JPS6018545A - Adhesive polyorganosiloxane composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having excellent durability and adhesivity, giving a cured product having excellent surface rubber elasticity, and compounded with a compound containing polyoxyalkylene chain to prevent the hydrolytic resinification of an organic silicon compound used as an adhesivity improving agent. CONSTITUTION:The objective composition is produced by compounding (A) 100pts.wt. of a polydiorganosiloxane of formula I (R<1> is univalent hydrocarbon group; n is a number to give the component A having a viscosity of 100-500,000 cP at 25 deg.C) and having terminals blocked with hydroxyl group, (B) 0.5-25pts.wt. of a silane compound containing >=3 ketoxime groups bonded to Si in a molecule, (C) 0.01-3pts.wt. of a curing catalyst, (D) 0.01-20pts.wt. of a silane compound of formula II (R<2> is organic group having >=1 amino group bonded through C to Si; R<3> is methyl; R<4> is 1-4C alkyl, etc.; a is 1 or 2; b is 0 or 1; a+b is 1 or 2) and (E) 0.1-50pts.wt. of a compound containing polyoxyalkylene chain.

Description

[Detailed description of the invention] The present invention is stable in the absence of moisture.

The present invention relates to a polyorganosiloxane composition that cures into a rubbery state at room temperature in the presence of moisture, and more particularly to an adhesive polyorganosiloxane composition that does not cause the surface of silicone rubber to become resinous.

Polyorganosiloxane compositions that are stable in a sealed, moisture-free state and harden at room temperature when exposed to moisture are widely known from Japanese Patent Publication No. 39-27643 and Japanese Patent Publication No. 40-21631, and are known for their so-called l-packaging. It is widely used as a shaped silicone sealant, coating material, elastic adhesive, etc. in industries such as architecture, civil engineering, electricity, electronics, and automobiles, as well as in general households. The adhesion and stability of such polyorcasiloxane compositions have been improved by adding various additives. For example, in order to improve the adhesion of such room temperature moisture-curing polyorganosiloxane compositions,
As seen in Publication No. 6-11272, excellent adhesive properties are obtained by adding an organosilicon compound in which a N-W substituted or unsubstituted aminoalkyl group and a hydrolyzable group are bonded to a silicon atom. There is.

However, when adding an organosilicon compound having a hydrolyzable group bonded to a silicon atom and a carbon functional group in one molecule, especially when the amount of the organosilicon compound added exceeds a certain limit, one composition Since the organosilicon compound is hydrolyzed after curing, the surface of the rubber-like hardened composition becomes resinous, resulting in a decrease in physical properties and durability. Therefore, in practical use, it has been difficult to add a sufficient amount of the organosilicon compound to improve adhesion and stability.

As a result of intensive studies aimed at preventing such surface resinization, the present inventors discovered that the composition contains a compound having a polyoxyalkylene chain, particularly polyoxyalkylene or a copolymer of polyoxyalkylene and polyorganosiloxane. The present inventors have discovered that by doing so, the surface resin formation can be prevented, and the present invention has been completed.

The following technique is known as an example of blending a compound having a polyoxyalkylene chain into a polyorganosiloxane composition that can be cured at room temperature.

(1) JP-A-54-127960 When adding 2-(4-thiazolyl)-benzimidazole as a mold inhibitor to moisture-curing polyorganosiloxane, the presence of a surfactant improves the mold prevention effect. . As the surfactant, those having a polyoxyalkylene button in the molecule may also be used.

(2) Japanese Patent Publication No. 56-34226 A moisture-curable polyorganosiloxane composition using a silicon compound having an acyloxy group, an acyloxy group and an alkoxy group, or an α,β-substituted vinyloxy group as a crosslinking agent has a polyoxyalkylene chain. When a polyorganosiloxane-polyoxyalkylene copolymer having a hydroxyl group at the terminal is blended, it is possible to impart so-called non-sag properties that do not sag in the uncured stage even when applied to a vertical surface.

(3) JP-A-55-60557 This is a technique for obtaining a moisture-curable elastic body from polyorganosiloxane and polyoxyalkylene into which a silicon-containing group with a silicon functional group bonded to the terminal is introduced. Compounds with alkylene buttons form an elastic network structure.

