JP6269828B2 - Primer composition - Google Patents

Description

  The present invention relates to a primer composition useful for adhesion between a room temperature curable organopolysiloxane composition and various adherends, and has a short time until adhesion is obtained and is excellent in storage stability. Relates to the composition.

  In the bonding of room temperature curable organopolysiloxane compositions used as building sealants, general industrial sealants, and adhesives to various substrates, silane coupling agents, titanates and solvents are the main components. The “silane primer”, the “urethane primer” based on a polyisocyanate compound, the silane-modified acrylic resin, the “acrylic primer” based on a solvent, etc. have been used (Patent Documents 1 to 3). 4).

  As the silane coupling agent for the silane primer, those having an amino group, an epoxy group, a mercapto group or an isocyanate group are generally used. As a polyisocyanate compound of a urethane primer, those obtained by an addition reaction between an isocyanate compound and a polyol such as polyethylene glycol are known.

  The silane-based primer is useful for inorganic adherends such as metal and glass, and has good heat resistance, weather resistance, and durability. However, silane-based primers often do not have sufficient adhesion to organic adherends such as various resins, and in recent years, mainly used are acrylic resins that are highly used for aluminum sashes. Adhesiveness to acrylic resin electrodeposited aluminum, which is electrodeposited on aluminum, and fluororesin paint, which is mainly composed of fluororesin, is insufficient.

  On the other hand, the urethane-based primer can provide a certain degree of satisfactory adhesion to a wide range of adherends including metal-based and organic-based adherends. Since the durability such as the property and water resistance is insufficient, it is generally unsuitable for the use of a silicone curable composition that requires long-term durability. Further, even when silane-based and polyisocyanate-based blend primers are used, it is difficult to achieve both adhesiveness and durability.

  By the way, a silane-based or acrylic primer is often used in the silicone-based curable composition. The acrylic primer is mainly composed of an acrylic resin having an alkoxysilyl group and a solvent. As such acrylic primers, many are commercially available in which room temperature curable organopolysiloxane compositions exhibit good adhesion to various resins such as acrylic resins and polystyrene resins which are difficult to bond without a primer. Some of these materials adhere well to acrylic electrodeposition coated aluminum and fluororesin coated aluminum and have higher heat resistance, weather resistance and water resistance than urethane-based primers. For this reason, the acrylic primer has been suitably used as a primer for resin-coated surfaces or metal-coated surfaces.

Shoko 53-005043 Japanese Patent No. 2522856 JP-A-4-224879 JP-A-8-295852

  However, the acrylic primer having good adhesion has a slow onset of adhesive force with the room temperature curable organopolysiloxane composition (room temperature curable silicone rubber composition), and therefore the room temperature curable organopolysiloxane composition There is a problem that peeling occurs when the substrate is moved immediately after curing or a force is applied to the bonding interface.

  Therefore, in recent years, in various industrial fields, it has become essential to shorten the bonding process time with a room temperature curable silicone rubber composition in order to increase production efficiency. It has been desired to develop a primer capable of expressing good adhesion to an adherend. There is also a need for a primer composition with high storage stability that does not deteriorate adhesiveness even after long-term storage.

  Accordingly, an object of the present invention is to provide a primer composition that is excellent in various durability, can exhibit good adhesiveness to various adherends in a short time after construction, and has high storage stability.

  As a result of various studies on the primer composition according to the above-mentioned invention, the present inventors have mixed the acrylic copolymer having a specific structure and the titanium compound having a specific structure at a predetermined ratio. As a result, the inventors have found that the above problems can be solved, and have reached the present invention.

That is, the present invention
(1) A cured product of a room temperature curable organopolysiloxane composition (typically a condensation reaction curable room temperature curable silicone rubber composition), an organic resin, a metal, and a coated metal surface (for example, an acrylic resin or A primer composition that improves adhesion to a substrate selected from a metal surface such as aluminum coated with a coating mainly composed of a fluororesin (A) (A1) containing an alkoxysilyl group (meta ) acrylic acid ester, as (A2) alkoxy containing no silyl group-containing (meth) viewed contains an acrylic acid ester, 100% by mass of total monomer components of the (a) component containing (A1) alkoxysilyl group (Meth) acrylic acid ester 1 to 10% by mass and (A2) (meth) acrylic acid ester 80 to 99% by mass not containing an alkoxysilyl group Acrylic copolymer 100 parts by weight of a copolymer of free monomer component, a titanium compound 0.3 to 10 parts by weight of (B) represented by formula (1), and (C) a solvent 100 to 5000 parts by weight A primer composition comprising at least
_{Ti (i-C 3 H 7} O) a (C 5 H 7 O 2) b (C 6 H 9 O 3) c (1)
(A, b and c are any integers from 0 to 4, provided that a + b + c = 4)

(2) The (meth) acrylic acid ester containing the alkoxysilyl group of the component (A1) and the alkoxysilyl group of the component (A2) when the whole acrylic copolymer of the component (A) is 100% by mass. The primer composition according to (1) , wherein the other monomer component other than (meth) acrylic acid ester containing no benzene is 0% by mass .

