JP2017149789A - Two-component mixing type adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-component mixing type adhesive having excellent adhesive strength, curing rate, hot strength and liquid dripping preventing properties.SOLUTION: There is provided a two-component mixing type adhesive which comprises a first composition and a second composition, where the first composition contains a complex having a group derived from an organoborane and its protective group and the second composition causes a deprotection reaction with the protective group and contains a compound capable of polymerizing the deprotection reaction product. The protective group of the complex is preferably derived from a compound having two or more functional groups. The compound derived from the protective group preferably is a diamine. The compound in the second composition preferably is a (meth)acrylate having an isocyanate group. The first composition, the second composition or both of the first composition and the second composition preferably contain a (meth)acrylate having no isocyanate group or a polymer component.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a two-component mixed adhesive.

  In order to deal with recent environmental problems, there is a demand for weight reduction of automobiles and the like, and therefore resin materials are being used. For this resin material, it is necessary to use an adhesive for joining the resin materials or joining different materials such as metals. However, among resin materials, polypropylene and the like, which are excellent in terms of recycling and cost, are materials that are difficult to bond with an adhesive.

  In recent years, an adhesive using an organoborane complex has been studied as a material capable of adhering such a difficult-to-adhere material (see Japanese Patent Publication No. 11-512123 and International Publication No. 2012/160452). In this adhesive, one composition contains a group derived from an organoborane and a complex having the protecting group, and the other composition contains a compound that acts on the protecting group to liberate the organoborane. It is. According to this adhesive, by mixing the two compositions at the time of bonding, the organoborane having radical polymerization initiating ability is liberated, and the adhesive component can be cured and bonded. In this case, radicals generated from the liberated organoborane and oxygen molecules can modify the surface of difficult-to-adhere materials such as polypropylene, so that excellent adhesion can be achieved without plasma treatment or the like. Has been.

  However, with the above conventional adhesives, the adhesive strength, the curing rate, and the hot strength showing the adhesiveness at high temperature are still insufficient for the market demand, and the dripping at the time of adhesion cannot be suppressed. There is also an inconvenience.

Japanese National Patent Publication No. 11-512123 International Publication No. 2012/160452

  This invention is made | formed based on the above situations, The objective is to provide the 2 liquid mixing type adhesive which is excellent in adhesive strength, a cure rate, hot strength, and dripping suppression property.

  The invention made to solve the above problems comprises a first composition (hereinafter also referred to as “composition (I)”) and a second composition (hereinafter also referred to as “composition (II)”). A two-component mixed adhesive, wherein the composition (I) contains a complex having a group derived from an organoborane and a protecting group thereof (hereinafter also referred to as “[A] complex”), and the composition (II) Contains a compound (hereinafter also referred to as “[D] compound”) capable of polymerizing the deprotection reaction product with the protecting group.

  The two-component mixed adhesive includes the composition (I) containing the [A] complex and the composition (II) containing the [D] compound, so that the adhesive strength, the curing rate, the hot strength, Excellent sag control. The reason why the two-component mixed adhesive has the above-described configuration and thus achieves the above effect is not necessarily clear, but can be inferred as follows, for example. That is, when the protecting group of the [A] complex and the [D] compound undergo a deprotection reaction, the released organoborane and the polymerization site in the deprotection reaction product are located closer to each other, resulting in more effective polymerization. It is considered that the curing rate is improved. In addition to the improvement in the curing rate, the adhesive layer formed by polymerization contains a group generated by the deprotection reaction, so that the strength is further improved and the interaction with the adherend is increased. It is considered that the hot strength is improved. Furthermore, it is considered that thixotropy is increased and liquid dripping suppression is improved due to the fact that moderate interaction is exerted between groups generated by the deprotection reaction.

  [A] The protecting group of the complex is preferably derived from a compound having two or more functional groups. Thus, the deprotection reaction product formed from the protective group of [A] complex and the [D] compound by making the compound derived from the protective group of [A] complex have two or more functional groups. As a result of the product having a plurality of polymerization sites, the curing rate is further improved, and since the resulting polymer has a three-dimensional cross-linked structure, the adhesive strength and the hot strength can be further improved. Furthermore, it is thought that the interaction between groups produced by the above-mentioned deprotection reaction increases, and the dripping suppression property is further improved.

  A diamine is preferred as the compound derived from the protecting group. Thus, by using the diamine as the compound derived from the protective group of the [A] complex, the speed of the deprotection reaction is increased and the curing rate is further improved, and the group formed by the deprotection reaction exhibits hydrogen bonds. As a result, it is considered that the strength of the adhesive layer and the interaction with the adherend can be further increased, and the adhesive strength and the hot strength are further improved. Moreover, since a hydrogen bond can be appropriately formed between groups generated by the deprotection reaction, the dripping suppression property can be further improved.

  The compound in the composition (II) is preferably a (meth) acrylate having an isocyanate group. As described above, by using the specific compound as the compound, the deprotection reaction rate and the polymerization rate are further increased, the curing rate is further improved, and the interaction between groups formed by the deprotection reaction is increased. As a result of further increasing the adhesive strength, the hot strength, and the dripping suppression property can be further improved.

  It is preferable that the composition (I), the composition (II) or both further contain a (meth) acrylate or polymer component having no isocyanate group. Thus, since the composition (I) and / or the composition (II) contains a (meth) acrylate or polymer component having no isocyanate group, the two-component mixed adhesive has the strength of the adhesive layer. Further, the adhesive strength and the hot strength are further improved, and the initial adhesive strength can be improved and the curing shrinkage can be suppressed.

