JP2018095795A - Moisture-curable reactive hot melt adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture- curable reactive hot melt adhesive which contains a novel acrylic polymer having a crosslinking silicon group, can be easily produced, is inexpensive and has sufficient properties as a hot melt.SOLUTION: The reactive hot melt adhesive is provided that contains (A) a (meth)acrylic ester polymer having a crosslinkable silicon group and a glass transition temperature of -20 to 50°C of 100 pts.mass, (B) a silanol condensation catalyst of 0.01 to 20 pts.mass and (C) a compound having the crosslinkable silicon group and an amino group of 0.1 to 30 pts.mass. It is preferred that the (A) (meth)acrylic acid ester polymer in the reactive hot melt adhesive is a copolymer obtained by a radical polymerization of methacrylic acid methyl, (meth)acrylic acid (C2 to 30) alkyl ester and an unsaturated compound having the crosslinkable silicon group using a heat polymerization initiator.SELECTED DRAWING: None

Description

  The present invention relates to an acrylic moisture-curing reactive hot melt adhesive with a simple manufacturing process.

  Acrylic adhesives are excellent in weather resistance, transparency and adhesive performance, and are used in various applications. As described in Patent Document 1, an acrylic hot melt adhesive is also known as an acrylic adhesive. In general, hot melt adhesives have a high bonding speed, can automate production lines and can be omitted, and are widely used from the viewpoint of environmental compatibility because they are solvent-free. However, since the hot melt adhesive melts by heat and solidifies by cooling and develops an adhesive force, the adhesive force, particularly heat resistance, is limited, and the range of use is limited.

  Therefore, in recent years, as a means for improving the problems of the hot melt adhesive, a reactive hot melt adhesive using a crosslinking reaction (curing reaction) after bonding has been actively developed. A typical example is a urethane-based reactive hot melt adhesive that has a prepolymer having an isocyanate group in the molecule as a main component and has improved heat resistance using a crosslinking reaction of the isocyanate group after bonding. Are known. However, urethane type reactive hot melt adhesives use highly toxic isocyanate compounds, and there is a problem that they volatilize during the manufacturing process and use of the adhesive. Accordingly, a reactive hot melt adhesive using a polymer having a crosslinkable silicon group has been developed as a reactive hot melt adhesive excluding an isocyanate compound.

  Patent Documents 2 to 4 are obtained by copolymerizing an acrylic monomer, an acrylic macromonomer containing a polymer unit having a high glass transition temperature (Tg) such as polystyrene, and an unsaturated monomer having a crosslinkable silicon group. A moisture curable reactive hot melt adhesive containing an acrylic polymer is disclosed. However, a special macromonomer is used, resulting in an expensive adhesive.

  Patent Document 5 discloses a moisture curable reactive hot melt adhesive containing an acrylic polymer having a crosslinkable silicon group. This hot melt adhesive also uses a special polymer such as a graft copolymer and becomes an expensive adhesive.

  Patent Documents 6 to 7 disclose a moisture-curable reactive hot melt adhesive containing an oxyalkylene polymer having a crosslinkable silicon group and an acrylic polymer having a crosslinkable silicon group. This hot melt adhesive also uses a special polymer such as an oxyalkylene polymer having a crosslinkable silicon group, and becomes an expensive adhesive. Furthermore, since the oxyalkylene polymer having a crosslinkable silicon group is a liquid polymer at room temperature, high adhesive strength may not be expected immediately after bonding as a hot melt.

  Patent Document 8 discloses a moisture curable reactive hot melt adhesive containing an acrylic polymer having a crosslinkable silicon group. This hot melt adhesive also uses a special polymer as an acrylic polymer having a crosslinkable silicon group, and becomes an expensive adhesive. Further, since this polymer is a liquid polymer at room temperature, high adhesive strength cannot be expected immediately after bonding as a hot melt.

Japanese Patent Laid-Open No. 02-218780 Japanese Patent Laid-Open No. 03-149277 Japanese Patent Laid-Open No. 03-259984 Japanese Patent Laid-Open No. 04-359983 Japanese Patent Laid-Open No. 05-320608 Japanese Patent Laid-Open No. 04-33080 International Publication 2011/152002 JP 2000-086998 A

  The problem to be solved by the present invention is to provide a moisture curable reactive hot melt adhesive containing an acrylic polymer having a novel crosslinkable silicon group. Another problem to be solved by the present invention is to provide a reactive hot melt adhesive that can be easily manufactured and is inexpensive and has sufficient hot melt properties.

  The present inventor uses a commonly used acrylic monomer to produce a reactive hot melt adhesive having sufficient characteristics as a hot melt even when an acrylic polymer that can be obtained by ordinary radical polymerization is used. I found out that I can do it. That is, the present invention is the following reactive hot melt adhesive.

