JP2003049063A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable composition effective for improving the elastic modulus of its cured product without remarkably lowering the strength and elongation and produced by using a polyoxyalkylene polymer containing a reactive silicon group. SOLUTION: This curable composition is produced by adding 5-300 pts.wt. of one or more materials selected from kaolin, clay, talc and mica to a system containing 100 pts.wt. of the polyoxyalkylene polymer containing the reactive silicon group and/or 5-100 pts.wt. of a copolymer composed of an alkyl acrylate and/or alkyl methacrylate monomer unit and/or 5-180 pts.wt. of an epoxy resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention, when used as a sealing material, an adhesive, an injecting material, a putty material, etc., can obtain a cured product having a high elastic modulus without significantly reducing strength and elongation. Sex composition.

[0002]

A curable composition using a polyoxyalkylene polymer containing a reactive silicon group is used in civil engineering, construction, industry because of its excellent workability, curability, adhesiveness, strength and conformability to deformation. Sealing materials, adhesives, injection materials for applications,
Widely used for putty materials. However, when a high elastic modulus is required for such applications without lowering the strength or elongation of the cured product, it has been difficult to achieve that.

For example, Japanese Patent No. 1396791 discloses the use of calcium carbonate and carbon black as fillers. However, if a high elastic modulus is sought only by adjusting these amount ratios, there are problems that workability is greatly reduced and elongation is extremely reduced.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a curable composition having an improved elastic modulus without significantly reducing the strength and elongation of the cured product.

[0005]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to solve the above problems, and found that a reactive silicon group-containing polyoxyalkylene polymer and / or an alkyl acrylate and / or It has been found that it is effective to add one or more of kaolin, clay, talc and mica to a system containing an alkyl methacrylic acid copolymer and / or an epoxy resin, and to complete the present invention. I arrived.

That is, the first aspect of the present invention is such that (A) 100 parts by weight of a reactive silicon group-containing polyoxyalkylene polymer and (D) one or more of kaolin, clay, talc and mica are added in an amount of 5 to 300. The present invention relates to a curable composition characterized by containing parts by weight.

The second aspect of the present invention is (A) 100 parts by weight of a reactive silicon group-containing polyoxyalkylene polymer, (B)
Copolymer 5 to 10 whose molecular chain is substantially composed of one or more kinds of acrylic acid alkyl ester monomer units and / or methacrylic acid alkyl ester monomer units
The present invention relates to a curable composition containing 0 parts by weight of (D) 5 to 300 parts by weight of one or more of kaolin, clay, talc and mica.

A third aspect of the present invention is (A) 100 parts by weight of a reactive silicon group-containing polyoxyalkylene polymer, (C)
5 to 180 parts by weight of epoxy resin, 5 to 300 parts by weight of (D) kaolin, clay, talc, mica
The present invention relates to a curable composition characterized by containing parts by weight.

The fourth aspect of the present invention is (A) 100 parts by weight of a reactive silicon group-containing polyoxyalkylene polymer, (B)
Copolymer 5 to 10 whose molecular chain is substantially composed of one or more kinds of acrylic acid alkyl ester monomer units and / or methacrylic acid alkyl ester monomer units
0 parts by weight, (C) epoxy resin 5 to 180 parts by weight,
(D) A curable composition comprising 5 to 300 parts by weight of one or more of kaolin, clay, talc and mica.

[0010] As a preferred embodiment, the reactive silicon group of component (A), the general formula (1): - (Si ( R 1 2-b) (X b) O) m Si (R 2 3-a ) X _a (1) (wherein R ¹ and R ² are alkyl groups having 1 to 20 carbon atoms,
An aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a triorganosiloxy group represented by (R ′) ₃ SiO—, wherein two or more R ¹ or R ² are present, May be the same or different. Here, R ′ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R ′ may be the same or different. X represents a hydroxyl group or a hydrolyzable group, and when two or more X are present, they may be the same or different. a represents 0, 1, 2 or 3 and b represents 0, 1, or 2 and satisfies a + Σb ≧ 2. Also, m-Si (R ¹ _2-b ) (X _b ).
Regarding b in the —O— group, they may be the same or different. m represents an integer of 0 to 19. And the curable composition according to any one of the above.

In a further preferred embodiment, the main chain skeleton of the polyoxyalkylene polymer as the component (A) is
The curable composition according to any one of the above, wherein the curable composition comprises polyoxypropylene.

[0012] In a further preferred embodiment, the component (B) is composed of an acrylic acid alkyl ester monomer unit and / or a methacrylic acid alkyl ester whose molecular chain has substantially (a) an alkyl group having 1 to 8 carbon atoms. A copolymer comprising a monomer unit and (b) an alkyl acrylate monomer unit and / or a methacrylic acid alkyl ester monomer unit having an alkyl group having 10 or more carbon atoms. The curable composition according to any one of the above.

[0013] In a further preferred embodiment, the component (B) is a copolymer having a silicon-containing group that can be crosslinked by forming a siloxane bond, and the curable composition according to any one of the above. Regarding things.

In a more preferred embodiment, the curable composition as described in any one of the above, wherein the kaolin as the component (D) has an average particle size within the range of 0.1 to 3.0 μm. .

As a further preferred embodiment, the curable composition according to any one of the above is characterized in that the average particle diameter of the clay as the component (D) is within the range of 0.5 to 15 μm.

As a further preferred embodiment, the curable composition according to any one of the above, wherein the talc which is the component (D) has an average particle diameter within the range of 0.5 to 30 μm.

As a further preferred embodiment, the curable composition according to any one of the above, wherein the mica as the component (D) has an average particle size in the range of 2 to 60 μm.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.

