JPH0160074B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an adhesive sealant, and more specifically, it is suitable as a sealant for joints in buildings, and particularly exhibits excellent adhesiveness (adhesiveness) without pre-treatment of the surface to which it is applied, and This invention relates to an adhesive sealant whose surface has good adhesion to general paints and spray materials. A polyorganosiloxane composition that cures at room temperature to form a rubber-like elastic body has excellent heat resistance, cold resistance, and weather resistance, and has little change in physical properties due to temperature.
In addition, it is widely used as a sealing material for buildings because of its low deterioration due to ozone and ultraviolet rays. However, when adhering these curable polyorganosiloxane compositions to adherends,
Pretreatment of the surface to be adhered is required, and adhesion may not be possible depending on the type of adherend. In addition, the exterior walls of buildings made of concrete, precast concrete, lightweight concrete, lightweight foamed concrete, etc. are filled with a sealant and then painted for aesthetic reasons and for the purpose of making the exterior wall material watertight. There are many things. Therefore, it is desirable to be able to paint the surface of the sealant filled in the joints of these exterior wall materials, but the adhesion of general paints to the surface of curable silicone sealants is poor, and the paint film is difficult to coat. There was a problem in that the material peeled off and fell off. Examples of sealant compositions that can provide good adhesion without pre-treating the surface to which they are adhered include a room temperature surface-curable polyorganosiloxane composition disclosed in JP-A-56-86951. It will be done. This composition consists of a silanol group-terminated polydiorganosiloxane, an aminoxy group-containing organosilicon compound having at least three aminoxy groups in one molecule directly bonded to silicon atoms, a monohydric alcohol or alkoxysilane, and an inorganic filler. It is. According to this composition, it is possible to obtain a rubber-like elastic body whose surface is hardened but whose interior is in a semi-hardened state with tackiness. It has good adhesive properties. however,
This elastic material has the problem that the hardened surface layer does not have adhesion with other general paints or spraying materials, and as a result, the applied paints or spraying materials peel off and fall off. In this respect, it is no different from conventional polyorganosiloxane sealants. However, according to the inventor's study, when monohydric alcohol is used as an additive, if its vapor pressure is less than 0.1 mmHg at 20°C, the hardening of the surface layer of the elastic body does not proceed, and its It was found that even after the inside was cured, the surface layer remained sticky. The present inventor previously developed a type of polyorganosiloxane that cures at room temperature by reacting a silanol group-endblocked polydiorganosiloxane with an aminoxy group-containing organic compound having an average number of organoaminoxy groups exceeding two in the molecule. By adding a primary or secondary monounsaturated alcohol having an alkynyl group to a siloxane composition, the resulting rubber-like elastic body has adhesive properties with general paints and spray materials on its surface. I discovered that it is something. However, like general curable sealing compositions, such elastic bodies require pretreatment on the surface to which they are adhered in order to adhere to the adherend. Depending on the type, it may be impossible to bond them together, which is a problem. On the other hand, as a non-curing sealant, a material is disclosed in which a silicon compound containing two amino groups or aminoxy groups is added to a silanol group end-capped polydiorganosiloxane and reacted with it (JP-A-Sho). 55-66983). However, since such sealants use only bifunctional amino group- or aminoxy group-containing silicon compounds, the reaction rate is extremely slow, and as a result, they develop stickiness and do not function as sealants. It takes 4 to 7 days at room temperature for this to occur, and during that time, it is prone to wear off, cracks, runoff due to rain, and the resulting deterioration of aesthetics, making it unsuitable for use as a building sealant. had the problem of being inappropriate. The present invention was made in such a situation, and its purpose is to quickly thicken it upon use,
When the reaction is completed, both the surface layer and the inside maintain adhesiveness without being completely cured, and as a result, the sealant exhibits good adhesion to the adherend without pre-treating the adherend surface, and The object of the present invention is to provide an adhesive sealing material that has good adhesion to general paints and spray materials applied to the surface layer. As a result of extensive research, the present inventors have discovered that a silanol group-terminated polydiorganosiloxane and an aminoxy group-containing organic compound having an average number of more than two organoaminoxy groups and less than three organoaminoxy groups in the molecule. A type of polyorganosiloxane composition that hardens at room temperature by reaction with a silicon compound,