(1) (A) 100 parts by mass of (meth) acrylic acid ester polymer having a crosslinkable silicon group and a glass transition temperature of minus 20 ° C. to 50 ° C., and (B) 0.01-20 mass of silanol condensation catalyst. And (C) a reactive hot melt adhesive containing 0.1 to 30 parts by mass of a compound having a crosslinkable silicon group and an amino group.
(2) (A) A (meth) acrylic acid ester polymer having a crosslinkable silicon group and having a glass transition temperature of minus 20 ° C. to 50 ° C. is a polymer obtained by radical polymerization using a thermal polymerization initiator. The reactive hot melt adhesive according to (1).
(3) (A) A (meth) acrylic acid ester polymer having a crosslinkable silicon group and having a glass transition temperature of minus 20 ° C. to 50 ° C. is methyl methacrylate and an alkyl group having 2 to 30 carbon atoms (meta The reactive hot melt adhesive according to (1) or (2), which is a copolymer of an alkyl acrylate ester and an unsaturated compound having a crosslinkable silicon group.
(4) (A) In a (meth) acrylic acid ester polymer having a crosslinkable silicon group and a glass transition temperature of minus 20 ° C. to 50 ° C., methyl methacrylate and an alkyl group having 2 to 30 carbon atoms (meta The reactive hot melt adhesive according to any one of (1) to (3), wherein the repeating unit derived from the alkyl acrylate ester is 50% by mass or more.
(5) (A) In a (meth) acrylic acid ester polymer having a crosslinkable silicon group and a glass transition temperature of minus 20 ° C. to 50 ° C., methyl methacrylate and an alkyl group having 2 to 30 carbon atoms (meta ) The repeating unit derived from the monomer unit other than the unsaturated compound having an alkyl acrylate ester and a crosslinkable silicon group is 0 to less than 10% by mass, according to any one of (1) to (4) Reactive hot melt adhesive.
(6) (B) The silanol condensation catalyst is one or two or more compounds selected from the group consisting of an organic tin compound having an alkyl group having 5 or more carbon atoms, an aluminum compound, a bismuth compound, and a titanium compound. The reactive hot melt adhesive according to any one of (5).
(7) (C) The reactive hot melt adhesive according to any one of (1) to (6), wherein the compound having a crosslinkable silicon group and an amino group has a molecular weight of 250 or more.
(8) The reactive hot melt adhesive according to any one of (1) to (7), further comprising (D) a liquid polymer compound.
(9) 100 parts by mass or less of (D) liquid polymer compound with respect to 100 parts by mass of (A) a (meth) acrylic acid ester polymer having a crosslinkable silicon group and a glass transition temperature of minus 20 ° C. to 50 ° C. The reactive hot melt adhesive according to any one of (1) to (8), which is contained.
(10) The reactive hot melt adhesive according to any one of (1) to (9), wherein the liquid polymer compound (D) is a (meth) acrylic acid ester polymer and / or an oxyalkylene polymer. .

  The reactive hot melt adhesive of the present invention is a hot melt adhesive using a novel acrylic polymer and has sufficient hot melt properties. In addition, since the polymer used for this hot melt adhesive can be obtained by a commonly used acrylic monomer or a normal radical polymerization method, it can be easily produced and is inexpensive.

(A) Crosslinkable silicon group-containing (meth) acrylic acid ester polymer (A) The crosslinkable silicon group in the acrylic acid ester polymer having a crosslinkable silicon group as a component and having a glass transition temperature of minus 20 ° C. to 50 ° C. It is a group that has a hydroxyl group or hydrolyzable group bonded to a silicon atom and can be crosslinked by a silanol condensation reaction. As a representative example of the crosslinkable silicon group, the formula (1):

(In the formula, R ¹ represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or R ² ₃ SiO— (Wherein R ² is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms). When two or more R ¹ are present, they may be the same or different, X represents a hydrolyzable group, and when two or more X are present, they are the same. A may be 0, 1, 2 or 3, b may be 0, 1 or 2, and n formulas (2):

B in need not be the same. n shows the integer of 0-19. However, a + (sum of b) ≧ 1 is satisfied. ).

  The hydrolyzable group can be bonded to one silicon atom in the range of 1 to 3, and a + (sum of b) is preferably in the range of 1 to 5. When two or more hydrolyzable groups are bonded to the crosslinkable silicon group, they may be the same or different.

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

Formula (3):

A crosslinkable silicon group represented by the formula (wherein R ¹ , X and a are the same as described above) is preferable from the viewpoint of easy availability. In the crosslinkable silicon group of the formula (3), a is preferably 2 or 3. When a is 3, the curing rate is higher than when a is 2.

Specific examples of R ¹ include alkyl groups such as methyl and ethyl groups, cycloalkyl groups such as cyclohexyl groups, aryl groups such as phenyl groups, aralkyl groups such as benzyl groups, R ² ₃ SiO— (R ² is a triorganosiloxy group represented by a hydrocarbon group such as a methyl group or an ethyl group. Of these, a methyl group is preferred.

  It does not specifically limit as a hydrolysable group shown by said X, What is necessary is just a conventionally well-known hydrolysable group. Specific examples 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, a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group, and an alkenyloxy group are preferable, and an alkoxy group, an amide group, and an aminooxy group are more preferable. An alkoxy group is particularly preferred from the viewpoint of mild hydrolysis and easy handling. Among the alkoxy groups, those having a smaller number of carbon atoms have higher reactivity, and the reactivity increases as the number of carbon atoms increases in the order of methoxy group> ethoxy group> propoxy group. Although it can be selected according to the purpose and application, a methoxy group or an ethoxy group is usually used. In the case of the crosslinkable silicon group represented by the formula (3), a is preferably 2 or more in consideration of curability.

Specific examples of the crosslinkable silicon group include trialkoxysilyl groups such as a trimethoxysilyl group and a triethoxysilyl group, dialkoxy such as —Si (OR ³ ) ₃ , a methyldimethoxysilyl group, and a methyldiethoxysilyl group. And a silyl group, —SiR ¹ (OR ³ ) ₂ . Here, R ¹ is the same as described above, and R ³ is an alkyl group such as a methyl group or an ethyl group.