The reactive silicon group of the reactive silicon group-containing polyoxyalkylene polymer of the component (A) used in the present invention is not particularly limited, but representative ones are shown below. Examples thereof include groups represented by general formula (1). -(Si (R ¹ _2-b ) (X _b ) O) _m Si (R ² _3-a ) X _a (1) (wherein R ¹ and R ² are alkyl groups having 1 to 20 carbon atoms,
An aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a triorganosiloxy group represented by (R ′) ₃ SiO—, wherein two or more R ¹ or R ² are present, May be the same or different. Here, R ′ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R ′ may be the same or different. X represents a hydroxyl group or a hydrolyzable group, and when two or more X are present, they may be the same or different. a represents 0, 1, 2 or 3 and b represents 0, 1, or 2 and satisfies a + Σb ≧ 2. Also, m-Si (R ¹ _2-b ) (X _b ).
Regarding b in the —O— group, they may be the same or different. m represents an integer of 0 to 19. The hydrolyzable group of X is not particularly limited as long as it is a conventionally known hydrolyzable group. Specifically, for example,
Examples thereof include a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group and an alkenyloxy group. Among these, methoxy group, ethoxy group, in terms of mild hydrolyzability and easy handling,
An alkoxy group such as a propoxy group or an isopropoxy group is particularly preferable.

The above-mentioned hydroxyl group or hydrolyzable group can be bonded to 1 to 3 silicon atoms, and (a + Σ
Preferably b) is in the range 2-5. When two or more hydroxyl groups or hydrolyzable groups are present in the reactive silicon group, they may be the same or different.

The number of silicon atoms in the reactive silicon group may be one or two or more, but may be about 20 in the case of a reactive silicon group in which silicon atoms are linked by a siloxane bond or the like.

[0022] In particular, the following general formula (2): is represented by _{^{-Si (R 2 3-c)}} X c (2) ( wherein R ^2, X is the same .c said indicates a 2 or 3.) Reactive silicon groups are preferable because they are easily available.

R in the general formula (1) or (2)
Specific examples of ¹ and R ² include, for example, an alkyl group such as a methyl group and an ethyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, an aralkyl group such as a benzyl group, and R ′ being a methyl group or phenyl. Groups such as (R ')
_{3 A} triorganosiloxy group represented by SiO— and the like can be mentioned. Above all, from the viewpoint of ensuring appropriate reactivity, R
^A methyl group is particularly preferable as ¹ , R ² and R ′.

The main chain structure of the polyoxyalkylene polymer as the component (A) used in the present invention is -RO-
Any polymer having a repeating unit represented by the following formula may be used, and at this time, R may be a divalent organic group having 1 to 20 carbon atoms. Further, it may be a homopolymer in which all of the repeating units are the same, or a copolymer containing two or more types of units. Further, the main chain may have a branched structure.

Specific examples of R include --CH₂CH₂-,-
CH (CH₃) CH₂-, -CH (C ₂H_Five) CH₂-,-
C (CH₃)₂CH₂-, -CH₂CH₂CH₂-, -CH₂
CH₂CH₂CH₂-And the like. R is a polymerization
Providing moderate flexibility to the cured product and the ability to lower the viscosity of the body
From the point that it can be imparted, -CH (CH₃) CH₂− Preferred
Good

The main chain skeleton of the polyoxyalkylene polymer as the component (A) can be obtained, for example, by ring-opening polymerization of a monoepoxide in the presence of an initiator and a catalyst.

Specific examples of the initiator include allyl alcohol, methallyl alcohol, ethylene glycol, propylene glycol, butanediol, hexamethylene glycol, bisphenol A, hydrogenated bisphenol A,
Monovalent alcohols such as neopentyl glycol, polybutadiene diol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polypropylene triol, polypropylene tetraol, dipropylene glycol, glycerin, trimethylol methane, trimethylol propane, pentaerythritol and divalent alcohols Examples thereof include alcohols, polyhydric alcohols, and various oligomers having a hydroxyl group.

Specific examples of the monoepoxide include ethylene oxide, propylene oxide, α-butylene oxide, β-butylene oxide, hexene oxide, cyclohexene oxide, styrene oxide,
Alkylene oxides such as α-methylstyrene oxide, and alkyl glycidyl ethers such as methyl glycidyl ether, ethyl glycidyl ether, isopropyl glycidyl ether and butyl glycidyl ether,
Examples thereof include allyl glycidyl ethers and aryl glycidyl ethers.

As the catalyst, there are already known alkali catalysts such as KOH and NaOH, acidic catalysts such as trifluoroborane-etherate, and complex metal cyanide complex catalysts such as aluminoporphyrin metal complex and cobalt zinc cyanide-glyme complex catalyst. Things are used. In particular, the use of a double metal cyanide complex catalyst is preferable because of less side reactions, but other catalysts may be used.

In addition to the above-mentioned method, for example, the main chain skeleton of a polyoxyalkylene polymer is a hydroxyl group-terminated polyoxyalkylene polymer and a basic compound such as KOH or Na.
In the presence of OH, KOCH ₃ , NaOCH _3, etc., a bifunctional or higher functional alkyl halide such as CH ₂ Cl ₂ , CH ₂ Br ₂
It can also be obtained by chain extension and the like. Also,
A method of chain-extending the hydroxyl group-terminated polyoxyalkylene polymer with a bifunctional or trifunctional isocyanate compound may also be used.

The method of introducing the reactive silicon group into the polyoxyalkylene polymer is not particularly limited, and various methods can be used. In particular, in one molecule, the general formula (3): CH ₂ ═CH—R ³ —O— (3) or the general formula (4): CH ₂ ═C (R ⁴ ) —R ³ —O— (4) ( In the formula, R ³ is a divalent organic group having 1 to 20 carbon atoms, R ⁴ is a hydrocarbon group having 10 or less carbon atoms, and a polyoxyalkylene polymer having an unsaturated group at the terminal, and a general formula ( 5): H- (Si (R ¹ _2-b ) (X _b ) O) _m Si (R ² _3-a ) X _a (5) (wherein R ¹ , R ² , X, a, b, m Is the same as described above), and a reactive silicon group-containing compound represented by the formula (1) is reacted in the presence of a Group VIII transition metal catalyst.