The present inventors have discovered that the above object can be achieved by using a composition containing a primary or secondary monohydric alcohol having a vapor pressure of less than 0.1 mmHg at °C, and have completed the present invention. That is, the adhesive sealant of the present invention contains (A) 100 parts by weight of a polydiorganosiloxane whose ends are capped with silanol groups and whose viscosity at 25°C is 100 to 200,000 cSt; (B) an average of 2 polydiorganosiloxanes in the molecule; (C) 5 to 300 parts by weight of an inorganic filler, and (D ) The following general formula; (representing a primary or secondary hydrocarbon group), containing 0.01 to 10 parts by weight of a monohydric alcohol having a vapor pressure of less than 0.1 mmHg at 20°C and a freezing point of 20°C or lower. It is characterized by consisting of: In the following, the invention will be explained in more detail. The polydiorganosiloxane of component (A) used in the present invention is the same as the silanol group end-blocked polydiorganosiloxane that is normally used in condensed polysiloxane compositions that cure at room temperature, and is suitable for use in sealants with moderate workability. The viscosity at 25° C. should be in the range of 100 to 200,000 cSt in order to impart properties as well as physical properties suitable for use as an architectural sealant. If the viscosity is less than 100 cSt, the development of tackiness after the completion of the reaction is insufficient, and if it exceeds 200,000 cSt, a uniform composition cannot be obtained and extrusion workability decreases. A particularly preferred viscosity range is 500 to 50,000 cSt in order to harmonize these two properties. Examples of organic groups directly bonded to the silicon atom of polydiorganosiloxane include alkyl groups such as methyl, ethyl, propyl, butyl, and hexyl groups; alkenyl groups such as vinyl and allyl groups; phenyl and tolyl groups; Aryl groups such as groups; aralkyl groups such as benzyl groups and phenylethyl groups;
Examples include monovalent substituted hydrocarbon groups such as 3,3,3-trifluoropropyl group, chloromethyl group, and β-cyanoethyl group. Among these, monovalent hydrocarbon groups such as a methyl group, a vinyl group, or a phenyl group are preferred from the viewpoint of ease of synthesis.In particular, a methyl group not only allows the raw material intermediate to be obtained most easily, but also makes it possible to form a polysiloxane. In order to provide the lowest viscosity compared to the degree of polymerization and to improve the balance between extrusion workability and physical properties of the sealant, it is preferable that 85% or more of all organic groups be methyl groups, and substantially It is further preferred that all organic groups are methyl groups. However, if cold resistance or heat resistance is required, it is preferable to use phenyl groups as part of the organic groups. The aminoxy group-containing silicon compound used in the present invention as component (B) is one that performs a dehydroxylamine reaction with the terminal silanol group of the polydiorganosiloxane as component (A) to crosslink and extend the chain length of the polysiloxane. and may be a silane derivative and/or a linear, cyclic or branched siloxane derivative. The number of aminoxy groups contained in component (B) must be greater than 2 on average in the molecule in order to quickly thicken after use and function as a sealant, and , for the purpose of ensuring sufficient pot life.
The number needs to be less than 3 on average. In order to obtain a sealing material having particularly good reactivity and excellent adhesiveness, it is preferable to use a combination of cyclic polysiloxanes containing two or three aminoxy groups in one molecule. Examples of the organic group to be bonded to the aminoxy group include methyl group,
Two monovalent hydrocarbon groups such as ethyl group, propyl group, butyl group, cyclohexyl group, or butylene group,
One divalent hydrocarbon group such as a pentylene group is exemplified. Among these, the use of ethyl group is advantageous due to the ease of obtaining raw materials, ease of synthesis, reactivity,
It is preferable because of the ease of volatilization of the organohydroxylamine to be released. Examples of such aminoxy group-containing organosilicon compounds include the following. Hereinafter, for the sake of brevity, the following abbreviations will be used for each organosilicon compound. (Abbreviation) Me: Methyl group, Et: Ethyl group, Bu: Butyl group, Vi: Vinyl group, Ph: Phenyl group Si(ONEt ₂ ) ₄ , MeSi(ONEt ₂ ) ₃ , PhSi
(ONMe ₂ ) ₃ , PhSi(ONEt ₂ ) ₃ ,