  Further, the crosslinkable silicon group may be used alone or in combination of two or more. The crosslinkable silicon group can be present in the main chain, the side chain, or both.

  It is preferable that at least one, preferably 1.1 to 5, crosslinkable silicon groups are present in one molecule of the polymer. When the number of crosslinkable silicon groups contained in the molecule is less than one, the curability is insufficient, and when the number is too large, the network structure becomes too dense, and good mechanical properties are not exhibited.

The (meth) acrylic acid ester polymer is a polymer having a repeating unit represented by the general formula (4).
^{_{-CH 2 C (R 4) C}} (COOR 5) - (4)
(Wherein R ⁴ represents a hydrogen atom or a methyl group, and R ⁵ represents a hydrocarbon group which may have a substituent)

  This polymer may be a homopolymer or a copolymer. In addition, (meth) acrylic acid ester shows acrylic acid ester and / or methacrylic acid alkylester.

  As a monomer which becomes a repeating unit, (meth) acrylic acid alkyl ester is preferable. Examples of the alkyl acrylate compound include those conventionally known, such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, and tert-butyl acrylate. N-hexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, undecyl acrylate, lauryl acrylate, tridecyl acrylate, myristyl acrylate, cetyl acrylate, stearyl acrylate, behenyl acrylate, biphenyl acrylate, etc. Can be mentioned.

  Examples of the methacrylic acid ester compounds include those conventionally known, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-methacrylate. Butyl, n-hexyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, undecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, myristyl methacrylate, cetyl methacrylate, stearyl methacrylate, behenyl methacrylate, biphenyl methacrylate, etc. Is mentioned.

  The hydrocarbon group such as an alkyl group of the (meth) acrylic acid ester may have a substituent such as a hydroxyl group, a halogen atom, an epoxy group, or an isocyanate group. Examples of such compounds include acrylic acid esters having a hydroxyl group such as hydroxyethyl acrylate and hydroxyethyl methacrylate, acrylic acid esters having an epoxy group such as glycidyl acrylate and glycidyl methacrylate, amino groups such as diethylaminoethyl acrylate and diethylaminoethyl methacrylate. And acrylic acid esters having an isocyanate group such as acrylic acid esters, acryloyloxyethyl isocyanate, and methacryloyloxyethyl isocyanate. An unsaturated compound (macromonomer or macromer) having a polymer chain such as an acrylate ester having a polystyrene chain described in Patent Documents 2 to 4 can also be used.

  Furthermore, in the (meth) acrylic acid ester polymer of the component (A), in addition to the repeating unit derived from the (meth) acrylic acid ester compound, a repeating unit derived from a compound copolymerizable with these may be included. . Examples of compounds copolymerizable with (meth) acrylic acid ester compounds include acrylic acid such as acrylic acid and methacrylic acid; amide compounds such as acrylamide, methacrylamide, N-methylolacrylamide, and N-methylolmethacrylamide, alkyl Vinyl ether compounds such as vinyl ether and aminoethyl vinyl ether; other examples include acrylonitrile, styrene, α-methylstyrene, vinyl chloride, vinyl acetate, vinyl propionate, and ethylene.

Various known methods can be used to introduce the crosslinkable silicon group into the (meth) acrylic acid ester polymer of component (A). The following method can be mentioned as an example of the method of introducing a crosslinkable silicon group.
(1) Copolymerizing an unsaturated compound having a crosslinkable silicon group.
(2) Polymerization is performed using an initiator or a chain transfer agent having a crosslinkable silicon group.
(3) A (meth) acrylic acid ester polymer having a functional group such as a hydroxyl group is reacted with another functional group capable of reacting with the functional group such as epoxysilane and a compound having a crosslinkable silicon group.
As a method for introducing a crosslinkable silicon group, (1) a method of copolymerizing an unsaturated compound having a crosslinkable silicon group is preferable from the viewpoint of easily introducing a crosslinkable silicon group.

Unsaturated compound having a crosslinkable silicon group The unsaturated compound having a crosslinkable silicon group is preferably a (meth) acrylic acid alkyl ester or vinylsilane having a crosslinkable silicon group. Examples of such compounds include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylalkoxysilane such as γ-methacryloxypropyltriethoxysilane, and γ-acryloxypropyl. Vinyl alkoxysilanes such as trimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-acryloxypropylalkoxysilane such as γ-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane Etc. Among these, (meth) acrylic acid alkyl esters having a substituted alkyl group having 10 or less, preferably 3 or less carbon atoms of an alkyl group having a crosslinkable silicon group are preferred. The amount of unsaturated compound having a crosslinkable silicon group is such that the average number of crosslinkable silicon groups per molecule of the polymer of component (A) is 1.1 to 5, preferably 1.1 to 3. It is good to make it.

Glass transition temperature The (A) component (meth) acrylic acid ester polymer has a glass transition temperature (hereinafter also referred to as Tg) of minus 20 ° C to 50 ° C. A glass transition temperature of minus 10 to 40 ° C. is preferred, and a glass transition temperature of minus 10 to 30 ° C. is more preferred. If the glass transition temperature is less than minus 20 ° C, the adhesive strength immediately after bonding tends to be inferior. On the other hand, when the glass transition temperature exceeds 50 ° C., the melt viscosity becomes high and it tends to be difficult to apply the hot melt adhesive to the adherend. The glass transition temperature can be easily estimated from the type and amount of the monomer component using the Fox equation. The glass transition temperature of the present invention is measured by the DSC method.