  The molar ratio of the isocyanate group to the diamine is preferably 1 or more and 3 or less. Thus, by making the said molar ratio into the said specific range, adhesive strength, a cure rate, hot strength, and dripping suppression property can further be improved.

  The thixotropy index (TI) is preferably 3 or more. The said 2 liquid mixture type adhesive can exhibit high dripping suppression property by making the value of TI into the said range.

  As described above, according to the two-component mixed adhesive of the present invention, high adhesive strength and hot strength can be obtained at a high curing rate while suppressing liquid dripping. Therefore, the two-component mixed adhesive can be suitably used for bonding various materials including difficult-to-adhere materials such as automobile outer plates.

It is a measurement chart of the temperature dependence of storage elastic modulus (E ') and loss tangent (tan delta) about the two-component mixed type adhesive of an example and a comparative example.

<Two-component mixed adhesive>
The two-component mixed adhesive includes a composition (I) and a composition (II). The two-component mixed adhesive includes the composition (I) containing the [A] complex and the composition (II) containing the [D] compound, so that the adhesive strength, the curing rate, the hot strength, Excellent sag control.

In the two-component mixed adhesive, the composition (I) and the composition (II) are mixed so that the [D] compound in the composition (II) is converted into the [A] in the composition (I). A reaction (deprotection reaction) occurs with the protecting group constituting the complex, and as a result, a reaction product of organoborane and the protecting group with the [D] compound (hereinafter also referred to as “deprotection reaction product (p)”). ) Is generated. This deprotection reaction product (p) can be polymerized, and the produced organoborane is polymerized as a polymerization initiator, and in addition, bonds with the adherend are formed by radicals formed from the organoborane. Adhesion proceeds.
The two-component mixed adhesive can exhibit the above effects without requiring the inclusion of a curing accelerator such as an acid halide compound.
The reason why the two-component mixed adhesive has the above-described configuration provides the above-mentioned effect is not necessarily clear, but can be inferred as follows, for example. That is, when the protective group of the [A] complex and the [D] compound undergo a deprotection reaction, the liberated organoborane and the polymerization site in the deprotection reaction product become closer to each other, resulting in more effective polymerization. It is believed that the cure rate is improved. In addition to the improvement in the curing rate, the adhesive layer formed by polymerization contains a group generated by the above deprotection reaction, so that the strength is further improved and the interaction with the adherend is increased, so the adhesive strength is improved. In addition, it is considered that the hot strength is improved. Furthermore, it is considered that thixotropy is increased and liquid dripping suppression is improved due to the fact that moderate interaction is exerted between groups generated by the deprotection reaction.
In addition, according to the two-component mixed adhesive, the deprotection reaction product (p) is bonded to the adhesive layer by polymerization and taken in by adopting the above configuration, so that the bleed out from the adhesive layer is prevented. It is thought to be reduced.
In addition to the composition (I) and the composition (II), the two-component mixed adhesive further includes another composition that does not contain the [A] complex and the [D] compound, and is a mixture of three or more components. A mold adhesive may be used.

  Hereinafter, the composition (I) and the composition (II) will be described.

<Composition (I)>
Composition (I) contains a [A] complex. The composition (I) preferably contains a compound having one polymerizable group (hereinafter also referred to as “[B] polymerizable compound”) and / or a [C] polymer component. In the range which does not impair this, you may contain other components other than said [A]-[C] component.
Hereinafter, each component will be described.

[[A] complex]
[A] The complex is a complex having a group derived from organoborane and a protecting group thereof. [A] The complex is usually formed from an organoborane and a compound (a) capable of forming a protective group by coordination bonding to the organoborane and suppressing the polymerization initiation ability of the organoborane.

(Organoborane)
The organoborane is a compound in which the hydrogen atom of borane is substituted with an organic group. An organic group refers to a group containing at least one carbon atom. As said organoborane, the compound etc. which are represented by following formula (1) are mentioned, for example.

In the formula ^(1), R 1, ^{R 2} and ^{R 3} represents a monovalent organic group having 1 to 20 carbon atoms.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ , R ² and R ³ include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms and carbon-carbon of the hydrocarbon group. And a group (α) having a divalent heteroatom-containing group in between, a group in which part or all of the hydrogen atoms of the hydrocarbon group and group (α) are substituted with a monovalent heteroatom-containing group, and the like .

  Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and carbon. Examples thereof include monovalent aromatic hydrocarbon groups of several 6 to 20.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include:
Alkyl groups such as methyl, ethyl, propyl and butyl groups;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group and butynyl group.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include:
Cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, norbornyl group, adamantyl group, tricyclodecyl group;
And cycloalkenyl groups such as a cyclopentenyl group, a cyclohexenyl group, a norbornenyl group, and a tricyclodecenyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include:
Aryl groups such as phenyl, tolyl, xylyl, naphthyl and anthryl;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, and naphthylmethyl group.

  Examples of the hetero atom contained in the monovalent and divalent heteroatom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, and a silicon atom.

Examples of the divalent hetero atom-containing group include —O—, —CO—, —NR′—, —S—, —CS—, —SO—, —SO ₂ —, —POR ′ ₂ —, — Examples thereof include SiR ′ ₂ — and a group obtained by combining these. R ′ is a monovalent hydrocarbon group having 1 to 10 carbon atoms.

Examples of the monovalent heteroatom-containing group include —OH, —COOH, —NH ₂ , —CN, —NO ₂ , —SH and the like.

