JPH0332580B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel room temperature curable silicone composition, particularly a moisture curable one-component composition comprising a silyl urea compound and an organic compound of titanium or zirconium. Various types of room-temperature-curable silicone curing compositions have been proposed, such as deacetic acid type, dealcoholized type, deamined type, and deoxime type, but they produce corrosive by-products, have a slow curing speed, or have problems with adhesion. As is well known, it had drawbacks such as low power. Therefore, there has been a need to develop a moisture-curing composition that does not generate corrosive products during curing and exhibits a rapid curing rate. Therefore, the present inventors investigated compositions using a new crosslinking agent and curing agent system, and found that the compositions containing a silyl urea compound and an organic compound of titanium or zirconium were favorable as they did not produce corrosive by-products. The inventors have discovered that this material exhibits excellent moisture curing properties, leading to the present invention. Thus, the present invention provides a terminal hydroxydiorganopolysiloxane with three or more

The present invention provides a silicone curing composition containing a silyl urea compound having a bond of the formula: and an organic compound of titanium or zirconium. As mentioned above, the silyl urea compound that can be used in the present invention has three or more silyl urea compounds in the molecule.

[Formula] A compound having a bond, and this compound can be easily synthesized by reacting silyl isocyanate with ammonia, organic amine, silylamine, etc. To illustrate this compound,

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etc. can be mentioned. The silyl urea compounds are used in addition to terminal hydroxy polyorganosiloxanes, such as ω,ω'-dihydroxydimethylpolysiloxanes, ω,ω'-dihydroxymethylphenylpolysiloxanes. Compounds with various viscosities of terminal hydroxydiorganosiloxane are known, so it is possible to use a compound with a viscosity depending on the purpose of use. The viscosity is not particularly limited, but if the molecular weight is low, the physical properties of the product may not be sufficient, so it is generally 25
It is desirable to use a material with a temperature of 500 cps or more at °C. Practical moisture curing performance cannot be obtained simply by mixing a silyl urea compound with a terminal hydroxydiorganopolysiloxane. In order to obtain practical performance, it is necessary to further add an organic compound of titanium or zirconium. Organic compounds of titanium or zirconium that can be used as curing agents are alkoxides, chelates, and acylates of these metals, or have at least one Ti-O-P bond or Zr-O- in the molecule.
It is preferably a non-aqueous compound that has a P bond, does not contain inorganic anions such as inorganic halogen groups, sulfate groups, and nitrate groups and can be dissolved in the terminal hydroxydiorganopolysiloxane. Examples of such compounds include the following compounds. Namely, titanium tetraisopropoxide, titanium tetrabutoxide, butoxytitanium polymer, zirconium tetrapropoxide, zirconium butoxide, butoxyzirconium polymer, diisoproboxytitanium bisacetylacetonate, dibutoxyzirconium bisacetylacetonate, propylene glycol titanium bismethylacetonate. Acetate, ethylene glycol titanium bisacetylacetonate,
Ethylene glycol zirconium bisacetylacetonate, octylene glycol titanium, hexylene glycol zirconium, triethanolamine titanate, triethanolamine zirconium, diethanolaminoxy titanium bisacetylacetonate, dibutoxytitanium adipate, butoxyzirconium phthalate, zirconium octoate, zirconium Naphthate, tetrakis (dibutyl phosphate) titanium, bis (monobutyl phosphate) titanium, bis (butyl pyrophosphate) titanium, tetrakis (dibutyl phosphate) zirconium, and bis (monobutyl phosphate) zirconium. These titanium and zirconium compounds include primary, secondary, and tertiary amines such as dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-butylamine, pyridine, picoline, toluidine, dimethyl-p-toluidine, morpholine, and monoethanolamine. ,
It can also be used in the form of adducts such as trimethylsilylamine and trimethylsilylethylamine. When preparing a composition, silyl urea should be added to 100 parts of terminal hydroxydiorganopolysiloxane.
If it is less than 0.1 part, the crosslinking effect will not be sufficient, and if it is more than 20 parts, there will be disadvantages such as excessive crosslinking.
It is advisable to use 20 parts, particularly preferably 0.5 to 10 parts. Also, organic compounds of titanium and zirconium
If the amount is 0.05 parts, the curing speed will not be sufficient, and if it exceeds 10 parts, the physical properties of the silicone rubber will be diminished, so it is desirable to use 0.05 to 10 parts, particularly preferably 0.1 to 5 parts. Silica, calcium carbonate, talc, titanium oxide, zinc oxide, carbon black, aluminum powder, copper powder, glass fibers, metal fibers, etc. can be added to this composition if desired.
Further, if desired, a coloring agent or the like may be added. When preparing the composition, it is desirable to sufficiently dehumidify and dry the equipment and materials used. Although the physical properties of the prepared composition vary depending on the formulation,
A composition made by adding a vinylsilyl triurea compound and tetrakis (dibutyl phosphate) titanium to 3000 cp ω, ω′ dihydroxydimethylpolysiloxane has excellent fluidity and is dry to the touch at 60% RH and 23°C in 25 minutes. It has good adhesion to materials and does not produce corrosive by-products, so it is effective as a protective film for electronic components. According to the method of the present invention, it can be used as a sealant, coating agent, molding agent, etc. in architecture, electrical equipment, vehicles, etc.
Effective in civil engineering and other industrial fields, as well as in the field of daily necessities. Examples and comparative examples are listed below. In this specification, parts represent parts by weight. Example 1-10 To 100 parts of a mixture prepared at 25°C by mixing 2000 cps and 10000 cps of ω, ω' dihydroxydimethylpolysiloxane to 3000 cps, 5 parts of vinylsilyl tris-urea and 1.5 parts of the following titanium or zirconium compound were added.
A composition was obtained by thoroughly mixing and dissolving the mixture in a dry system. The resulting composition was stable for more than 3 months in a closed container and exhibited good curability when applied to a glass plate to a thickness of 0.5 mm.