  The molecular weight of the (A) component (meth) acrylate polymer is a number average molecular weight (polystyrene equivalent molecular weight measured by the GPC method), preferably 3000 to 50,000, more preferably 5000 to 30,000, and more preferably 6000 to 6000. 15,000 is more preferred. If the number average molecular weight is 3000 or less, the initial adhesive strength after coating is low, and if it is 50,000 or more, the viscosity during the coating operation becomes too high and workability deteriorates. The polymer of component (A) is preferably a solid at room temperature.

Radical polymerization method As the polymerization method, a radical polymerization method can be used. For example, a usual solution polymerization method or bulk polymerization method using a thermal polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile can be used. Moreover, the method of superposing | polymerizing by irradiating light or a radiation using a photoinitiator can also be used. In radical copolymerization, a chain transfer agent such as lauryl mercaptan or 3-mercaptopropyltrimethoxysilane may be used to adjust the molecular weight. A normal radical polymerization method using a thermal polymerization initiator can be used, and the polymer of the component (A) used in the present invention can be easily obtained by such a method. However, other polymerization methods such as a living radical polymerization method described in Patent Document 8 can also be used.

Monomers other than monomers having a crosslinkable silicon group used for the polymer of component (A) Monomers other than monomers having a crosslinkable silicon group used for the polymer of component (A) of the present invention As the body, (meth) acrylic acid alkyl ester is preferable, (meth) acrylic acid alkyl ester having 1 to 30 carbon atoms in the alkyl group is more preferable, and alkyl group having 1 to 30 carbon atoms and no substituent ( A meta) acrylic acid alkyl ester is particularly preferred. Since the polymer of the component (A) of the present invention is used for hot melt, it is preferably in a state having little solidity or fluidity at room temperature. In particular, in order to obtain a polymer having a glass transition temperature of minus 20 ° C. to 50 ° C., methyl methacrylate (Tg of the polymer is 105 ° C.) as a monomer and an alkyl group having no substituent of 2 to 30 carbon atoms ( It is preferable to use a (meth) acrylic acid alkyl ester, particularly an acrylic acid alkyl ester, from the viewpoint of ease of production and cost. Further, it is particularly preferable to use methyl methacrylate and butyl acrylate (Tg of the polymer is minus 55 ° C.) from the viewpoint of ease of production and cost. When methyl methacrylate is used, the amount of the repeating unit derived from methyl methacrylate in the polymer of component (A) is preferably 20% by mass or more, and more preferably 30% by mass or more.

Use ratio of monomer A preferable monomer used in the polymer of the component (A) is 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass in the polymer of the component (A). As mentioned above, it is desirable to use it so that it may become 90 mass% or more especially further 95 mass% or more. In particular, it is desirable to use an alkyl acrylate ester having no substituent of 2 to 30 carbon atoms such as methyl methacrylate and butyl acrylate in the above amounts. In addition, a macromonomer may be used as a monomer used in the polymer of component (A), but when used, the amount of macromonomer is 10% by mass or less in the polymer of component (A), It is preferable to use so that it may become 5 mass% or less, especially 3 mass% or less.

(B) Silanol condensation catalyst
Examples of the silanol condensation catalyst as component (B) of the present invention include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; dibutyltin dilaurate, dibutyltin diacetylacetonate, dibutyltin maleate, dibutyltin diacetate, dibutyltin Organotin compounds such as dimethoxide, dioctyltin dilaurate, dioctyltin diacetylacetonate, dioctyltin maleate, dioctyltin diacetate, dioctyltin dimethoxide, tin octylate, tin naphthenate; (C ₂ H ₅ O) ₄ Zr, (iso _{-C 3 H 7 O) 4 Zr} , (n-C 4 H 9 O) 4 Zr, (C 8 H 17 O) 4 Zr, Zr (acac) 4 (acac means acetylacetonate, also in the following the same meaning _{is), (n-C 4 H} 9 _{) 3 Zr (acac), (} n-C 4 H 9 O) 2 Zr (acac) 2, (n-C 4 H 9 0) Zr (acac) 3, (CH 3 CO 2) 2 ZrO (C 7 H Zirconium compounds such as ₁₅ CO ₂ ) ₂ ZrO, (C ₁₅ H ₃₁ CO ₂ ) ₂ ZrO; (iso-C ₃ H ₇ O) ₃ Al, (iso-C ₃ H ₇ O) ₂ Al (sec-C _{4 H 9 O), (sec-} C 4 H 9 O) 3 Al, (iso-C 3 H 7 O) 2 Al (acac), Al (acac) 3, (iso-C 3 H 7 O) 2 Al ( ethyl _{acetoacetate, (iso-C 3 H 7} O) 2 Al ( methyl _{acetoacetate), (iso-C 3 H} 7 O) 2 Al ( propyl acetoacetate), Al (ethyl _{acetoacetate)} 3, Al (Mechiruasetoa Tate) _3, Al (propyl acetoacetate) ₃ aluminum compounds, such as 2-ethylhexyl bismuth, bismuth neodecanoate, versatic acid, bismuth compounds such as oleic acid bismuth; lead octylate, butylamine, octylamine, dibutylamine, Monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, octylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2,4,6-tris (Dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 1,3-diazabicyclo (5,4,6) un Amine-based compounds such as sen-7 or their carboxylates; reactants and mixtures of amine-based compounds and organotin compounds such as laurylamine and tin octylate reactants or mixtures; excess polyamines and polybasic acids A low molecular weight polyamide resin obtained from the above: one or more known silanol catalysts such as a reaction product of an excess polyamine and an epoxy compound may be used as necessary.