(4) JP-A-56-76452, JP-A-56-7
No. 6453: When a surfactant is blended into a moisture-curable polyorganosiloxane composition, particularly a composition using an organosilicon compound having a diorganoaminoxy group as a crosslinking agent, it has the effect of preventing surface staining. As the surfactant, one having a polyoxyalkylene button in one molecule may also be used.

However, none of these known documents mentions the prevention of surface resinization of the cured composition, which is the objective of the present invention, and the formulation of compounds having polyoxyalkylene chains is considered from a completely different perspective. ing. Accordingly, the present invention provides a new technique that cannot be more easily predicted than these existing techniques.

That is, the present invention focuses on the following components (A) to (E), namely (A) general formula HO[" 2 SlO] n H (wherein R1 is the same or different monovalent substituted or unsubstituted carbonized (Hydrogen group, n indicates the number that makes the viscosity of (A) at 25°C 100 to 500, OOO, cP)
100 parts by weight of a polydicasiloxane whose terminals are blocked with hydroxyl groups represented by (B) 0.5 to 0.5 parts by weight of a silane or a partially hydrolyzed condensate thereof having three or more ketoxime groups bonded to silicon atoms in one molecule 25 parts by weight, (C) curing catalyst 0. 1 to 3 parts of O, (0) General formula R2RheSl (OR') 4-a
-5 (However, R2 is an organic group containing at least one substituted or unsubstituted 7-amino group bonded to a silicon atom through a carbon atom, R3 is a methyl group, and R4 is a C1-C4 Alkyl group or alkoxyalkyl group having a total of 1 to 6 carbon atoms, a is the number 1 or 2, b is O or l
, a+b indicates the number 1 or 2). O1~2o*! k) part, and (hi) polyoxyalkylene chain-containing compound (1,1-5
The present invention relates to an adhesive polyorganosiloxane composition characterized in that it comprises 0 parts by weight.

The polydiol methioxane (A) used in the present invention is generally 2〇〇[R25iO]nH(R
', n are as described above), and is an α,ω-dihydroxypoly(diocassiloxane) having a viscosity of 100 to 500.0QQcP at 25°C. R1
Examples include monovalent hydrocarbon groups such as methyl, ethyl, propyl, butyl, vinyl, and phenyl groups;
Examples include monovalent substituted hydrocarbon groups such as chloromethyl group, cyanethyl group, and 3,3.3-trifluoropropyl group. It is preferable that 85% or more of R1 is a methyl group in order to have an appropriate curing speed, appropriate wave properties before curing and ease of handling, and physical properties after curing, especially low modulus. For ease of use, it is best for all of R1 to be methyl groups, but if heat resistance and cold resistance are particularly required, phenyl groups are preferably used as part of R1. The range of n varies depending on the type of R1 and its molar ratio, but based on ease of handling, fluidity of the composition, physical properties after curing, etc., the viscosity of (A) at 25°C is 100 to 5.
00,0θOcP, and when all R1 are methyl groups, n is 20 to 3,00 (corresponds to 1).Among these, it is more preferable that the viscosity is between 500 and 200,000 cP. This is because if it is lower than this range, it becomes difficult to obtain good physical properties, and if it is higher than this range, extrusion workability and curing properties tend to deteriorate.

(B) used in the present invention is a crosslinking agent that crosslinks (A) to give a network structure, and for this purpose, silane having three ketoxime groups bonded to a silicon atom or a partially hydrolyzed condensate thereof is used. things are used. Examples of the ketoxime group bonded to a silicon atom include dialkylketoxime groups such as dimethylketoxime group, diethylketoxime group, and methylethylketoxime group;
Examples of such compounds include methyltris(diethylketoxime)silane, methyltris(methylethylketoxime)silane, vinyltri(methylethylketoxime)silane, phenyl;・su(methylethylketoxime)silane, and partially hydrolyzed condensates thereof. Examples are given as representative examples. Although these dialkyl ketoxime group-containing silanes are slightly corrosive to copper-based metals, they are not corrosive to other metals, and have a good balance of properties such as curing speed and adhesion.
It has no irritating odor and is easy to synthesize. The amount of component (B) silane or its partially hydrolyzed condensate added is 0.5 to 2.
The amount is 5 parts by weight, preferably 3 to 10 parts by weight.
If it is less than 0.5 parts by weight, it will be insufficient as a crosslinking agent and the curability of the composition will decrease, and if it is more than 25 parts by weight, it will be liberated and form a film on the surface, increasing the modulus. .

