JP5976361B2 - Bonding method - Google Patents

Description

  The present invention relates to a bonding method.

  Conventionally, as a method for adhering a member such as a vehicle part, generally, a one-component adhesive composed only of a main agent or a two-component adhesive composed of a main agent and a curing agent is applied to an object to be adhered, A method of bonding objects together to form an adhesive structure is used.

  For example, in Patent Document 1, in adhering an object to be bonded using an adhesive that can be cured only by the main agent and that accelerates the curing by adding the curing agent, only the main agent is bonded to the object to be bonded. First application process for starting application of adhesive, second application process for applying adhesive while adding a curing agent to the main agent after the first application process, and applying only the main agent after the second application process There has been proposed an adhesion method including a third application step of ending application of an adhesive.

JP 2006-274170 A

  However, in the method disclosed in Patent Document 1, when an adhesive structure is formed using an adhesive object after formation of the adhesive, in a short time of about 10 minutes from the formation of the adhesive, There was a problem that the bonded state could not be maintained and the bonded structure could not be moved.

  Further, in recent years, in addition to making the bonded structure movable in a short time, the bonded structure may be heated after several hours have elapsed since the formation of the adhesive. In such a case, depending on the method using a one-pack type adhesive consisting only of the main agent, there is a problem that the bonding state between the bonding objects constituting the bonding structure cannot be maintained during heating.

  The present invention has been made in view of the above circumstances, and can move an adhesive structure obtained by adhering objects to be bonded in a short time, and can maintain the adhesion state between the objects to be bonded even if heated. An object of the present invention is to provide a bonding method capable of achieving the above.

In order to solve such problems, the present inventor diligently studied and completed the following invention. The present invention includes the following (1) to (2).
(1) includes a main agent and a crystallizing agent crystallizable urethane prepolymer and the melting point M, and both ends crystallizing agent and polyether polyol is a carboxyl group having a polyester skeleton, having a polyester skeleton The content of the crystallization agent whose both ends are carboxyl groups is 1% by mass or more and 10% by mass or less based on the total amount of the polyether polyol and the crystallization agent having both ends of the polyester skeleton having carboxyl groups. And a heating step of the main agent and the curing agent, wherein the curing agent is heated to a temperature of (melting point M-10) ° C. or higher,
A mixing step of mixing the main agent and the curing agent;
An adhesive structure forming step of applying the mixed adhesive composition to at least one of a plurality of objects to be bonded, and bonding the objects to be bonded to form an adhesive structure;
An adhesive structure heating step of heating the adhesive structure;
A bonding method comprising the steps of:
(2) The adhesion method according to (1), wherein the melting point M of the crystallization agent contained in the main agent is 50 ° C. or higher and 80 ° C. or lower.

  According to the bonding method of the present invention, the bonded structure can exhibit the initial bonding strength in a short time and can maintain the bonding state between the bonding objects even when heated.

FIG. 1 is a diagram showing the procedure of the bonding method according to the present embodiment.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.

  FIG. 1 is a diagram showing the procedure of the bonding method according to the present embodiment. The adhesion method according to the present embodiment includes a main agent containing a crystallization agent having a melting point M, a crystallization agent having both ends having a polyester skeleton and a polyether polyol, and both ends having the polyester skeleton are Curing in which the content of the crystallization agent which is a carboxyl group is 1% by mass or more and 10% by mass or less based on the total amount of the polyether polyol and the crystallization agent having both ends of the polyester skeleton having a carboxyl group. A main component and a curing agent heating step (step S1) for heating the agent to a temperature of (melting point M-10) ° C. or higher, and a main agent heated to a temperature of (melting point M-10) ° C. or higher. A mixing step (step S2) in which an adhesive composition is obtained by mixing a curing agent, and the mixed adhesive composition is applied to at least one of a plurality of bonding objects, and the bonding objects are bonded together An adhesive structure forming step (step S3) for forming an adhesive structure, an adhesive structure moving step (step S4) for moving the adhesive structure, and an adhesive structure heating step for heating the adhesive structure ( Step S5).