  The hot melt adhesive is usually applied to the adherend in a melted state at a high temperature of about 100 ° C. or higher. For this reason, when a highly active silanol condensation catalyst is used, a curing reaction proceeds at the time of melting, resulting in a high viscosity, which may make the coating operation difficult. Patent Documents 3 and 4 disclose that an increase in viscosity can be prevented by using an isocyanate compound. When one or two or more compounds selected from the group consisting of an organotin compound having an alkyl group having 5 or more carbon atoms, an aluminum compound, a bismuth compound and a titanium compound are used in the above-mentioned curing catalyst, the hot melt adhesive has a high temperature. It is preferable to use these silanol condensation catalysts, because the increase in viscosity at the time can be prevented. The amount of the silanol condensation catalyst which is the component (B) is 0.01 to 10 parts by mass, and further 0.1 to 5 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester polymer of the component (A). It is preferred to use.

(C) Compound having a crosslinkable silicon group and amino group (C) The crosslinkable silicon group in the compound having a crosslinkable silicon group and amino group (hereinafter also referred to as aminosilane) as described in component (A) is as described in the description of component (A). It has a hydroxyl group or hydrolyzable group bonded to a silicon atom, and can be crosslinked by silanol condensation reaction.

  Aminosilane is known as an adhesion-imparting agent, but also acts as a curing catalyst in the present invention. In particular, when the component (B) is an organotin compound, the curing of the component (A) hardly proceeds unless the component (C) is present. As the amino group, a primary to tertiary amino group can be used.

  Examples of aminosilanes include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, N- (2-amino) Ethyl) -3-aminopropylmethyldiethoxysilane, γ-ureidopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropylmethyldimethoxysilane, N-benzyl-γ- Aminopropyltrimethoxysilane, Mention may be made of N-vinylbenzyl-γ-aminopropyltriethoxysilane and N-cyclohexylaminomethyldiethoxymethylsilane. Moreover, derivatives, such as the reaction material of these aminosilane compounds, an epoxy compound, and an acrylic ester compound, can be used.

  Among these, N-phenyl-γ-aminopropylmethyldimethoxysilane and a compound having a molecular weight of 250 or more, such as a reaction product of an aminosilane compound and an epoxy compound or an acrylic ester compound, volatilize when the hot melt melts. It is preferable because it is difficult. In addition, a compound having a secondary amino group is preferable because a curing reaction proceeds when the hot melt is melted and does not easily become high viscosity, and the curing reaction also proceeds after bonding.

  Aminosilane may be used alone or in combination of two or more. 0.01-20 mass parts is preferable with respect to 100 mass parts of (A) component, as for the usage-amount of aminosilane, 0.1-10 mass parts is more preferable, and 1-5 mass parts is especially preferable. If it is less than 0.01 parts by mass, the effect of imparting adhesiveness and the effect as a curing catalyst are insufficient. On the other hand, if it exceeds 20 parts by mass, the action as a catalyst according to the amount added is not remarkable and economical. It is not preferable.

  The reactive hot melt adhesive of the present invention can be used in combination with other additives as necessary. Examples of such additives include a liquid polymer, a polymer having a crosslinkable silicon group other than the component (A), a tackifier resin, an adhesion promoter other than the component (C), a filler, a plasticizer, Stabilizers, flame retardants, curability modifiers, radical inhibitors, metal deactivators, ozone degradation inhibitors, phosphorus peroxide decomposers, lubricants, pigments, foaming agents, fungicides, and the like. These additives may be used alone or in combination of two or more.

  The liquid polymer has an effect of reducing the viscosity when the hot melt is melted. Furthermore, the liquid polymer has an effect of extending the open time (the time when bonding is possible, the time when bonding can be performed after hot melt application). The liquid polymer has a viscosity at room temperature (B-type viscometer) of preferably 100 Pa · s or less, more preferably 50 Pa · s or less, and particularly preferably 20 Pa · s or less. The liquid polymer may have a crosslinkable silicon group.

  Examples of the main chain skeleton of the liquid organic polymer include polyoxyalkylene polymers such as polyoxypropylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer; ethylene-propylene copolymer, polyisobutylene, Polyisoprene, polybutadiene, hydrocarbon polymers such as hydrogenated polyolefin polymers obtained by hydrogenating these polyolefin polymers; condensation of dibasic acids such as adipic acid and glycols, or lactones Polyester polymers obtained by ring-opening polymerization; (meth) acrylate polymers obtained by radical polymerization of monomers such as ethyl (meth) acrylate and butyl (meth) acrylate; (meth) acrylate monomers Monomers such as vinyl acetate, acrylonitrile and styrene Vinyl polymers obtained by dical polymerization; graft polymers obtained by polymerizing vinyl monomers in organic polymers; polysulfide polymers; polyamide polymers; polycarbonate polymers; diallyl phthalate polymers, etc. Is mentioned. Two or more kinds of these skeletons may be included in blocks or randomly. Among these polymers, a polyoxyalkylene polymer and / or a (meth) acrylic acid ester polymer are preferable because they are easy to handle and have a large effect of increasing the open time.