[Formula] Et ₂ NOMe ₂ SiSiMe ₂ ONEt ₂ ,
Et ₂ NOMe ₂ SiOSiMe ₂ ONEt ₂ ,
Et ₂ NOMe ₂ SiOPh ₂ SiOSiMe ₂ ONEt ₂

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] MeSi [OMe ₂ SiONEt ₂ ] ₃ , PhSi [OMe ₂ SiONEt ₂ ] ₃ The amount of such aminoxy group-containing organosilicon compound added is 0.1 to 30 parts by weight per 100 parts by weight of component (A), It is preferably selected from the range of 1 to 15 parts by weight. If the amount of the aminoxy group-containing organosilicon compound added is less than 0.1 part by weight, the reaction rate with the silanol-terminated polydiorganosiloxane will become too fast and sufficient working time will not be obtained; if the amount added exceeds 30 parts by weight, , the reaction rate becomes slower, and after being used as a sealant, it takes longer to develop adhesiveness and perform its function as a sealant.
During this time, problems such as rubbing off and cracking are likely to occur. The inorganic filler, component (C), used in the present invention imparts appropriate viscosity to the sealant and has the physical properties required for architectural sealants, depending on the purpose of use and processing conditions of the sealant. There is no particular limitation as long as it is an inorganic fine powder. Such inorganic fillers include:
Examples include fumed silica, precipitated silica, silica aerogel, ground silica, diatomaceous earth, iron oxide, titanium oxide, calcium carbonate, etc., and one or more selected from the group consisting of these are used. . The amount of such inorganic filler added is the same as component (A).
5 to 300 parts by weight, preferably 30 parts by weight per 100 parts by weight
~200 parts by weight. If the amount of inorganic filler is less than 5 parts by weight, the non-flowability required for use as a building sealant cannot be obtained;
If it exceeds 300 parts by weight, workability will decrease. Such an inorganic filler may further be used as a coloring agent.
For example, pigments such as titanium oxide, cobalt oxide, red iron oxide, carbon black, and phthalocyanine pigments may be appropriately added in amounts commonly used as colorants. The monohydric alcohol used as component (D) in the present invention is used to maintain adhesiveness without completely curing the surface layer and interior of the sealant even when the reaction of the sealant composition is completed. This allows the sealant to exhibit good adhesion to the adherend without pre-treating the surface to be adhered to, and also to exhibit good adhesion with general paints and spray materials applied to the surface layer. It is something that can be done. Such a monohydric alcohol, as described above,
It is selected from monohydric alcohols having a primary or secondary hydrocarbon group and a vapor pressure of less than 0.1 mmHg at 20°C. When the hydrocarbon group is tertiary, it is not preferable because it has a poor ability to maintain the adhesiveness of the surface layer and inside of the sealant. Also, 20℃
If the vapor pressure at is 0.1mmHg or more,
Since the alcohol on the surface layer of the sealant easily evaporates into the atmosphere, the adhesiveness of the surface layer disappears, and therefore,
Good adhesion with general paints and spray materials cannot be obtained. Furthermore, component (D) must have a freezing point of 20°C or lower, and in particular, when the sealant of the present invention is used in a relatively low-temperature environment, the freezing point must be 10°C or lower.
It is preferably below ℃, more preferably 0
below ℃. The reason for this is that when component (D) is in a solid state, the function of component (D) cannot be fully demonstrated.
This is because the object of the present invention cannot be achieved. Examples of the monohydric alcohol used as component (D) include n-decyl alcohol, undecyl alcohol, trimethylnonyl alcohol, diethyl tridecyl alcohol, isostearyl alcohol, oleyl alcohol, linoleyl alcohol, etc. One or more types selected from the group consisting of these are used. The amount of monohydric alcohol added is
0.01 to 10 parts by weight per 100 parts by weight, preferably
It ranges from 0.05 to 5 parts by weight. If the amount of monohydric alcohol is less than 0.01 parts by weight, the adhesiveness inside and on the surface of the sealant cannot be maintained sufficiently, and the adhesion to the adherend and the adhesion of general paints and spray materials will decrease; If it exceeds 10 parts by weight, the crosslinking and thickening reaction will not proceed sufficiently and its function as a sealing material will deteriorate, so not only will it not be possible to obtain adhesive strength to the adherend, but the adhesion of general paints and spray materials will also decrease. do. The adhesive sealing material of the present invention is a two-component type in which, among the above-mentioned components, only component (B) is normally stored alone and the other components are stored in a mixed state. A sealant mixture is prepared by mixing the following. The adhesive sealant of the present invention obtained in this way is in the form of a paste that is easy to work with before and during use, and after mixing the two liquids, the workable time is 1.5 to 3 hours, which is a sufficiently long time. After completion of the reaction, the reaction progresses quickly and the time required for the sealant to function as a sealant is within 12 hours, so the possibility of various problems occurring during curing is extremely low. . Furthermore, the adhesive sealant of the present invention has good adhesion to the adherend without pre-treating the surface of the adherend, and can be used with general paint or spray paint applied to the surface of the sealant. The adhesion of the material to the sealant is also good. Therefore, the adhesive sealant of the present invention is suitable as a sealant for buildings that require application of general paint or spray material after filling with the sealant. In the following, the present invention will be explained in more detail with reference to examples. In the examples, all parts represent parts by weight. Example 1 100 parts of silanol end-capped polydimethylsiloxane with a viscosity of 5000 cSt at 25°C, 50 parts of ground calcium carbonate with an average particle size of 1μ and an average particle size of 0.2μ
25 parts of light calcium carbonate treated with stearic acid were added thereto, and these were kneaded to obtain a base compound. For 100 parts of this base compound,

