JP5500030B2 - Method for producing curable composition - Google Patents

Description

The present invention relates to a method for producing a curable composition containing a specific acrylic copolymer, cured with moisture in the air, and giving a cured product having excellent adhesion to a coated resin portion of a resin-coated steel sheet. .

  Conventionally, a polymer having a functional group at a side chain or terminal is crosslinked by itself or in combination with a curing agent to give a cured product excellent in adhesiveness, heat resistance, durability, and the like. ing. Among them, a polymer having a crosslinkable silyl group is a typical one. For example, a polymer having a crosslinkable silyl group at the end absorbs moisture in the air in the presence of an appropriate curing agent. Gives a cured product.

  The main chain skeleton of such a polymer having a crosslinkable silyl group includes: (meth) acrylic acid ester polymer; polyether polymer such as polyethylene oxide, polypropylene oxide, polytetramethylene oxide; polybutadiene, poly Hydrocarbon polymers such as isoprene, polychloroprene, polyisobutylene or hydrogenated products thereof; polyester polymers such as polyethylene terephthalate, polybutylene terephthalate, polycaprolactone, etc. are known, and the main chain skeleton and cross-linked form It is used for various purposes. For example, a combination of a base metal and a surface layer resin, which combines functions such as weather resistance, durability, insulation, nonflammability, and antifouling properties and design, and is a composite material suitable for building materials, electrical equipment, vehicles, sundries, etc. A resin-coated steel sheet (resin decorative steel sheet) is widely used. As resin components constituting the surface resin, polyvinyl chloride resins, polyolefin resins, polyester resins, fluorine resins, and the like are known.

However, an adhesive having excellent adhesion between the surface layer resin of the resin-coated steel sheet and other members is required, and among the polymers exemplified above, curability including a (meth) acrylic acid ester-based polymer. Patent documents 1 and 2 are known as a composition.
In Patent Document 1, an oxyalkylene polymer having a silicon-containing functional group that can be crosslinked by forming a siloxane bond, which gives a cured product having excellent mechanical properties and adhesive properties, is crosslinked by forming a siloxane bond. Having a silicon-containing functional group and a molecular chain substantially having a (meth) acrylic acid alkyl ester monomer unit having an alkyl group having 1 to 2 carbon atoms and an alkyl group having 7 to 9 carbon atoms A curable resin composition containing a copolymer composed of (meth) acrylic acid alkyl ester monomer units and a curing accelerator is disclosed.

  Patent Document 2 discloses a composition that provides sufficient extensibility as a sealing material and tensile strength, and also provides excellent adhesion to adherends that are difficult to adhere, such as fluororesin-coated steel sheets. A main chain is essentially a polyalkylene oxide, a polymer having a hydrolyzable silyl group capable of crosslinking at the terminal, an acrylic copolymer having a hydrolyzable silyl group capable of crosslinking, and an amino acid A room temperature curable composition comprising a group having a group and an alkoxysilyl group is disclosed.

International Publication WO03 / 035755 Pamphlet JP-A-8-225707

When the curable composition disclosed in Patent Documents 1 and 2 is applied to a resin-coated steel sheet containing a vinyl chloride resin as a surface layer resin, sufficient adhesion may not be obtained.
An object of the present invention is to provide a curable composition (moisture-curing property) containing a specific acrylic copolymer, which is cured with moisture in the air, and gives a cured product excellent in adhesion to a surface layer resin in a resin-coated steel sheet. It is to provide a method for producing a composition.

The present invention is as follows.
1. Structural unit (a1) derived from alkyl acrylate ester (m1) containing an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and alkyl acrylate ester (m2) containing an aliphatic hydrocarbon group having 4 to 8 carbon atoms A structural unit derived from (a2) and a hydrolyzable silyl group, and the content ratio of the structural unit (a1) and the structural unit (a2) is the sum of all structural units constituting the copolymer. Is a method for producing a curable composition containing an acrylic copolymer of 20 to 90% by mass and 10 to 80% by mass, respectively ,
The acrylic copolymer is a monomer mixture (t1) containing the alkyl acrylate (m1), the alkyl acrylate (m2), a polymerizable unsaturated compound having a hydrolyzable silyl group, and a polymerization initiator. ) and, while supplying continuously to the reaction system, the production method of the curable composition characterized in that it is obtained by a process comprising a polymerization step of polymerizing at a temperature of 160 ° C. to 350 ° C..
2. 2. The curable composition according to 1 above , wherein the amount of the polymerization initiator used is 0.001 to 2 parts by mass with respect to 100 parts by mass of the monomer component contained in the monomer mixture (t1) . Manufacturing method .
3. The monomer mixture (t1) contains an organic solvent, and the content ratio of the organic solvent is 0 to 80 parts by mass with respect to 100 parts by mass of the monomer component contained in the monomer mixture (t1). method for producing a curable composition according to one the above 1 or 2.
4). 4. The method for producing a curable composition according to any one of 1 to 3 , wherein the acrylic copolymer has a number average molecular weight of 1,000 to 10,000 .
5. Production of the curable composition according to any one of 1 to 4 above , wherein the polymerization initiator is at least one selected from an organic peroxide, an azo compound, an inorganic peroxide, and a redox polymerization initiator. Way .

According to the curable composition obtained by the production method of the present invention, since it contains a specific acrylic copolymer, it hardens with moisture in the air and is excellent in adhesion to the surface resin in the resin-coated steel sheet. Cured product can be obtained.

Furthermore, since the acrylic copolymer is a polymer obtained by a specific production method, it has a composition that is stable in terms of physical properties as compared with the case where a conventionally known polymer is used. Things can be formed.

The present invention will be described in detail below.
In the present specification, “(meth) acryl” means acryl and methacryl, and “(co) polymer” means a homopolymer and a copolymer.
In addition, the number average molecular weight (hereinafter sometimes referred to as “Mn”) and the weight average molecular weight (hereinafter sometimes referred to as “Mw”) of the polymer are both determined by gel permeation chromatography (GPC). ) Measured in terms of polystyrene.

The curable composition obtained by the production method of the present invention includes a structural unit (a1) derived from an alkyl acrylate ester (m1) containing an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a carbon number 4 to 8 carbon atoms. The structural unit (a2) derived from an alkyl acrylate ester (m2) containing an aliphatic hydrocarbon group and a hydrolyzable silyl group, the content ratio of the structural unit (a1) and the structural unit (a2) However, when the total of all the structural units constituting the copolymer is 100% by mass, the acrylic copolymer (hereinafter referred to as “acrylic copolymer”) is 20 to 90% by mass and 10 to 80% by mass, respectively. Polymer (A) ").

（式中、Ｒ^１は、それぞれ、独立に、炭化水素基であり、Ｘは、それぞれ、独立に、ハロゲン原子、水素原子、ヒドロキシル基、アルコキシ基、アシルオキシ基、ケトキシメート基、アミド基、酸アミド基、メルカプト基、アルケニルオキシ基及びアミノオキシ基より選ばれる反応性基であり、ｎは、０、１又は２である。） The hydrolyzable silyl group contained in the acrylic copolymer (A) has a silicon atom and a hydroxyl group and / or a hydrolyzable functional group bonded to the silicon atom. And a group capable of forming a crosslinked structure. Although it does not specifically limit as a hydrolysable silyl group, The group represented by following General formula (1) is preferable.

(Wherein R ¹ is independently a hydrocarbon group, and X is independently a halogen atom, hydrogen atom, hydroxyl group, alkoxy group, acyloxy group, ketoximate group, amide group, acid amide) A reactive group selected from a group, a mercapto group, an alkenyloxy group and an aminooxy group, and n is 0, 1 or 2.)

In the general formula (1), R ¹ is preferably an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 0 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. When n = 2, the plurality of R ¹ may be the same as or different from each other.
When n = 0 or 1, the plurality of Xs may be the same as or different from each other. X in the general formula (1) is preferably an alkoxy group.