The organoborane is preferably a compound in which R ^{1 to} R ^{3 in} the above formula (1) are hydrocarbon groups from the viewpoint of high polymerization initiating ability, stability, and availability, more preferably trialkylborane, Borane, triethylborane, tripropylborane and tributylborane are more preferred, and triethylborane is particularly preferred.

(Compound (a))
Compound (a) is a compound that serves as a protective group for organoborane and can undergo a deprotection reaction with the [D] compound described below.

Examples of the compound (a) include compounds having a functional group (hereinafter also referred to as “functional group (x)”).
The functional group (x) is preferably a functional group containing a hetero atom from the viewpoint of both the ability to form a complex with an organoborane and the ease of deprotection reaction with the [D] compound.
As said hetero atom, a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom etc. are mentioned, for example.

As the functional group containing the hetero atom,
As the functional group containing a nitrogen atom, for example, an amino group, a substituted amino group (a hydrogen atom of —NH ₂ substituted with a hydrocarbon group), an imino group (—CH═N—), etc.
As a functional group containing an oxygen atom, for example, a hydroxy group, an ether group, etc.
Examples of the functional group containing a sulfur atom include a sulfanyl group and a thioether group.
Examples of the functional group containing a phosphorus atom include a phosphino group and a substituted phosphino group (in which a hydrogen atom of —PH ₂ is substituted with a hydrocarbon group).

As a compound having an amino group, for example,
Monoamines such as methylamine, ethylamine, propylamine, butylamine, aniline, ethanolamine;
1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1 , 8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,12-diaminododecane, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methyl Diamines such as ethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene;
And triamines such as 1,2,3-triaminopropane, 1,2,4-triaminobutane, 1,3,5-triaminocyclohexane, 1,3,5-triaminobenzene, and the like.

  Examples of the compound having a substituted amino group include dimethylamine, diethylamine, dipropylamine, dibutylamine, cyclopentylamine, cyclohexylamine, dicyclopentylamine, dicyclohexylamine, N, N′-dimethyl-1,3-diaminopropane, N, N, N ′, N′-tetramethyl-1,3-diaminopropane, diethanolamine and the like can be mentioned.

  Examples of the compound having an imino group include N-methylbutylaldimine.

As a compound having a hydroxy group, for example,
Monoalcohols such as methanol and ethanol;
Diols such as ethylene glycol, 1,4-butanediol, 1,2-cyclohexanediol;
Examples include triols such as glycerin and trimethylolpropane.

  Examples of the compound having an ether group include diethyl ether, dibutyl ether, tetrahydrofuran and the like.

Examples of the compound having a sulfanyl group include monothiols such as mercaptan and ethanethiol;
And dithiols such as ethanedithiol and butanedithiol.

  Examples of the compound having a thioether group include diethyl thioether, dibutyl thioether, tetrahydrothiophene and the like.

Examples of the compound having a phosphino group include monophosphines such as ethylphosphine and butylphosphine;
Examples include diphosphinoethane and diphosphinobutane.

  Examples of the compound having a substituted phosphino group include diethyl phosphine and dibutyl phosphine.

  The number of functional groups (x) possessed by the compound (a) may be 1 or 2 or more, preferably 2 or more, more preferably 2 to 4, more preferably 2 or 3 Two are particularly preferred. By setting the number of functional groups (x) within the above range, a deprotection reaction product having a plurality of polymerization sites (A) and a protective group of the [A] complex formed from the compound (a) and a compound [D] ( As a result of the formation of p), the curing rate is further improved, and the resulting polymer has a three-dimensional crosslinked structure, so that the adhesive strength and the hot strength can be further improved. Moreover, it is thought that the interaction between groups which arises by the above-mentioned deprotection reaction increases, and dripping suppression property improves more.

  As the functional group (x), those having a hetero atom to which at least one hydrogen atom is bonded are preferable from the viewpoint of facilitating the deprotection reaction between the protective group and the [D] compound. Examples of such a functional group (x) include an amino group, —NHR, a hydroxy group, a sulfanyl group, a phosphino group, and —PHR. R is a monovalent hydrocarbon group. Among these, from the viewpoint of further facilitating the deprotection reaction, an amino group and -NHR are preferable, and an amino group is more preferable.

  The compound (a) is preferably an active hydrogen-containing compound having a hetero atom to which at least one hydrogen atom is bonded, from the viewpoint of facilitating the deprotection reaction between the protecting group and the [D] compound. Among these, the compound (a) is preferably a compound containing an amino group, more preferably a diamine or a triamine, from the viewpoint of further facilitating the deprotection reaction and further increasing the adhesive strength and hot strength. More preferred are diaminoalkanes, particularly preferred are C2-C4 diaminoalkanes, and most preferred is 1,3-aminopropane.

  The molar ratio of the compound (a) to the organoborane in the [A] complex is preferably 0.5 to 3, more preferably 0.7 to 2, and 0.9 from the viewpoint of the stability of the [A] complex. -1.5 is more preferable, and 1 is particularly preferable.

  The lower limit of the content of the [A] complex in the composition (I) is 0.1 mass from the viewpoint of further improving the adhesive strength, curing rate, hot strength, and sag suppression of the two-component mixed adhesive. % Is preferable, 0.5% by mass is more preferable, 1% by mass is further preferable, and 2% by mass is particularly preferable. The upper limit of the content is preferably 20% by mass, more preferably 10% by mass, further preferably 6% by mass, and particularly preferably 4% by mass from the viewpoint of easy handling of the two-component mixed adhesive.