  Next, the adhesive composition used in the bonding method according to this embodiment will be described. The adhesive composition of this embodiment is a two-component mixed type containing a main agent and a curing agent. The two-component mixed adhesive composition can be quickly cured and has excellent heat resistance after curing. As the two-component mixed adhesive composition used in the present embodiment, for example, a urethane-based adhesive composition is preferable in terms of curing speed, hardness after curing, and the like.

<Main agent>
The main agent of this embodiment contains a crystallization agent having a melting point M and a crystallizable polymer. The crystallizable polymer contained in the main agent of the present embodiment is a polymer that cures to a hardness of at least about 20% of the final hardness in about 10 minutes or less after the mixing step (step S2) described later is completed. Means. Curing of the crystallizable polymer is accomplished by crystallization of the polymer upon cooling of the adhesive composition.

[Crystallizable polymer]
Examples of the crystallizable polymer contained in the main agent of the present embodiment include a urethane prepolymer containing a plurality of isocyanate groups in the molecule at the molecular ends. Hereinafter, the isocyanate group-containing urethane prepolymer of the present embodiment is referred to as “urethane prepolymer”. The urethane prepolymer is preferably liquid at room temperature from the viewpoint of handling. In addition, the room temperature in this embodiment is 20 degreeC or more and 30 degrees C or less, Preferably it is the temperature of 25 degreeC vicinity. The method for producing the urethane prepolymer is not particularly limited, and conventionally known methods can be mentioned. The urethane prepolymer is, for example, a reaction product obtained by reacting a polyisocyanate compound and a polyol compound so that isocyanate groups (NCO groups) are excessive with respect to hydroxy groups (OH groups). In general, the urethane prepolymer preferably contains 0.5% by mass or more and 10% by mass or less of NCO groups at the molecular ends. This isocyanate group may be bonded to either an aromatic hydrocarbon or an aliphatic hydrocarbon.

(Polyisocyanate compound)
The polyisocyanate compound contained in the urethane prepolymer is not particularly limited as long as it is used in the production of the urethane prepolymer and has two or more isocyanate groups in the molecule. Examples of the polyisocyanate compound include an aromatic polyisocyanate in which an isocyanate group is bonded to an aromatic hydrocarbon, an aliphatic polyisocyanate in which an isocyanate group is bonded to an aliphatic hydrocarbon, and an isocyanate group having an alicyclic hydrocarbon. And an alicyclic polyisocyanate bonded to the.

  Examples of the aromatic polyisocyanate include toluene such as TDI (for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), or a mixture thereof. Diisocyanate), MDI (e.g., diphenylmethane diisocyanate such as 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), or mixtures thereof), 1 , 4-phenylene diisocyanate, diphenyl diisocyanate, polymethylene polyphenylene polyisocyanate, tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (1,5-NDI), diphenyl ether diisocyanate, trif Such as methane triisocyanate.

  Aliphatic polyisocyanates include propylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), xylylene diisocyanate (XDI), tetramethyl. And xylylene diisocyanate (TMXDI).

Examples of the alicyclic polyisocyanate include cyclohexane diisocyanate, methylene bis (cyclohexyl isocyanate), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanate methyl) cyclohexane (H ₆ XDI), dicyclohexylmethane diisocyanate (H ₁₂ MDI).

  These aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanate carbodiimide-modified polyisocyanates, biuret-modified polyisocyanates, allophanate-modified polyisocyanates, polymethylene polyphenyl polyisocyanates (crude MDI or polymeric MDI), isocyanurates Examples thereof include modified polyisocyanates.

  Such polyisocyanate compounds can be used alone or in combination of two or more. Among these polyisocyanate compounds, TDI and MDI are preferable among the aromatic polyisocyanates, and among the aliphatic polyisocyanates, the viscosity becomes low after the reaction and the handling of the main agent containing the urethane-based prepolymer is easy. Among HDI, XDI and alicyclic polyisocyanate, IPDI is preferred.