When the acrylic copolymer (A) contains a hydrolyzable silyl group, Si—O—Si bond is formed by hydrolysis condensation, and a cured product such as a film having excellent strength may be formed. it can.
The hydrolyzable silyl group when X in the general formula (1) is an alkoxy group is an alkoxysilyl group, such as a trimethoxysilyl group, a methyldimethoxysilyl group, a dimethylmethoxysilyl group, a triethoxysilyl group, Examples thereof include a methyldiethoxysilyl group and a methyldimethoxyethoxysilyl group. Among these, a trimethoxysilyl group and a methyldimethoxysilyl group are particularly preferable from the viewpoint of the balance between curing speed and flexibility.

  The average value of the number of hydrolyzable silyl groups contained in the acrylic copolymer (A) is preferably 0.2 to 4 from the viewpoint of adhesion to the adherend and tensile properties of the cured product. More preferably, it is 0.5-3, More preferably, it is 0.5-2. When the number of hydrolyzable silyl groups is less than 0.2, the composition may be insufficiently cured, and when it exceeds 4, the cured product may be too hard.

The position of the hydrolyzable silyl group contained in the acrylic copolymer (A) is not particularly limited, and can be a side chain and / or a terminal of the polymer.
When the hydrolyzable silyl group is present at the end of the polymer, it is derived from a residue such as a polymerization initiator, a hydrolyzable silyl group-containing thiol compound, a hydrolyzable silyl group-containing vinyl monomer, etc. It can be.
When the hydrolyzable silyl group is present in the side chain of the polymer, the structural unit containing the hydrolyzable silyl group is a compound having a polymerizable unsaturated bond and a hydrolyzable silyl group (hereinafter, “ Also referred to as “polymerizable unsaturated compound having hydrolyzable silyl group”.

（式中、Ｒ^３は、水素原子又はメチル基であり、Ｒ^４は、それぞれ、独立に、炭素数１〜２０の炭化水素基であり、Ｚは、直接結合、又は、−ＣＯＯＲ^６−（Ｒ^６は、炭素数１〜６の２価のアルキレン基）、−ＣＨ_２Ｃ_６Ｈ_４ＣＨ_２ＣＨ_２−、−ＣＨ_２ＯＣＯＣ_６Ｈ_４ＣＯＯ（ＣＨ_２）_３−等の２価の有機基であり、Ｘは、それぞれ、独立に、ハロゲン原子、水素原子、ヒドロキシル基、アルコキシ基、アシルオキシ基、ケトキシメート基、アミド基、酸アミド基、メルカプト基、アルケニルオキシ基及びアミノオキシ基より選ばれる反応性基であり、ｍは、０、１又は２である。） Examples of the compound having a polymerizable unsaturated bond and a hydrolyzable silyl group (polymerizable unsaturated compound having a hydrolyzable silyl group) include compounds represented by the following general formula (2).

(In the formula, R ³ is a hydrogen atom or a methyl group, R ⁴ is each independently a hydrocarbon group having 1 to 20 carbon atoms, and Z is a direct bond or —COOR ⁶ — ( R ⁶ is a divalent organic group having 1 to 6 carbon atoms), —CH ₂ C ₆ H ₄ CH ₂ CH ₂ —, —CH ₂ OCOC ₆ H ₄ COO (CH ₂ ) ₃ — and the like. Each X is independently selected from a halogen atom, a hydrogen atom, a hydroxyl group, an alkoxy group, an acyloxy group, a ketoximate group, an amide group, an acid amide group, a mercapto group, an alkenyloxy group, and an aminooxy group. A reactive group, and m is 0, 1 or 2.)

The hydrocarbon group having 1 to 20 carbon atoms represented by R ⁴ in the general formula (2) is preferably an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 0 carbon atoms, or an aralkyl having 7 to 20 carbon atoms. It is a group. When m = 2, the plurality of R ² may be the same as or different from each other.
When m = 0 or 1, the plurality of Xs may be the same as or different from each other.

Examples of the polymerizable unsaturated compound having a hydrolyzable silyl group represented by the general formula (2) include CH ₂ ═CHSi (CH ₃ ) (OCH ₃ ) ₂ , CH ₂ ═CHSi (CH ₃ ) Cl _2. CH ₂ = CHSi (OCH ₃ ) ₃ , CH ₂ = CHSiCl ₃ , CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , CH ₂ = CHCOO (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) Cl ₂ , CH ₂ = CHCOO (CH ₂ ) ₂ SiCl ₃ , CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₂ Si (CH ₃ ) ) (OCH ₃ ) ₂ , CH ₂ ═C (CH ₃ ) COO (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CH ₂ ═C (CH ₃ ) COO (CH ₂ ) ₃ Si (CH ₃ ) (O _{CH 3) 2, CH 2 =} C (CH 3) COO (CH 2) 3 Si (OCH 3) 3, CH 2 = C (CH 3) COO (CH 2) 2 Si (CH 3) Cl 2, CH 2 _{= C (CH 3) COO (} CH 2) 2 SiCl 3, CH 2 = CHCH 2 OC (O) -Ph-COO (CH 2) 3 Si (CH 3) (OCH 3) 2, CH 2 = CHCH 2 OC _{(O) -Ph-COO (CH} 2) 3 Si (OCH 3) 3, CH 2 = CHCH 2 OC (O) -Ph-COO (CH 2) 3 Si (CH 3) Cl 2, CH 2 = CHCH 2 _{OC (O) -Ph-COO (} CH 2) 3 SiCl 3 , and the like. “Ph” means a paraphenylene group.

  As described above, the acrylic copolymer (A) includes a structural unit (a1) derived from an alkyl acrylate ester (m1) containing an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and 4 to 4 carbon atoms. And a structural unit (a2) derived from an alkyl acrylate ester (m2) containing 8 aliphatic hydrocarbon groups. This copolymer may be a random copolymer or a block copolymer.

  The content ratio of the structural unit (a1) and the structural unit (a2) is 20 to 90% by mass and 10 to 80% by mass, respectively, when the total of all the structural units constituting the copolymer is 100% by mass. %, Preferably 35 to 70% by mass and 30 to 65% by mass. By using the acrylic copolymer (A) having a structural unit having a content ratio in the above range, it is cured with moisture in the air, and a curable composition having excellent adhesion to the surface layer resin in the resin-coated steel sheet is obtained. be able to.

  The acrylic copolymer (A) may contain other structural units (hereinafter referred to as “structural units (a3)”) in addition to the structural units (a1) and (a2). When the acrylic copolymer (A) includes the structural unit (a3), the upper limit of the content is preferably 50% by mass, more preferably 40% by mass when the total amount of the structural units is 100% by mass. %, More preferably 30% by mass.

  The structural unit (a3) is not particularly limited as long as it is derived from a polymerizable unsaturated compound. For example, a methacrylic acid alkyl ester, a methacrylic acid cycloalkyl ester, a methacrylic acid aryl ester, a fatty acid having 9 or more carbon atoms. Acrylic acid alkyl ester, acrylic acid cycloalkyl ester, acrylic acid aryl ester, aromatic vinyl compound (styrene, etc.), unsaturated carboxylic acid (acrylic acid, methacrylic acid, etc.), unsaturated acid anhydride, Examples include hydroxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, amide group-containing unsaturated compounds, alkoxyl group-containing unsaturated compounds, cyano group-containing unsaturated compounds, nitrile group-containing unsaturated compounds, and maleimide compounds. These compounds can be used alone or in combination of two or more.

  The acrylic copolymer (A) has a number average molecular weight (Mn) of 1,000 to 10,000, preferably 1,000 to 8,000, more preferably 1,000 to 5,000. . By using the composition containing the acrylic copolymer (A) having Mn in the above range, a cured product having excellent adhesion to the surface resin in the resin-coated steel sheet can be obtained. In addition, when the polymer with too large Mn is used, the viscosity of the resulting composition is high, and workability when using the composition may be reduced. On the other hand, if a polymer having too small Mn is used, it may cause a decrease in the weather resistance or heat resistance of the cured product.

  Moreover, the polydispersity (Mw / Mn) calculated from the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the acrylic copolymer (A) is preferably 1.1 to 5.0. Preferably it is 1.1-4.0. By using a composition containing an acrylic copolymer (A) having a polydispersity in the above range, it has a suitable viscosity when applied to applications and the like described later, and has an excellent balance of adhesive strength and breaking elongation. A curable composition that gives a cured product can be obtained.