[[B] polymerizable compound]
[B] The polymerizable compound is a compound having one polymerizable group (provided that the compounds corresponding to the [C] polymer component and the [D] compound are excluded). By including the [B] polymerizable compound, the two-component mixed adhesive can improve the strength of the adhesive layer, and as a result, the adhesive strength and the hot strength can be further improved.

Examples of the polymerizable group include a carbon-carbon double bond-containing group such as a vinyl group, an allyl group, a styryl group, and a (meth) acryloyl group; a carbon-carbon triple bond-containing group such as an ethynyl group and a propargyl group. It is done.
Among these, a carbon-carbon double bond-containing group is preferable, and a (meth) acrylolyl group is more preferable from the viewpoint of superior polymerizability.

[B] As the polymerizable compound, for example,
Olefins such as butene, pentene, hexene, octene, decene, dodecene;
Styrene compounds such as styrene, α-methylstyrene and methylstyrene;
Vinyl carboxylates such as vinyl acetate, vinyl propionate and vinyl laurate;
Halogenated olefins such as vinyl chloride and vinylidene chloride;
Vinyl compounds such as methyl vinyl ketone and methyl vinyl ether;
Alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate;
Cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecan-yl (meth) acrylate;
Aryl (meth) acrylates such as phenyl (meth) acrylate and tolyl (meth) acrylate;
Heteroatom-containing (meth) acrylates such as hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate;
(Meth) acrylamide, N-methyl (meth) acrylamide, (meth) acrylonitrile, etc. are mentioned.

Among these, (meth) acrylate is preferable from the viewpoint of superior polymerizability, and (meth) acrylate having no isocyanate group is more preferable.
Among them, from the viewpoint of reducing the odor of the two-component mixed adhesive and from the viewpoint of dissolving the [C] polymer component described later, a heteroatom-containing (meth) acrylate is preferable, and tetrahydrofurfuryl (meth) acrylate is more preferable. .
From the viewpoint of imparting flexibility to the adhesive layer, alkyl (meth) acrylate is preferable, and 2-ethylhexyl (meth) acrylate is more preferable.
From the viewpoint of further improving the hot strength and further increasing the elongation rate of the adhesive layer, cycloalkyl (meth) acrylate is preferable, and tricyclodecyl (meth) acrylate is more preferable.
[B] One or two or more polymerizable compounds may be used.

  As a minimum of content of [B] polymeric compound in composition (I), 10 mass% is preferable, 30 mass% is more preferable, 50 mass% is further more preferable, 60 mass% is especially preferable. As an upper limit of the said content, 99 mass% is preferable, 95 mass% is more preferable, 90 mass% is further more preferable, 85 mass% is especially preferable. By setting the content to be between the lower limit and the upper limit, the strength of the adhesive layer can be further improved, and as a result, the adhesive strength and the hot strength can be further improved.

[[C] Polymer component]
The composition (I) preferably contains a [C] polymer component from the viewpoint of improving the initial adhesive strength and adjusting the viscosity of the two-component mixed adhesive, and suppressing the curing shrinkage of the adhesive layer.

  [C] The polymer component is not particularly limited as long as it is a polymer, and examples thereof include polyolefin, polystyrene, styrene copolymer, poly (meth) acrylate, acrylic copolymer, and thermoplastic elastomer. Further, an ethylene-vinyl acetate copolymer, an epoxy resin, a phenol resin, a silicone resin, a polyester resin, a urethane resin, or the like can also be used.

Examples of the polyolefin include polyethylene, polypropylene, and ethylene-α-olefin copolymers.
Examples of the polystyrene include polystyrene and poly (α-methylstyrene).
Examples of the styrene copolymer include styrene-methyl methacrylate copolymer, styrene-acrylic acid copolymer, styrene-maleic anhydride copolymer, styrene-acrylonitrile copolymer, ABS (acrylonitrile-butadiene-styrene). Copolymer) and the like.
Examples of the poly (meth) acrylate include polymethyl (meth) acrylate, polyethyl (meth) acrylate, polybutyl (meth) acrylate and the like.
As said acrylic copolymer, the polymer which has multiple types of (meth) acrylic acid ester unit, a butyl (meth) acrylate-acrylonitrile copolymer, etc. are mentioned, for example.
Examples of the thermoplastic elastomer include SBS (styrene-butadiene-styrene block copolymer), SEBS (styrene-ethylene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), Non-hydrogenated products of conjugated diene copolymers such as SEPS (styrene-ethylene-propylene-styrene block copolymer), hydrogenated products thereof and the like can be mentioned.

  Among these, from the viewpoint of having a more appropriate viscosity, a thermoplastic elastomer and poly (meth) acrylate are preferable, and a thermoplastic elastomer is more preferable.

[C] The polymer component preferably has a polymerization site. [C] Since the polymer component has a polymerization site, the [C] polymer component and the deprotection reaction product (p), etc. are copolymerized. As a result, the above-mentioned improvement in initial adhesive strength, viscosity adjustment and cure shrinkage Suppression can be performed more effectively. Examples of the polymerization site include a carbon-carbon double bond in the polymer main chain, a polymerizable group in the side chain or terminal of the polymer, and the like.
Examples of the [C] polymer component having a polymerization site include an unhydrogenated product of a conjugated diene copolymer. Among these, SBS is preferable from the viewpoint of having a more appropriate viscosity.