In addition to this, addition of a reactive silicon group-containing isocyanate compound to a hydroxyl group-terminated polyoxyalkylene polymer, reaction between an isocyanate group-terminated polyoxyalkylene polymer and a reactive silicon group-containing amine compound, isocyanate group It can also be obtained by a reaction between a terminal polyoxyalkylene polymer and a reactive silicon group-containing mercaptan compound.

As a method for producing the polyoxyalkylene polymer having an unsaturated group represented by the general formula (3) or (4) at the terminal, a conventionally known method may be used, for example, a hydroxyl group-terminated polyoxyalkylene polymer. Examples thereof include a method in which a compound having an unsaturated bond is reacted with the polymer to bond it with an ether bond, an ester bond, a urethane bond, a carbonate bond, or the like. For example, when an unsaturated group is introduced by an ether bond, -OM (M is Na
Or (K or the like) is produced, and then the general formula (6): CH ₂ ═CH—R ³ —X ² (6) or the general formula (7): CH ₂ ═C (R ⁴ ) —R ³ —X ² ( 7) A method of reacting an unsaturated group-containing compound represented by the formula (wherein R ³ and R ⁴ are the same as described above, X ² is a halogen atom).

Specific examples of the unsaturated group-containing compound represented by the general formula (6) or (7) include CH ₂ ═CH—CH _{2
-Cl, CH 2 = CH-CH} 2 -Br, CH 2 = CH-C 2
_{H 4 -Cl, CH 2 = CH} -C 2 H 4 -Br, CH 2 = CH
_{-C 3 H 6 -Cl, CH 2} = CH-C 3 H 6 -Br, CH 2 =
_{C (CH 3) -CH 2 -Cl} , CH 2 = C (CH 3) -CH
_{2 -Br, CH 2 = C (} CH 2 CH 3) -CH 2 -Cl, C
_{H 2 = C (CH 2 CH} 3) -CH 2 -Br, CH 2 = C (C
_{H 2 CH (CH 3) 2} ) -CH 2 -Cl, CH 2 = C (CH 2
_{CH (CH 3) 2) -CH} 2 -Br, etc., and particularly from the viewpoint of _{reactivity, CH 2 = CH-CH 2} -Cl, CH 2 =
C (CH ₃₎ -CH ₂ -Cl is preferred.

Other than this, as a method of introducing the unsaturated group, a CH ₂ ═CH—CH ₂ — group or CH ₂ ═C (CH ₃ ) —CH ₂
It is also possible to use an isocyanate compound having a-group or the like, a carboxylic acid, or an epoxy compound.

As the Group VIII transition metal catalyst, a metal complex catalyst selected from Group VIII transition metal elements such as platinum, rhodium, cobalt, palladium and nickel is effectively used. For example, H ₂ PtCl ₆ .6H ₂ O, platinum-vinylsiloxane complex, platinum-olefin complex, Pt metal,
RhCl (PPh ₃ ) ₃ , RhCl ₃ , Rh / Al ₂ O ₃ ,
RuCl ₃ , IrCl ₃ , FeCl ₃ , PdCl ₂ · 2H ₂
Compounds such as O and NiCl ₂ can be used, but H ₂ PtCl ₆ .6H can be used from the viewpoint of reactivity of hydrosilylation.
It is preferably any one of ₂ O, a platinum-vinyl siloxane complex, and a platinum-olefin complex.

Such a manufacturing method is disclosed, for example, in Patent No. 13
It is described in Japanese Patent No. 96791, Japanese Patent No. 1727750, Japanese Patent No. 2135751, Japanese Patent Laid-Open No. 3-72527, and the like.

The molecular weight of the polyoxyalkylene polymer is not particularly limited, but GPC (HLC manufactured by Tosoh Corp.)
The number average molecular weight in terms of polystyrene in (-8120 GPC, THF solvent) is preferably 500 to 100,000. Even 1,000 to 70,000
Is preferable from the viewpoint of easy handling.
When the number average molecular weight is less than 500, the cured product becomes brittle, and when it exceeds 100,000, the viscosity of the polymer becomes too high, which is not preferable.

Component (B) used in the present invention is a copolymer having a molecular chain consisting essentially of one or more kinds of acrylic acid alkyl ester monomer units and / or methacrylic acid alkyl ester monomer units. As the acrylic acid alkyl ester monomer unit in the polymer (hereinafter referred to as the copolymer (B)), conventionally known ones can be widely used, and examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, and acrylic acid. n-butyl, isobutyl acrylate, tert-butyl acrylate, n-acrylate
Hexyl, 2-ethylhexyl acrylate, decyl acrylate, undecyl acrylate, lauryl acrylate,
Examples thereof include tridecyl acrylate, myristyl acrylate, cetyl acrylate, stearyl acrylate, behenyl acrylate, and biphenyl acrylate. As the methacrylic acid ester monomer unit, conventionally known ones can be widely used, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate. , N-hexyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate,
Examples thereof include undecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, myristyl methacrylate, cetyl methacrylate, stearyl methacrylate, behenyl methacrylate, biphenyl methacrylate and the like.

The molecular chain of the copolymer (B) consists essentially of one or more kinds of acrylic acid alkyl ester monomer units and / or methacrylic acid alkyl ester monomer units. Substantially consisting of the above monomer units means that the total ratio of the alkyl acrylate ester monomer units and / or the methacrylic acid alkyl ester monomer units present in the copolymer (B) exceeds 50%. It means that it is preferably 70% or more.

In the combination of these monomers, the molecular chain is substantially (a) in view of compatibility and stability.
Acrylic acid alkyl ester monomer unit and / or methacrylic acid alkyl ester monomer unit having an alkyl group having 1 to 8 carbon atoms and (b) Acrylic acid alkyl ester monomer unit having an alkyl group having 10 or more carbon atoms And / or a copolymer composed of methacrylic acid alkyl ester monomer units is preferred.

