-hexanol with respect to monoclinic birnessite having a sodium content of 0.07% by weight and protons introduced between layers. It is.

Synthesis Comparative Example 5
To 100 parts of manganese dioxide obtained in Synthesis Comparative Example 1 (interlayer distance: 7.19 mm, sodium content: 0.07 wt%, monoclinic banesite with protons introduced between layers), 1-heptanol (sum) Comparison of synthesis by adding 2 parts of Kojunyaku Kogyo Co., Ltd., 1 hydroxyl group, boiling point of 176 ° C, viscosity of 20 m measured by E-type viscometer 5.5 mPa · s) and grinding in an automatic mortar for 1 hour The manganese dioxide of Example 5 was obtained. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Comparative Example 5.

  Manganese dioxide of Synthesis Comparative Example 5 is a surface-treated powder coated with 2.0% by weight of 1-heptanol with respect to monoclinic birnessite having a sodium content of 0.07% by weight and protons introduced between layers. It is.

Synthesis Comparative Example 6
To 100 parts of manganese dioxide obtained in Synthesis Comparative Example 1 (interlayer distance: 7.19 mm, sodium content: 0.07% by weight, monoclinic banesite with protons introduced between layers), 1-dodecanol (sum) A synthetic comparison was made by adding 2 parts of Kojunyaku Kogyo Co., Ltd., having a hydroxyl number of 1, a boiling point of 259 ° C. and a viscosity of 15.5 mPa · s at 20 ° C. measured with an E-type viscometer, and grinding in an automatic mortar for 1 hour. The manganese dioxide of Example 6 was obtained. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Comparative Example 6.

  Manganese dioxide of Synthesis Comparative Example 6 is a surface-treated powder coated with 2.0% by weight of 1-dodecanol with respect to monoclinic birnessite having a sodium content of 0.07% by weight and protons introduced between layers. It is.

Synthesis Comparative Example 7
To 100 parts of manganese dioxide obtained in Synthesis Comparative Example 1 (interlayer distance: 7.19 mm, sodium content: 0.07% by weight, monoclinic banesite with protons introduced between layers), propylene glycol (Wako Pure Chemical Industries, Ltd.) Synthetic Comparative Example by adding 2 parts of Yakuhin Kogyo Co., Ltd., having 2 hydroxyl groups, boiling point of 188 ° C., viscosity of 20 ° C. measured by E-type viscometer is 34.0 mPa · s), and grinding for 1 hour in an automatic mortar 7 manganese dioxide was obtained. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Comparative Example 7.

  Manganese dioxide of Synthesis Comparative Example 7 is a surface-treated powder coated with 2.0% by weight of propylene glycol with respect to monoclinic birnessite having a sodium content of 0.07% by weight and protons introduced between layers. is there.

Synthesis Comparative Example 8
400 parts of the filtrate (1) obtained in the same manner as in Synthesis Comparative Example 1 was added to an aqueous solution consisting of 441 parts of calcium chloride dihydrate and 3000 parts of distilled water, and the mixture was stirred for 24 hours. Next, the obtained suspension is filtered and washed with water until the electric conductivity of the filtrate reaches 100 microsiemens (μS / cm), and then the filtrate is recovered and dried at 80 ° C. for 10.5 hours. A dried product (2) was obtained. The obtained dried product (2) was pulverized in a mortar to obtain manganese dioxide of Synthesis Comparative Example 8. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Comparative Example 8.

  From these results, the manganese dioxide of Synthesis Comparative Example 8 is a monoclinic birnessite having a sodium content of 0.01% by weight and having calcium ions introduced between layers.

Synthesis Example 7
Manganese dioxide of Synthesis Example 7 was obtained by adding 2.0 parts of diethylene glycol to 100 parts of the dried product (2) obtained in the same manner as in Synthesis Comparative Example 2 and pulverizing it in an automatic mortar for 1 hour. Table 1 shows the interlayer distance and chemical composition ratio of the manganese dioxide of Synthesis Example 7.

  From these results, manganese dioxide of Synthesis Example 7 was coated with 2.0% by weight of diethylene glycol with respect to monoclinic birnessite having a sodium content of 0.02% by weight and calcium ions introduced between the layers. It is a surface-treated powder.

Synthesis Example 8
Manganese dioxide of Synthesis Example 8 was obtained by adding 2.0 parts of triethanolamine to 100 parts of the dried product (2) obtained in the same manner as in Synthetic Comparative Example 28, and grinding it in an automatic mortar for 1 hour. . Table 1 shows the interlayer distance and chemical composition ratio of manganese dioxide of Synthesis Example 8.