  The lower limit of the content of the [C] polymer component in the composition (I) is preferably 1% by mass, more preferably 5% by mass, further preferably 8% by mass, and particularly preferably 10% by mass. As an upper limit of the said content, 60 mass% is preferable, 45 mass% is more preferable, 35 mass% is further more preferable, 30 mass% is especially preferable. By setting the content to be between the lower limit and the upper limit, it is possible to effectively improve the initial adhesive strength, adjust the viscosity, suppress the curing shrinkage of the adhesive layer, and the like.

[Other ingredients]
The composition (I) may contain, for example, a crosslinkable compound, a plasticizer, an inorganic filler, a colorant, a polymerization inhibitor and the like as other components other than the above-described components [A] to [C]. . These other components may contain 1 type (s) or 2 or more types, respectively.

(Crosslinkable compound)
The crosslinkable compound is a compound having two or more polymerizable groups. By including a crosslinkable compound in the composition (I), the hot strength and the elongation percentage of the adhesive layer can be further increased.

  As a polymeric group which the said crosslinkable compound has, what was illustrated as a polymeric group which the said [B] polymeric compound has, etc. are mentioned, for example. Among these, a (meth) acryloyl group is preferable from the viewpoint that the polymerization rate can be increased and the hot strength can be further increased.

  The number of polymerizable groups possessed by the crosslinkable compound is preferably 2 to 4, more preferably 2 or 3, and even more preferably 2 from the viewpoint of improving the hot strength.

Examples of the crosslinkable compound include:
Chain glycol crosslinkable compounds such as ethylene glycol di (meth) acrylate and triethylene glycol di (meth) acrylate;
Alicyclic glycol-based crosslinkable compounds such as tricyclodecanediyl di (meth) acrylate;
Trimethylolpropane-based crosslinkable compounds such as trimethylolpropane tri (meth) acrylate;
Bisphenol crosslinkable compounds such as bisphenol A bis (polyethylene glycol (meth) acrylate);
Imido isocyanurate crosslinkable compounds such as tri (N-hydroxyethyl) isocyanurate di (meth) acrylate;
Urethane-based crosslinkable compounds such as compounds represented by the following formula (2);
Examples thereof include terminal bismaleimide-modified polyimide crosslinkable compounds such as a compound represented by the following formula (3).

In said formula (2), m is an integer of 1-20.
In said formula (3), n is an integer of 1-20. R ⁴ and R ⁵ are each independently an alkylene group having 1 to 20 carbon atoms. Ar ¹ is an arylene group having 6 to 20 carbon atoms. When n is 2 or more, the plurality of R ⁴ may be the same or different, and the plurality of Ar ¹ may be the same or different.

  The content of the crosslinkable compound in the composition (II) is preferably 0% by mass to 20% by mass, more preferably 0.1% by mass to 15% by mass from the viewpoint of further increasing the hot strength and the elongation rate of the adhesive layer. More preferably, 0.5% by mass to 12% by mass is further preferable, and 2% by mass to 10% by mass is particularly preferable.

  Examples of the plasticizer include phthalic acid esters such as dibutyl phthalate, di (2-ethylhexyl) phthalate, and butyl benzyl phthalate; non-aromatic dibasic acid esters such as dioctyl adipate and dioctyl sebacate; dipropylene glycol dibenzoate; And benzoic acid esters such as triethylene glycol dibenzoate.

  Examples of the inorganic filler include alumina, silica, titanium dioxide, and the like.

  Examples of the colorant include carbon black.

  The metal salt can be contained for adjusting the pot life of the two-component mixed adhesive. Examples of the metal salt include copper (II) bromide, copper (II) chloride, copper (II) 2-ethylhexanoate and the like.

  Examples of the polymerization inhibitor include hydroquinone and hydroquinone monomethyl ether.

<Composition (II)>
Composition (II) contains a [D] compound. The composition (II) preferably contains the [B] polymerizable compound ”and / or the [C] polymer component, and may contain other components, like the composition (I). .
Hereinafter, each component will be described.

[[D] Compound]
The compound [D] is a compound that forms a deprotection reaction product (p) by deprotection reaction with the protecting group of the above-mentioned [A] complex, and this deprotection reaction product (p) can be polymerized. As described above, when the two-component mixed adhesive is used, by mixing the composition (I) and the composition (II), the [D] compound undergoes a deprotection reaction with the protecting group of the [A] complex. As a result, a deprotection reaction product (p) and an organoborane are produced, and the deprotection reaction product (p) is polymerized due to the polymerization initiation ability of the organoborane, whereby the adhesion proceeds.

  Examples of the compound [D] include a compound having a group capable of deprotecting with the protecting group (hereinafter also referred to as “group (a)”) and a polymerizable group.

The group (a) is not particularly limited as long as it can react with the protecting group.
A group having a heteroatom-containing multiple bond such as a carbonyl group, a thiocarbonyl group, a nitroso group, an imino group (—CH═N—), an isocyanate group, an isothiocyanate group, an isocyanide group, or a phosphate group;
A cyclic group containing a hetero atom such as an epoxy group or a cyclic carbonate group;
Examples include an acid halide group, an ester group, an amide group, an acid anhydride group, and a leaving group-containing group such as a carboxy group.
The group (a) includes a vinyl group corresponding to a polymerizable group described later.
Among these, a group having a heteroatom-containing multiple bond is preferable from the viewpoint of easier deprotection reaction and higher curing rate, and higher interaction between groups formed by the deprotection reaction, and adhesion. From the viewpoint of further increasing the strength, hot strength, and dripping suppression, an isocyanate group and an isothiocyanate group are more preferable, and an isocyanate group is further preferable.