( 3 ) When the whole monomer component of the component (A) is 100% by mass, the proportion of at least one (meth) acrylic acid ester not containing the (A2) alkoxysilyl group is 80 % by mass or more and 99% by mass. The primer composition according to ( 1 ) or ( 2 ), wherein the primer composition is less than%.

(4) the component (B), (B1) a mixture preparation of a titanium tetraalkoxide and / or alkoxy group-containing titanium chelate compound (B2) acetylacetone, alkoxy groups of the titanium compound in (B1) 1 mole pairs (B2) acetylacetone 0.8 mol or more, characterized in that it is a ratio of less than 2.0 mole (1) to the primer composition according to any one of (3).

( 5 ) The primer composition according to any one of (1) to ( 4 ), further comprising (D) 1 to 100 parts by mass of an alkyltrialkoxysilane.

( 6 ) The primer according to any one of (1) to ( 5 ), wherein the titanium compound of the component (B) is an integer compound in which a = 2 and b + c = 2 in the formula (1) Composition.

  In accordance with the present invention, a primer composition that exhibits good adhesion to various adherends such as acrylic electrodeposition coated aluminum and fluororesin coated aluminum in a short period after construction, and is excellent in various durability and storage stability. Can be provided.

  Hereinafter, the present invention will be described in more detail. It should be noted that the present invention is not limited by the following embodiments, and the present invention includes those configured by appropriately combining the following constituent elements. In the present specification, (meth) acrylic acid means acrylic acid and / or methacrylic acid, and the same applies to other compounds.

The primer composition of the present invention comprises:
(A) an acrylic copolymer containing an alkoxysilyl group (that is, (A1) a (meth) acrylic acid ester containing an alkoxysilyl group and (A2) a (meth) acrylic acid ester not containing an alkoxysilyl group look including the entire monomer component of the component (a) as 100 wt%, (A1) containing an alkoxysilyl group and (meth) 1 to 10 wt% of acrylic acid esters, containing no (A2) alkoxysilyl group ( 100 parts by mass of an acrylic copolymer composed of a copolymer of monomer components containing 80 to 99% by mass of (meth) acrylic acid ester ,
(B) 0.3 to 10 parts by mass of a titanium compound represented by the formula (1);
_{Ti (i-C 3 H 7} O) a (C 5 H 7 O 2) b (C 6 H 9 O 3) c (1)
(A, b and c are any integers from 0 to 4, provided that a + b + c = 4)
(C) a solvent 100 to 5000 parts by weight, consists Nde least contains a.
Below, each component contained in the primer composition of this invention is explained in full detail.

<(A) Acrylic copolymer>
The alkoxysilyl group-containing acrylic copolymer (A) is a component that is a main component of the primer composition of the present invention after drying, and is a component that determines the adhesion between the substrate and the primer composition. .

  The acrylic copolymer contained in the primer composition of the present invention comprises at least one (meth) acrylic acid ester (hereinafter referred to as an alkoxysilyl group-containing component (A1)) containing an alkoxysilyl group in the molecule, A monomer component containing at least one (meth) acrylic acid ester not containing an alkoxysilyl group in the molecule (hereinafter referred to as an alkoxysilyl group-free component (A2)) is copolymerized. In the present invention, (meth) acrylic acid refers to methacrylic acid or acrylic acid, or a mixture (mixed acid) thereof. Similarly, (meth) acrylic acid ester refers to methacrylic acid ester or acrylic acid ester, or a mixture (mixed ester) thereof. (Meth) acrylate refers to methacrylate or acrylate, or a mixture thereof.

  The polymerization reaction method for copolymerizing the monomer components is not particularly limited, and examples thereof include radical polymerization, cationic polymerization, and anionic polymerization. Among them, random radical polymerization using an organic peroxide or an organic azo compound as an initiator is effective as a simple method.

[Alkoxysilyl group-containing component (A1)]
This alkoxysilyl group-containing component (A1) is a monomer component containing at least one (meth) acrylic acid ester containing an alkoxysilyl group in the molecule. In this monomer, the (meth) acrylic acid ester (A1) containing an alkoxysilyl group can be used alone or in combination of two or more. The (meth) acrylic acid ester (A1) containing an alkoxysilyl group has at least 1, preferably 2 or 3 alkoxysilyl groups in one molecule.