The acrylic acid alkyl ester monomer unit and / or methacrylic acid alkyl ester monomer unit having an alkyl group having 1 to 8 carbon atoms, which is the monomer unit (a), has the general formula (8): CH ₂ = C (R ⁵ ) COOR ⁶ (8) (wherein R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents an alkyl group having 1 to 8 carbon atoms).

Examples of R ^{6 in the} general formula (8) include a methyl group and an ethyl group. The monomer represented by the general formula (8) may be used alone or in combination of two or more.

The monomer unit (b) has 10 carbon atoms.
The acrylic acid alkyl ester monomer unit and / or methacrylic acid alkyl ester unit having the above alkyl group has the following general formula (9): CH ₂ ═C (R ⁵ ) COOR ⁷ (9) (wherein R ⁵ is R ⁷ represents an alkyl group having 10 or more carbon atoms).

Examples of R ^{7 in the} above general formula (9) include long chain alkyl groups such as lauryl group and stearyl group. The monomer represented by the general formula (9) may be used alone or in combination of two or more.

The copolymer (B) contains, in addition to the acrylic acid alkyl ester monomer unit and / or the methacrylic acid alkyl ester monomer unit, a monomer unit copolymerizable therewith. Good. Examples of the copolymerizable monomer unit include monomers containing a carboxylic acid group such as acrylic acid and methacrylic acid; acrylamide, methacrylamide, N-methylolacrylamide and N-.
Monomers containing amide groups such as methylol methacrylamide; monomers containing epoxy groups such as glycidyl acrylate, glycidyl methacrylate; diethylaminoethyl acrylate, diethylaminoethyl methacrylate,
Amino group-containing monomers such as aminoethyl vinyl ether; and other monomer units derived from acrylonitrile, styrene, α-methylstyrene, alkyl vinyl ether, vinyl chloride, vinyl acetate, vinyl propionate, ethylene and the like.

The molecular weight of the copolymer (B) component is not particularly limited, but it is preferable that the number average molecular weight in terms of polystyrene in GPC is 500 to 50,000,
Those of 1,000 to 20,000 are more preferable from the viewpoint of easy handling. When the number average molecular weight is less than 500, the cured product becomes brittle, and when it exceeds 50,000, the viscosity of the polymer becomes too high, which is not preferable.

The copolymer (B) can be obtained by a usual vinyl polymerization method, for example, a solution polymerization method by a radical reaction or a bulk polymerization method, but is not particularly limited to these methods. Polymerization is usually carried out by adding the above-mentioned monomer, radical initiator, chain transfer agent, solvent and the like to 50
It is carried out by reacting at ~ 150 ° C.

Examples of the radical initiator include azo radical initiators such as azobisisobutyronitrile and organic peroxides such as benzoyl peroxide, and examples of the chain transfer agent include n- Examples thereof include mercaptans such as dodecyl mercaptan, t-dodecyl mercaptan, and lauryl mercaptan, and halogen-containing compounds. As the solvent, it is preferable to use non-reactive solvents such as ethers, hydrocarbons and esters.

The copolymer (B) is, for example, a silicon-containing group (hereinafter referred to as a silicon-containing group that can be crosslinked by forming a siloxane bond) from the viewpoint of final adhesive strength when the curable composition of the present invention is used as an adhesive. , A reactive silicon group).

There are various methods for introducing a reactive silicon group into the copolymer (B). For example, a compound having a polymerizable unsaturated bond and a reactive silicon group is used as a monomer (a). And a method of copolymerizing with (b), a compound having a polymerizable unsaturated bond and a reactive functional group (hereinafter referred to as Y group) (for example, acrylic acid) is copolymerized with the monomers (a) and (b), Thereafter, the resulting copolymer is reacted with a compound having a functional group capable of reacting with a reactive silicon group and a Y group (hereinafter referred to as Y ′ group) (for example, a compound having an isocyanate group and a —Si (OCH ₃ ) ₃ group). Method, a method of copolymerizing the monomers (a) and (b) in the presence of a mercaptan containing a reactive silicon group as a chain transfer agent, an azobisnitrile compound or disulfide containing a reactive silicon group Monomer a compound as the initiator (a) and a method of copolymerizing (b), the monomer by living radical polymerization method (a) and (b)
And a method of introducing a reactive silicon group at the terminal of the molecular chain, but the method is not particularly limited thereto. It is also possible to arbitrarily combine the above methods.

The compounds having a polymerizable unsaturated bond and a reactive silicon group described in general formula _{(10): CH 2 = C} (R 5) COOR 8 - (Si (R 1 2-b) (X b) O) _m Si (R ² _3-a ) X _a (10) (wherein R ⁵ is the same as above. R ⁸ represents a divalent alkylene group having 1 to 6 carbon atoms. R ¹ , R ² , X , A, b, m are the same as above.) Or the general formula (11): CH ₂ ═C (R ⁵ )-(Si (R ¹ _2-b ) (X _b ) O) _m Si (R ² _{3- a} ) X _a (11) (wherein R ⁵ , R ¹ , R ² , X, a, b and m are the same as described above).

Examples of R ^{8 in the} general formula (10) include methylene group, ethylene group, propylene group and the like. The monomer represented by the general formula (10) or (11) may be used alone or in combination of two or more.

Examples of the compound represented by the general formula (10) or (11) having a polymerizable unsaturated bond and a reactive silicon group include, for example, γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropylmethyl. Γ-methacryloxypropylalkylpolyalkoxysilanes such as dimethoxysilane and γ-methacryloxypropyltriethoxysilane; γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-acryloxypropyltriethoxysilane and the like [Gamma] -acryloxypropylalkylpolyalkoxysilanes; vinylalkylpolyalkoxysilanes such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, and vinyltriethoxysilane.