As said polymeric group, the group similar to what was illustrated as a polymeric group which the said [B] polymeric compound has, etc. are mentioned, for example.
Among these, a (meth) acryloyl group is preferable from the viewpoints of high polymerizability and a higher curing rate.

[D] The number of groups (a) contained in the compound is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1 from the viewpoint of facilitating the deprotection reaction.
[D] The number of polymerizable groups possessed by the compound is preferably 1 to 3, more preferably 1 or 2, more preferably 1 from the viewpoint of further increasing the polymerization rate of the deprotection reaction product (p) to be formed. preferable.
[D] As the combination of the number of groups (a) and the number of polymerizable groups in the compound, the number of groups (a) is preferably 1 or 2, and the number of polymerizable groups is preferably 1 or 2, and the group (a) And the number of polymerizable groups is preferably 1.

[D] As the compound, for example,
As a compound having an isocyanate group,
Isocyanatoalkyl (meth) acrylates such as isocyanatoethyl (meth) acrylate and isocyanatopropyl (meth) acrylate; (meth) acrylates having an isocyanate group such as an adduct of diisocyanate and hydroxyalkyl (meth) acrylate;
Examples thereof include alkenes having an isocyanate group such as isocyanatobutene, isocyanatopentene, and isocyanatohexene.

In addition, as a compound having an isothiocyanate group,
Isothiocyanatoalkyl (meth) acrylates such as isothiocyanatoethyl (meth) acrylate and isothiocyanatopropyl (meth) acrylate; having an isothiocyanate group such as an adduct of diisothiocyanate and hydroxyalkyl (meth) acrylate ( (Meth) acrylate;
Examples include alkene having an isothiocyanate group such as isothiocyanatobutene, isothiocyanatopentene, isothiocyanatohexene and the like.

  Among these, (meth) acrylate having an isocyanate group, (meth) acrylate having an isothiocyanate group are preferable, (meth) acrylate having an isocyanate group is more preferable, isocyanatoalkyl (meth) acrylate is further preferable, and isocyanate Natoethyl (meth) acrylate is particularly preferred.

  The lower limit of the content of the [D] compound in the composition (II) is preferably 0.2% by mass, more preferably 1% by mass, further preferably 2% by mass, and particularly preferably 2.5% by mass. As an upper limit of the said content, 40 mass% is preferable, 20 mass% is more preferable, 10 mass% is further more preferable, 7 mass% is especially preferable. By setting the content of the [D] compound between the lower limit and the upper limit, the adhesive strength and the curing rate of the two-component mixed adhesive can be further increased.

  [D] As a combination of the group (a) in the compound and the functional group (x) of the compound (a) in the [A] complex, the group (a) is an isocyanate group or an isothiocyanate group, and the group (x) is It is preferably an amino group, more preferably the group (a) is an isocyanate group and the group (x) is an amino group. When the group (a) and the functional group (x) are combined as described above, a urea group is generated by the deprotection reaction, and as a result, the thixotropic property of the two-component mixed adhesive is further increased. This is presumably because, for example, an appropriate hydrogen bond works between the urea groups of the deprotection reaction product (p).

  The lower limit of the molar ratio of the group (a) to the protecting group is preferably 0.5, more preferably 0.7, still more preferably 1, and particularly preferably 1.5. The upper limit of the molar ratio is preferably 6, more preferably 4, more preferably 3, and particularly preferably 2.5. By setting the molar ratio between the lower limit and the upper limit, it is possible to further increase the adhesion rate, the curing rate, the hot strength, and the dripping suppression property of the two-component mixed adhesive.

  When the group (a) is an isocyanate group and the protective group-derived compound is a diamine, the lower limit of the molar ratio of the isocyanate group to the diamine is preferably 1, more preferably 1.3, and even more preferably 1.5 1.7 is particularly preferable. The upper limit of the molar ratio is preferably 3, more preferably 2.7, even more preferably 2.5, and particularly preferably 2.3. By setting the molar ratio between the lower limit and the upper limit, it is possible to further increase the adhesion rate, the curing rate, the hot strength, and the dripping suppression property of the two-component mixed adhesive.

  The lower limit of the thixotropy index (TI) of the two-component mixed adhesive is preferably 3 as a value immediately after mixing the composition (I) and the composition (II), more preferably 5, and further 6 preferable. The upper limit of the TI is preferably 10, more preferably 9, and even more preferably 8. The said 2 liquid mixture type adhesive can exhibit high dripping suppression property by making TI value between the said minimum and the said upper limit. In addition, the said TI value can be calculated | required by preparing what does not contain an [A] complex in composition (I), and measuring this and mixing with composition (II).

[[B] polymerizable compound]
The composition (II) preferably contains [B] a polymerizable compound. [B] The explanation about the polymerizable compound, the preferred one and the content thereof are the same as in the case of the composition (I).

[[C] Polymer component]
The composition (II) preferably contains a [C] polymer component. [C] The explanation, preferred and content of the polymer component are the same as in the case of the composition (I).

[Other ingredients]
The composition (II) may contain other components. About description, preferable thing, and content about another component, it is the same as that of the case of composition (I).

<Method for preparing two-component mixed adhesive>
The two-component mixed adhesive is prepared by, for example, preparing the composition (I) by mixing the [A] complex and, if necessary, the [B] polymerizable compound, the [C] polymer component and other components. Separately, it can be obtained by preparing the composition (II) by mixing the [D] compound and, if necessary, the [B] polymerizable compound, the [C] polymer component and other components.