  The viscosity of the acrylic copolymer (A) is preferably 1 to 1,000 Pa · s, more preferably 1 to 1,000 Pa · s, when measured using an E-type viscometer under the conditions of a temperature of 25 ° C. and a rotational speed of 5 rpm. 100 Pa · s, more preferably 1 to 50 Pa · s. When the viscosity of the acrylic copolymer (A) is in the above range, the workability in preparing the composition is excellent.

  A method for producing the acrylic copolymer (A) will be described later.

  The curable composition is further combined with the acrylic copolymer (A) in order to form a cured product having excellent tensile properties as well as adhesiveness to the surface resin in the resin-coated steel sheet. An oxyalkylene polymer having a decomposable silyl group (hereinafter referred to as “oxyalkylene polymer (B)”) can be contained.

The oxyalkylene polymer (B) is not particularly limited as long as it contains a repeating unit represented by the following general formula (3).
^-O-R 7 - (3)
(In the formula, R ⁷ is a divalent hydrocarbon group.)

As R ⁷ in the general formula (3), —CH (CH ₃ ) —CH ₂ —, —CH (C ₂ H ₅ ) —CH ₂ —, —C (CH ₃ ) ₂ —CH ₂ —, —CH ₂ CH ₂ CH ₂ CH ₂ — and the like. Of these, —CH (CH ₃ ) —CH ₂ — is preferred. In addition, the said oxyalkylene type polymer (B) may contain the said repeating unit individually by 1 type, and may contain it in 2 or more types of combinations.

  The hydrolyzable silyl group contained in the acrylic copolymer (A) can be applied as it is to the hydrolyzable silyl group contained in the oxyalkylene polymer (B).

  The average value of the number of hydrolyzable silyl groups contained in the oxyalkylene polymer (B) is preferably 1 to 4 from the viewpoints of adhesion to the surface layer resin and tensile properties of the cured product in the resin-coated steel sheet. More preferably, the number is 1.5 to 3. If the number of hydrolyzable silyl groups is less than 1, curing of the composition may be insufficient, and if it exceeds 4, the cured product may be too hard.

The position of the hydrolyzable silyl group contained in the oxyalkylene polymer (B) is not particularly limited, and can be a side chain and / or a terminal of the polymer.
The oxyalkylene polymer (B) may be either a linear polymer or a branched polymer. Moreover, you may use combining these.

  The production method of the oxyalkylene polymer (B) is not particularly limited, but is a production method using an alkali catalyst such as KOH, a production method using a transition metal compound-porphyrin complex catalyst, or a composite metal cyanide complex. Examples thereof include a production method using a catalyst and a production method using phosphazene. Among these, the production method using a double metal cyanide complex catalyst is suitable for obtaining a polymer having a high molecular weight and a narrow molecular weight distribution. When this polymer is used as an oxyalkylene polymer (B), It is preferable because the balance between the viscosity of the composition and the elongation at break of the cured product is excellent.

  The number average molecular weight (Mn) of the oxyalkylene polymer (B) is preferably 2,000 to 50,000, more preferably 5,000 to 30,000. By using the composition containing the oxyalkylene polymer (B) having Mn in the above range, a cured product having excellent adhesion to the surface resin and tensile properties in the resin-coated steel sheet can be obtained.

  When the curable composition contains the oxyalkylene polymer (B), the content of the acrylic copolymer (A) and the oxyalkylene polymer (B) is 100% in total. %, Preferably 5 to 90 mass% and 10 to 95 mass%, more preferably 5 to 50 mass% and 50 to 95 mass%, respectively. By using a composition containing the acrylic copolymer (A) and the oxyalkylene polymer (B) in the above proportions, a cured product that is more excellent in adhesion to the surface resin and tensile properties of the resin-coated steel sheet. Can be obtained.

  The curable composition may contain other polymers except the acrylic copolymer (A) and the oxyalkylene polymer (B) as long as the effect is not impaired. The upper limit of the content of the other polymer is usually 50 parts by mass, preferably 30 parts by mass with respect to 100 parts by mass of the acrylic copolymer (A).

  Other polymers include (meth) acrylic (co) polymers excluding the acrylic copolymer (A), such as the structural units (a1) and (a2), hydrolyzable silyl groups, and the like. And an acrylic copolymer having a Mn of less than 1,000 or more than 10,000; a structure derived from an alkyl (meth) acrylate except the above structural units (a1) and (a2) Examples include (meth) acrylic copolymers having units and hydrolyzable silyl groups.

  In addition to the above-mentioned polymer, the curable composition may further include a curing accelerator, a filler, a plasticizer, an antioxidant, an ultraviolet absorber, a flame retardant, an antifoaming agent, a lubricant, depending on the purpose and application. Weather stabilizer, light stabilizer, heat stabilizer, colorant (pigment, dye, etc.), fluorescent brightener, adhesion-imparting agent, anti-sagging agent, conductivity-imparting agent, anti-static agent, water repellent, oil repellent Further, it may contain additives such as preservatives and dehydrating agents, organic solvents, and the like.

The said hardening accelerator will not be specifically limited if it is a component which accelerates | stimulates moisture hardening reaction.
Examples of the curing accelerator include an organic tin compound; an organic titanium compound; an organic aluminum compound; an organic zirconium compound; an organic iron compound; an organic vanadium compound; an amine compound; an acidic phosphate ester; A saturated or unsaturated polyvalent carboxylic acid and an acid anhydride thereof; a reaction product (such as a salt) of a carboxylic acid compound and an amine compound; These may be used alone or in combination of two or more.

  Examples of the organic tin compounds include dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, dioctyltin maleate, dibutyltin phthalate, and dibutyltin bis (alkyl maleate); tin octylate, oleic acid Divalent tin carboxylates such as tin, tin stearate, tin naphthenate, tin stearate and tin versatate; alkoxide derivatives of dialkyl tin such as dibutyltin dimethoxide and dibutyltin diphenoxide; dibutyltin diacetylacetonate and dibutyltin Intramolecular coordination derivatives (chelate compounds) of dialkyltin such as acetoacetate; reaction products of dibutyltin oxide and phthalates, reaction products of dibutyltin oxide and ester compounds such as dibutyltin oxide and The reaction product according to Riketo compounds.

  Examples of the organic titanium compounds include titanium alkoxides such as tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetra (2-ethylhexyl titanate); titanium tetraacetylacetonate, titanium ethyl acetoacetate, etc. Chelate compounds; and triethanolamine titanate.

  Examples of the organoaluminum compound include aluminum alkoxides such as aluminum isopropylate, monosec-butoxyaluminum diisopropylate, and aluminum sec-butyrate; aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate, and the like. Examples include chelate compounds.

  Examples of the organic zirconium compound include zirconium alkoxides such as zirconium tetraisopropoxide and zirconium tetrabutoxide; zirconium monoacetylacetonate, zirconium bisacetylacetonate, zirconium tetraacetylacetonate, zirconium acetylacetonate bisethylacetoacetate, zirconium Examples include chelate compounds such as acetate.

  Examples of the amine compound include butylamine, octylamine, laurylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, Ethylenediamine, dibutylamine-2-ethylhexoate, guanidine, diphenylguanidine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8 -Diazabicyclo (5, 4, 0) undecene-7 (DBU) etc. are mentioned.

  As said hardening accelerator, an organic tin compound is preferable from a viewpoint of a cure rate and storage stability.

  When the curable composition contains a curing accelerator, the content thereof is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 100 parts by mass of the acrylic copolymer (A). -10 parts by mass. When content of the said hardening accelerator exists in the said range, hardening reaction can be advanced efficiently and the hardened | cured material more excellent in the adhesiveness to surface layer resin in a resin-coated steel plate and a tensile characteristic can be obtained.