(Polyol compound)
The polyol compound contained in the urethane prepolymer is not particularly limited as long as it has two or more hydroxy groups. Examples of the polyol compound include polyoxyalkylene polyols, polyester polyols, polyether polyols, other polyols, and mixed polyols thereof. A natural polyol compound such as castor oil may be used.

  Examples of the polyoxyalkylene polyol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3-butanediol, Polyol obtained by adding at least one selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and polyoxytetramethylene oxide to at least one selected from the group consisting of 1,4-butanediol and pentaerythritol Etc.

  The polyester polyol is, for example, selected from the group consisting of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, 1,1,1-trimethylolpropane, and other low molecular polyols. And at least one selected from the group consisting of glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid, fumaric acid, maleic acid, phthalic acid or other low-molecular carboxylic acids and oligomeric acids And a ring-opening polymer such as propionlactone, valerolactone, and caprolactone; and the like.

  Examples of the polyether polyol include polytetramethylene glycol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3- At least one polyhydric alcohol selected from butanediol, 1,4-butanediol, 4,4′-dihydroxyphenylpropane, 4,4′-dihydroxyphenylmethane, pentaerythritol, etc., and ethylene oxide, propylene oxide, butylene Polyether polyol obtained by adding at least one selected from the group consisting of oxide, styrene oxide and polyoxytetramethylene oxide; polyoxytetramethylene oxide; And the like. Specific examples of the polyether polyol include polyoxypropylene glycol, polytetramethylene ether glycol, polyethylene glycol, polyoxypropylene triol and the like.

  Other polyols include, for example, polymer polyols; polycarbonate polyols; polybutadiene polyols; hydrogenated polybutadiene polyols; acrylic polyols, etc .; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, hexanediol, etc. And low molecular weight polyols.

  Such polyol compounds can be used alone or in combination of two or more.

  The amount of the polyisocyanate compound and the polyol compound in producing the urethane prepolymer is such that the equivalent ratio of isocyanate group to hydroxyl group (isocyanate group (NCO group) / hydrosyl group (OH group)) is 1.2 or more. 0.5 or less is preferable, and 1.5 or more and 2.0 or less is more preferable. When the equivalence ratio is within such a range, the viscosity of the obtained urethane prepolymer becomes appropriate, and the remaining amount of the unreacted polyisocyanate compound in the urethane prepolymer can be reduced.

  The production method of the urethane prepolymer is not particularly limited. For example, the urethane prepolymer is produced by heating and stirring the polyisocyanate compound and the polyol compound having the above-described equivalent ratio (NCO group / OH group) at 50 ° C. or higher and 130 ° C. or lower. Can do. Moreover, if necessary, for example, a urethanization catalyst such as an organic tin compound, organic bismuth, or amine can be used.

  A urethane prepolymer can be used individually or in combination of 2 types or more, respectively.

[Crystallizing agent]
Examples of the crystallization agent having a melting point M contained in the main agent of the present embodiment include a polyester compound having an isocyanate group.

  The polyester compound having an isocyanate group has a number average molecular weight of 1000 or more and 20000 or less and an average functionality (number of isocyanate groups held per molecule of prepolymer) of 1.6 or more and 3.0 or less. Can be used. The polyester compound having an isocyanate group can be obtained, for example, by reacting a polyester polyol with a compound having an isocyanate group.

  The polyester polyol is, for example, selected from the group consisting of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, 1,1,1-trimethylolpropane, and other low molecular polyols. And at least one selected from the group consisting of glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid or other low molecular carboxylic acids and oligomeric acids. A ring-opening polymer such as propionlactone, valerolactone, and caprolactone; and the like.

  As the compound having an isocyanate group, conventionally known polyisocyanates used for the synthesis of urethane-based prepolymers and the like can be used. Specifically, for example, paraphenylene diisocyanate, tolylene diisocyanate (TDI), tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), octadecyl diisocyanate, naphthalene diisocyanate (NDI), 4,4'- Examples thereof include diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), p-MDI, triphenylmethane triisocyanate, and modified products thereof. Such polyisocyanate compounds may be used alone or in combination of two or more.