<How to use a two-component mixed adhesive>
The two-component mixed adhesive can be used by a known method. For example, during the bonding operation, the composition (I) and the composition (II) are mixed, the obtained mixture is applied to one of the adherends, and the other adherend is adhered to the applied mixture. It is possible to perform such as by overlapping. Moreover, after apply | coating the said mixture to both to-be-adhered materials, you may make it closely adhere these applied mixtures. As the adherend, polypropylene (PP), polyethylene (PE), polyphenylene sulfide (PPS), polyamide 6 (PA6), polyamide 66 (PA66) and other resin materials; stainless steel (SUS), hot dip galvanized steel (SGHC) ), Metal materials such as electrodeposited steel (ED), etc., and the same or different materials can be used, and resin materials, metal materials and resin materials-metal materials can be bonded. Can do. The thickness of the adhesive layer formed between the two adherends is usually 0.01 mm to 5 mm, preferably 0.05 mm to 3 mm, and more preferably 0.1 mm to 1 mm.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

<Preparation of two-component mixed adhesive>
[Example 1] (Preparation of two-component mixed adhesive (J-1))
(Preparation of [B] polymerizable compound and [C] polymer component mixed solution)
A 300 mL separable flask equipped with a stirrer was charged with 20 g of SBS and 60 g of tetrahydrofurfuryl methacrylate (THFMA) and stirred in an oil bath at 40 ° C. for 3 hours to completely dissolve SBS in THFMA. Next, 17.5 g of 2-ethylhexyl methacrylate (2EHMA) was added, and the mixture was further stirred and mixed for 1 hour, and then degassed under reduced pressure for 2 hours to prepare a mixed solution (a).
(Preparation of composition (I))
97.5 g of the prepared mixed solution (a) and 2.5 g of triethylborane-diaminopropane complex (TEB-DAP) as the [A] complex were placed in a plastic container and mixed to obtain a composition (I- 1) was prepared.
(Preparation of composition (II))
95.5 g of the prepared mixed solution (a) and 4.5 g of 2-isocyanatoethyl methacrylate (MOI) as the [D] compound were placed in a plastic container and mixed to obtain a composition (II-1). Was prepared.

In addition, the following were used for each component used for preparation.
SBS: “TR2787” from JSR
THFMA: “Light Ester THF” from Kyoeisha Chemical Company
2EHMA: Kyoeisha Chemical Company's “Light Ester EH”
TEB-DAP: “TEB-DAP” from BASF Japan
MOI: “Karenz MOI” from Showa Denko

[Examples 2 to 5] (Preparation of two-component mixed adhesives (J-2) to (J-5))
For the composition (I), the composition (I-1) prepared in Example 1 was directly used as the compositions (I-2) to (I-5).
For the composition (II), the mass of the mixed solution (a) used / the mass of MOI used in the preparation of the composition (II-1) of Example 1 was 6.75 g / 93.25 g, 5. Compositions (II-2) to (II-5) were prepared in the same manner as in Example 1 except that 4g / 94.6g, 3.6g / 96.4g, and 2.25g / 97.75g were used. Prepared.

[Comparative Example 1] (Preparation of two-component mixed adhesive (CJ-1))
For the composition (I), the composition (I-1) prepared in Example 1 was directly used as the composition (IC).
Composition (II) was prepared as follows.
A 300 mL separable flask equipped with a stirrer was charged with 20 g of SBS and 54.75 g of THFMA, and stirred in an oil bath at 40 ° C. for 3 hours to completely dissolve SBS in THFMA. Next, 15 g of 2EHMA, 10 g of mono 2- (methacryloyloxy) ethyl maleate and 0.25 g of p-toluenesulfonyl chloride were added, and the mixture was further stirred for 1 hour and then degassed under reduced pressure for 2 hours. )

<Evaluation>
Using each of the two-component mixed adhesives prepared above, a test piece for measuring adhesive strength was prepared according to the following method, and the adhesive strength (shear strength) was measured and evaluated by the following shear test.

[Test piece preparation method]
Prepare two adherends (each 2.5 cm long × 10 cm wide) and immediately before applying the adhesive, clean the surface with a paper wiper containing acetone (“Kimwipe” from Nippon Paper Crecia). Removed.
Next, the composition (I) and the composition (II) were mixed by a bag mixing method. That is, in a polyethylene bag, the composition (I) and the composition (II) are respectively weighed so as to have a mass ratio of 1: 1, sealed, and mixed uniformly. Mix for 1 minute by rolling.
Next, the corners of the bag were cut with scissors, and the mixed adhesive was uniformly applied to one 1.25 cm square portion of the adherend. In order to make the thickness of the adhesive constant, glass beads having a diameter of 0.25 mm were sandwiched, and the other adherend was stacked on top to prepare a test piece.

[Shear test method]
About the produced test piece, the tensile shear strength of the bonded portion was measured according to JIS-K6850 using a tensile tester (“Autograph AG5000B” manufactured by Shimadzu Corporation). The measurement conditions were as follows: temperature: 23 ° C., distance between chucks: 110 mm, test speed: 5 mm / min.

[Adhesive strength and curing speed]
Table 1 (in the case of PP / PP) and Table 2 (in the case of ED / ED) show the relationship between the curing time and the adhesive strength for the two-component mixed adhesives of Example 1 and Comparative Example 1.

  From the results of Tables 1 and 2, it was shown that the two-component mixed adhesives of the examples were superior in both curing speed and adhesive strength as compared with the comparative examples.

