JP2019119800A - Powder type polysulfide and powder type polysulfide-containing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powdery polysulfide excellent in storage stability, and a powdery polysulfide-containing composition having the characteristics of high peel strength and high cohesive failure (CF) rate.
A powdered polysulfide surface-treated with sodium stearate or magnesium stearate having an amount of agglomerated particles of 425 μm or more after storage at 50 ° C. for 6 months is less than 10% by weight.
[Selected figure] None

Description

  The present invention relates to powdered polysulfides. Furthermore, the present invention relates to a powdery polysulfide-containing composition.

  The liquid polysulfide polymer has a thiol group at the end and is easily oxidized and cured by an oxidizing agent such as lead dioxide or manganese dioxide. The rubber-like cured product obtained by curing the liquid polysulfide polymer contains sulfur in the main chain of the molecule and does not contain double bonds, so it has oil resistance, weather resistance, water tightness and airtightness. It has excellent features and also good adhesion. As commercial products of liquid polysulfide polymers, various types of products having different molecular weights and crosslinking amounts known under the name of “Thiocol LP” manufactured by Toray Fine Chemical Co., Ltd. are widely used as sealing materials, adhesives and paints. ing.

  On the other hand, there has been a demand for treating the polysulfide polymer as a solid, not as a liquid, in order to facilitate mixing operation with various rubbers and resins, measurement, and the like. However, those obtained by solidifying and grinding a liquid polysulfide polymer have variations in shape, and when left to stand, there is a problem that the particles themselves aggregate. In order to solve the above, a powdery polysulfide which does not aggregate is developed, and a production method is reported in JP-A-3-139563 (see Patent Document 1). Powdered polysulfides not surface-treated with stearic acid exhibited significant secondary aggregation when left at room temperature for 24 hours, but powder polysulfides surface-treated with stearic acid remained even when left at room temperature for 24 hours. Secondary aggregation did not occur. The powdery polysulfide surface-treated with stearic acid was a stable powdery polysulfide as compared to the powdery polysulfide not surface-treated with stearic acid. However, when the powdery polysulfide is stored under more severe conditions, even if it is the powdery polysulfide surface-treated with stearic acid, since aggregation occurs, it is necessary to further improve the stability.

  It can maintain flexibility even at low temperatures, and has high oil resistance as a sealant that covers joint surfaces by bolts, rivets and welds due to fuel and chemical resistance and good adhesion when exposed to fuel. Polysulfide-based sealants are widely used in aircraft fuselages. Since the sealing material for aircraft follows the displacement of the adherend due to the vibration of the airframe and the temperature difference, in order to cope with the large load applied to the joint, high peel strength and adhesiveness are required. There has been a demand for an aircraft sealing material having higher peel strength than conventional polysulfide-based sealing materials while maintaining oil resistance that is a characteristic of polysulfide polymers.

JP-A-3-139563

  An object of the present invention is to provide a powdery polysulfide having good storage stability. Another object of the present invention is to provide a composition having higher adhesion to metal and higher peel strength than conventional polysulfide-based sealants.

The present invention is sodium stearate or powdered polysulfide surface-treated with magnesium stearate, in which the amount of agglomerated particles of 425 μm after storage for six months at 50 ° C. is less than 10% by weight.

  The present invention provides sodium stearate having a content of 425 μm agglomerated particles of less than 10% by weight after storage for six months at 50 ° C., or powdered polysulfide surface-treated with magnesium stearate, liquid polysulfide polymer, and It is a hardening type composition containing manganese.

  The powdery polysulfide of the present invention has little variation in shape, and does not aggregate itself even when it is left for a long time, and its storage stability is good.

  The composition containing the powder polysulfide of the present invention is excellent in oil resistance, weather resistance, water tightness and air tightness similarly to a curable composition using a conventional liquid polysulfide polymer. Furthermore, the composition containing the powdery polysulfide of the present invention has a high peel strength and cohesive failure (CF) rate in the peel test, as compared to the composition not containing the powdery polysulfide.

  Therefore, the composition containing the powder polysulfide of the present invention can be used as an adhesive, sealing material, potting material, coating material, modifier for resin, primer and the like, and in particular, for aircraft, for vehicles, civil engineering, It is most suitable as an additive for construction materials and electrical and electronic sealing materials.

  In order to follow the displacement of the adherend due to the vibration of the airframe and the temperature difference, the sealing material for aircraft is required to have high peel strength and adhesiveness that can cope with a large load applied to the joint. The composition containing the powdered polysulfide of the present invention has high peel strength and high adhesion. The composition containing the powder polysulfide of the present invention is excellent in oil resistance, weather resistance, water tightness, air tightness, and further has good adhesion, so it is particularly suitable for a sealing material for aircraft. .

It is a model figure of 100% of cohesive failure (CF) rates. It is a model figure of a cohesive failure (CF) rate 75%. It is a model figure of 50% of cohesive failure (CF) rates. It is a model figure of cohesive failure (CF) rate 15%.

  Hereinafter, the present invention will be described in detail.