The number of reactive silicon groups contained in the copolymer (B) is not particularly limited, but from the viewpoint of the effect on the adhesive force and the cost, one molecule of the copolymer (B) is included. It is preferable that the average number is 0.1 or more and 3.0 or less, more preferably 0.5 or more and 2.5 or less.

Such a manufacturing method is described in, for example, JP-A-59-59.
No. 1222541 and JP-A No. 63-112642.

The amount of the copolymer (B) used in the composition of the present invention is 5 to 100 relative to 100 parts by weight of the component (A).
The range of parts by weight is preferable, and the range of 10 to 90 parts by weight is more preferable, and the range is usually selected according to the intended use and performance. If the amount of the copolymer (B) used is less than 5 parts by weight, the adhesiveness may decrease, and if it exceeds 100 parts by weight, the viscosity of the composition may excessively increase, which is not preferable.

As the epoxy resin which is the component (C) of the present invention, conventionally known ones can be widely used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin. Or hydrogenated epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, novolac type epoxy resin, urethane modified epoxy resin having urethane bond, fluorinated epoxy resin, polybutadiene or acrylonitrile- Examples thereof include a rubber-modified epoxy resin containing a butadiene copolymer rubber, and a flame-retardant epoxy resin such as glycidyl ether of tetrabromobisphenol A. These epoxy resins may be used alone or in combination of two or more kinds. Among these epoxy resins, bisphenol A is used in terms of balance among workability, curability, adhesive strength, versatility of adherend, water resistance, durability, etc.
Type epoxy resins are preferred.

Such an epoxy resin is obtained by using component (A) 100
It is preferably used in the range of usually 5 to 180 parts by weight, more preferably 10 to 150 parts by weight, based on parts by weight. The amount of epoxy resin used is 5
If the amount is less than 1 part by weight, sufficient strength may not be obtained, and 1
If it exceeds 80 parts by weight, the physical properties may be deteriorated due to a decrease in compatibility and the like, which is not preferable.

As the kaolin, clay, talc and mica which are the component (D) of the present invention, conventionally known ones can be widely used. As kaolin, kaolin mineral, which is a kind of hydrous aluminum silicate mineral, is pulverized by dry method or crushed by wet method, or what is refined by wet method is burned to remove the structural water in the crystal. can do. Specific examples of kaolin minerals include, but are not limited to, kaolinite, dickite, nacrite and halloysite. Further, as the clay, it is possible to use one obtained by crushing a wax ore, which is a kind of hydrous aluminum silicate mineral, by a dry method or by a wet method. Specific examples of the wax ore include pyrophyllite, but are not limited thereto. Talc is a hydrous magnesium silicate ore in which crystal structures in which a silicic acid layer covers both sides of a magnesia plate layer having a hydroxyl group are overlapped, and pulverized by impact crushing or milling is used. It The talc used in the present invention is represented by the chemical formula of 4SiO ₂ .3MgO.H ₂ O, but its composition is slightly different depending on the place of origin. 2 for mica
The unit in which the silicic acid plate layers are stacked via aluminum or magnesium ions is a silicate mineral that is stacked via ions such as potassium, and those that have been finely ground by dry or wet grinding are used. To be done. Specific examples of mica include muscovite, phlogopite, biotite, and fluorophlogopite, but are not limited thereto. Kaolin has an average particle size of 0.05 to
It is preferably in the range of 5.0 μm, and more preferably 0.
More preferably, it is in the range of 1 to 3.0 μm. The average particle size of the clay is preferably in the range of 0.2 to 20 μm, and more preferably in the range of 0.5 to 15 μm. The average particle size of talc is 0.
It is preferably in the range of 2 to 40 μm, and more preferably in the range of 0.5 to 30 μm.
The average particle size of mica is preferably in the range of 1 to 80 μm, and more preferably in the range of 2 to 60 μm. When the particle diameter is less than the above range, the viscosity is high and the workability is deteriorated, and when the particle diameter exceeds the above range, a sufficient elastic modulus cannot be obtained. These may be used alone or in combination of two or more.

The component (D) is preferably used in an amount of usually 5 to 300 parts by weight, and more preferably 10 to 200 parts by weight, based on 100 parts by weight of the component (A). preferable. If it is less than 5 parts by weight, sufficient cohesive force cannot be obtained, and if it exceeds 300 parts by weight, the viscosity of the composition increases, which is not preferable.

By using the component (D), it is possible to obtain a high elastic modulus without lowering the strength and elongation of the cured product.

The curable composition of the present invention may optionally contain a silane coupling agent, a curing catalyst, a curing agent for epoxy resin, a filler, a thixotropic agent, a plasticizer, a coloring agent, a stabilizer and the like. You can

Specific examples of the silane coupling agent include:
For example, γ-aminopropyltrimethoxysilane, γ-
Aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl)
Aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ-
(2-Aminoethyl) aminopropylmethyldiethoxysilane, γ-ureidopropyltrimethoxysilane, N
-Phenyl-γ-aminopropyltrimethoxysilane,
Amino group-containing silanes such as N-benzyl-γ-aminopropyltrimethoxysilane and N-vinylbenzyl-γ-aminopropyltriethoxysilane; γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ- Mercapto group-containing silanes such as mercaptopropylmethyldimethoxysilane and γ-mercaptopropylmethyldiethoxysilane; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxy Silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,3
Epoxy group-containing silanes such as 4-epoxycyclohexyl) ethyltriethoxysilane; β-carboxyethyltriethoxysilane, β-carboxyethylphenylbis (2-methoxyethoxy) silane, N-β- (carboxymethyl) aminoethyl- Carboxysilanes such as γ-aminopropyltrimethoxysilane; Vinyl type unsaturated group-containing silanes such as vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-acryloxypropylmethyltriethoxysilane Halogen-containing silanes such as γ-chloropropyltrimethoxysilane; Isocyanurate silanes such as tris (trimethoxysilyl) isocyanurate; γ-isocyanatopropyltrimethoxysilane, γ-isocyanate Pills triethoxysilane,
γ-isocyanatopropylmethyldiethoxysilane,
Examples include isocyanate group-containing silanes such as γ-isocyanatopropylmethyldimethoxysilane. Further, modified derivatives of these, amino-modified silyl polymers, silylated amino polymers, unsaturated aminosilane complexes, blocked isocyanate silanes, phenylamino long-chain alkylsilanes, aminosilylated silicones, silylated polyesters, etc. are also used as silane coupling agents. Can be used. These silane coupling agents may be used alone or in combination of two or more.