  If too much liquid polymer is used, the properties as a hot melt such as heat resistance may be impaired. For this reason, 0-100 mass parts is preferable with respect to 100 mass parts of (A) component, as for the content of a liquid polymer, it is more preferable that it is 0-60 mass parts, More preferably, it is 0-30 mass parts. .

  Examples of the polymer having a crosslinkable silicon group other than the component (A) and not in liquid form include the polymers having a crosslinkable silicon group disclosed in Patent Documents 2 to 5. In the present invention, only the polymer (A) is sufficient as the polymer having a crosslinkable silicon group. For this reason, the content of the polymer having a crosslinkable silicon group other than the component (A) is preferably 0 to 100 parts by mass, more preferably 0 to 60 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is 0-30 mass parts.

  Examples of tackifying resins include terpene resins, aromatic modified terpene resins and hydrogenated terpene resins obtained by hydrogenation thereof, terpene-phenol resins obtained by copolymerizing terpenes with phenols, phenol resins, modified phenol resins, Xylene-phenol resin, cyclopentadiene-phenol resin, coumarone indene resin, rosin resin, rosin ester resin, hydrogenated rosin ester resin, xylene resin, low molecular weight polystyrene resin, styrene copolymer resin, styrene block copolymer And hydrogenated products of styrene block copolymers, petroleum resins (for example, C5 hydrocarbon resins, C9 hydrocarbon resins, C5C9 hydrocarbon copolymer resins, etc.), hydrogenated petroleum resins, DCPD resins, and the like. These may be used alone or in combination of two or more.

  Examples of styrenic block copolymers and hydrogenated products thereof include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), styrene-ethylenebutylene-styrene block copolymers. Examples thereof include a polymer (SEBS), a styrene-ethylenepropylene-styrene block copolymer (SEPS), and a styrene-isobutylene-styrene block copolymer (SIBS).

  The tackifying resin may be added in an amount of 0 to 100 parts by mass, further 0 to 60 parts by mass, and particularly 0 to 30 parts by mass with respect to 100 parts by mass of the component (A). However, in the present invention, only the polymer (A) is sufficient as a polymer having a crosslinkable silicon group, and the use of a tackifier resin may impair hot melt properties such as heat resistance. For this reason, it is preferable that the content of tackifying resin is 0 to less than 10 parts by mass, further 0 to 5 parts by mass, and particularly 0 to 3 parts by mass with respect to 100 parts by mass of component (A).

Examples of adhesion-imparting agents other than the component (C) include mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane; epoxy group-containing silanes such as γ-glycidoxypropyltrimethoxysilane; vinyltrimethoxy Examples include silanes containing vinyl unsaturated groups such as silanes; silanes containing isocyanate groups such as γ-isocyanatopropyltrimethoxysilane, and these silane coupling agents may be used alone. Two or more types may be mixed and used.

  Examples of fillers include calcium carbonate, magnesium carbonate, titanium oxide, carbon black, fused silica, precipitated silica, diatomaceous earth, white clay, kaolin, clay, talc, wood powder, walnut shell powder, rice husk powder, anhydrous Silica, quartz powder, aluminum powder, zinc powder, asbestos, glass fiber, carbon fiber, glass beads, alumina, glass balloon, shirasu balloon, silica balloon calcium oxide, magnesium oxide, silicon oxide and other inorganic fillers, pulp, Organic fillers such as wood fillers such as cotton chips, powder rubber, recycled rubber, fine powders of thermoplastic or thermosetting resins, hollow bodies such as polyethylene, and the like. Only one type of filler may be added, or multiple types may be added in combination.

  Examples of plasticizers include: phthalates such as dioctyl phthalate and diisodecyl phthalate; aliphatic dibasic esters such as dioctyl adipate; epoxy plasticizers such as epoxidized soybean oil and epoxidized linseed oil; polypropylene glycol And polyethers such as derivatives thereof; vinyl polymers obtained by polymerizing vinyl monomers by various methods, and the like. These plasticizers may be used alone or in combination of two or more.

  Specific examples of the stabilizer include an antioxidant, a light stabilizer, and an ultraviolet absorber. When an antioxidant is used, the weather resistance and heat resistance of the cured product can be improved. Examples of the antioxidant include hindered phenols, monophenols, bisphenols, and polyphenols, with hindered phenols being particularly preferred. When a light stabilizer is used, photooxidation deterioration of the cured product can be prevented. Examples of the light stabilizer include benzotriazole-based, hindered amine-based, and benzoate-based compounds, and hindered amine-based compounds are particularly preferable. When the ultraviolet absorber is used, the surface weather resistance of the cured product can be enhanced. Examples of ultraviolet absorbers include benzophenone, benzotriazole, salicylate, substituted tolyl, and metal chelate compounds, with benzotriazole being particularly preferred. Further, it is preferable to use a phenolic or hindered phenolic antioxidant, a hindered amine light stabilizer and a benzotriazole ultraviolet absorber in combination.

  In the reactive hot melt adhesive of the present invention, the total amount of the component (A), the component (B), and the component (C) is 50% by mass or more, further 60% by mass or more, particularly 70% in the hot melt adhesive. It is preferable from a viewpoint of the characteristic of a hot-melt-adhesive that it is mass% or more.

  The reactive hot melt adhesive of the present invention can be prepared as a one-component type in which all the components are pre-blended and stored and cured by moisture in the air after construction. It can also be prepared as a two-component type in which the components are blended and the compounding material and the polymer composition are mixed before use.