Content of this alkoxy silyl group containing component (A1) is 1-10 mass% when the whole monomer component of (A) component is 100 mass%. Moreover, in this invention, it is preferable to contain the methacrylic acid ester containing an alkoxy silyl group as a component (A1), and especially the methacrylic acid ester containing an alkoxy silyl group is 1 to 1 of the whole monomer component of (A) component. It is most preferable to contain 10% by mass. When the content of the component (A1) is less than 1% by mass of the entire monomer component (A), adhesion development cannot be obtained. Further, when the content of the component (A1) is more than 20% by mass of the whole monomer component of the component (A), the adhesion to the adherend is lowered.

  Here, as the (meth) acrylic acid ester containing an alkoxysilyl group in the molecule, for example, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- ( And (meth) acryloxypropylmethyldimethoxysilane and 3- (meth) acryloxypropylmethyldiethoxysilane. Particularly preferred is 3- (meth) acryloxypropyltrimethoxysilane.

[Alkoxysilyl group-free component (A2)]
This alkoxysilyl group-free component (A2) is a monomer component containing at least one (meth) acrylic acid ester not containing an alkoxysilyl group in the molecule. In this monomer, the (meth) acrylic acid ester (A2) which does not contain an alkoxysilyl group can be used alone or in combination of two or more.

The content of the alkoxysilyl group-free component (A2), when taken as 100% by mass of total monomer components in the component (A) is less than 99 wt% 8 0% by mass or more. If it is out of this range, the adhesion to the adherend will decrease. Moreover, in this invention, it is preferable to contain the methacrylic acid ester which does not contain an alkoxy silyl group as a component (A2).

  Examples of the (meth) acrylic acid ester not containing an alkoxysilyl group in the molecule include (meth) acrylic acid aliphatic hydrocarbon ester, (meth) acrylic acid alicyclic hydrocarbon ester, and (meth) acrylic acid. Aromatic hydrocarbon esters, and esters of alcohols containing ether linkages with (meth) acrylic acid.

  Examples of the aliphatic hydrocarbon ester of (meth) acrylic acid include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl ( Examples include (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl meta (meth) arylate, and stearyl (meth) acrylate.

  Examples of (meth) acrylic acid alicyclic hydrocarbon esters include cyclohexyl (meth) acrylate and isobornyl (meth) acrylate.

  Examples of the aromatic hydrocarbon ester of (meth) acrylic acid include phenyl (meth) acrylate, benzyl (meth) acrylate, and toluyl meta (meth) arylate.

  Examples of the ester of an alcohol having an ether bond and (meth) acrylic acid include alkoxyalkyl (meth) acrylates such as 2-methoxyethyl (meth) acrylate and 2-methoxybutyl (meth) acrylate; glycidyl (meth) acrylate And epoxy group-containing (meth) acrylates such as methyl glycidyl (meth) acrylate.

  The (meth) acrylic acid ester not containing an alkoxysilyl group is preferably an aliphatic hydrocarbon ester of (meth) acrylic acid, more preferably an alkyl group having 1 to 20 carbon atoms (meta ) Acrylic acid alkyl ester, more preferably (meth) acrylic acid alkyl ester having an alkyl group having 1 to 10 carbon atoms. Particularly preferred are methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and tert-butyl (meth) acrylate. Moreover, in this invention, when the whole monomer component shall be 100 mass%, it is especially preferable to contain methyl (meth) acrylate 30 mass% or more and less than 99 mass%. Most preferably, it contains 30% by mass or more and less than 99% by mass of methyl methacrylate.

[Other ingredients]
(A) The acrylic copolymer may contain other monomer components other than the alkoxysilyl group-containing component (A1) and the alkoxysilyl group-free component (A2). Other monomer components include acrylics such as N, N-dimethylacrylamide, N-methylol (meth) acrylamide, N-vinylpyrrolidone, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, vinyl acetate, and styrene. Examples include vinyl monomers other than monomers. This other monomer component is 0 mass% when the whole monomer component of (A) component is 100 mass%.