The silane coupling agent is preferably used in an amount of usually 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, based on 100 parts by weight of the component (A). More preferably. If the amount of the silane coupling agent used is less than 0.5 parts by weight, the adhesiveness may decrease, and if it exceeds 20 parts by weight, the reactivity of the composition may decrease, which is not preferable. Particularly, from the viewpoint of adhesiveness, aminosilane, a reaction product thereof, epoxysilane, and isocyanatesilane are preferable.

Specific examples of the curing catalyst include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, tin octylate, tin naphthenate, dibutyltin oxide and phthalate. Reaction products with acid esters, organotin compounds such as dibutyltin bisacetylacetonate; organoaluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminumethylacetoacetate; zirconium tetraacetylacetonate , Chelate compounds such as titanium tetraacetylacetonate; lead octylate; butylamine, octylamine, dibutylamine, laurylamine Monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2,4,6
Amines such as -tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8-diazabicyclo [5,4,0] undecene-7 (hereinafter abbreviated as DBU) Compound,
Alternatively, salts of these amine compounds with carboxylic acids, etc .; acidic phosphoric acid esters; reaction products of acidic phosphoric acid esters and amines; saturated or unsaturated polyvalent carboxylic acids or acid anhydrides thereof; excess polyamines and polybasic acids. A low molecular weight polyamide resin obtained from the above; a reaction product of an excess polyamine and an epoxy compound; a silane coupling having an amino group such as γ-aminopropyltrimethoxysilane and N- (β-aminoethyl) aminopropylmethyldimethoxysilane Examples include silanol condensation catalysts such as agents; known silanol condensation catalysts such as other acidic catalysts and basic catalysts. These catalysts may be used alone or in combination of two or more.

The curing catalyst is usually used in an amount of 0.01 to 15 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the component (A). More preferably. If it is less than 0.01 part by weight, the curability of the composition will be lowered, and if it exceeds 15 parts by weight, storage stability and adhesiveness will be lowered, which is not preferable. In particular, it is preferable to use a tetravalent tin catalyst from the viewpoints of curing speed and storage stability.

Specific examples of the curing agent for epoxy resin include:
For example, aliphatic amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, hexamethylenediamine, methylpentamethylenediamine, trimethylhexamethylenediamine, guanidine, oleylamine; menthenediamine, isophoronediamine. , Norbornanediamine, piperidine, N, N'-dimethylpiperazine, N-aminoethylpiperazine, 1,
2-diaminocyclohexane, bis (4-amino-3-
Methylcyclohexyl) methane, bis (4-aminocyclohexyl) methane, polycyclohexylpolyamine,
Alicyclic amines such as DBU; metaphenylenediamine,
Aromatic amines such as 4,4′-diaminodiphenylmethane and 4,4′-diaminodiphenylsulfone; m-xylylenediamine, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris ( Aliphatic aromatic amines such as dimethylaminomethyl) phenol; 3,9-bis (3-aminopropyl) -2,
Amine having an ether bond such as 4,8,10-tetraoxaspiro [5,5] undecane (ATU), morpholine, N-methylmorpholine, polyoxypropylenediamine, polyoxypropylenetriamine, polyoxyethylenediamine; diethanolamine, Hydroxyl group-containing amines such as triethanolamine; acid anhydrides such as tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hexahydrophthalic anhydride, dodecylsuccinic anhydride; diethylenetriamine and triethylenetetramine as dimer acids Polyamides obtained by reacting polyamines such as, and polyamide amines such as polyamides using polycarboxylic acids other than dimer acid;
Imidazoles such as 2-ethyl-4-methylimidazole; dicyandiamide; polyoxypropylene-based amines such as polyoxypropylene-based diamine and polyoxypropylene-based triamine; phenols; obtained by reacting the above amines with an epoxy compound Epoxy modified amines, Mannich modified amines obtained by reacting the above amines with formalin and phenols, modified amines such as Michael addition modified amines, ketimines and aldimines;
Examples include amine salts such as 2-ethylhexanoate of 2,4,6-tris (dimethylaminomethyl) phenol. These curing agents may be used alone or in combination of two or more.

Such a curing agent for epoxy resin is preferably used in an amount of usually 1 to 100 parts by weight, and more preferably 5 to 90 parts by weight, based on 100 parts by weight of the component (C). More preferably. If the amount of the curing agent for the epoxy resin used is less than 1 part by weight, the curing of the epoxy resin will be insufficient, and if it exceeds 90 parts by weight, the adhesiveness may decrease due to bleeding at the interface, which is not preferable. Particularly, from the viewpoint of curability and adhesiveness, 2,4,6-tris (dimethylaminomethyl) phenol and polyoxypropylene-based diamine are preferable in the two-component system, and ketimine and aldimine are preferable in the one-component system.

Specific examples of the filler include, for example, calcium carbonate, magnesium carbonate, titanium oxide, carbon black, fused silica, precipitated silica, diatomaceous earth, clay, wood powder, walnut shell powder, chaff powder, anhydrous. Inorganic fillers such as silicic acid, quartz powder, aluminum powder, zinc powder, asbestos, glass fibers, carbon fibers, glass beads, alumina, glass balloons, shirasu balloons, silica balloons, silicon oxide, and wood materials such as pulp and cotton chips. Filling material,
Examples of the organic filler include powder rubber, recycled rubber, fine powder of thermoplastic or thermosetting resin, and hollow bodies such as polyethylene. These fillers may be used alone or 2
You may use together more than one kind.