  Specific examples of the polyester compound having an isocyanate group include a compound in which hexamethylene diisocyanate (HDI) is bonded to the terminal of a polyester polyol produced from sebacic acid and 1,6-hexanediol.

  The melting point M of the crystallization agent contained in the main agent of the present embodiment is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 55 ° C. or higher and 70 ° C. or lower. When the melting point M of the crystallization agent is 50 ° C. or higher, the curability in summer is good, and when it is 80 ° C. or lower, it is advantageous in terms of energy cost, and thermal deterioration of the main agent can be suppressed.

  The main agent of this embodiment can contain carbon black, calcium carbonate, a catalyst, a plasticizer, clay, etc. in addition to the crystallizable polymer and the crystallization agent having a melting point M. Carbon black, calcium carbonate, catalyst, plasticizer, clay and the like are not particularly limited, and commercially available products can be used.

  Examples of the carbon black include N110, N220, N330, N550, N770, and the like, or a mixture thereof according to the American Society for Testing Materials standard. The content of carbon black is preferably 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the crystallizable polymer.

 Examples of calcium carbonate include heavy calcium carbonate, precipitated calcium carbonate (light calcium carbonate), colloidal calcium carbonate, and the like. Moreover, the surface treatment calcium carbonate surface-treated with a fatty acid, a resin acid, a fatty acid ester, a higher alcohol addition isocyanate compound, etc. can also be used. These may be used alone or in combination of two or more.

  As the catalyst, a curing catalyst such as a tertiary amine or an organic tin compound, or a mixture thereof can be used. As the catalyst, specifically, for example, a mixture composed of dioctyltin dilaurate (Neostan U-810, manufactured by Nitto Kasei Co., Ltd.) and bis (2-dimethylaminoethyl) ether (BL-19, manufactured by Air Products Japan Co., Ltd.) is used. Can be mentioned. These may be used alone or in combination of two or more.

  Examples of the plasticizer include phthalate ester plasticizers, fumarate ester plasticizers, sulfonate ester plasticizers, citrate ester plasticizers, adipate ester plasticizers, and benzoate ester plasticizers. Can be mentioned. These may be used alone or in combination of two or more.

  Examples of the clay include wax stone clay, kaolin clay, and fired clay. These may be used alone or in combination of two or more.

<Curing agent>
The hardening | curing agent of this embodiment contains the crystallizing agent and polyether polyol which have both ends which have a polyester frame | skeleton, and a carboxyl group.

(Polyether polyol)
Examples of the polyether polyol contained in the curing agent of the present embodiment include polytetramethylene glycol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2, At least one of polyhydric alcohols selected from 5-hexanetriol, 1,3-butanediol, 1,4-butanediol, 4,4′-dihydroxyphenylpropane, 4,4′-dihydroxyphenylmethane, pentaerythritol and the like Polyether polyol obtained by adding at least one selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, styrene oxide and polyoxytetramethylene oxide to the seed; Shi tetramethylene oxide and the like. Specific examples of the polyether polyol include polyoxypropylene glycol, polytetramethylene ether glycol, polyethylene glycol, polyoxypropylene triol and the like.

  These polyether polyols may be used alone or in combination of two or more. In any case, it is preferable to use a polyether polyol having a weight average molecular weight of 400 or more and 5000 or less, particularly 1000 or more and 4000 or less because well-balanced physical properties can be obtained.

  The average functionality of the polyether polyol (the number of active hydrogens that can be reacted with isocyanate groups per molecule) is preferably 1.5 or more and 4.5 or less. By making the average functionality within the above range, it can sufficiently react with the isocyanate group. When the average functionality is less than 1.5, it cannot react sufficiently with the isocyanate group, and thus is not preferable. On the other hand, if the average functionality exceeds 4.5, the toughness and elongation of the cured product decrease, which is not preferable.

(Crystallization agent)
The crystallizing agent contained in the curing agent of the present embodiment is a polyester compound having a polyester skeleton and both ends are carboxyl groups.