  Examples of the filler include light calcium carbonate, colloidal calcium carbonate, heavy calcium carbonate, magnesium carbonate, zinc carbonate, aluminum hydroxide, magnesium hydroxide, carbon black, clay, talc, fumed silica, calcined silica, precipitated silica, Ground silica, fused silica, kaolin, diatomaceous earth, zeolite, titanium oxide, quicklime, iron oxide, zinc oxide, barium oxide, aluminum oxide, magnesium oxide, aluminum sulfate, glass fiber, carbon fiber, glass balloon, shirasu balloon, saran Examples include balloons and phenol balloons. These can be used alone or in combination of two or more. As the filler, calcium carbonate is preferable, and it is particularly preferable to use heavy calcium carbonate and light calcium carbonate in combination.

  When the curable composition contains a filler, the content thereof is preferably 20 to 300 parts by mass, more preferably 100 parts by mass of all the polymers including the acrylic copolymer (A). It is 50-200 mass parts. When the filler is a combination of light calcium carbonate and heavy calcium carbonate, it is preferably light calcium carbonate / heavy calcium carbonate = 90/10 to 50/50 (mass ratio). When the content of the filler is in the above range, the mechanical properties are excellent.

  Examples of the plasticizer include phthalic acid ester, trimellitic acid ester, pyromellitic acid ester, aliphatic monobasic acid ester, aliphatic dibasic acid ester, phosphoric acid ester, polyhydric alcohol ester, epoxy plasticizer, high Examples include molecular plasticizers and chlorinated paraffins. These can be used alone or in combination of two or more.

  Examples of the phthalic acid esters include dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate, di-n-hexyl phthalate, dicyclohexyl phthalate, and diheptyl phthalate. Di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, diphenyl phthalate, di (2-ethylhexyl) phthalate, di (2-butoxyethyl phthalate) ), Benzyl 2-ethylhexyl phthalate, benzyl n-butyl phthalate, benzylisononyl phthalate, dimethyl isophthalate and the like.

  Examples of trimellitic acid esters include tributyl trimellitic acid, trihexyl trimellitic acid, tri-n-octyl trimellitic acid, tri-2-ethylhexyl trimellitic acid, and triisodecyl trimellitic acid.

  Examples of the pyromellitic acid ester include tetrabutyl pyromellitic acid, tetrahexyl pyromellitic acid, tetra-n-octyl pyromellitic acid, tetra-2-ethylhexyl pyromellitic acid, tetradecyl pyromellitic acid, and the like.

  Examples of the aliphatic monobasic ester include butyl oleate, methyl oleate, methyl octoate, butyl octoate, methyl dodecanoate, butyl dodecanoate, methyl palmitate, butyl palmitate, methyl stearate, butyl stearate, Examples thereof include methyl linoleate, butyl linoleate, methyl isostearate, butyl isostearate, methyl acetyl ricinolate, and butyl acetyl ricinolate.

  Examples of the aliphatic dibasic acid ester include dimethyl adipate, diethyl adipate, di-n-propyl adipate, diisopropyl adipate, diisobutyl adipate, di-n-octyl adipate, di (2-ethylhexyl) adipate , Diisononyl adipate, diisodecyl adipate, di (2-butoxyethyl) adipate, di (butyl diglycol) adipate, heptylnonyl adipate, dimethyl azelate, di-n-octyl azelate, di (2- Ethylhexyl), diethyl succinate, dimethyl sebacate, diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di (2-ethylhexyl) sebacate, dibutyl fumarate, di (2-ethylhexyl) fumarate, malee Dimethyl acid Diethyl maleate, di -n- butyl, maleate, di (2-ethylhexyl), and the like.

  Examples of the phosphate ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-n-amyl phosphate, triphenyl phosphate, tri-o-cresyl phosphate, trixylenyl phosphate, and diphenyl 2-ethylhexyl phosphate. , Diphenyl cresyl phosphate, tris phosphate (2-butoxyethyl), tris phosphate (2-ethylhexyl) and the like.

  Examples of the polyhydric alcohol ester include diethylene glycol diacetylate, diethylene glycol dibenzoate, glycerol monooleate, glycerol tributyrate, glycerol triacetate, glyceryl-tri (acetylricinoleate), and triethylene glycol diacetate.

Examples of the epoxy plasticizer include epoxidized vegetable oil plasticizers and epoxidized fatty acid alkyl esters.
Examples of the epoxidized vegetable oil-based plasticizer include epoxidized soybean oil and epoxidized linseed oil.
Examples of the epoxidized fatty acid alkyl ester include epoxy methyl stearate, butyl epoxy stearate, 2-ethylhexyl epoxy stearate and the like.
In addition, epoxidized polybutadiene, tris (epoxypropyl) isocyanurate, 3- (2-xenoxy) -1,2-epoxypropane, bisphenol A diglycidyl ether, vinyldicyclohexene diepoxide, 2,2-bis (4-hydroxy) And a polycondensate of phenyl) propane and epichlorohydrin.

  Examples of the polymer plasticizer include a liquid polyurethane resin, a polyester plasticizer obtained from a dicarboxylic acid and a glycol; an etherified product or an esterified product of a polyalkylene glycol such as polyethylene glycol or polypropylene glycol; a polyvalent saccharide such as sucrose. Polyether plasticizers such as saccharide-based polyethers obtained by addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide to alcohol and then etherification or esterification; polystyrene plastics such as poly-α-methylstyrene And a poly (meth) acrylate plasticizer having no hydrolyzable silyl group.

  Among the above plasticizers, a poly (meth) acrylate plasticizer having an Mw of 1,000 to 7,000 and a glass transition temperature of −10 ° C. or lower maintains durability such as weather resistance of the cured product. Is particularly preferable. As the poly (meth) acrylate plasticizer, “ARUFON UP1000”, “ARUFON UP1010”, “ARUFON UP1020”, “ARUFON UP1060”, “ARUFON UP1080”, “ARUFON UP1110”, “ARUFON UH2000” manufactured by Toagosei Co., Ltd. , “ARUFON UH2130”, etc. (above, trade name; “ARUFON” is a trademark of Toagosei Co., Ltd.). These plasticizers can also be blended during the production of the acrylic copolymer (A).

  When the curable composition contains a plasticizer, the content thereof is preferably 0 to 100 parts by mass, more preferably 100 parts by mass of all the polymers including the acrylic copolymer (A). It is 0-70 mass parts, More preferably, it is 5-50 mass parts.

  Examples of the adhesion-imparting agent include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N Examples include-(β-aminoethyl) -γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, 1,3-diaminoisopropyltrimethoxysilane, and the like. These may be used alone or in combination of two or more.

  When the curable composition contains an adhesion-imparting agent, the content thereof is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of all the polymers including the acrylic copolymer (A). More preferably, it is 0.1-10 mass parts.

  The dehydrating agent is used to remove moisture during storage of the curable composition and maintain storage stability. For example, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane , Phenyltrimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldimethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, phenylmethyldiethoxysilane, dimethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, Examples include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. These can be used alone or in combination of two or more.

  When the curable composition contains a dehydrating agent, the content thereof is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of all the polymers including the acrylic copolymer (A). Preferably it is 0.1-10 mass parts.

  As said organic solvent, aromatic hydrocarbons, such as toluene, acetate ester, alcohol, etc. are mentioned.

Next, the manufacturing method of an acrylic copolymer (A) is demonstrated.
The acrylic copolymer (A), Ru der those obtained by applying a specific manufacturing method. In a curable composition, the acrylic obtained by the manufacturing method provided with the polymerization method of the following (x) or (y) rather than the composition containing the acrylic copolymer obtained by the manufacturing method provided with the batch polymerization method. towards a composition comprising a system copolymer, Ri stable der of property, in the present invention, that apply the former method. In the former manufacturing method, problems such as contamination of impurities and coloring may be caused. In order to obtain the above-mentioned specific configuration, more processes are required, and the latter manufacturing method is more economical.
(X) Acrylic acid alkyl ester (m1) containing an aliphatic hydrocarbon group having 1 to 3 carbon atoms, an alkyl alkyl ester (m2) containing an aliphatic hydrocarbon group having 4 to 8 carbon atoms, and hydrolyzability While continuously supplying a monomer mixture containing a polymerizable unsaturated compound having a silyl group and a polymerization initiator (hereinafter referred to as “monomer mixture (t1)”) to the reaction system, a temperature of 160 ° C. A method comprising a polymerization step of polymerizing at a temperature of ˜350 ° C.
(Y) Monomer containing acrylic acid alkyl ester (m1) containing an aliphatic hydrocarbon group having 1 to 3 carbon atoms and acrylic acid alkyl ester (m2) containing an aliphatic hydrocarbon group having 4 to 8 carbon atoms A method comprising a polymerization step of living radical polymerization of a body component (hereinafter referred to as “monomer component (t2)”).