The curing catalyst (C) used in the present invention includes carboxylic acid metal salts such as iron octoate, cobalt octoate, manganese octoate, zinc octoate, tin naphthinate, tin cabrylate, and tin oleate; dibutyltin diacetate, dibutyltin dioctoate; ,
Examples include organic tin compounds such as dibutyltin dilaurate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diacetate, dibutyltin dimethoxide, dibutylbis(triethoxysiloxy)tin, and dioctyltin dilaurate, but only in trace amounts. Organic tin compounds are strongly preferred, since they have a large catalytic ability in the presence of a dicarboxylic acid, and among them, dicarboxylic acid salts, which have good curability, are particularly preferred. The amount of the hard hard catalyst (C) added is 0.01 to 3 parts. If the amount added is less than this, it will not work as a curing catalyst and will take a long time to cure, and curing will be poor in areas far from the contact surface with air. If the amount is more than 4m, it is not suitable because the stability of the composition decreases. More preferably, the range of the amount of I/) dissipating power (I) is 0.1 to 2 parts by weight.

Component (0) used in the present invention 1, general formula as shown in Nn R:R 1(OR'), a-b(R,R
,R.

a and b are silanes represented by (as described above). As mentioned above, such silanes are used as adhesion improvers for moisture-curable polyorganosiloxane compositions using crosslinking agents such as (B), but they do not cause the surface of the composition to become resinous after curing. There are drawbacks that lead to However, according to the present invention, the adhesion improver can be effectively used without such disadvantages due to component (E) described below. Among component (D), the carbon functional group is γ-aminopropyl group, δ-aminobutyl group, N-methyl-γ-aminopropyl group, N-(β-amino/ethyl)-γ-aminopropyl group. In some cases, the effect of improving adhesion is remarkable and plays an important role in imparting adhesion to the composition during curing, but on the other hand, they also have an effect on the surface resinization after curing. It's big. Examples of such compounds include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, δ-aminobutyltrimethoxysilane, δ-aminobutyltriethoxysilane.
- Shown are xysilane, N-methyl-γ-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane. The amount of component (D) added is 0.01 to 20 parts by weight, preferably 0.1 to 5 parts by weight.
Parts by weight. If the amount added is less than this, it will be insufficient to improve the adhesive properties, and if it is more than this, the storage stability of the composition will be lowered or yellowing will occur after curing.

The polyoxyalkylene chain-containing compound (E) used in the present invention forms the basis of the present invention, and (A) (
B) It is effective in preventing the surface of the rubber-like elastic body obtained by curing the composition consisting of (C) and (D) from becoming resinous and improving its physical properties and durability. Examples of the polyoxyalkylene group include a polyoxyethylene group, a polyoxypropylene group, and a polyoxytrimethylene group. Specific compounds include C4H3O[CH2C)I20], )I (p=5-5
00); G, H80ICH2(I20], CH3(p=
5-500);C4H90[CH2(I20]p[CH
2C)1(C)I3)019H(p+q=5-500.
p/q=0.01~+00).

)10rcH0H(CH)OIOH(q=5~400
)';2 3q C4)190[CH20H(C)I2)0190)!
(+1=5-400), their alkyl ethers, alkylphenyl ethers and (C:R3)3SiO[(CH3)25IO], [(O
H3) SIROI, 5r(OH3)3 (where R5 represents a polyoxyalkylene bonded to the silicon atom via one or more carbon atoms. X = 0-100
．． Examples include polyorcasiloxane-polyoxyalkylene copolymers such as y=1-20). All of these are commercially produced and easily available.