<(B) Titanium compound>
The component (B) titanium compound is an organic titanium compound represented by the following formula (1):
_{Ti (i-C 3 H 7} O) a (C 5 H 7 O 2) b (C 6 H 9 O 3) c (1)
(A, b and c are any integers from 0 to 4, provided that a + b + c = 4)
It contains at least one of acetylacetonate (C ₅ H ₇ O ₂ ), isopropoxide (i-C ₃ H ₇ O) and ethyl acetoacetate (C ₆ H ₉ O ₃ ). Preferably, it contains at least one of acetylacetonate (C ₅ H ₇ O ₂ ) and isopropoxide (i-C ₃ H ₇ O) (that is, 1 ≦ a + b ≦ 4 in formula (1)), More preferably, it contains only acetylacetonate (C ₅ H ₇ O ₂ ) (that is, b = 4 in formula (1)).
In the above formula (1), a, b, and c are each an integer of 0 to 4, and satisfy a + b + c = 4, but a, b, and c are preferably 0, 2, or 4, respectively, in particular, a = 0, b = 4, c = 0 combination, a = 2, b = 2, c = 0 combination, a = 4, b = 0, c = 0 combination, a = 2, b = 0, c = 2 combination, a = 0, b = 0, c = 4 combination, a = 0, b = 2, c = 2 combination, etc. It is done.
This component (B) serves as an adhesion promoter that improves the adhesion of the primer composition of the present invention to the substrate and shortens the time required for the adhesion of the curable composition and the primer composition. Bear.

  (B) The compounding quantity of a component is 0.3-10 mass parts with respect to 100 mass parts of (A) component. Preferably, it is 0.3-5 mass parts, More preferably, it is 0.4-3 mass parts, More preferably, it is 0.45-2.5 mass parts. If it is less than 0.3 part by mass, the onset of adhesiveness is delayed and the desired adhesiveness cannot be obtained in a short time. On the other hand, when the amount exceeds 10 parts by mass, the storage stability of the primer composition is lowered, and it becomes impossible to obtain the adhesion of the primer composition to various substrates after the production for a long time. The cured product of the curable composition often peels off from the substrate together with the primer composition.

As a commercial product containing such a titanium tetraacetylacetonate compound, for example, ORGATICS TC-401 (manufactured by Matsumoto Fine Chemical Co., Ltd.) (in formula (1), a = 0, b = 4, c = 0 is represented. Isopropyl alcohol solution containing 65% by mass of a titanium tetraacetylacetonate compound of Ti (C ₅ H ₇ O ₂ ) ₄ ), ORGATICS TC-100 (manufactured by Matsumoto Fine Chemical Co., Ltd.) (in formula (1), a = 2, b = 2, Ti represented by _{c = 0 (i-C 3} H 7 O) 2 (C 5 H 7 O 2) 2 of the titanium diisopropoxy bis (acetylacetonate) isopropyl alcohol containing compound 75 wt% Solution), ORGATIX TA-10 (Matsumoto Fine Chemical Co., Ltd.) (in formula (1), a = 4, b = 0, c = 0 That _{Ti (i-C 3 H 7} O) 4 of titanium tetraisopropoxide compound 99 mass%), a = 2 in Orgatix TC-750 (manufactured by Matsumoto Fine Chemical Co., Ltd.) (Formula (1), b = 0 , Ti represented by _{c = 2 (i-C 3} H 7 O) 2 (C 6 H 9 O 3) 2 of titanium diisopropoxy bis (ethylacetoacetate) isopropyl alcohol solution of the compound containing 95 weight%) of Can be mentioned. Among these, from the viewpoint of adhesiveness, ORGATICS TC-401 is preferable.

  As component (B), titanic acid alkyl ester and / or alkoxy group-containing titanium chelate compound and acetylacetone are used in an amount of 0.8 mol or more and less than 2.0 mol of acetylacetone per 1 mol of titanium atom in the titanium-containing compound. You may use what was prepared by mixing in a ratio. When using the component (B) prepared in this way, it may be mixed in advance before the production of the primer composition of the invention, and added separately when producing the primer composition of the present invention, You may mix and prepare in a primer composition.

The component (B) is a mixture of (B1) titanium tetraalkoxide and / or an alkoxy group-containing titanium chelate compound and (B2) acetylacetone, and comprises 1 mol of alkoxy groups in the titanium compound in (B1). acetylacetone pairs can also be prepared by mixing in a ratio of less than 2.0 mol 0.8 mol or more.

<(C) Solvent>
The solvent of the component (C) is used for facilitating the coating operation and imparting quick drying properties by dissolving or dispersing the component (A) and the component (B). The type of the solvent of component (C) is not particularly limited as long as the primer composition does not lose transparency and uniformity, but is selected according to the solvent resistance of the target adherend, the brush working conditions, etc. Is done.