  In the above method (x), the monomer component contained in the monomer mixture (t1) is an acrylic acid alkyl ester (m1), an acrylic acid alkyl ester (m2), and a polymerizable compound having a hydrolyzable silyl group. It consists of an unsaturated compound and other polymerizable unsaturated compounds used as necessary. The ratio of these compounds is selected in consideration of the polymerization conversion rate and the like so that the resulting acrylic copolymer (A) has the above-mentioned specific configuration.

The polymerization initiator contained in the monomer mixture (t1) is not particularly limited, and a conventionally known polymerization initiator that can generate a radical at a predetermined polymerization temperature can be used. .
Examples of the polymerization initiator include organic peroxides, azo compounds, inorganic peroxides, and redox polymerization initiators.

  Examples of the organic peroxide include tert-amyl-tert-butyl peroxide, tert-butyl-tert-hexyl peroxide, tert-amyl-tert-hexyl peroxide, di (tert-butyl) peroxide, di (tert). -Amyl) peroxide, di (tert-hexyl) peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, 1,1-bis (tert-butylperoxy) -3, 3,5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, cumene hydroperoxide, 2,5-di Tilhexane-2,5-dihydroperoxide, 1,3-bis (tert-butylperoxy) -m-isopropyl) benzene, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, Diisopropylbenzene peroxide, tert-butylcumyl peroxide, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, bis (tert-butylcyclohexyl) peroxydicarbonate, tert-butylperoxide Examples thereof include oxybenzoate and 2,5-dimethyl-2,5-di (benzoylperoxy) hexane.

  Examples of the azo compound include 2,2′-azobis (isobutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile), azocumene, and 2,2′-azobis (2-methylbutyronitrile). 2,2′-azobisdimethylvaleronitrile, 4,4′-azobis (4-cyanovaleric acid), 2- (tert-butylazo) -2-cyanopropane, 2,2′-azobis (2,4,4) 4-trimethylpentane), 2,2′-azobis (2-methylpropane), dimethyl 2,2′-azobis (2-methylpropionate) and the like.

Examples of the inorganic peroxide include potassium persulfate, sodium persulfate, and ammonium persulfate.
Redox polymerization initiators include sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, ferrous sulfate, etc. as reducing agents, potassium peroxodisulfate, hydrogen peroxide, tert-butyl hydroper What used an oxide etc. as an oxidizing agent can be used.

As the polymerization initiator, an organic peroxide and an azo compound in which an initiator radical hardly causes extraction of a hydrogen atom are preferable, and in particular, di (tert-butyl) peroxide, di (tert-amyl) peroxide, and Di (tert-hexyl) peroxide is preferred.
The usage-amount of the said polymerization initiator is 0.001-2 mass parts normally with respect to 100 mass parts of monomer components contained in a monomer mixture (t1).

The monomer mixture (t1) may contain an organic solvent.
Examples of the organic solvent include linear or branched aliphatic hydrocarbons; alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene; one or more hydrogen atoms in these hydrocarbons are halogen atoms Halogen-substituted compounds substituted with: cyclic ethers such as tetrahydrofuran and dioxane; acetic acid esters such as ethyl acetate, methyl acetate and butyl acetate; ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; methyl orthoformate and orthoacetic acid Examples thereof include orthocarboxylic acid esters such as methyl; alcohols such as methanol, ethanol and isopropanol. These organic solvents may be used alone or in combination of two or more. When an organic solvent excellent in solubility of the acrylic copolymer is used, production defects such as scale growth on the walls of the reactor can be suppressed.

  The usage-amount of the said organic solvent is 0-80 mass parts normally with respect to 100 mass parts of monomer components contained in a monomer mixture (t1).

In the polymerization step in the above process (x), the monomer mixture (t1), while supplying continuously to the reaction system, 160 ° C. to 350 ° C., more preferably the polymerization at 160 ° C. to 300 ° C.. When the polymerization reaction is stabilized, an amount of the reaction liquid corresponding to the supply amount of the monomer mixture (t1) is extracted and collected.
The polymerization of the monomer mixture (t1) may be performed under pressure, atmospheric pressure, or reduced pressure. In the present invention, it is preferable to polymerize under pressure. When polymerization is carried out under pressure, a pressurizable reactor is used, and the pressure depends on the reaction temperature and the boiling point of the monomer mixture and solvent used, but does not affect the reaction. Any pressure may be used as long as the reaction temperature can be maintained.

In the polymerization step, the monomer mixture (t1) is continuously supplied to the reaction system and is usually polymerized with stirring.
The polymerization time (residence time) of the monomer mixture (t1) is preferably 1 to 60 minutes, more preferably 2 to 40 minutes. When the polymerization time (residence time) is too short, the polymerization conversion rate of the monomer tends to be low. On the other hand, if the polymerization time (residence time) is too long, the polymerization conversion rate of the monomer increases, but the productivity tends to decrease.

In the method (x), after the polymerization step, the acrylic copolymer (A) can be recovered from the reaction solution by a volatile component removal step such as an organic solvent by a known means. .
As an apparatus used in this volatile component removal process, a falling evaporator, a thin film evaporator, an extruder dryer, etc. are mentioned, for example. The heating temperature of the reaction solution is preferably 300 ° C. or lower, more preferably 270 ° C. or lower, particularly preferably 250 ° C. or lower. If the heating temperature is too high, the resulting acrylic copolymer (A) may be colored or a low molecular weight component may be generated by decomposition. Moreover, it is preferable to perform removal of a volatile component under reduced pressure, for example, can be 50 kPa or less. A more preferable pressure is 30 kPa or less, and particularly preferably 10 kPa or less. By setting it as the said pressure, a volatile component can fully be removed.

  On the other hand, in the method (y), the monomer component (t2) is a monomer component containing an alkyl acrylate ester (m1) and an alkyl acrylate ester (m2), and other components used as necessary. The polymerizable unsaturated compound. The ratio of these compounds is selected so that the acrylic copolymer (A) to be obtained has the above-mentioned specific configuration as in the case of the method (x). Examples of other polymerizable unsaturated compounds include polymerizable unsaturated compounds having a hydrolyzable silyl group and compounds exemplified as the polymerizable unsaturated compound forming the structural unit (a3).

The polymerization step in the above method (y) is a step of living radical polymerization of the monomer component (t2). According to the living radical polymerization, a polymer having a narrow molecular weight distribution and a low viscosity can be obtained, and a specific functional group can be introduced at any place of the polymer.
Specific examples of living radical polymerization include the ATRP method using copper bromide as a catalyst disclosed in JP-A-11-130931, and the thiocarbonylthio compound disclosed in JP 2000-515181 A. Examples thereof include an addition-fragmentation chain transfer method (RAFT method) in which a vinyl monomer is polymerized in the presence, a living radical polymerization method using a nitrooxide radical disclosed in JP-T-2003-500378. Of these, the living radical polymerization method using a nitrooxide radical is preferable because it does not require the use of a highly toxic copper compound unlike the ATRP method.