The powdered polysulfide of the present invention has the following general formula:
~ (R ^1- S _x ) _n ~
It is a polymer. R ¹ is an organic group containing an —O—CH ₂ —O— bond, and n is an integer of 200 or more. x is an integer of 1 to 5 and the average value of x is 1 to 2.5.

The powdery polysulfide of the present invention preferably has a chemical structure represented by the following general formula:
~ (R ² -S _p ) _m ~
It is a polymer. R ² is a divalent organic group containing an —O—CH ₂ —O— bond, and m is an integer of 200 or more. p is an integer of 1 to 5 and the average value of p is 1 to 2.5. R ² is preferably
_{-C 2 H 4 -O-CH 2} -O-C 2 H 4 -
It is.

The powdery polysulfide of the present invention preferably has a chemical structure represented by the following general formula:
~ (R ³ -S _p ) ~
Furthermore, it has a chemical structure represented by the following general formula
~ (R ^4- S _q ) ~
It is a polymer. R ³ is a divalent organic group containing an —O—CH ₂ —O— bond. p is an integer of 1 to 5 and the average value of p is 1 to 2.5. R ³ is preferably
_{-C 2 H 4 -O-CH 2} -O-C 2 H 4 -
It is. R ⁴ is the following formula

It is indicated by. q is an integer of 1 to 5 and the average value of q is 1 to 2.5.

More preferably, the powdery polysulfide of the present invention has a chemical structure represented by the following general formula:
~ (R ³ -S _p ) ~
A chemical structure represented by the following general formula
~ (R ^4- S _q ) ~
80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more.

The powdered polysulfide of the present invention preferably has a chemical structure represented by the following general formula:
~ (R ³ -S _p ) ~
A chemical structure represented by the following general formula
~ (R ^4- S _q ) ~
The total of is 200 or more, preferably an integer of 200 to 10,000,000.

  The powdery polysulfide of the present invention is a powdery solid. The average particle diameter of the powdery polysulfide of the present invention is preferably 1 to 1000 μm, more preferably 1 to 500 μm, and still more preferably 50 to 500 μm. If the particle size is 1 μm or less, it may be difficult to handle, such as scattering during operation or making it difficult to measure due to static electricity. In addition, when the particle size is 1000 μm or more, it may be a foreign matter or a defect when the cured product is formed.

  The powdered polysulfide of the present invention can be produced, for example, using an aqueous latex of polysulfide rubber particles. An aqueous latex of polysulfide is a suspension in which particles of polysulfide rubber having an average particle diameter of approximately 1 to 100 μm are dispersed in water, and those obtained in the conventional process for producing polysulfide polymer are used. Can. An aqueous latex of polysulfide is preferably reacted in the presence of a nucleating agent and an anionic surfactant in water with an alkali polysulfide, an alpha, omega dihalo organic compound containing a formal bond, and optionally at least one branched trihalo organic compound. It can be obtained by performing purification such as filtration, decantation, water washing after being allowed to grow on latex rubber particles.

  As the alpha, omega dihalo organic compound containing a formal bond, bis (2-chloroethyl) formal is preferable. As a branched trihalo organic compound, 1,2,3-trichloropropane is preferable.

The nucleating agent is preferably precipitated magnesium hydroxide. Precipitated magnesium hydroxide can be generated in situ by the reaction of an alkali hydroxide such as sodium hydroxide with magnesium chloride. As the anionic surfactant, sodium alkylnaphthalene sulfonates can be used. The alkali metal polysulfide is represented by M ₂ S _X , wherein M is an alkali metal such as sodium, potassium, lithium and the like, x is an integer of 1 to 5, and the average value of x is 1 to 2.5. is there.

  The ratio (solid content) of the polysulfide rubber particles in the aqueous latex is preferably 30 to 80 wt%, based on 100 wt% of polysulfide rubber particles + water. If it is less than 30% by weight, the productivity is deteriorated, and if it exceeds 80% by weight, the fluidity is low and the handling becomes difficult.

  The powdery polysulfide of the present invention is surface-treated with sodium stearate or magnesium stearate to avoid agglomeration. As a surface treatment method of sodium stearate, it is preferable to add sodium stearate or magnesium stearate to a polysulfide aqueous latex, remove excess water by solid-liquid separation, and dry it.

  The addition ratio of sodium stearate or magnesium stearate is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the solid content of polysulfide in the aqueous latex.

  Sodium stearate or magnesium stearate is preferably added as an aqueous solution or suspension water, more preferably as an aqueous solution. The concentration of these aqueous solutions or suspending waters is usually 0.1 to 3% by weight.