In the present invention, the amount of the polyoxyalkylene chain-containing compound (E) added is 0.000 parts per 100 parts by weight of (A).
The amount is 1 to 50 parts by weight, or 0.3 to 10 parts by weight. If it is less than 0.1 part by weight, the effect of preventing surface resin formation will not be exhibited, and if it is too much, it is not only meaningless and uneconomical, but also
The cured product becomes soft and oil bleed is more likely to occur.

In the present invention, fillers and other additives may be added as necessary.

Fillers include reinforcing and non-reinforcing fillers, and reinforcing fillers include fumed silica, pyrogenic silica,
Examples include precipitated silica, fumed titanium, and those whose surfaces are made hydrophobic with orcacchlorosilanes, polyorganosiloxanes, hexamethyldisilazane, etc. Non-reinforcing fillers include calcium carbonate,
Organic acid surface treatment includes calcium carbonate, diatomaceous earth, crushed silica, aluminosilicate, magnesia, alumina, etc. Note that, when a particularly low modulus is required, it is preferable to use a non-reinforcing filler among these fillers.

Additives include pigments, thixotropic agents,
It is also possible to add various additives to improve extrusion workability, such as a viscosity modifier, an ultraviolet inhibitor, a fungicide, a heat resistance improver, and a flame retardant.

The composition of the present invention can be obtained by mixing all of the above components and optionally various additives in a moisture-protected state.

The obtained composition can be stored as it is in a closed container and used as a so-called l-packaged room-temperature-curable polyorganosiloxane composite acid I, which is cured only by exposure to moisture in the air at the time of use. .

The composition of the present invention can also be used as a so-called two-pack room-temperature-curable polyorganosiloxane composition, in which these components are stored in separate containers as appropriate, and mixed at the time of use.

According to the present invention, it becomes easy to prevent the surface of a cured product of a room temperature moisture-curable polyorganosiloxane composition from becoming resinous, and it is possible to improve physical properties and durability. In addition, with this technology, even when a component (D) that has an adverse effect on the surface resinization of the composition after curing is used as an adhesion improver, the presence of (E) eliminates such an adverse effect while adding the component. You can increase the amount. Such compositions can be used as industrial, architectural or domestic sealants, coatings,
Useful as an elastic adhesive. Further, the composition according to the present invention is simple but highly effective because it contains an easily available polyoxyalkylene chain-containing compound, and it is also easy to produce.

The present invention will be explained in more detail with reference to Examples below. In the description of Examples, all parts mean parts by weight, and the viscosity is 25°C.
is the value at . In addition, in the examples, the following polyoxyalkylene chain-containing compounds include A-1 to
A-8 was used.

-1 (R2) 3UI to H2 to H20'' 14H-4 A-5 -13 Example 1 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 200,000cP was added with a specific surface area of 200rrf/
14 parts of dry process silica (g) was added and kneaded uniformly to obtain base comparan FB-1. On the other hand, 6 parts of methyltri(methylethylketoxime)silane, 3 parts of γ-aminopropyltriethoxysilane, and 1 part of dibutyltin dilaure were uniformly mixed to obtain a crosslinking agent mixture C-1.

Take 100 parts of base compound B-1, mix it with 6 parts of C-1, and the polyoxyalkylene chain-containing compound shown in Table 1 until the mixture becomes homogeneous while keeping moisture out. Samples 11 to 16 were prepared. In addition, comparative example sample 1 using a small amount of polyoxyalkylene chain-containing compound
Sample No. 17 and Comparative Example Sample No. 18 without using Sample No. 17 were prepared. These were extruded into a 2111 m sheet and cured by moisture in the air to obtain a rubber-like elastic body. The physical properties and surface conditions of these rubber-like elastic bodies were as shown in Table 1. Table 1 also shows the results of observing the conditions of these samples when they were stored in a sealed container for 6 months. Note that the physical properties of the rubber-like elastic body were measured according to JISK f (301).