[Formula] 94% by weight,

Samples 10 to 13 were obtained by adding and mixing 3.0 parts of a crosslinking agent mixture of 6% by weight and monohydric alcohol in the amounts shown in Table 1. At the same time, three types of samples were prepared as comparative examples. Sample 14 contains no monohydric alcohol, sample 15 contains monohydric alcohol with a vapor pressure of 0.1 mmHg or more at 20°C, and sample 16 contains monohydric alcohol with a freezing point of more than 20°C. . Among them, stearyl alcohol of Sample 16 was prepared after being added to the base compound, heated to 60°C, mixed, and cooled to room temperature.

【table】

[Table] Next, test specimens as shown in the drawings were prepared using the above samples 10 to 16. Such a specimen has a width of 50
The sample was filled between two mortar plates having a length of 15 mm and a length of 15 mm. The specimen thus prepared was cured and cured at room temperature for 14 days, and then subjected to a tensile test. The results are shown in Table 2. Further, Samples 10 to 16 were coated on a slate board to a thickness of 15 mm, and after curing and curing at room temperature for 14 days, the paints shown in Table 2 were coated on the surface of each sample. After applying the paint, it was dried at room temperature for 7 days, and then a glass cloth tape with a width of 20 mm was adhered to the paint surface using a cyanoacrylate adhesive (manufactured by Toagosei Kagaku Co., Ltd., trade name: Aron Alpha). After sufficient adhesion, the peel stress between the paint film and the sample was measured by pulling one end of the glass cloth tape. The results are also shown in Table 2.

[Table] Example 2 65 parts of colloidal calcium carbonate treated with rosin acid and having an average particle size of 0.6 μm were added to 100 parts of silanol group end-blocked polydimethylsiloxane with a viscosity of 3000 cSt at 25°C, and these were mixed to form a base compound. Obtained. For 100 parts of this base compound,

[Formula] 95% by weight,

Samples 20 to 25 were obtained by adding and mixing 3.5 parts of a crosslinking agent mixture of 5% by weight and monohydric alcohol in the amounts shown in Table 3. At the same time, a sample to which no monohydric alcohol was added (sample 26) was prepared as a comparative example. Using these samples, a tensile test and peel stress measurements were performed in the same manner as in Example 1. The results are also shown in Table 3.