  Moreover, as a method of surface-treating non-water-soluble fatty acid polyvalent metal salt to polysulfide rubber particles in water-based latex, a double decomposition method which is one of metal soap manufacturing methods can be used. In the metathesis method, when water-soluble fatty acid alkali is dissolved in water, a water-soluble polyvalent metal salt of 0.5 molar equivalent or more is added to cause a metal exchange reaction, thereby forming a fatty acid polyvalent metal salt. It is a method to generate. Examples of the water-soluble fatty acid alkali include sodium stearate and potassium stearate. Examples of water-soluble polyvalent metal salts include sulfates such as magnesium, calcium and zinc, nitrates such as magnesium, calcium and zinc, and chlorides such as magnesium, calcium and zinc, and can be used as an aqueous solution. . As an example, when surface treating magnesium stearate with polysulfide rubber particles in aqueous latex, first add sodium stearate in aqueous latex, and then add 0.5 molar equivalent of magnesium sulfate to add metal ions. By exchanging, magnesium stearate can be produced in the system. Sodium stearate is preferably added as an aqueous solution, and the amount of addition is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of solid polysulfide content in the aqueous latex. The concentration of the aqueous solution is preferably 0.1 to 3% by weight.

  When producing the powdery polysulfide of the present invention, it is preferable to first surface-treat the rubber particles by adding sodium stearate or magnesium stearate to the aqueous latex of polysulfide. At this time, in order to perform surface treatment with sodium stearate or magnesium stearate sufficiently, it is preferable to stir for 5 to 30 minutes after the addition.

  Thereafter, an aqueous latex containing rubber particles surface-treated with sodium stearate or magnesium stearate is usually subjected to solid-liquid separation, and the resulting wet product is dried and powdered. Solid-liquid separation is preferably carried out in that it can remove water-soluble impurities. Solid-liquid separation can be performed by, for example, a pressure filter, a vacuum filter, a rotary dehydrator, or the like. For drying and pulverization, for example, a tray dryer, a rotary dryer, a vibration dryer, or any of various powder dryers with a crushing function can be used. Moreover, when drying and pulverizing the latex slurry which contains much water directly, it can carry out by a spray type powder dryer and a freezing type powder dryer, for example.

  The powdered polysulfide of the present invention has an amount of 425 μm agglomerated particles of less than 10% by weight after storage at 50 ° C. for 6 months. The particle size distribution is as follows: 4 stainless steel test sieves with openings of 425 μm, 180 μm, 100 μm, and 53 μm (frame diameter 75 mm, depth 20 mm, JIS Z 8801 compliant) on top of the tray Then, 2 g of powdered polysulfide was placed in the uppermost sieve and manually sieved for 5 minutes while tapping the frame by hand. The weight of the powder remaining on the sieve or pan was measured and divided by the total amount to determine the sieve residue (%) in each particle size range. When the amount of 425 μm agglomerated particles is less than 10% by weight, the powdery polysulfide remaining on the 425 μm stainless steel test sieve when using the four stainless steel test sieves of the openings 425 μm, 180 μm, 100 μm and 53 μm mentioned above. Indicates that the amount is less than 10% by weight.

  The powdery polysulfides of the present invention preferably have an aggregated particle amount of 425 μm after storage for six months at 50 ° C. of less than 10% by weight, more preferably less than 5% by weight.

  The powdery polysulfide of the present invention preferably has an aggregated particle amount of 425 μm after storage for one month at 50 ° C. of less than 5% by weight, more preferably less than 1% by weight.

  The powdery polysulfides of the present invention preferably have an aggregate particle amount of 425 μm of less than 5% by weight, more preferably less than 1% by weight before storage at 50 ° C. for 6 months.

  The powdered polysulfides of the present invention preferably have an aggregate particle amount of 180 to 425 μm of less than 10% by weight, more preferably less than 5% by weight, before storage at 50 ° C. for 6 months.

  Since the powdery polysulfide of the present invention does not cause secondary aggregation, the practicability is extremely improved as a compounding agent.

  The powdery polysulfide of the present invention can be added to a curable composition using a conventional liquid polysulfide polymer. Powdered polysulfides can also be added to compositions that do not contain liquid polysulfide polymers.

  The powdery polysulfide-containing composition of the present invention is surface-treated with sodium stearate or magnesium stearate, and the powdery polysulfide having an amount of aggregated particles of 425 μm or more after storage for 6 months at 50 ° C. is less than 10% by weight. It contains a liquid polysulfide polymer and manganese dioxide.

  In the powdery polysulfide-containing composition of the present invention, the content of the powdery polysulfide in the composition is preferably 0.1 to 100 parts by weight, more preferably 1 to 50 parts by weight per 100 parts by weight of the liquid polysulfide polymer. Parts, even more preferably 1 to 10 parts by weight.

  The powdered polysulfide-containing composition of the present invention contains manganese dioxide.

  The content of manganese dioxide is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the liquid polysulfide polymer. The content of manganese dioxide is more preferably 1 to 30 parts by weight, still more preferably 1 to 20 parts by weight, and still more preferably 5 to 15 parts by weight with respect to 100 parts by weight of the liquid polysulfide polymer. It is.

  The powdery polysulfide-containing composition of the present invention can contain a filler. The filler may, for example, be an inorganic filler such as calcium carbonate, aluminum oxide, aluminum hydroxide, silica, silicate or sulfate, carbon black or the like, with carbon black being preferred.

  The content of the filler is preferably 0.1 to 500 parts by weight with respect to 100 parts by weight of the liquid polysulfide polymer. More preferably, it is 1 to 300 parts by weight, still more preferably 10 to 200 parts by weight, and still more preferably 30 to 60 parts by weight.