[Type of substrate]
The adhesion between various adherends was evaluated. Adhesive materials include polypropylene (PP), polyethylene (PE), polyphenylene sulfide (PPS), polyamide 6 (PA6) and polyamide 66 (PA66) as resin materials, and stainless steel (SUS) and molten zinc as metal materials. The adhesion strength was measured by using plated steel (SGHC) and electrodeposited steel (ED) in combinations shown in Table 3 below. The measured values of shear strength are shown in Table 3 below.
Moreover, the fracture mode was evaluated visually. The fracture modes indicate A: interface fracture, B: material fracture, B ′: material stretching, and C: cohesive fracture, respectively. “C> A” indicates that the fracture mode is complex, mainly cohesive fracture, and partially interfacial fracture). The subscripts A and B in the failure mode indicate the material in which the failure occurred.

  From the results of Table 3, it is shown that the two-component mixed adhesive of the example can exhibit high adhesive strength to various types of adherends, and the two-component mixed adhesive of the comparative example It was also shown that a high adhesive strength can be obtained even for an adherend having a low adhesive strength in the case of an agent.

[Hot strength]
The hot strength was evaluated by performing a tensile test in a 90 ° C. atmosphere on a test piece cured for 7 days at room temperature (the results of the tensile test performed at room temperature are also shown). As the adherend, two ED plates were used. The evaluation results are shown in Table 4 below. The destruction mode is also shown.

  From the results in Table 4, it was shown that according to the two-component mixed adhesive of the example, the heat resistance of the adhesive layer is higher than that of the comparative example, and the strength reduction during heating can be suppressed.

[Dynamic viscoelasticity]
For the two-component mixed adhesive, the dynamic viscoelasticity of the cured product obtained by curing at room temperature for four days after mixing two components using a dynamic viscoelasticity measuring device (UBE "Rheogel-E4000") The temperature dependence of the storage elastic modulus (E ′) and loss tangent (tan δ) and the glass transition temperature (Tg) were determined. The measurement chart is shown in FIG. 1 ((A) the two-component mixed adhesive (J-1) of Example 1 and (B) the two-component mixed adhesive (CJ-1) of Comparative Example 1). Tg was 76 ° C. in Example 1 and 68 ° C. in Comparative Example 1.
In the two-component mixed adhesives of Examples, the Tg was higher than that of Comparative Examples, and the storage elastic modulus in the viscous region was high, so that an increase in crosslinking density was observed.

[Molar ratio of isocyanate group to amino group]
The evaluation results of the shear strength and fracture mode of the two-component mixed adhesives prepared in Examples 1 to 5 above are the molar ratios of isocyanate groups / diamines (and NCO groups / NH ₂ groups included in the two-component mixed adhesives). Are shown in Table 5 below together with the value of (Molar ratio). “-” In Table 5 indicates that no destruction was observed.

  From the results in Table 5, it can be seen that setting the molar ratio of the isocyanate group to the diamine to be 1 or more and 3 or less is effective for further increasing the adhesive strength.

[Thixotropic index (TI)]
In the preparation of the composition (I) of Example 1 and Comparative Example 1, 1.08 g of 1,3 was added to the mixed solution (a) containing no TEB-DAP complex so as to have the same number of moles as TEB-DAP. -What added diaminopropane (composition (I ')), and composition (I') and each composition (II) (composition (II-1) and (II-C) are mass ratio. The mixed solutions (J′-1) and (CJ′-1) were prepared by mixing 1: 1, and the viscosity of the obtained mixed solution was measured with a viscometer (“RE-85U viscometer” manufactured by Toki Sangyo Co. ) using, as determined by 5rpm and different rotational numbers of 50 rpm, seeking the viscosity (eta ₅ and eta _50), TI values from these measurements (= η ₅ / η ₅₀₎ was calculated. the viscosity of the The measured values and the calculated TI values are shown in Table 6 below.

  From the results of Table 6, it was shown that the two-component mixed adhesives of the examples had higher thixotropic properties than those of the comparative examples. This high thixotropy is caused by the reaction between the isocyanate group and the amino group by mixing the composition (I) and the composition (II) in the two-component mixed adhesive (J-1) of Example 1. It is considered that a urea group is generated as a group generated by the deprotection reaction, and an appropriate hydrogen bond is formed between the urea groups. Due to this high thixotropy, dripping during use of the two-component mixed adhesive is suppressed.

According to the two-component mixed adhesive of the present invention, high adhesive strength and hot strength can be obtained at a high curing rate while suppressing liquid dripping. Therefore, the two-component mixed adhesive can be suitably used for bonding various materials including difficult-to-adhere materials such as automobile outer plates.

Claims (7)

A two-component mixed adhesive comprising a first composition and a second composition,
The first composition contains a complex having a group derived from organoborane and a protecting group thereof,
A two-component mixed adhesive, wherein the second composition contains a compound capable of causing a deprotection reaction with the protecting group and capable of polymerizing the deprotection reaction product.   The two-component mixed adhesive according to claim 1, wherein the protective group of the complex is derived from a compound having two or more functional groups.   The two-component mixed adhesive according to claim 1 or 2, wherein the protective group-derived compound is a diamine.   The two-component mixed adhesive according to claim 1, 2 or 3, wherein the compound in the second composition is a (meth) acrylate having an isocyanate group.   The two-component mixed adhesive according to any one of claims 1 to 4, wherein the first composition, the second composition, or both contain a (meth) acrylate or polymer component having no isocyanate group. .   The two-component mixed adhesive according to claim 4 or 5, wherein the molar ratio of the isocyanate group to the diamine is 1 or more and 3 or less. The two-component mixed adhesive according to any one of claims 1 to 6, wherein the thixotropy index (TI) is 3 or more.

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