  From these results, manganese dioxide of Synthesis Example 8 was coated with 2.0% by weight of triethanolamine with respect to monoclinic birnessite having a sodium content of 0.02% by weight and calcium ions introduced between the layers. Surface-treated powder.

  In Table 1, the interlayer distance of each sample of the commercial product 1, Synthesis Examples 1-8, and Synthesis Comparative Examples 1-8, the content of each metal, and the type and amount of organic compounds used for the surface-coated manganese dioxide showed that. The samples of the commercial product 1, Synthesis Examples 1 to 8 and Synthesis Comparative Examples 1 to 8 are all manganese dioxide having a monoclinic birnessite monolayer structure with an interlayer distance of about 7 angstroms. It was confirmed. In addition, each sample of Synthesis Examples 3 to 8 and Synthesis Comparative Examples 1 to 8 has a sodium content between layers of 0.15% by weight or less.

Example 1
Based on the following formulation, as a main agent, liquid polysulfide polymer (thiocol "LP-23", manufactured by Toray Fine Chemical Co., Ltd.), butyl benzyl phthalate, precipitated calcium carbonate, heavy calcium carbonate, 3-glycidoxypropyltrimethoxysilane Were mixed using a mixer. As a curing agent, manganese dioxide, butylbenzyl phthalate, phthalic acid plasticizer, tetramethylthiuram disulfide, heavy calcium carbonate, and SFR carbon of Synthesis Example 1 were kneaded using a three-roll mill.

Composition of base agent: Thiocol "LP-23" (Toray Fine Chemical Co., Ltd.) 100 parts by weight, butylbenzyl phthalate (Daihachi Chemical Co., Ltd.) 37 parts by weight, precipitated calcium carbonate (Shiraishi Calcium Co., Ltd., White Glossy CC)・ Heavy calcium carbonate (White SSB red, manufactured by Shiraishi Calcium Co., Ltd.) 90 parts by weight ・ 3-Glycidoxypropyltrimethoxysilane 3 parts by weight (Toray Dow Corning SH-6040)

Composition of hardener: Manganese dioxide (Synthesis Example 1) 10 parts by weight-Butyl benzyl phthalate (Daihachi Chemical Co., Ltd.) 2.5 parts by weight-Phthalic acid plasticizer (Santisizer 278, Ferro Co., Ltd.) 10.5 Parts by weight, 0.5 parts by weight of tetramethylthiuram disulfide (Noxeller TT manufactured by Ouchi Shinsei Chemical Co., Ltd.)
・ 5 parts by weight of heavy calcium carbonate (NCC # 410, manufactured by Nitto Flour Industry Co., Ltd.) ・ 0.5 parts by weight of SRF carbon

  Table 2 shows the results of evaluating the types and properties of manganese dioxide used as a curing agent and the characteristics of the obtained curable composition by the following methods.

(Evaluation of hardness after 6 hours of mixing)
The main agent and the curing agent obtained as described above were thoroughly kneaded by hand to obtain a curable composition comprising the mixture. A test piece having a thickness of 10 mm was prepared from the obtained curable composition. The test piece was cured under an atmosphere of 23 ° C., and hardness was measured with a type A durometer described in JIS K6253 6 hours after mixing the main agent and the curing agent. The results are shown in Table 2.

(Evaluation of hardness after 6 hours of mixing after curing at 70 ° C. for 3 days)
The curing agent obtained as described above was cured at 70 ° C. for 3 days and then left in a laboratory at 23 ° C. for 1 day to return the curing agent to room temperature. The curing agent after heat curing was well kneaded with the main agent obtained above by hand kneading, and a test piece having a thickness of 10 mm was prepared from a curable composition comprising the mixture. This test piece was cured under an atmosphere of 23 ° C., and the hardness was measured with a type A durometer described in JIS K6253 6 hours after mixing the curing agent after heat curing with the main agent. The results are shown in Table 2.

(Evaluation of volume swelling rate of cured product)
The main agent and the curing agent obtained as described above were thoroughly kneaded by hand to obtain a curable composition comprising the mixture. The obtained curable composition was sandwiched between iron plates adjusted to have a gap of 2 mm and cured for 7 days in an atmosphere of 23 ° C. and 50% RH. Three pieces of 30 mm × 30 mm test pieces were cut from the obtained sheet-like cured product. Each test piece was immersed in warm water at 80 ° C. for 10 days, and then the volume swelling ratio was determined by the following formula. Table 2 shows the average value of the three test pieces as the volume swelling ratio.
Volume swelling ratio (%) = [(w3-w4)-(w1-w2)] / (w1-w2) × 100
(W1 is the initial weight in air, w2 is the initial weight in water, w3 is the weight after immersion in air, and w4 is the weight after immersion in water.)