  The method for preparing the reactive hot melt adhesive of the present invention is not particularly limited. For example, the above-described components are blended and kneaded using a mixer, roll, kneader or the like at room temperature or under heating, or a small amount of a suitable solvent. Ordinary methods such as dissolving and mixing the components can be used.

  The reactive hot melt adhesive of the present invention preferably has a viscosity at 80 ° C. of 100 Pa · s or less. When the viscosity at 80 ° C. exceeds 100 Pa · s, the coatability and workability are lowered, or it is necessary to apply at a higher temperature to ensure the coatability and workability. In that case, the range of use is limited, for example, it becomes difficult to use the base material with low heat resistance. More preferably, the temperature at 80 ° C. is 50 Pa · s or less.

  The curable composition of the present invention can be suitably used in production lines such as architecture, automobiles, electricity / electronics, textile / leather / clothing / binding. Further, by using a warming hand gun or the like, it is possible to suitably use other than the production line such as a construction site or DIY.

  The most frequently used reactive hot melt adhesive is a urethane-based reactive hot melt adhesive. However, when one or both of the adherends are wood-based materials such as wood, plywood or wood-based fiberboard, or moisture-permeable materials such as paper, the adhesive strength can be increased by using a urethane-based reactive hot melt adhesive. It was found to decrease over time. This tendency is particularly great in a high humidity atmosphere. When the reactive hot melt adhesive of the present invention is used instead of the urethane-based reactive hot melt adhesive, the adhesive strength does not decrease with time, and the reactive hot melt adhesive of the present invention is a moisture-permeable material as described above. This is particularly useful when used as an adherend.

Production Example 1 (Production of acrylic polymer)
Butyl acetate was charged as a solvent in a reaction vessel equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel, and the temperature was raised to 110 ° C. while introducing nitrogen gas. Thereafter, γ-methacryloxypropyltrimethoxysilane, methyl methacrylate and n-butyl acrylate were charged. Next, butyl acetate of 2,2′-azobis (2-methylbutyronitrile) was added dropwise for polymerization. After completion of dropping, the mixture was aged at 110 ° C. for 2 hours and then cooled, and butyl acetate was added to the resin solution to obtain an acrylic polymer. The obtained acrylic polymer has a number average molecular weight (polystyrene equivalent molecular weight measured by GPC method) of 10,000, an average of 3 crosslinkable silicon groups per polymer molecule, and a glass transition temperature (by DSC method). The measured glass transition temperature was 5 ° C.

Examples 1-6
After mixing the component (A) and the antioxidant in the ratio shown in Table 1 (component (A) describes the amount of solids), butyl acetate was devolatilized by heating under reduced pressure at 120 ° C. Next, the component (D) (when used) shown in Table 1 was added and stirred, and then the components (C) and (B) were added and stirred. Finally, it was degassed under reduced pressure, and a metal container was filled with a one-component moisture-curing reactive hot melt adhesive. The following evaluation was performed using the obtained one-component moisture-curing reactive hot melt adhesive. The results are shown in Table 1.

80 ° C. Melt Viscosity The viscosity of the moisture-curing reactive hot melt adhesive at 80 ° C. was measured using a Brookfield RST-CPS rheometer (spindle RST-25).

Open time (possible bonding time after application)
The moisture-curable reactive hot melt adhesive was heated to 120 ° C. and sufficiently melted, and then poured out of a metal container and applied to corrugated cardboard with a thickness of 100 μm using a spatula. An EB sheet (manufactured by Dai Nippon Printing Co., Ltd.) was attached every minute, and two reciprocating pressings were performed using a 2 kg roller. The time for which the cardboard broke was defined as the curing time. The curing time was measured in an atmosphere having a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 10%.

Shear strength immediately after bonding The moisture-curing reactive hot melt adhesive was heated to 120 ° C. and sufficiently melted, and then poured out of a metal container and applied to alumite-treated aluminum with a thickness of 100 μm using a spatula. Immediately after application, anodized aluminum was bonded. After confirming that the test body became 23 ° C., the shear strength immediately after bonding was confirmed using an autograph (manufactured by Shimadzu Corporation) at a pulling rate of 50 mm / min. The test was carried out in an atmosphere having a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 10%.

One week later Shear strength A moisture-curable reactive hot melt adhesive was heated to 120 ° C. and sufficiently melted, then poured out of a metal container and applied to an alumite-treated aluminum with a thickness of 100 μm using a spatula. Immediately after application, anodized aluminum was bonded. After curing for 1 week in an atmosphere of a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 10%, the shear strength after one week was measured at a pulling rate of 50 mm / min using an autograph (manufactured by Shimadzu Corporation).

Peel strength after 1 week A moisture-curable reactive hot melt adhesive was heated to 120 ° C. and sufficiently melted, and then poured out of a metal container and applied to anodized aluminum with a thickness of 100 μm using a spatula. Immediately after the application, an EB sheet (manufactured by Dai Nippon Printing Co., Ltd.) was attached, and two reciprocating pressings were performed using a 2 kg roller. After curing for 1 week in an atmosphere of a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 10%, a 180 ° peel test was performed at a peel rate of 200 mm / min using an autograph (manufactured by Shimadzu Corporation).