  Examples of such a good solvent for the component (A) include ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and butyl acetate, and aromatic hydrocarbons such as toluene and xylene. Moreover, you may use alcohol and aliphatic hydrocarbons as a poor solvent of (A) component. Examples of alcohols include methanol, ethanol, isopropyl alcohol, and 2-ethyl-1-hexanol. Examples of the aliphatic hydrocarbons include n-hexane, n-heptane, and isooctane (2,2,4-trimethylpentane).

  (C) The compounding quantity of a component is 100-5000 mass parts with respect to 100 mass parts of (A) component, Preferably it is 200-3000 mass parts, More preferably, it is 300-1000 mass parts. When the blending amount of the component (C) is less than 100 parts by mass, the film thickness of the alkoxysilyl group-containing acrylic copolymer remaining on the substrate surface after the primer composition is applied and dried is too thick. In addition to being easily peeled off, the use cost of the acrylic copolymer is increased, which is disadvantageous in terms of cost. On the other hand, when the amount of component (C) exceeds 5000 parts by mass, the layer of the primer composition after drying becomes too thin, and the function of improving the adhesiveness is lost.

<(D) Additive>
As an additive of the component (D), an alkyltrialkoxysilane, acetylacetone, or the like may be contained as an optional component as required in order to improve the storage stability of the primer composition of the present invention. Among the components (D), examples of the alkyltrialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, and vinyltrimethoxysilane. Methoxysilane and acetylacetone are preferred.

  (D) The compounding quantity of a component is 0.1-100 mass parts with respect to 100 mass parts of (A) component. Preferably, it is 0.5-10 mass parts, More preferably, it is 1-5 mass parts. When the amount is less than 0.1 parts by mass, the primer composition thickens during storage, so the period until gelation is accelerated. When the amount exceeds 100 parts by mass, there is almost no disadvantage in terms of performance, but the cost is reduced. Disadvantageous.

<Other additives>
Other optional components can be added to the primer composition of the present invention as long as the performance is not impaired. These components include, as silanol condensation catalysts, organotin compounds such as dibutyltin dimethoxide, dibutyltin diacetate, dibutyltin dioctanoate, dibutyltin dilaurate; aluminum alkoxides such as aluminum acetylacetonate; zirconium alkoxides such as zirconium acetylacetonate A silane coupling agent etc. are mentioned as an adhesion imparting agent. These types and addition amounts are selected according to the application.

<Adhesion method using primer composition>
To bond and cure a cured product of a room temperature curable organopolysiloxane composition (typically a condensation reaction curing type room temperature curable silicone rubber composition) to various substrates using the primer composition of the present invention, The primer composition of the present invention is applied to the surface of various substrates such as metal, painted metal (for example, coated metal surface such as aluminum coated with acrylic resin or fluorine resin as a main component), or organic resin. After drying, the curable composition is brought into contact with the coated surface and cured.

  The drying time of the primer composition after application is preferably in the range of 5 minutes to 480 minutes at room temperature (25 ° C.), more preferably 10 minutes to 120 minutes. If the drying time is shorter than 5 minutes, the solvent is not sufficiently dried and the strength of the primer layer after drying cannot be obtained. Moreover, when drying time exceeds 480 minutes, there exists a possibility that contaminants, such as dust in the air or dust, may adhere to the surface, and there exists a possibility of inhibiting adhesion | attachment.

  The primer composition of the present invention is effective as an adhesion-imparting agent, an adhesion improver and an adhesion development improver for bonding a cured product (silicone rubber) of a room temperature curable organopolysiloxane composition to various substrates. In addition to room temperature curable organopolysiloxane compositions, curable compositions having a silyl group capable of forming a siloxane bond with the primer composition, such as modified silicone curable compositions and silylated polyurethane systems. Is also effective.

  EXAMPLES Hereinafter, although an Example demonstrates the detail of this invention, this invention is not limited by these.

<(A) Preparation of acrylic copolymer>
Based on the components shown in Table 1, the copolymers of Synthesis Examples 1 to 4 were produced by the following adjustment method.

[Synthesis Example 1]
Into a 5 L glass four-necked flask equipped with a reflux condenser, a rotary stirrer, a nitrogen inlet tube and a thermometer through which cooling water at 10 ° C. was passed, 150.0 g of ethyl acetate and 150.0 g of isopropyl alcohol were placed. Mix under nitrogen bubbling. Next, 20.0 g of methyl methacrylate, 20.0 g of n-butyl methacrylate, and 2.0 g of 3-trimethoxysilylpropyl methacrylate are added and mixed, and the temperature of the mixed solution in the flask becomes 80 ° C. using an oil bath. Heated. Next, 1.5 g of 2,2′-azobis (2-methylbutyronitrile) was added, mixed and dissolved. A mixed solution of 60.0 g of methyl methacrylate, 60.0 g of n-butyl methacrylate, and 6.0 g of 3-trimethoxysilylpropyl methacrylate was placed in the dropping funnel and dropped into the flask over 2 hours. At this time, the solution temperature in the flask was adjusted to 75 ° C to 80 ° C. After completion of the dropwise addition, the mixture was further aged at 80 ° C. for 2 hours, and then the heating with the oil bath was terminated and the mixture was cooled to 40 ° C. After cooling, 200.0 g of ethyl acetate and 300.0 g of isopropyl alcohol were added and mixed until uniform to synthesize a colorless and transparent acrylic copolymer solution.