  The curable composition of the present invention preferably contains a plasticizer and a curing accelerator for the purpose of improving economy, workability in applying the composition and physical properties after curing.

As a plasticizer, phthalic acid esters such as dibutyl phthalate, butyl benzyl phthalate, alkyl phthalate (C ₇ -C ₉ ) benzyl, chlorinated paraffin, dipropylene glycol dibenzoate, diethylene glycol dibenzoate, triethylene glycol dibenzoate And dipropylene glycol monobenzoate, hydrogenated terphenyl, hydrocarbon plasticizers, halogen-terminated sulfur-containing polymers, and the like. The plasticizer is preferably phthalic ester, chlorinated paraffin, dipropylene glycol dibenzoate, halogen-terminated sulfur-containing polymer.

  The content of the plasticizer is set depending on the strength and elongation of the cured product and the design of the viscosity before curing, but is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the liquid polysulfide polymer. More preferably, it is 1 to 50 parts by weight, and still more preferably, 1 to 30 parts by weight.

  As curing accelerators, there may be mentioned aldehydes, ammonia and aldehydes, amines, thioureas, guanidines, thiazoles, sulfenamides, thiurams, dithiocarbamates, xanthates, etc. . The curing accelerator is preferably a thiuram vulcanization accelerator or a guanidine vulcanization accelerator. More preferably, it is tris (dimethylaminomethyl) phenol, diphenylguanidine, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, hexamethylenetetramine.

  The content of the curing accelerator is set according to the curing speed of the curable composition and the temperature of use, but is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the liquid polysulfide polymer. More preferably, it is 1 to 5 parts by weight, still more preferably 1 to 3 parts by weight.

  The curable composition of the present invention is a multifunctional crosslinking agent, an adhesion promoter, an ultraviolet absorber, an antioxidant, a tackifier, a rubber / elastomer, a fungicide, depending on the use of the curable composition. It may also contain at least one of corrosion inhibitors, pigments, masking agents or additives having different effects.

  Examples of the polyfunctional crosslinking agent include trimethylolpropane trimercaptopropionate, trimethylolpropane trimercaptoacetate, pentaerythritol-tetrakis-3-mercaptopropionate and the like. You may use Thiokol LP, polythiol QE-340M, etc. with a high crosslinking rate. Moreover, you may use 2 or more types of said polyfunctional crosslinking agents.

  The adhesion promoter includes a silane coupling agent containing a hydrolyzable silyl group and a reactive organic functional group. Specifically, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4 epoxycyclohexyl) 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- 3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide and the like. In addition, a terminal trimethoxysilane-modified polysulfide polymer synthesized by reacting the polysulfide polymer "Thiocol LP-3" described in JP-A No. 6-271833 with 3-glidoxypropyltrimethoxysilane is also used as a silane coupling agent. Can. Two or more of these silane coupling agents may be used.

  Examples of the UV absorber include benzophenones, benzotriazoles, phenyl salicylates, triazines, nickel salts and nickel complex salts. Specifically, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- [2-hydroxy-3 (3,4,5,6-tetra-hydrophthalimidomethyl) -5-methylphenyl] ben Sotriazole, 2- (2-hydroxy-3-t-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-4-octylphenyl) benzotriazole, 2- (2-hydroxy-) 3,5-t-Butylphenyl) benzotriazole, 2- (2-hydroxy-3,5-t-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-5-t-octylphenyl) benzo Triazole, 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole, nickel dibutyl dithiocarb Over DOO, [2,2'-thiobis (4-t-octyl phenolate)] - 2-ethylhexylamine - such as nickel and the like.

  Examples of the antioxidant include amine-based antioxidants, phenol-based antioxidants, phosphite-based antioxidants, and thioether-based antioxidants. Specifically, 1,3,5-tris [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] -1,3,5-triazine-2,4,6 ( 1H, 3H, 5H) -trione, 1,1,3-tris (5-tert-butyl-4-hydroxy-2-methylphenyl) butane, 1,1-bis (4-hydroxy-2-methyl-5-) tert-Butylphenyl) butane, 2,2-bis [[[[3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] oxy] methyl] propane-1,3-diol 1,3-diol Bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], bis (3-tert-butyl-4-hydroxy-5-methylbenzenepropanoic acid) ethylene bis (oxyethylene) ), 4,4 ', 4' '-[(2,4,6-trimethylbenzene-1,3,5-triyl) tris (methylene)] tris (2,6-di-tert-butylphenol) etc. Be

As a tackifier, a phenol resin, coumarone-indene resin, coumarone resin, naphthene oil, rosin, rosin ester, hydrogenated rosin derivative, terpene resin, modified terpene resin, terpene / phenol resin, hydrogenated terpene resin, α- pinene resins, alkylphenol-acetylene resin, alkylphenol-formaldehyde resins, styrene resins, C ₆ petroleum resins, C ₉ petroleum resins, alicyclic petroleum resins, C 6 _/ C ₉ copolymer petroleum resin, Xylene-formaldehyde resin etc. are mentioned.