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*23℃ 62%RH
Comparative Example In Example-1, the composition that did not use titanium or zirconium organic compounds had a dry-to-touch time of 24 hours or more under the same conditions as Example-1, which was not preferable. Example 11 10 parts of surface trimethylsilylated silica (320 mesh or less) was added to 100 parts of the composition of Example 6 and uniformly kneaded to obtain a translucent composition. When this composition was applied to a polished copper plate to a thickness of 0.5 mm, the drying time to the touch was 20 minutes at 23°C and 62% RH, and there was no discoloration of the copper plate. After this film was left for 72 hours under the same conditions, the surface resistance of the cured film was 1.8×10 ^-15 Ω/mouth. Example 12 100 parts of ω, ω′ dihydroxydimethylpolysiloxane of 30,000 cps at 25°C, methylsilyltritris urea, 20 parts of titanium oxide of 320 mesh or less, 20 parts of titanium-treated calcium carbonate, 2 parts of zirconium octoate, and diisopropoxytitanium bis 1.5 parts of acetylacetonate was added and thoroughly kneaded in a dehumidifying system to obtain a white paste. This paste is stable for more than 3 months at 25°C in a closed container, and when applied to aluminum or glass surfaces, it takes 15 minutes to dry to the touch, and the adhesion to the substrate is good, resulting in no discoloration of metal surfaces. There was no.

Claims (1)

[Claims] 1. A silicone curing composition containing a terminal hydroxydiorganopolysiloxane, a compound having three or more [Formula] bonds in the molecule, and an organic compound of titanium or zirconium. 2 The organic compound of titanium or zirconium contains at least one Ti-O-P or Zr in the alkoxide, chelate, acylate or molecule of these metals.
2. The cured composition according to item 1, which is a phosphorus-containing organic compound having an -O-P bond or an amine adduct of these compounds.