Such a filler is preferably used in an amount of usually 50 to 1000 parts by weight, and more preferably 60 to 900 parts by weight, based on 100 parts by weight of the component (A). More preferable. If the amount of the filler used is less than 50 parts by weight, the cost of the composition increases, while if it exceeds 1000 parts by weight, the viscosity increases and the workability decreases, which is not preferable. In particular, calcium carbonate is preferable in terms of quality and cost.

Specific examples of the thixotropic agent include hydrogenated castor oil, organic amide wax, organic bentonite, calcium stearate and the like. These thixotropic agents may be used alone or in combination of two or more kinds.

The thixotropic agent is preferably used in the range of 0.1 to 50 parts by weight, more preferably 1 to 30 parts by weight, based on 100 parts by weight of the component (A). Is more preferable. When the amount of the thixotropic agent used is less than 0.1 parts by weight, sufficient thixotropic properties may not be obtained, and when it exceeds 50 parts by weight, the cost is increased, which is not preferable.

Specific examples of the plasticizer include phthalic acid esters such as dioctyl phthalate, dibutyl phthalate and butylbenzyl phthalate; aliphatic dibasic acid esters such as dioctyl adipate, isodecyl succinate and dibutyl sebacate; Glycol esters such as diethylene glycol dibenzoate and pentaerythritol ester; aliphatic esters such as butyl oleate and methyl acetylricinoleate; tricresyl phosphate,
Phosphate esters such as trioctyl phosphate, octyl diphenyl phosphate, etc., epoxy plasticizers such as epoxidized soybean oil, epoxidized linseed oil, benzyl epoxy stearate; polyesters such as polyesters of dibasic acid and dihydric alcohol Plasticizers; polyethers such as polypropylene glycol and its derivatives; polystyrenes such as poly-α-methylstyrene and polystyrene; polybutadiene, butadiene-acrylonitrile copolymer, polychloroprene, polyisoprene, polybutene, chlorinated paraffins, etc. Is mentioned. These plasticizers may be used alone or in combination of two or more.

The plasticizer is preferably used in an amount of usually 10 to 300 parts by weight, and more preferably 20 to 250 parts by weight, based on 100 parts by weight of the component (A). More preferable. If the amount of the plasticizer used is less than 10 parts by weight, the viscosity of the composition may be too high, and if it exceeds 300 parts by weight, the plasticizer may exude from the cured product, which is preferable. Absent.

The curable composition of the present invention has appropriate viscosity, curability, adhesiveness, strength, deformation followability, weather resistance, and high elastic modulus, and therefore has a wide range of fields such as civil engineering, construction, and industrial applications. It can be used as a sealing material, adhesive, injection material, putty material, etc. Specifically, the inner and outer walls, floor,
Suitable for use in joints such as various concrete and metal joints, adhesion of floor materials for interior and exterior, adhesion of tiles, stone materials, decorative panels to interior and exterior walls, seal adhesion of clay pipes, manholes, cables, potting, etc. it can.

[0077]

EXAMPLES In order to further clarify the present invention, specific examples will be described below, but the present invention is not limited thereto. (Synthesis Example 1) Propylene oxide was polymerized using polypropylene glycol as an initiator and a zinc hexacyanocobaltate glyme complex catalyst to obtain an average molecular weight of 10,000.
0 polyoxypropylene glycol was obtained. Subsequently, 1.2 times equivalent of a methanol solution of NaOMe with respect to the hydroxyl group of the hydroxyl group-terminated polyether oligomer is added to distill off the methanol, and 3-chloro-1-propene is further added to allyl the terminal hydroxyl group. Converted to base. Next, 10 g of hexane was added to 500 g of the obtained oligomer, and azeotropic dehydration was performed at 90 ° C. The hexane was distilled off under reduced pressure, and then the atmosphere was replaced with nitrogen. On the other hand, platinum divinyldisiloxane complex (3 wt% xylene solution in terms of platinum) 30μ
9.0 g of dimethoxymethylsilane (hereinafter, abbreviated as DMS) was slowly added dropwise while adding l. After reacting the mixed solution at 90 ° C. for 2 hours, unreacted DM
S was distilled off under reduced pressure to obtain a reactive silicon group-containing polyoxypropylene polymer. From the ¹ H-NMR analysis of the obtained polymer, it was confirmed that the rate of introduction of the reactive silicon group at the terminal was 82% (Polymer A). (Synthesis Example 2) Propylene oxide was polymerized using polypropylene glycol as an initiator and a zinc hexacyanocobaltate glyme complex catalyst to obtain an average molecular weight of 20,000.
0 polyoxypropylene glycol was obtained. Subsequently, 1.2 times equivalent of a methanol solution of NaOMe with respect to the hydroxyl group of the hydroxyl group-terminated polyether oligomer was added to distill off methanol, and 3-chloro-2-methyl-
1-Propene was added to convert the terminal hydroxyl group into a methallyl group. Next, 10 g of hexane was added to 500 g of the obtained oligomer, and azeotropic dehydration was performed at 90 ° C. After distilling hexane off under reduced pressure, the inside of the container was replaced with 8% O ₂ / N ₂ .
On the other hand, sulfur (1 wt% toluene solution) 24μ
1, platinum divinyldisiloxane complex (xylene solution of 3% by weight in terms of platinum) 54 μl were added, and while stirring, D
11.5 g of MS was slowly added dropwise. After reacting at 90 ° C. for 10 hours, unreacted DMS was distilled off under reduced pressure to obtain a reactive silicon group-containing polyoxypropylene polymer. From the ¹ H-NMR analysis of the obtained polymer, it was confirmed that the rate of introduction of the reactive silicon group at the terminal was 98% (Polymer B). (Synthesis example 3) 6.0 g of butyl acrylate, 66 g of methyl methacrylate in 43 g of toluene heated to 110 ° C.
2.6 g of azobisisobutyronitrile as a polymerization initiator was dissolved in a mixture of 13 g of stearyl methacrylate, 5.4 g of γ-methacryloxypropylmethyldimethoxysilane, 7.0 g of γ-mercaptopropylmethyldimethoxysilane and 23 g of toluene. After the solution was added dropwise over 4 hours, post-polymerization was performed for 2 hours to obtain a solid content concentration of 60
%, A copolymer having a number average molecular weight (Mn) of 2,200 by GPC (polystyrene conversion) was obtained.