  As rubbers and elastomers, natural rubber, polybutadiene rubber, acrylic rubber, polyisoprene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, olefin elastomer, styrene elastomer, vinyl chloride elastomer, polyester elastomer, polyamide Based elastomers, polyurethane elastomers, polysiloxane elastomers, etc. may be mentioned.

  The powdery polysulfide-containing composition of the present invention has oil resistance, chemical resistance, weather resistance, water tightness, air tightness, barrier properties to various gases, impact resistance, as in the case of a curable composition using a conventional liquid polysulfide polymer. It has the characteristics of excellent elasticity, vibration control characteristics, electrical characteristics and flexibility. The powdery polysulfide of the present invention greatly contributes to the improvement of the properties of the sealing material.

  As to the powdered polysulfide-containing composition of the present invention, AS 5127/1 (Aerospace Standard Test Methods for Aerospace Sealants Two-Component Synthetic Rubber Compounds) 8. Test pieces were prepared and subjected to the peel test according to the described peel test method.

Powdery polysulfide-containing composition of the present invention, peel strength, preferably, a 2300N / mm ^2, more preferably, 2500N / mm ^2, even more preferably 3000N / mm ^2.

  The powdery polysulfide-containing composition of the present invention preferably has a cohesive failure (CF) rate of 90 to 100% or more, more preferably 95 to 100%, still more preferably 100% in a peel test. is there.

  The powdery polysulfide-containing composition of the present invention can be used as an adhesive, sealing material, potting material, coating material, modifier for resin, primer and the like, and in particular, for aircraft, for vehicles, for civil engineering and construction, And it is most suitable as a sealing material for electricity and electronics. The curable composition of the present invention is excellent in oil resistance, weather resistance, water tightness, and airtightness, and further has good adhesion, so it is particularly suitable for a sealing material for aircraft.

  The invention is further illustrated by the following examples.

(1) Measurement of particle size distribution of powdery polysulfide Four stainless steel test sieves with openings of 425 μm, 180 μm, 100 μm and 53 μm (frame diameter of 75 mm, depth of 20 mm according to JIS Z 8801) The resulting powdery polysulfide 2 g was placed on top of the sieve, and manually sieved for 5 minutes while tapping the frame by hand. The weight of the powder remaining on the sieve or pan was measured and divided by the total amount to determine the sieve residue (%) in each particle size range.

(2) Presence rate of particles of 425 μm or more of powdered polysulfide A stainless steel test sieve with an opening of 425 μm (a frame 75 mm in diameter, 20 mm in depth conforming to JIS Z 8801) was used. The powdery polysulfide stored at 23 ° C. for 24 hours was placed in a stainless steel test sieve with an opening of 425 μm, and manually sieved for 5 minutes while tapping the frame by hand. The mass of the powder remaining on the sieve was measured and divided by the total amount to determine the abundance of particles of 425 μm or more in powdered polysulfide.

(3) Measurement of particle size distribution of powdered polysulfide after storage at 50 ° C. The powdered polysulfide was sealed and stored in a 50 ° C. thermostat. Thereafter, the powdery polysulfide was returned to room temperature, and the presence ratio of particles of 425 μm or more of the powdery polysulfide was measured in the same manner as (2).

(4) Preparation of main component of curable composition As a main component, liquid polysulfide polymer (Thiocol "LP-32" or "LP-55", Toray Fine Chemical Co., Ltd.), powdery polysulfide, precipitated carbon dioxide with the following composition Calcium, ground calcium carbonate, fumed silica, hollow spheres and 3-glycidoxypropyltrimethoxysilane were mixed using a mixer.
-Thiokol "LP-32" or "LP-55" 100 parts by weight (manufactured by Toray Fine Chemicals Co., Ltd.)
Powdered polysulfide 4 parts by weight Precipitated calcium carbonate (Shiroishi calcium white glaze CCR) 25 parts by weight Fumed silica (Evonik Aerosil R 202) 0.80 parts by weight Hollow spheres (Nippon Phillite Expander 551 DE 20) 0. 73 parts by weight · 3-glycidoxypropyl trimethoxysilane 0.50 parts by weight (manufactured by Toray Dow Corning SH-6040)
(5) Measurement of viscosity of main agent Viscosity of viscometer made by Toki Sangyo Co., Ltd. The main agent viscosity was measured at 23 ° C. using H7 at a rotational speed of 1 rpm.

(6) Preparation of Curing Agent of Hardening Type Composition As a curing agent, manganese dioxide, phthalic acid based plasticizer, tetramethylthiuram disulfide, and diphenyl guanidine were kneaded using a triple roll mill according to the following composition.
Manganese dioxide (Honeywell Type FA) 10 parts by weight Phthalic acid plasticizer (Valtris sancizer 278) 10 parts by weight Tetramethyl Thiuram Disulfide (Ouchi emerging chemical industry Noxceler TT) 0.5 parts by weight Diphenylguanidine (Ouchi Shinko Chemical Noxeseller D) 0.5 parts by weight.