[Synthesis Example 2]
Into a 5 L glass four-necked flask equipped with a reflux condenser, a rotary stirrer, a nitrogen inlet tube and a thermometer through which cooling water at 10 ° C. was passed, 150.0 g of ethyl acetate and 150.0 g of isopropyl alcohol were placed. Mix under nitrogen bubbling. Next, 40.0 g of methyl methacrylate and 2.0 g of 3-trimethoxysilylpropyl methacrylate were added and mixed, and the temperature of the mixed solution in the flask was heated to 80 ° C. using an oil bath. Next, 1.5 g of 2,2′-azobis (2-methylbutyronitrile) was added, mixed and dissolved. A mixed solution of 120.0 g of methyl methacrylate and 6.0 g of 3-trimethoxysilylpropyl methacrylate was placed in the dropping funnel and dropped into the flask over 2 hours. At this time, the solution temperature in the flask was adjusted to 75 ° C to 80 ° C. After completion of the dropwise addition, the mixture was further aged at 80 ° C. for 2 hours, and then the heating with the oil bath was terminated and the mixture was cooled to 40 ° C. After cooling, 200.0 g of ethyl acetate and 300.0 g of isopropyl alcohol were added and mixed until uniform to synthesize a colorless and transparent acrylic copolymer solution.

[Synthesis Example 3] (Comparative Synthesis Example)
Into a 5 L glass four-necked flask equipped with a reflux condenser, a rotary stirrer, a nitrogen inlet tube and a thermometer through which cooling water at 10 ° C. was passed, 150.0 g of ethyl acetate and 150.0 g of isopropyl alcohol were placed. Mix under nitrogen bubbling. Next, 15.0 g of methyl methacrylate, 15.0 g of n-butyl methacrylate and 12.0 g of 3-trimethoxysilylpropyl methacrylate are added and mixed, and the temperature of the mixed solution in the flask becomes 80 ° C. using an oil bath. Heated. Next, 1.5 g of 2,2′-azobis (2-methylbutyronitrile) was added, mixed and dissolved. A mixed solution of 45.0 g of methyl methacrylate, 45.0 g of n-butyl methacrylate, and 36.0 g of 3-trimethoxysilylpropyl methacrylate was placed in the dropping funnel and dropped into the flask over 2 hours. At this time, the solution temperature in the flask was adjusted to 75 ° C to 80 ° C. After completion of the dropwise addition, the mixture was further aged at 80 ° C. for 2 hours, and then the heating with the oil bath was terminated and the mixture was cooled to 40 ° C. After cooling, 200.0 g of ethyl acetate and 300.0 g of isopropyl alcohol were added and mixed until uniform to synthesize a colorless and transparent acrylic copolymer solution.

[Synthesis Example 4] (Comparative Synthesis Example)
A colorless and transparent acrylic copolymer solution was synthesized in the same manner as in Synthesis Example 3 except that n-butyl methacrylate was replaced with tert-butyl methacrylate.

<Examples and Comparative Examples>
Based on the components shown in Table 2, Examples 1 to 7 and Comparative Examples 1 to 3 were produced by the following method.

[Example 1]
Into 577 parts by mass of the acrylic copolymer solution obtained in Synthesis Example 1 (including 100 parts by mass of the acrylic copolymer of component (A), 208 parts by mass of ethyl acetate, and 268 parts by mass of isopropyl alcohol), 40 parts by mass of ethyl acetate. , 30 parts by mass of isopropyl alcohol, 4.8 parts by mass of 2-ethyl-1-hexanol, 40 parts by mass of isooctane, 2.0 parts by mass of methyltrimethoxysilane, and then titanium tetraacetyl 65% by mass of titanium tetraacetylacetonate By adding and mixing 1.2 parts by mass of isopropyl alcohol solution of acetylacetonate (Matsumoto Fine Chemical Co., Ltd., ORGATICS TC-401) (ie 0.78 parts by mass in terms of mass of titanium tetraacetylacetonate) A light yellow transparent primer composition was obtained.