Example 2 Ketoxime group-containing silanes, amide 7-group-containing silanes, and dibutyltin dilaurate shown in Table 2 were uniformly mixed to obtain crosslinking agent mixtures G-2 to G-6. Sample 21 was prepared by mixing 6 parts each of these crosslinking agent mixtures and 1 part each of polyoxyalkylene chain-containing compound A-1 with 1100 parts of the base compound B-1 used in Example 1 in the same manner as in Example 1. ~25 were prepared. These samples were cured in the same manner as in Example 1 to obtain rubber-like elastic bodies. The physical properties and surface conditions of these rubber-like elastic bodies are shown in Table 3, and no resinization of the surface was observed in any of them. In addition, these samples were stored in a sealed container for 6 months.
No changes were observed in either case.

Table 3 Example 3 To 100 parts of α,ω-dihydroxypolydimethylsiloxane with viscosity T & 10.000 cP, a specific surface area of 200 m'/
14 parts of dry process silica of 1.3 g was added and kneaded uniformly to obtain a base compound B-2. Samples 31 to 33 were prepared by mixing 8 parts of the crosslinking agent mixture C-1 used in Example 1 and the polyoxyalkylene chain-containing compounds shown in Table 4 in the same manner as in Example 1. These samples were cured in the same manner as in Example 1 to obtain rubber-like elastic bodies. The physical properties and surface conditions of these rubber-like elastic bodies are shown in Table 4, and no resinization of the surface was observed in any of them. In addition, samples for measuring tensile shear adhesive strength using aluminum as an adherend were prepared from these samples by the method of JIS K 6B50, and the shear adhesive strength was measured after curing. The results are also shown in Table 4.

Table 4 Example 4 To 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 3,000 cP, 14 parts of dry process silica with a specific surface area of 200 rn'/g and 20 parts of trimethylsilyl-terminated polydimethylsiloxane with a viscosity of 100 cP were added. , uniformly &! By kneading, a base compound B-3 was obtained. Sample 41 was prepared by mixing 17 parts of the crosslinking agent mixture C-1 used in Example 1 and 11 parts of the polyoxyalkylene chain-containing compound ^-1 in the same manner as in Example 1. Comparative Example Trial 142 was also prepared without using A-1. These samples were cured in the same manner as in Example 1 to obtain rubber-like elastic bodies. The physical properties and surface conditions of these rubber-like elastic bodies are shown in Table 5.

Claims (1)

[Claims] 1. Components (A) to (, E) of the following order, that is, (A) general formula HO[R2S + 0 ] n) 1 (however, R
1 is the same or different monovalent substituted or unsubstituted hydrocarbon group, n is the viscosity of (A) at 25 ° C
100 parts by weight of a polydicasiloxane whose terminal end is blocked with a water-resistant group represented by (representing the number of 100 to 500.000 cP), (B) 9 ketoxime groups bonded to a silicon atom, 3 per molecule. 0.5 to 25 parts by weight of a silane or a partially hydrolyzed condensate thereof having the above, (C) 0.01 to 3 parts by weight of a curing catalyst, 23 4 (D) General formula RR5i (OR) 4-a-bb (however, R2 has at least one substituted or unsubstituted amino group bonded to a silicon atom via a carbon atom in the molecule.
R is a methyl group, R4 is a carbon number of 1 to 4
7 alkyl group or alkoxyalkyl group having a total of 1 to 6 carbon atoms, a is the number 1 or 2, b is the number O or 1, a
+b indicates the number 1 or 2) Silane 0.0
1 to 20 parts by weight, and (E) 0.1 to 50 parts of polyoxyalkylene button-containing compound
An adhesive polyorcasiloxane composition comprising a heavy portion. 2. The composition according to claim 1, wherein R' is a methyl group. 3. The composition according to claim 1 or 2, wherein R2 is a γ-aminopropyl group. 4. The composition according to any one of claims 1 to 3, wherein 4(C) is a diorganotin dicarboxylate. 5. The composition according to any one of claims 1 to 4, wherein 5(E) is polyoxyalkylene. 5. The composition according to claim 1, wherein 6(E) is a polyorganosiloxane-polyoxyalkylene copolymer. 7. The composition according to claim 1, wherein the amount of 7(E) is 0.1 to 10 parts by weight.