(7) Preparation of Cured Product The main agent and the curing agent obtained as described above were mixed at a weight ratio of 10: 1, thoroughly kneaded with a spatula, and then cured to prepare a cured product.

(8) Measurement of peel strength and adhesion by peel test AS 5127/1 (Aerospace Standard Test Methods for Aerospace Sealants Two-Component Synthetic Rubber Compounds) 8. Test pieces were prepared and subjected to the peel test according to the described peel test method. As a panel base material, JIS H4000 A2024PT3 treatment (1.6 × 70 × 150 mm) manufactured by Engineering Test Service Co., Ltd. was used, and SUS304φ0.2530MESH was used as a steel wire cloth pulled 180 ° with respect to the panel base material. As a primer, Hamatite primer no. Using a 40 (Yokohama rubber), the curable composition was aged for 2 weeks in an atmosphere of 23 ° C. and 50% RH to prepare a peel test piece.

  The peel test was carried out using an Orientec Tensilon RTF-1325, moving the wire cloth downward at 50 mm / min and cutting with a cutter knife at intervals of about 25 mm. Moreover, the state in a peeling surface was confirmed visually and the cohesive failure (CF) rate was evaluated. The number of tests was 1 sample, n = 2, and the average value was taken as the measurement result. A model diagram of cohesive failure (CF) rate 100% is shown in FIG. A model diagram of cohesive failure (CF) rate 75% is shown in FIG. 2, a model diagram of cohesive failure (CF) rate 50% is shown in FIG. 3, and a model diagram of cohesive failure (CF) rate 15% is shown in FIG.

(9) Measurement of Dumbbell Tensile Properties The curable composition was sandwiched by an iron plate adjusted to have a gap of 2 mm, and cured for 2 weeks in an atmosphere of 23 ° C. and 50% RH to prepare a sheet-like cured product. Three dumbbell test pieces were cut out from the sheet-like cured product having a diameter of about 120 mm × 2 mm using a punching blade adjusted to a dumbbell shape No. 5 according to JIS K6251.

Dumbbell tensile properties and hardness were measured in an atmosphere at 23 ° C. Dumbbell tensile properties were carried out at 500 mm / min using Tensilon RTA-500 manufactured by Orientec Co., Ltd. by attaching a 20 mm standard line to the cut out dumbbell test piece. In the dumbbell tension measurement, M ₁₀₀ (N / mm ² ) is the stress at 100% elongation (when the marked line reaches 40 mm), T _max (N / mm ² ) is the maximum tensile stress, and E _max (%) is It is the elongation at maximum load. The number of tests was one, n = 3, and the average value was taken as the measurement result.

(10) Measurement of Hardness Three dumbbell test pieces are cut out from a sheet-like cured product having a diameter of about 110 mm × 2 mm, and the remaining sheets are stacked to obtain a block-like cured product having a thickness of about 50 mm × about 50 mm × 8 mm. did. The hardness of the cured product adjusted to a block shape having a thickness of 8 mm was measured with a type A durometer according to JIS K6253 in an atmosphere at 23 ° C.

Synthesis example 1
In a 2 L separable flask equipped with a thermometer, a stirrer, a condenser and a jacket, 230 g of a 20% aqueous solution of sodium disulfide was charged, and the temperature was raised to 60 ° C. while stirring. Next, 0.4 g of Sandead Chemical Industries, Ltd. Sanded XB-L (a mixture of 34% by weight of anionic surfactant and 66% by weight of water), 4.5 g of 10% aqueous solution of sodium hydroxide and 6% aqueous solution of magnesium chloride 9. 0 g was added, and a mixture of 55.7 g of bis (2-chloroethyl) formal and 0.3 g of 1,2,3-trichloropropane was added dropwise, and reacted at 90 ° C. for 3 hours. Next, 950 g of water was added, stirring was stopped, and after standing for 1 hour, the supernatant was removed by decantation. Thereafter, the same water washing was carried out 5 times to obtain 100 g of an aqueous latex of 50% by weight of polysulfide rubber particles.

Example 1
To 100 parts of an aqueous latex (solid content: 50% by weight, water: 50% by weight) of the polysulfide rubber particles synthesized in Synthesis Example 1, 100 parts of a 2% by weight aqueous sodium stearate solution prepared at 75 ° C. is added and stirred. While cooling with a water bath for 30 minutes. The latex slurry solution was subjected to solid-liquid separation and then rinsed with 50 parts of water to remove water-soluble impurities. Subsequently, the filter cake was placed in a vacuum dryer, dried at 60 ° C. and 5 Torr, for 12 hours, and then lightly ground in a mortar to obtain a powdery polysulfide surface-treated with sodium stearate. The results of measuring the particle size distribution are shown in Table 1.

  The powdery polysulfide of Example 1 stored at 23 ° C. for 24 hours was placed in a stainless steel test sieve with an opening of 425 μm, and the abundance ratio (%) of particles of 425 μm or more was determined. The results are shown in Table 2.