[Example 2]
In place of 1.2 parts by mass of isopropyl alcohol solution of titanium tetraacetylacetonate containing 65% by mass of titanium tetraacetylacetonate of Example 1 (Orgatechs TC-401, manufactured by Matsumoto Fine Chemical Co., Ltd.), diisopropoxytitanium bis ( Isopropyl alcohol solution of diisopropoxytitanium bis (acetylacetonate) containing 75% by mass of acetylacetonate (manufactured by Matsumoto Fine Chemical Co., Ltd., ORGATICS TC-100) 0.84 parts by mass (that is, diisopropoxytitanium bis (acetylacetate) A light yellow transparent primer composition was obtained by adding 0.63 parts by mass in terms of mass of natto) and 0.36 parts by mass of acetylacetone.

[Example 3]
In place of 1.2 parts by mass of isopropyl alcohol solution of titanium tetraacetylacetonate containing 65% by mass of titanium tetraacetylacetonate of Example 1 (Orgatechs TC-401, manufactured by Matsumoto Fine Chemical Co., Ltd.), tetraisopropyl titanate (effective It is light by adding 0.48 parts by mass of 99% by mass of ingredients, manufactured by Matsumoto Fine Chemical Co., Ltd., ORGATIX TA-10) (ie 0.48 parts by mass in terms of mass of tetraisopropyl titanate) and 0.72 parts by mass of acetylacetone. A yellow transparent primer composition was obtained.

[Example 4]
In Example 1, a primer composition was obtained in the same manner as in Example 1 except that the acrylic copolymer solution of Synthesis Example 2 was used instead of the acrylic copolymer solution of Synthesis Example 1.

[Example 5]
In place of 1.2 parts by mass of isopropyl alcohol solution of titanium tetraacetylacetonate containing 65% by mass of titanium tetraacetylacetonate of Example 1 (Orgatechs TC-401, manufactured by Matsumoto Fine Chemical Co., Ltd.), diisopropoxytitanium bis ( Ethyl acetoacetate) (active ingredient 95% by mass or more, manufactured by Matsumoto Fine Chemical Co., Ltd., ORGATICS TC-750) 1.2 parts by mass (that is, 1.14 parts by mass in terms of mass of diisopropoxy titanium bis (ethyl acetoacetate)) A light yellow transparent primer composition was obtained in the same manner as in Example 1 except that (˜1.2 parts by mass) was added.

[Example 6]
A primer composition was obtained in the same manner as in Example 2 except that 0.36 parts by mass of acetylacetone was not added.

[Example 7]
A primer composition was obtained in the same manner as in Example 3 except that 0.72 parts by mass of acetylacetone was not added.

[Comparative Example 1]
Example 1 except that 1.2 parts by mass of an isopropyl alcohol solution of titanium tetraacetylacetonate containing 65% by mass of titanium tetraacetylacetonate (manufactured by Matsumoto Fine Chemical Co., Ltd., ORGATICS TC-401) is not added. A primer composition was obtained.

[Comparative Example 2]
In Example 1, a primer composition was obtained in the same manner as in Example 1 except that the acrylic copolymer solution of Synthesis Example 3 (Comparative Synthesis Example) was used instead of the acrylic copolymer solution of Synthesis Example 1. .

[Comparative Example 3]
In Example 1, a primer composition was obtained in the same manner as in Example 1 except that the acrylic copolymer solution of Synthesis Example 4 (Comparative Synthesis Example) was used instead of the acrylic copolymer solution of Synthesis Example 1. .

<Evaluation of adhesiveness>
About each primer composition obtained in Examples 1-7 and Comparative Examples 1-3, the adhesiveness with respect to an aluminum coating board was evaluated with the following method.

[Preparation of specimen]
Each primer composition was applied to an acrylic electrodeposition coated aluminum plate with a brush and left for 30 minutes under conditions of 23 ° C. and 50% relative humidity (RH), followed by dealcoholizing type two-component silicone sealant ( SEALANT-FC-295SG (manufactured by Shin-Etsu Chemical Co., Ltd.) and a mixture of a main agent and a curing agent are applied to the application surface of an aluminum plate to which each primer composition has been applied, 10 mm wide, 50 mm long, 2 mm. A test piece was formed by molding with a spatula into a thick shape.

[Adhesion test]
After curing this test piece under the following conditions, the cured product of the silicone sealant was cut with a knife, the cut part was peeled off by hand (pick by hand), and the peeled state was observed (hand by knife cutting). The state of the adhesion interface between the adherend and the primer composition was evaluated by performing a peeling test.