（式中、Ｒ^８は水素原子又は炭素数１〜２のアルキル基であり、Ｒ^９は炭素数１〜２のアルキル基又はニトリル基であり、Ｒ^１０は−（ＣＨ_２）_ｓ−（ｓは０、１又は２である。）であり、Ｒ^１１は互いに独立して炭素数１〜４のアルキル基である。） The method (y) is preferably one in which the polymerization is continued while the hydrolyzable silyl group is present at one end of the polymer formed by the polymerization of the monomer component (t2). If necessary, a polymerizable unsaturated compound having a hydrolyzable silyl group is added to the final stage of the polymerization, and the hydrolyzable silyl group derived from this monomer is added at or near the other end. Can be arranged. In this method, specifically, as a living radical polymerization initiator, a nitroxide compound represented by the following general formula (4) is used as a compound having a hydrolyzable silyl group, a hydrolyzable silyl group and an epoxy bond. In this method, each of the compounds having the above is used together with the monomer component (t2). In this reaction system, stable nitroxy free radicals are generated, which allows polymerization growth while the terminal is in an inactive state and the active state in an equilibrium state, and the polydispersity is adjusted. The produced living polymer is efficiently produced. In addition, since the compound which has a hydrolyzable silyl group and an epoxy bond is used, since the epoxy part in this compound and the carboxyl group in the nitroxide compound represented by the following general formula (4) undergo an addition reaction, A polymer in which an inactive hydrolyzable silyl group remains can be produced.

(In the formula, R ⁸ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ⁹ is an alkyl group having 1 to 2 carbon atoms or a nitrile group, and R ¹⁰ is — (CH ₂ ) _s — (s Is 0, 1 or 2.) and R ¹¹ is independently an alkyl group having 1 to 4 carbon atoms.

  The usage-amount of the nitroxide compound represented by the said General formula (4) is 2-20 mass parts normally with respect to 100 mass parts of monomer components (t2).

  Examples of the compound having a hydrolyzable silyl group and an epoxy bond include 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, (2-glycidoxyethyl) methyldimethoxysilane, 3 -Glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3 , 4-epoxycyclohexyl) ethyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane, and the like.

  The amount of the compound having a hydrolyzable silyl group and an epoxy bond is preferably 0.8 to 2.0 mol, more preferably 1 with respect to 1 mol of the nitroxide compound represented by the general formula (4). 0.0 to 1.7 mol, particularly preferably 1.1 to 1.5 mol. By setting it as the said usage-amount, the number of the hydrolysable silyl groups contained in an acrylic copolymer (A) can be made into 0.5-4 pieces efficiently. In addition, when there are too few usage-amounts of the compound which has the said hydrolysable silyl group and an epoxy bond, the quantity of the hydrolysable silyl group introduce | transduced into the terminal will reduce, and the tensile physical property of hardened | cured material may fall. On the other hand, if the amount used is too large, the unreacted crosslinkable silyl group-containing glycidyl compound remains in the composition, and the crosslink density is excessively lowered during curing, which may reduce the mechanical properties of the cured product.

  For the living radical polymerization in the above method (y), a batch process, a semi-batch process, a tubular continuous polymerization process, a continuous stirred tank type process (CSTR), or the like can be applied. Preferred methods are batch processes, semi-batch processes and tubular continuous polymerization processes, particularly preferably batch processes. The polymerization format may be solution polymerization using an organic solvent, bulk polymerization without using an organic solvent, or the like.

  A preferred polymerization step in the method (y) is a step of polymerizing the monomer component (t2) in the presence of the nitroxide compound (living radical polymerization initiator) and a compound having a hydrolyzable silyl group and an epoxy bond. . When the acrylic copolymer (A) is produced using the nitroxide compound (living radical polymerization initiator) and the compound having a hydrolyzable silyl group and an epoxy bond, a catalyst is used to increase the production efficiency. Is preferably used. The catalyst is not particularly limited as long as it promotes the reaction between the glycidyl group and the carboxyl group and does not affect the hydrolyzable silyl group, but is preferably a quaternary ammonium salt.

  Examples of the quaternary ammonium salt include tetrabutylammonium bromide, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tributylammonium bromide and the like.

  The amount of the catalyst used is preferably from 0.1 to 2 parts by mass, more preferably from 0.2 to 1 part by mass, particularly from 100 parts by mass of the monomer component (t2), from the viewpoint of production efficiency. Preferably it is 0.3-0.5 mass part. In addition, when there is too little usage-amount of the said catalyst, the said effect may not fully be acquired. On the other hand, when there is too much usage-amount of a catalyst, when it is set as a curable composition, precipitation may be formed.

In the preferred polymerization step in the method (y), the polymerization of the monomer component (t2) is usually performed in an organic solvent.
Examples of the organic solvent include linear or branched aliphatic hydrocarbons; alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene; one or more hydrogen atoms in these hydrocarbons are halogen atoms Halogen-substituted compounds substituted with: cyclic ethers such as tetrahydrofuran and dioxane; acetic acid esters such as ethyl acetate, methyl acetate and butyl acetate; ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; methyl orthoformate and orthoacetic acid Examples thereof include orthocarboxylic acid esters such as methyl; alcohols such as methanol, ethanol and isopropanol. These organic solvents may be used alone or in combination of two or more.

  The amount of the organic solvent used is preferably 0 to 200 parts by weight, more preferably 0 to 100 parts by weight, still more preferably 5 to 35 parts by weight, particularly preferably 100 parts by weight of the monomer component (t2). Is 10 to 20 parts by mass. If the amount of the organic solvent used is too large, a chain transfer reaction caused by the organic solvent may occur, and the polymerization control such as molecular weight control, molecular weight distribution control, and terminal living property may be lowered. On the other hand, if the amount of the organic solvent used is too small, the hydrolyzable silyl group crosslinking reaction may proceed.

  In the polymerization step in the above method (y), the polymerization temperature of the monomer component (t2) accommodated in the reactor is preferably 100 ° C. to 150 ° C., more preferably 105 ° C. to 135 ° C., and still more preferably 110 ° C. to Polymerize at 125 ° C. When the polymerization temperature is too low, the polymerization rate tends to decrease. On the other hand, if the polymerization temperature is too high, the nitroxide radical cannot cap the growing radical, and the recombination reaction between the growing radicals, the disproportionation reaction, the hydrogen atom abstraction reaction from the polymer main chain, and the back-biting reaction. May cause a β-decomposition reaction and lose the living polymerizability, making it impossible to control radical polymerization.

  The polymerization of the monomer component (t2) may be performed under atmospheric pressure, increased pressure, or reduced pressure depending on the monomer used, the boiling point of the organic solvent, and the reaction temperature, and a polymerization method is appropriately selected.

  In the polymerization step in the above method (y), the polymerization conversion rate of the monomer component (t2) is preferably 70 to 99%, more preferably 85 to 98%, and particularly preferably 93 to 97%. . The polymerization time depends on the type of monomer, polymerization temperature and the like, but is usually 0.5 to 10 hours, preferably 1 to 5 hours.

  In the polymerization step, as described above, the monomer component (t2) may be used as an acrylic acid alkyl ester (m1) and an acrylic acid alkyl ester (m2), or an acrylic acid alkyl ester ( m1), an acrylic acid alkyl ester (m2), and a polymerizable unsaturated compound having a hydrolyzable silyl group may be used. In the latter case, the first monomer comprising the acrylic acid alkyl ester (m1) and the acrylic acid alkyl ester (m2) is polymerized, and the polymerization conversion is preferably 70 to 99%, more preferably 85 to 98. %, More preferably 93 to 97%, a polymerizable unsaturated compound having a hydrolyzable silyl group is added to the reaction system, and polymerization is continued. If the polymerization conversion rate is within the above range, the hydrolyzable silyl group can be efficiently introduced at or near the growth end. When a polymerizable unsaturated compound having a hydrolyzable silyl group is added when the polymerization conversion rate is less than 70%, it becomes close to the α-terminal silyl group, and excellent tensile properties may not be obtained. On the other hand, when a polymerizable unsaturated compound having a hydrolyzable silyl group is added at a place where the polymerization conversion rate is too high, the copolymerization rate is lowered and may not be introduced into the polymer chain.

In the method (y), after the polymerization step, the acrylic copolymer (A) can be recovered from the reaction solution by a volatile component removal step such as an organic solvent by a known means. .
As an apparatus used in this volatile component removal process, a falling evaporator, a thin film evaporator, an extruder dryer, etc. are mentioned, for example. The heating temperature of the reaction solution is preferably 250 ° C. or less, more preferably 170 ° C. or less, and particularly preferably 100 ° C. or less. By setting the heating temperature as described above, the living radical polymerization terminal is not dissociated, and generation of a low molecular weight component due to decomposition of the copolymer is suppressed, which is preferable. If the heating temperature is too high, the living radical polymerization terminal is dissociated, the polymer chain is partially decomposed, and a low molecular weight component is produced. Further, the resulting acrylic copolymer (A) is colored. There is a case. Moreover, it is preferable to perform removal of a volatile component under reduced pressure, for example, can be 10 kPa or less. A more preferable pressure is 5 kPa or less, and particularly preferably 1 kPa or less. By setting it as the said pressure, a volatile component can fully be removed.