  The powdery polysulfide of Example 1 was stored in a sealed manner in a 50 ° C. thermostat. The condition was confirmed after 1 and 6 months, but no aggregation was observed in any of them. Further, it was charged into a sieve with an aperture of 425 μm and sieved to determine the percentage (%) of particles having a diameter of 425 μm or more. The results are shown in Table 2.

Example 2
To 100 parts of an aqueous latex (solid content: 50% by weight, water: 50% by weight) of the polysulfide rubber particles synthesized in Synthesis Example 1 was added 100 parts of a 2% by weight aqueous solution of sodium stearate prepared at 75 ° C. Then, 8.5 parts of a 5% by weight aqueous solution of magnesium sulfate was slowly dropped, and cooled with a water bath for 30 minutes while stirring. The latex slurry solution was subjected to solid-liquid separation and then rinsed with 50 parts of water to remove water-soluble impurities. Subsequently, the filter cake was put in a vacuum drier, dried at 60 ° C. and 5 Torr, for 12 hours, and then lightly ground in a mortar to obtain powdery polysulfide surface-treated with magnesium stearate. The results of measuring the particle size distribution are shown in Table 1.

  The powdery polysulfide of Example 2 stored at 23 ° C. for 24 hours was placed in a stainless steel test sieve with an opening of 425 μm, and the abundance ratio (%) of particles of 425 μm or more was determined. The results are shown in Table 2.

  The powdered polysulfide of Example 2 was stored in a sealed manner in a 50 ° C. thermostat. The condition was confirmed after 1 and 6 months, but no aggregation was observed in any of them. Further, it was charged into a sieve with an aperture of 425 μm and sieved to determine the percentage (%) of particles having a diameter of 425 μm or more. The results are shown in Table 2.

Comparative Example 1
To 100 parts of an aqueous latex (solid content: 50% by weight, water: 50% by weight) of polysulfide rubber particles synthesized in Synthesis Example 1 was added 75 parts of a 2% by weight solution of ethanol in stearic acid to perform surface treatment of the latex particles. The The latex slurry was filtered and rinsed with 50 parts of water to remove water-soluble impurities. The filter cake was put in a vacuum drier, dried at 50 ° C. and 5 Torr, for 12 hours, and then lightly ground in a mortar to obtain a powdery polysulfide surface-treated with stearic acid. The results of measuring the particle size distribution are shown in Table 1.

  The powdery polysulfide of Comparative Example 2 stored at 23 ° C. for 24 hours was placed in a stainless steel test sieve with an opening of 425 μm, and the abundance ratio (%) of particles of 425 μm or more was determined. The results are shown in Table 2.

  The powdered polysulfide of Comparative Example 1 was sealed and stored in a 50 ° C. thermostat. The condition was confirmed after one month and six months, but in each case aggregation was observed. Further, it was charged into a sieve with an aperture of 425 μm and sieved to determine the percentage (%) of particles having a diameter of 425 μm or more. The results are shown in Table 2.

  As shown in Table 1, the powdery polysulfides of Example 1 and the powdery polysulfides of Example 2 were less in the absence of particles of 425 μm or more, and in the particles of 180 to 425 μm in 4%. The powdery polysulfide of Comparative Example 1 was relatively free of particles of 425 μm or more, and particles of 180 to 425 μm were 22%.

  As shown in Table 2, although the stearic acid-treated powdery polysulfide of Comparative Example 1 was in the form of powder after storage at 23 ° C. for 24 hours, aggregation occurred after one month at 50 ° C. and six months at 50 ° C. It is seen that particles of 425 μm or more increase. On the other hand, the powdery polysulfide treated with sodium stearate in Example 1 and the powdery polysulfide treated with magnesium stearate in Example 2 show no aggregation even after 50 ° C. for 6 months, and are 425 μm or more. There were no particles present. The sodium stearate-treated powdered polysulfide of Example 1 and the magnesium stearate-treated powdered polysulfide of Example 2 have improved storage stability.

Example 3
Using 4 parts of the powdery polysulfide of Example 1 with respect to 100 parts by weight of a liquid polysulfide polymer (Thiocol "LP-55", manufactured by Toray Fine Chemical Co., Ltd.), the main agent was prepared with the composition described in Table 3. The viscosity of the main agent is described in Table 3.

  The main agent and the curing agent were mixed at a weight ratio of 10: 1, thoroughly kneaded with a spatula, and then cured to form a cured product. Peel test, dumbbell tensile properties, hardness were measured. The obtained values are shown in Table 3. A model diagram of cohesive failure (CF) rate 100% is shown in FIG. Cohesive failure occurred on the adhesive surface in the peel test.

Example 4
The amount of the powdery polysulfide of Example 1 was changed to 2 parts by weight, and the peel test, the dumbbell tensile properties, and the hardness were measured in the same manner as in Example 3. The obtained values are shown in Table 3. In the peel test, cohesive failure occurred on all adhesive surfaces.

Example 5
The amount of the powdered polysulfide of Example 1 was changed to 1 part by weight, and the peel test, the dumbbell tensile properties, and the hardness were measured in the same manner as in Example 3. The obtained values are shown in Table 3. Cohesive failure occurred on the adhesive surface in the peel test.