Examples 2-8, Comparative Examples 1-9
As a curing agent, instead of manganese dioxide of synthesis example 1 of example 1, synthesis examples 2-8, commercially available product 1, and manganese dioxide of synthesis comparative examples 1-8 were used in the same manner as in example 1. A curing agent was prepared. Using the obtained curing agent and the main agent prepared in the same manner as in Example 1, a curable composition and a test piece were prepared in the same manner as in Example 1, and the volume swelling rate of the cured product, immediately after the preparation of the curing agent. The hardness after 6 hours of mixing the curable composition and the hardness after 6 hours of mixing of the curable composition after curing the curing agent at 70 ° C. for 3 days were determined. The results are shown in Table 2.

  From Table 2, when commercially available manganese dioxide coated with diethylene glycol or triethanolamine is used (Examples 1 and 2), even when a curing agent heated and cured at 70 ° C. for 3 days is used, it becomes an uncoated product (Comparative Example 1). In comparison, a decrease in curability is suppressed, and the hardness after 6 hours of mixing of the main agent and the curing agent is 24 or more. However, the volume swelling rate of the cured product is 30% or more.

  In addition, when manganese dioxide having a monoclinic proton-bahnite structure coated with diethylene glycol or triethanolamine is used (Examples 3 to 6), even if a curing agent heated and cured at 70 ° C. for 3 days is used, Compared with the coated product (Comparative Example 2), the decrease in curability is suppressed, and the hardness after 6 hours of mixing of the main agent and the curing agent is 35 or more. Further, when manganese dioxide coated with diethylene glycol or triethanolamine was used (Examples 3 to 6), manganese dioxide coated with an organic compound having a number of hydroxyl groups of less than 2 and / or a boiling point of less than 190 ° C. was used. Compared to sometimes (Comparative Examples 3 to 8), the curing characteristics of the curing agent heated and cured at 70 ° C. for 3 days can be greatly improved. Note that the volume swelling rate of the cured product is less than 10%.

  Further, when using manganese dioxide having a monoclinic calcium birnessite structure coated with diethylene glycol or triethanolamine (Examples 7 and 8), even if a curing agent heated and cured at 70 ° C. for 3 days is used, Compared with the coated product (Comparative Example 9), the curability decrease is suppressed, and the hardness after 6 hours of mixing of the main agent and the curing agent is 9 or more. In addition, the volume swelling rate of the cured product is less than 10%.

  By coating the surface of manganese dioxide with diethylene glycol or triethanolamine, it is possible to suppress a decrease in curability after curing curing at 70 ° C. for 3 days. Furthermore, the volume swelling rate of the cured product can be suppressed to less than 10% by using manganese dioxide having a monoclinic birnessite structure with a sodium content of 0.40% by weight or less.

Claims (10)

  Manganese dioxide used as a curing agent for a liquid polysulfide polymer, the manganese dioxide having a surface coated with a liquid organic compound at room temperature, and the organic compound having at least two hydroxyl groups in the molecule Manganese dioxide having a boiling point of 190 ° C. or higher.   2. The manganese dioxide according to claim 1, wherein the organic compound is at least one selected from diethylene glycol, ethylene glycol, 1,5-pentanediol, polyethylene glycol, triethanolamine, and diethanolamine.   3. The manganese dioxide according to claim 1, wherein the organic compound is at least one selected from diethylene glycol and triethanolamine. The manganese dioxide is represented by the following general formula (1)
Na _0.55 Mn ₂ O ₄ .1.5H ₂ O (1)
The monoclinic cation-substituted birnessite-type manganese dioxide in which sodium ions existing between the monoclinic sodium birnessite layers represented by the formula (1) are substituted with monovalent to trivalent cations is provided. The manganese dioxide in any one of -3 . A curable composition comprising the manganese dioxide according to any one of claims 1 to 4 and a liquid polysulfide polymer. The curable composition according to claim 5 , comprising at least one selected from a filler, a plasticizer, and a curing accelerator. The curable composition according to claim 6 , wherein the filler is at least one selected from carbon black, calcium carbonate, silica, and microballoons. The curable composition according to claim 6 or 7 , wherein the plasticizer is at least one selected from a phthalate ester, a chlorinated paraffin, dipropylene glycol dibenzoate, and a halogen-terminated sulfur-containing polymer. The curable composition according to any one of claims 6 to 8 , wherein the curing accelerator is at least one selected from a thiuram curing accelerator and a guanidine curing accelerator. The curable composition according to any one of claims 6 to 9 , which has a volume swelling rate of less than 20% after the cured product is immersed in warm water at 80 ° C for 10 days.