[Table] Example 3 100 parts of silanol group end-capped polydimethylsiloxane with a viscosity of 12000 cSt at 25°C, 50 parts of precipitated calcium carbonate with an average particle size of 0.5μ, and 50 parts of light calcium carbonate with an average particle size of 0.5μ
0.05μ stearic acid treated colloid camsium carbonate 25
parts were added and mixed to obtain a base compound. For 100 parts of this base compound,

[Formula] 93% by weight,

Samples 30 and 31 were obtained by adding and mixing 2.5 parts of a crosslinking agent mixture of 7% by weight and monohydric alcohol in the amounts shown in Table 4. As a comparative example, a sample to which no monohydric alcohol was added (sample 32) was prepared. Using these samples, test specimens shown in the drawings were prepared, and after curing and curing at room temperature for 14 days, the paints and spray materials shown in Table 4 were applied to the surfaces thereof. Then,
After curing and curing at room temperature for 7 days, the test specimen was mounted on a fatigue testing machine, and displacement of ±10% with respect to the sample joint width was repeated 2000 times, and the adhesion state of each paint and spray material was visually observed. The results are also shown in Table 4.

[Table] Example 4 Using the same samples 11, 12, and 13 as used in Example 1, an extrusion test was conducted in accordance with JIS A5758, and the number of seconds for extrusion was measured after 1.5 hours had elapsed from immediately after mixing the samples. did. The results are shown in Table 5. In addition, according to JIS A5758, the time when the extrusion time reaches 20 seconds is defined as the pot life.

[Table] As is clear from the above results, the adhesive sealant of the present invention exhibits good adhesion to the adherend without pre-treating the adherend surface, and It was confirmed that general paints and spray materials applied to the surface layer also adhered to the adhesive sealant of the present invention with good adhesion.

[Brief explanation of drawings]

The drawing is a perspective view of a tensile test specimen. 1... Sample, 2... Mortar material.

Claims (1)

[Scope of Claims] 1 (A) 100 parts by weight of a polydiorganosiloxane whose ends are capped with silanol groups and whose viscosity at 25°C is 100 to 200,000 cSt; (B) an average of more than 2 polydiorganosiloxanes in the molecule; 0.1 to 30 parts by weight of an aminoxy group-containing silicon compound having an average number of less than 3 organoaminoxy groups bonded to silicon atoms, (C) 5 to 300 parts by weight of an inorganic filler, and (D) the following general formula ; R-OH (wherein R is a primary or secondary group selected from the group consisting of a monovalent aliphatic hydrocarbon group (excluding those containing a -C≡C- group) and an aralkyl group; It is characterized by containing 0.01 to 10 parts by weight of a monohydric alcohol having a vapor pressure of less than 0.1 mmHg at 20°C and a freezing point of 20°C or less. Adhesive sealant. 2. The adhesive sealing material according to claim 1, wherein the monohydric alcohol as component (D) has a freezing point of 10°C or lower. 3. The adhesive sealing material according to claim 2, wherein the monohydric alcohol as component (D) has a freezing point of 0° C. or lower. 4 85% of organic groups bonded to silicon atoms in component (A)
The adhesive sealing material according to claim 1, which is a methyl group. 5. The adhesive sealing material according to claim 1, wherein the organic group bonded to the aminoxy group of component (B) is an ethyl group. 6. The adhesive sealing material according to claim 1, wherein the amount of component (B) added is 1 to 15 parts by weight per 100 parts by weight of component (A). 7 The amount of component (C) added per 100 parts by weight of component (A)
The adhesive sealant according to claim 1, wherein the amount is 30 to 200 parts by weight. 8 The amount of component (D) added per 100 parts by weight of component (A)
The adhesive sealant according to claim 1, wherein the amount is 0.05 to 5 parts by weight.