Example 6
The amount of the powdered polysulfide of Example 1 was changed to 6 parts by weight, and the peel test, the dumbbell tensile properties, and the hardness were measured in the same manner as in Example 3. The obtained values are shown in Table 3. Cohesive failure occurred on the adhesive surface in the peel test.

Example 7
The amount of the powdery polysulfide of Example 1 was changed to 8 parts by weight, and the peel test, the dumbbell tensile properties, and the hardness were measured in the same manner as in Example 3. The obtained values are shown in Table 3. Cohesive failure occurred on the adhesive surface in the peel test.

Example 8
The amount of the powdered polysulfide of Example 1 was changed to 10 parts by weight, and the peel test, the dumbbell tensile properties, and the hardness were measured in the same manner as in Example 3. The obtained values are shown in Table 3. Cohesive failure occurred on the adhesive surface in the peel test.

Example 9
Using the powdered polysulfide of Example 2 in place of the powdered polysulfide of Example 1, the peel test, the dumbbell tensile properties, and the hardness were measured in the same manner as in Example 3. The obtained values are shown in Table 3. Cohesive failure occurred on the adhesive surface in the peel test.

Comparative example 2
A peel test, dumbbell tensile properties, and hardness were measured in the same manner as in Example 3 except that 4 parts by weight of a phenol resin (PR-12603 manufactured by Sumitomo Bakelite) was used instead of the powdered polysulfide of Example 1. The obtained values are shown in Table 3. A model diagram of a cohesive failure (CF) rate of 75% is shown in FIG. In the peel test, the ratio of the cohesive failure area was about 3/4 of the entire adhesive surface.

Comparative example 3
The amount of the powdery polysulfide of Example 1 was changed to 0 parts by weight (unadded), and the peel test, the dumbbell tensile properties, and the hardness were measured in the same manner as in Example 3. The obtained values are shown in Table 3. A model diagram of a 50% cohesive failure (CF) rate is shown in FIG. The percentage of the cohesive failure area was about half of the entire adhesive surface.

Comparative example 4
A peel test, dumbbell tensile properties, and hardness were measured in the same manner as in Example 3 using 4 parts by weight of sodium stearate (manufactured by Junsei Chemical Co., Ltd.), which was ground with a mortar instead of the powdery polysulfide of Example 1. The obtained values are shown in Table 3. A model diagram of a cohesive failure (CF) rate of 15% is shown in FIG. The percentage of the cohesive failure area was about 15% of the entire adhesive surface.

Comparative example 5
A peel test, a dumbbell tensile property, and hardness were measured in the same manner as in Example 3 using the powdered polysulfide of Comparative Example 1 instead of the powdered polysulfide of Example 1. The obtained values are shown in Table 3. Cohesive failure occurred on the adhesive surface in the peel test.

Example 10
The peel test, the dumbbell tensile properties, and the hardness were measured in the same manner as in Example 3 using Thiocol “LP-32” (manufactured by Toray Fine Chemical Co., Ltd.) in place of Thiocol “LP-55” in Example 3. The obtained values are shown in Table 4. Cohesive failure occurred on the adhesive surface in the peel test.

Example 11
A peel test, dumbbell tensile properties, and hardness were measured in the same manner as in Example 10 using the powdered polysulfide of Example 2 in place of the powdered polysulfide of Example 1. The obtained values are shown in Table 4. Cohesive failure occurred on the adhesive surface in the peel test.

Comparative example 6
Peel test, dumbbell tensile properties in the same manner as in Example 10 except that the amount of powdery polysulfide of Example 1 is 0 parts by weight (unadded) and 4 parts by weight of a phenol resin (PR-12603 made by Sumitomo Bakelite) is mixed. The hardness was measured. The obtained values are shown in Table 4. The percentage of the cohesive failure area was about 85% of the entire adhesive surface.

As shown in Tables 3 to 5, compositions (Examples 3 to 11) containing the powdery polysulfide of the present invention have high peel strength. In addition, the adhesion is high because the cohesive failure (CF) rate is high.
When the powdery polysulfide of the present invention is not contained (Comparative Examples 2 to 6), the peel strength is low.

Claims (6)

Powdered polysulfide surface-treated with sodium stearate having less than 10% by weight of agglomerated particles of 425 μm or more after storage at 50 ° C. for 6 months. Powdered polysulfide surface-treated with magnesium stearate having an amount of aggregated particles of 425 μm or more after storage at 50 ° C. for 6 months is less than 10% by weight. The powdered polysulfide according to claim 1 or 2, wherein the amount of aggregated particles of 180 to 425 μm is less than 10% by weight before storage at 50 ° C for 6 months. A powdered polysulfide-containing composition comprising the powdered polysulfide according to claim 1, a liquid polysulfide polymer, and manganese dioxide. A powdered polysulfide-containing composition comprising the powdered polysulfide according to claim 2, a liquid polysulfide polymer, and manganese dioxide. The powdery polysulfide-containing composition according to claim 4 or 5, wherein the peel strength is 2300 N / mm ² .