The curable composition obtained by the production method of the present invention is prepared by preliminarily blending all the ingredients, and then the composition is stored in a sealed state, and when used, the seal is opened and the curable composition is used. It can be set as the 1-component type curable composition hardened | cured by absorbing the moisture in air later.
Moreover, it can also prepare as a 2 component type which mixes the hardening acceleration composition which does not contain an acrylic copolymer (A), and the curable composition which does not contain a hardening accelerator etc. before use.
In addition, as said hardening acceleration | stimulation composition, it can be set as the composition which mix | blended components, such as the said hardening accelerator, the said filler, and the said plasticizer.
Among these, the one-component type is more preferable because it is easy to handle and causes less trouble during use (construction).

Since the curable composition obtained by the manufacturing method of the present invention contains a specific acrylic copolymer, it is excellent in moisture curability. For example, when a composition is used to form a coating film or the like and then exposed to the atmosphere, it is cured while forming a three-dimensional network structure by the action of moisture, and a cured product having a rubber-like elasticity (solid film ) Is obtained. In addition, this cured product has excellent adhesion to the surface layer resin in a resin-coated steel sheet in which the skin resin is composed of a polyvinyl chloride resin, a polyolefin resin, a polyester resin, a fluorine resin, or the like. Therefore, the curable composition obtained by the production method of the present invention is an adhesive for civil engineering, architectural use, vehicle use, electrical product use, electronic component use, miscellaneous goods, in order to make use of such properties of the cured product. In addition to sealing agents, coating agents, and sealants, it is useful as a primer agent for civil engineering or architectural resin coating, wood coating, and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples as long as the gist of the present invention is not exceeded. In the following, “part” and “%” are based on mass unless otherwise specified.

1. Physical property measurement method and evaluation method The physical property measurement method and evaluation method according to the curable composition and the polymer component contained therein are as follows.
1-1. Weight average molecular weight (Mw) and number average molecular weight (Mn) of acrylic copolymer
Using a gel permeation chromatograph (model name “HLC-8120”, manufactured by Tosoh Corporation), Mw and Mn were measured under the following conditions, and converted to standard polystyrene.
<Measurement conditions>
Column: 4 TSKgel SuperMultipore HZ-M (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran Detector: RI

1-2. The average number of hydrolyzable silyl groups contained in the acrylic copolymer The number (average number) of alkoxysilyl groups that are hydrolyzable silyl groups is f in the spectrum obtained by ¹ H-NMR measurement of the copolymer. It calculated from the integral value by the following formula.
f = (integrated value derived from alkoxysilyl group) / {(integrated value derived from monomer) / (degree of polymerization)}
1-3. Viscosity of Acrylic Copolymer and Composition Measured using an E-type viscometer at a temperature of 25 ° C. ± 0.5 ° C.

1-4. Adhesiveness A vinyl chloride resin-coated steel sheet was used as an adherend for evaluating adhesiveness. Using this vinyl chloride resin-coated steel sheet and the curable composition, an H-type test piece was prepared according to JIS A5758, and cured for one week under conditions of a temperature of 23 ° C. and a humidity of 50% RH. Thereafter, a tensile tester “Tensilon 200” (model name) manufactured by Toyo Seiki Seisakusho was used and subjected to a tensile test under the condition of a tensile speed of 50 mm / min. And the maximum tensile strength (unit: N / mm < ² >) was measured and adhesive strength was evaluated. At that time, the form of tensile fracture was observed, and the ratio of the area of the cohesive fracture portion to the entire adhesion area was determined to obtain the cohesive fracture ratio (unit:%).

1-5. Workability Ease of charging into mixing tank when mixing 20 parts of acrylic copolymer and 100 parts of oxyalkylene polymer having hydrolyzable silyl group using a planetary mixer, mixing The ease of care was determined according to the following criteria.
“◯”: Good.
“△”: Slightly inferior.

2. Production of Acrylic Copolymer (A), etc. Synthesis Example 1 (Synthesis of Copolymer (A-1))
The temperature of the pressurized stirred tank reactor equipped with an oil jacket was kept at 200 ° C. Next, while keeping the pressure in the reactor constant (2.3 MPa), 25 parts of methyl acrylate (hereinafter referred to as “MA”) and 67 parts of acrylic acid n −, which were previously stored in the raw material tank. Butyl (hereinafter referred to as “nBA”), 8 parts of 3-methacryloxypropyltrimethoxysilane (hereinafter referred to as “MTMS”), 23 parts of methyl ethyl ketone (hereinafter referred to as “MEK”), 13 A monomer mixture consisting of 1 part of methyl orthoacetate (hereinafter referred to as “MOA”) and 1 part of di-tert-hexyl peroxide (polymerization initiator; hereinafter referred to as “DTBP”) Under the condition of 48 g / min, feeding to the reactor was started, and polymerization was simultaneously performed while stirring. Immediately after the start of the reaction, the temperature of the reaction system once decreased and a temperature increase due to the heat of polymerization was observed, but the reaction system was maintained at a temperature of 214 ° C. to 216 ° C. by controlling the oil jacket.
Thereafter, an amount of the reaction liquid corresponding to the supply amount of the monomer mixture is added to the reactor while keeping the residence time substantially constant (about 12 minutes) so that a certain amount of the reaction liquid stays in the reactor. It was continuously extracted from the discharge port arranged in and collected. The time when the temperature was stabilized from the start of the supply of the monomer mixture was regarded as the time when the polymerization was stabilized, and this was taken as the collection start point of the “reaction liquid containing an acrylic copolymer used in the curable composition”. did. Then, polymerization was carried out under the above conditions, and 1.2 kg of “reaction liquid containing an acrylic copolymer used for the curable composition” was recovered.
Next, the “reaction liquid containing the acrylic copolymer used for the curable composition” is introduced into a thin film evaporator to remove volatile components such as unreacted monomers, and then the acrylic copolymer (A -1) was obtained.
Mn of the acrylic copolymer (A-1) was 1,600, Mw was 2,900, and Mw / Mn was 1.8 (see Table 1). Further, the number f (Si) of alkoxysilyl groups per polymer chain of the polymer was 0.5.

Synthesis Examples 2 to 5 (Synthesis of copolymers (A-2) to (A-5))
Copolymers (A-2) to (A-5) were obtained in the same manner as in Synthesis Example 1 except that the monomers and polymerization initiators were used for polymerization with the types and amounts used in Table 1. (See Table 1).
In Table 1, “iBMA”, “nBA”, “MA”, “EA” and “2EHA” are isobutyl methacrylate, n-butyl acrylate, methyl acrylate, ethyl acrylate and acrylic acid 2 respectively. -Ethylhexyl.

Synthesis Example 6 (Synthesis of copolymer (A-6))
The composition of the monomer mixture was 25 parts MA, 70 parts 2EHA, 5 parts MTMS, 12 parts isopropyl alcohol (hereinafter referred to as “IPA”), 8 parts MOA, 10 parts MEK and 0. A copolymer (A-6) was obtained in the same manner as in Synthesis Example 1 except that 5 parts of DTBP was used and the temperature of the reaction system was maintained at 181 ° C. to 183 ° C. and used for polymerization (see Table 1).

Synthesis Example 7 (Synthesis of copolymer (A-7))
The composition of the monomer mixture is 25 parts MA, 72 parts 2EHA, 3 parts MTMS, 12 parts IPA, 8 parts MOA, 10 parts MEK and 0.2 parts DTBP, and the temperature of the reaction system. Was maintained at 169 ° C. to 171 ° C. and subjected to polymerization to obtain a copolymer (A-7) in the same manner as in Synthesis Example 1 (see Table 1).