The polymer A obtained in Synthesis Example 1 and this copolymer were blended at a solid content ratio (weight ratio) of 60/40,
Using an evaporator, devolatilization was performed under reduced pressure at 110 ° C. under heating conditions to obtain a transparent viscous liquid having a solid content concentration of 99% or more (Polymer C). (Examples 1 to 12 and Comparative Examples 1 to 5) The curable compositions of Examples 1 to 12 and Comparative Examples 1 to 5 were prepared with the compositions shown in Table 1, and the following evaluations were carried out. (Evaluation of physical properties) Tensile physical properties of cured product The curable composition is prepared into a sheet having a thickness of about 3 mm,
After curing at 23 ° C for 3 days and at 50 ° C for 4 days, JISK
The No. 3 dumbbell test piece described in -6251 was punched out.
Using Shimadzu autograph, 20mm between the marked lines,
A tensile test was carried out at a crosshead speed of 200 mm / min. The stress when the marked line stretches 50% is M50
The value of 100% was taken as the M100 value. In addition, the stress and elongation at break were taken as TB and EB values, respectively. In the present invention, the M50 value and the M100 value are expressed as the elastic modulus.

The evaluation results are shown in Tables 1 to 3.

[0080]

[Table 1]

[0081]

[Table 2]

[0082]

[Table 3] Examples 1 to 12 are stronger than the corresponding Comparative Examples 1 to 5 in strength,
The values of M50 and M100 were improved without significantly reducing the elongation.

[0083]

EFFECTS OF THE INVENTION By using the curable composition of the present invention, a cured product having a high elastic modulus can be obtained without significantly reducing strength and elongation.

Claims (12)

[Claims] 1. 5-300 of (A) 100 parts by weight of a reactive silicon group-containing polyoxyalkylene polymer and (D) one or more of kaolin, clay, talc and mica.
A curable composition, characterized by containing parts by weight. 2. (A) 100 parts by weight of a reactive silicon group-containing polyoxyalkylene polymer, (B) the molecular chain is substantially one kind or two or more kinds of acrylic acid alkyl ester monomer units and / or Or 5 to 100 parts by weight of a copolymer consisting of methacrylic acid alkyl ester monomer units, (D)
A curable composition comprising 5 to 300 parts by weight of one or more of kaolin, clay, talc and mica. 3. (A) 100 parts by weight of a reactive silicon group-containing polyoxyalkylene polymer, (C) an epoxy resin 5 to
A curable composition comprising 180 parts by weight of (D) 5 to 300 parts by weight of one or more of kaolin, clay, talc and mica. 4. (A) 100 parts by weight of a reactive silicon group-containing polyoxyalkylene polymer, (B) the molecular chain is substantially one kind or two or more kinds of acrylic acid alkyl ester monomer units and / or Or 5 to 100 parts by weight of a copolymer composed of methacrylic acid alkyl ester monomer units, (C)
5 to 180 parts by weight of epoxy resin, 5 to 300 parts by weight of (D) kaolin, clay, talc, mica
A curable composition, characterized by containing parts by weight. 5. The reactive silicon group of the component (A) has the general formula (1):-(Si (R ¹ _2-b ) (X _b ) O) _m Si (R ² _3-a ) X _a ( 1) (wherein R ¹ and R ² are an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and 7 to 20 carbon atoms)
Of the aralkyl group or the triorganosiloxy group represented by (R ′) ₃ SiO—, and when two or more R ¹ or R ² are present, they may be the same or different. Here, R ′ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R ′ may be the same,
It may be different. X represents a hydroxyl group or a hydrolyzable group, and when two or more X are present, they may be the same or different. a is 0, 1, 2 or 3, b is
Represent 0, 1, or 2, respectively, and satisfy a + Σb ≧ 2. Also, m-Si (R ¹ _2-b )
Regarding _{b in the} ( _Xb ) -O- group, they may be the same or different. m represents an integer of 0 to 19. ) Is represented by the following.
4. The curable composition according to any one of 4 above. 6. The curable composition according to any one of claims 1 to 5, wherein the main chain skeleton of the polyoxyalkylene polymer as the component (A) is composed of polyoxypropylene. 7. The component (B) comprises a (a) acrylic acid alkyl ester monomer unit and / or a methacrylic acid alkyl ester monomer unit, the molecular chain of which is (a) an alkyl group having 1 to 8 carbon atoms. (B) A copolymer comprising an alkyl acrylate monomer unit and / or an methacrylic acid alkyl ester monomer unit having an alkyl group having 10 or more carbon atoms.
The curable composition according to any one of to 6. 8. The curing according to claim 2, wherein the component (B) is a copolymer having a silicon-containing group that can be crosslinked by forming a siloxane bond. Sex composition. 9. The curable composition according to claim 1, wherein the kaolin as the component (D) has an average particle size within the range of 0.1 to 3.0 μm. 10. The curable composition according to any one of claims 1 to 8, wherein the clay as the component (D) has an average particle size in the range of 0.5 to 15 μm. 11. The talc as the component (D) has an average particle diameter of 0.5 to 30 μm.
The curable composition according to any one of 1. 12. The curable composition according to claim 1, wherein the mica which is the component (D) has an average particle diameter of 2 to 60 μm.