Heat-resistant creep test A moisture-curable reactive hot-melt adhesive was heated to 120 ° C. and sufficiently melted, then poured out of a metal container and applied to alumite-treated aluminum with a thickness of 100 μm using a spatula. Immediately after application, alumite-treated aluminum is pasted, cured for 1 week in an atmosphere of 23 ± 2 ° C and relative humidity of 50 ± 10%, and then loaded with 500g on one side of the test piece in a high-temperature humidifier set at 80 ° C. The shear direction deviation after 24 hours was applied. The case where the deviation was 0 mm was evaluated as ◯, and the case where the deviation was 1 mm or more was evaluated as x.

Comparative Example 1
Henkel AG & Co. Characteristic evaluation was performed in the same manner as in Example 1 using KGaA urethane-based reactive hot melt adhesive Technomelt PUR170-7310. The results are shown in Table 1.

In Table 1, the compounding amount of each compounding substance is indicated by g, and details of other compounding substances are as follows.
* 1 Dioctyltin dilaurate: U830 (manufactured by Nitto Kasei)
* 2 Aluminum chelate D (manufactured by Kawaken Fine Chemical Co., Ltd.)
* 3 KBM573 (manufactured by Shin-Etsu Chemical)
* 4 KBM603 (manufactured by Shin-Etsu Chemical)
* 5 KBM503 (manufactured by Shin-Etsu Chemical)
* 6 Actcol D5000 (Mitsui Chemicals Polyurethane SKC Co., Ltd.)
* 7 EST280 (manufactured by Kaneka Corporation)
* 8 UP1110 (manufactured by Toa Gosei Co., Ltd.)
* 9 AO60 (manufactured by ADEKA Corporation)

Example 7, Comparative Example 2
The moisture-curable reactive hot melt adhesive used in Example 3 was heated to 120 ° C. and sufficiently melted, and then poured out of a metal container and applied to an alumite-treated aluminum with a thickness of 100 μm using a spatula. Immediately after application, the canvas was pasted and two reciprocating pressings were performed using a 2 kg roller. After curing for 1 week in an atmosphere of a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 10%, a 180 ° peel test was performed at a peel rate of 200 mm / min using an autograph (manufactured by Shimadzu Corporation). In addition, the test piece that had been cured for one week was left to stand for one month in an atmosphere at a temperature of 50 ° C. and a relative humidity of 85%, and then subjected to moisture and heat resistance. After curing with heat and humidity resistance, the sample was allowed to stand for 24 hours under conditions of 23 ° C. and 50% RH, and a 180 ° peel test was performed (Example 7).
As in Example 7, Henkel AG & Co. A 180-degree peel test was performed using KGaA urethane-based reactive hot melt adhesive, Technomelt PUR170-7310 (Comparative Example 2). The results are shown in Table 2.

Claims (10)

  (A) 100 parts by mass of (meth) acrylic acid ester polymer having a crosslinkable silicon group and a glass transition temperature of minus 20 ° C. to 50 ° C., (B) 0.01-20 parts by mass of silanol condensation catalyst, and (C) A reactive hot melt adhesive containing 0.1 to 30 parts by mass of a compound having a crosslinkable silicon group and an amino group.   (A) The (meth) acrylic acid ester polymer having a crosslinkable silicon group and having a glass transition temperature of minus 20 ° C. to 50 ° C. is a polymer obtained by radical polymerization using a thermal polymerization initiator. 2. The reactive hot melt adhesive according to 1.   (A) A (meth) acrylic acid ester polymer having a crosslinkable silicon group and having a glass transition temperature of minus 20 ° C. to 50 ° C. is methyl methacrylate, and (meth) acrylic acid having an alkyl group with 2 to 30 carbon atoms. The reactive hot melt adhesive according to claim 1 or 2, which is a copolymer of an alkyl ester and an unsaturated compound having a crosslinkable silicon group.   (A) (meth) acrylic acid having a crosslinkable silicon group and having a glass transition temperature of minus 20 ° C. to 50 ° C., methyl methacrylate and an alkyl group having 2 to 30 carbon atoms The reactive hot melt adhesive according to any one of claims 1 to 3, wherein a repeating unit derived from the alkyl ester is 50% by mass or more.   (A) In a (meth) acrylic acid ester polymer having a crosslinkable silicon group and a glass transition temperature of minus 20 ° C. to 50 ° C., (meth) acrylic acid having methyl methacrylate and an alkyl group having 2 to 30 carbon atoms The reactive hot melt adhesion according to any one of claims 1 to 4, wherein a repeating unit derived from a monomer unit other than an unsaturated compound having an alkyl ester and a crosslinkable silicon group is 0 to less than 10% by mass. Agent.   (B) The silanol condensation catalyst is one or more compounds selected from the group consisting of an organotin compound having an alkyl group having 5 or more carbon atoms, an aluminum compound, a bismuth compound and a titanium compound. The reactive hot melt adhesive according to claim 1.   (C) The compound which has a crosslinkable silicon group and an amino group is molecular weight 250 or more, The reactive hot melt adhesive of any one of Claims 1-6.   The reactive hot melt adhesive according to any one of claims 1 to 7, further comprising (D) a liquid polymer compound.   (D) The liquid polymer compound contains (A) 100 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic acid ester polymer having a crosslinkable silicon group and a glass transition temperature of minus 20 ° C. to 50 ° C. Item 9. The reactive hot melt adhesive according to any one of Items 1 to 8. The reactive hot melt adhesive according to any one of claims 1 to 9, wherein the liquid polymer compound (D) is a (meth) acrylic acid ester polymer and / or an oxyalkylene polymer.