Synthesis Example 8 (Synthesis of copolymer (A-8))
The composition of the monomer mixture was divided into 25 parts MA, 73 parts 2EHA, 2 parts MTMS, 4 parts isopropyl alcohol (hereinafter referred to as “IPA”), 6 parts MOA, 10 parts MEK and 0. A copolymer (A-8) was obtained in the same manner as in Synthesis Example 1 except that 1 part of DTBP was used, and the temperature of the reaction system was maintained at 168 ° C. to 170 ° C. and used for polymerization (see Table 1).

Synthesis Examples 9 to 12 (Synthesis of copolymers (A-9) to (A-12))
Copolymers (A-9) to (A-12) were obtained in the same manner as in Synthesis Example 1 except that the monomers and polymerization initiators were used for polymerization with the types and amounts used in Table 1. (See Table 1).

その後、反応液を冷却して、反応器から抜き出した。そして、反応液を、蒸発器に導入して、減圧度０．３ｋＰａ及び温度９０℃の条件下、５時間かけて減圧乾燥し、アクリル系共重合体（Ａ−１３）を得た。尚、上記リビング重合開始剤のカルボキシル基の反応率は１００％であった。
アクリル系共重合体（Ａ−１３）のＭｎは４，５００、Ｍｗは７，１００、Ｍｗ／Ｍｎは１．６であった（表２参照）。また、この重合体の高分子鎖１本あたりのアルコキシシリル基の数ｆ（Ｓｉ）は１．０であった。 Synthesis Example 13 (Synthesis of copolymer (A-13))
In a pressurized stirred tank reactor equipped with an oil jacket, 27 parts of MA, 73 parts of 2EHA, 8.6 parts of the living polymerization initiator shown below, 10 parts of MOA, and 5.3 parts of 3- A mixed solution consisting of glycidoxypropyltrimethoxysilane and 0.3 part of tetra-n-butylammonium bromide was charged. Next, after the mixed solution was sufficiently deaerated by bubbling with nitrogen gas, the temperature of the reaction system was set to 110 ° C. by controlling the oil jacket, and polymerization was started with stirring. The temperature of the reaction system was maintained at 110 ° C., and polymerization was performed for 4 hours. At this time, the polymerization rate of MA was 99%, and the polymerization rate of 2EHA was 98%.

Thereafter, the reaction solution was cooled and extracted from the reactor. And the reaction liquid was introduce | transduced into the evaporator, and it dried under reduced pressure over 5 hours on the conditions of 0.3 kPa and 90 degreeC of pressure reduction, and obtained the acryl-type copolymer (A-13). The reaction rate of the carboxyl group of the living polymerization initiator was 100%.
Mn of the acrylic copolymer (A-13) was 4,500, Mw was 7,100, and Mw / Mn was 1.6 (see Table 2). Further, the number f (Si) of alkoxysilyl groups per polymer chain of this polymer was 1.0.

Synthesis Examples 14 to 15 (Synthesis of copolymers (A-14) to (A-15))
Copolymers (A-14) to (A-15) were obtained in the same manner as in Synthesis Example 1 except that the monomers and polymerization initiators were used for polymerization in the types and amounts used in Table 2. (See Table 2). The reaction rate of the carboxyl group in the living polymerization initiator was 100% in all cases.

Synthesis Example 16 (Synthesis of copolymer (A-16))
In a pressurized stirred tank reactor equipped with an oil jacket, 25 parts of MA, 73.8 parts of 2EHA, 1.9 parts of the living polymerization initiator used in Synthesis Example 13, and 1.9 parts of MOA And 1.2 parts of 3-glycidoxypropyltrimethoxysilane and 0.3 parts of tetra-n-butylammonium bromide were charged. Next, after the mixed solution was sufficiently deaerated by bubbling with nitrogen gas, the temperature of the reaction system was set to 110 ° C. by controlling the oil jacket, and polymerization was started with stirring. The temperature of the reaction system was maintained at 110 ° C., and after 4 hours, 1.2 parts of MTMS was added. And it was made to react for 1.5 hours as it is. At this time, the polymerization rate of MA was 96%, the polymerization rate of 2EHA was 94%, and the polymerization rate of MTMS was 95%.
Thereafter, in the same manner as in Synthesis Example 13, an acrylic copolymer (A-16) was obtained (see Table 2). The reaction rate of the carboxyl group of the living polymerization initiator was 100%.

3. Production and Evaluation of Curable Composition Examples 1 to 8, Reference Examples 1 to 4, and Comparative Examples 1 to 5
Using the copolymer (A) obtained in the above synthesis example and the following components, mixing was carried out for 1 hour under the conditions of a temperature of 60 ° C. and a pressure of 10 Torr using a planetary mixer in the proportions shown in Table 3. A curable composition was obtained. Various evaluations were performed. The results are shown in Table 3.

3-1. Oxyalkylene polymer having hydrolyzable silyl group (B)
A moisture-curing modified silicone polymer having a hydrolyzable silyl group at the terminal and having a polypropylene glycol skeleton (trade name “ES-S3430”, manufactured by Asahi Glass Co., Ltd.) was used. Mn is 16,000.
3-2. A plasticizer (meth) acrylic acid ester copolymer (trade name “UP-1110”, manufactured by Toagosei Co., Ltd.) was used.
3-3. Curing accelerator (D)
Dibutyltin diacetylacetonate was used.
3-4. As the filler (F-1), synthetic calcium carbonate (trade name “Shiraka Hana CCR”, manufactured by Shiraishi Calcium Co., Ltd.) and (F-2) as titanium oxide (trade name “R-820”, manufactured by Ishihara Sangyo Co., Ltd.) Was used.
3-5. Dehydrating agent Vinylsilane was used.
3-6. Adhesion imparting agent N-2- (aminoethyl) -3-aminopropyltrimethoxysilane was used.

  When exposed to the atmosphere, the curable composition of the present invention forms a three-dimensional network structure by the action of moisture, cures, and changes to a solid having rubbery elasticity. This cured product has excellent adhesion to the surface layer resin in a resin-coated steel sheet in which the skin resin is composed of a polyvinyl chloride resin, a polyolefin resin, a polyester resin, a fluorine resin, or the like. Therefore, the curable composition of the present invention can be used for civil engineering, architectural, vehicle, electrical product, electronic component, miscellaneous, adhesive, sealing agent, coating, etc. in order to make use of such properties of the cured product. It is useful as a primer agent for coatings for civil engineering and construction, wood coating, etc., as well as agents and sealants.

Claims (5)

Structural unit (a1) derived from alkyl acrylate ester (m1) containing an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and alkyl acrylate ester (m2) containing an aliphatic hydrocarbon group having 4 to 8 carbon atoms A structural unit derived from (a2) and a hydrolyzable silyl group, and the content ratio of the structural unit (a1) and the structural unit (a2) is the sum of all structural units constituting the copolymer. Is a method for producing a curable composition containing an acrylic copolymer of 20 to 90% by mass and 10 to 80% by mass, respectively ,
The acrylic copolymer is a monomer mixture (t1) containing the alkyl acrylate (m1), the alkyl acrylate (m2), a polymerizable unsaturated compound having a hydrolyzable silyl group, and a polymerization initiator. ) and, while supplying continuously to the reaction system, the production method of the curable composition characterized in that it is obtained by a process comprising a polymerization step of polymerizing at a temperature of 160 ° C. to 350 ° C.. The curable composition according to claim 1, wherein the amount of the polymerization initiator used is 0.001 to 2 parts by mass with respect to 100 parts by mass of the monomer component contained in the monomer mixture (t1). Manufacturing method. The monomer mixture (t1) contains an organic solvent, and the content ratio of the organic solvent is 0 to 80 parts by mass with respect to 100 parts by mass of the monomer component contained in the monomer mixture (t1). A method for producing a curable composition according to claim 1 or 2. The method for producing a curable composition according to any one of claims 1 to 3, wherein the acrylic copolymer has a number average molecular weight of 1,000 to 10,000. The curable composition according to any one of claims 1 to 4, wherein the polymerization initiator is at least one selected from an organic peroxide, an azo compound, an inorganic peroxide, and a redox polymerization initiator. Production method.