[Adhesion development]
The adhesion development was evaluated by a manual peeling test using the knife cut after curing for 4 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%. The evaluation was “「 ”when the ratio of the area of the cohesive failure of the sealing material was 100%,“ ◯ ”when it was 80% or more and less than 100%, and 50% or more and less than 80%. The thing which was less than 50% in the case of "△" was made into "x". Table 3 shows the test results of adhesion development when each primer composition was used. The silicone-based sealing material is a fast-curing sealing material that is mixed and rubberized after 1 hour after mixing the main agent and the curing agent.

[Initial adhesion]
The initial adhesiveness was evaluated by the same method as the test method for adhesion development after curing for 7 days in an environment of a temperature of 23 ° C. and a relative humidity of 50%. Table 3 shows the initial adhesion test results when each primer composition was used.

[Water-resistant adhesion]
The water-resistant adhesion was evaluated by the same method as the test method for adhesion development after being cured for 7 days in an environment of a temperature of 23 ° C. and a relative humidity of 50% and then immersed in warm water of 50 ° C. for 7 days. Table 3 shows the test results of water-resistant adhesion when each primer composition was used.

<Evaluation of storage stability>
About each primer composition obtained in Examples 1-4, the storage stability was evaluated by the following method.

[Storage stability]
Each of the obtained primer compositions was sealed in a glass bottle, left in a dryer adjusted to 50 ° C. for 28 days, taken out and returned to 23 ° C. by air cooling, and the above (acrylic electrodeposition) The state of the adhesion interface between the adherend and the primer composition was evaluated under the same conditions and methods as those for adhesion to coated aluminum, initial adhesion, and water-resistant adhesion.

  The above results (adhesiveness to acrylic electrodeposition coated aluminum, initial adhesion, water-resistant adhesion) are the same results in all tests, or “○” if the rate of cohesive failure increases. Even in one test, when the rate of cohesive failure decreased, it was marked as “x”. Table 4 shows the storage stability test results. This makes it possible to verify whether or not the primer composition can exhibit its performance even when it is used after being stored for a long time in an unused state.

  As shown in the Examples, it can be seen that the composition of the present invention has excellent adhesion to various adherends used in building sealing materials and is excellent in storage stability.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for bonding a room temperature curable organopolysiloxane composition used as a building sealing material, a general industrial sealing material, and an adhesive to various adherends.

Claims (6)

A primer composition that improves adhesion between a cured product of a room temperature curable organopolysiloxane composition and a substrate selected from an organic resin, a metal, and a painted metal surface,
(A) (A1) containing an alkoxysilyl group and (meth) acrylic acid ester, and (A2) not containing an alkoxysilyl group (meth) acrylic acid esters seen including,
100% by mass of the total monomer component of the component (A), (A1) 1 to 10% by mass of (meth) acrylic acid ester containing an alkoxysilyl group, and (A2) (meth) acrylic containing no alkoxysilyl group acrylic copolymer 100 parts by weight of a copolymer of monomer components including the ester 80 to 99% by weight,
(B) 0.3 to 10 parts by mass of a titanium compound represented by the formula (1);
_{Ti (i-C 3 H 7} O) a (C 5 H 7 O 2) b (C 6 H 9 O 3) c (1)
(A, b and c are any integers from 0 to 4, provided that a + b + c = 4)
(C) 100 to 5000 parts by mass of solvent;
A primer composition comprising at least When the whole acrylic copolymer of the component (A) is 100% by mass, the (meth) acrylic acid ester containing the alkoxysilyl group of the component (A1) and the alkoxysilyl group of the component (A2) are not contained. 2. The primer composition according to claim 1, wherein the monomer component other than (meth) acrylic acid ester is 0% by mass. When the total monomer component of the component (A) is 100% by mass, the ratio of the (A2) at least one (meth) acrylic acid ester not containing an alkoxysilyl group is 80 % by mass or more and less than 99% by mass. The primer composition according to claim 1 , wherein the primer composition is present. The component (B), (B1) a mixture preparation of a titanium tetraalkoxide and / or alkoxy group-containing titanium chelate compound (B2) acetylacetone, an alkoxy group 1 mol of the titanium compound in (B1) pairs (B2) acetylacetone primer composition according to any one of claims 1 to 3, characterized in that the ratio of less than 2.0 mol 0.8 mol or more. (D) The primer composition according to any one of claims 1 to 4 , further comprising 1 to 100 parts by mass of an alkyltrialkoxysilane. The primer composition according to any one of claims 1 to 5 , wherein the titanium compound as the component (B) is an integer compound in which a = 2 and b + c = 2 in the formula (1).