  As a polyester compound, polyester polyol etc. are mentioned, for example. Specific examples of the polyester polyol include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, 1,1,1-trimethylolpropane, and other low molecular weight polyols. At least one selected from the group consisting of: at least one selected from the group consisting of glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid or other low molecular carboxylic acids and oligomeric acids Condensation polymers with seeds; ring-opening polymers such as propionlactone, valerolactone, caprolactone; and the like. Such polyester compounds may be used alone or in combination of two or more.

  Specific examples of the polyester compound having both ends of the polyester skeleton having a carboxyl group include compounds having a polyester skeleton formed from sebacic acid and 1,6-hexanediol and having both ends being a carboxyl group. .

  The content of the crystallization agent is preferably 1% by mass or more and 10% by mass or less with respect to the total amount of the polyether polyol and the crystallization agent having both ends of the polyester skeleton having a carboxyl group. When the content of the crystallization agent is within the above range, the bonded structure according to the bonding method of the present embodiment can express the initial bonding strength in an extremely short time (around 5 minutes), and can be bonded even when heated. The adhesion state between each other can be maintained.

  The melting point M of the crystallization agent contained in the curing agent of the present embodiment is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 55 ° C. or higher and 70 ° C. or lower. When the melting point M of the crystallization agent is 50 ° C. or higher, curability in summer is good, and when it is 80 ° C. or lower, it is advantageous in terms of energy cost.

  The curing agent of the present embodiment can contain calcium carbonate, a catalyst, and the like in addition to the polyether polyol and the crystallization agent having both ends having a polyester skeleton are carboxyl groups. Calcium carbonate and catalyst are not particularly limited, and commercially available products can be used.

  Examples of calcium carbonate include heavy calcium carbonate, precipitated calcium carbonate (light calcium carbonate, colloidal calcium carbonate) and the like. Moreover, the surface treatment calcium carbonate surface-treated with a fatty acid, a resin acid, a fatty acid ester, a higher alcohol addition isocyanate compound, etc. can also be used. These may be used alone or in combination of two or more.

  As the catalyst, an organic metal compound, a curing catalyst such as amines, or a mixture thereof can be used. These may be used alone or in combination of two or more.

  The amount of the curing agent is preferably mixed so that the number of active hydrogen groups is 70% or more and 100% or less with respect to the number of isocyanate groups of the main agent (including polyester resins having isocyanate groups). By setting the number of active hydrogen groups relative to the isocyanate group within the above range, a cured product having excellent adhesiveness can be obtained.

  Moreover, the adhesive composition of this embodiment can contain various additives as needed in addition to the above-described components as long as the object of the present invention is not impaired. Examples of the additive include a filler, a curing accelerating catalyst, an antiaging agent, an adhesiveness imparting agent, a storage stability improving agent (dehydrating agent), a colorant, and a solvent. Each additive can be used in combination as appropriate.

  The method for producing the main agent and the curing agent of the adhesive composition of the present embodiment is not particularly limited. For example, each of the above components is agitated by a roll, a kneader, an extruder, a universal agitator, a static mixer, a mixing mixer, and the like. And kneading sufficiently using, and mixing by uniformly dispersing.

  Thus, the adhesive composition used in the bonding method of the present embodiment includes a main agent containing a crystallization agent having a melting point M, a crystallization agent having a polyester skeleton and carboxyl groups at both ends, and a polyether polyol. It is a two-component mixed adhesive composition characterized by heating the containing curing agent to a temperature of (melting point M-10) ° C. or higher.

  The adhesive composition used in the bonding method of the present embodiment includes a predetermined amount of a crystallization agent in the main agent and the curing agent, so that an extremely short time (5 minutes) after the completion of the adhesion structure forming step (step S3) described later. Before and after, that is, before the start of the bonded structure moving step (step S4) described later, the adhesive composition can be cured to such a strength that the bonded shape of the bonded structure can be maintained during movement. In this curing, the main agent and the curing agent in the adhesive composition are crystallized by cooling the adhesive composition containing the crystallization agent heated to a temperature of (melting point M-10) ° C. or higher. Thus, the initial adhesive strength is expressed, and the bonded structure can be moved in a very short time after the bonded structure forming step (step S3) is completed.

  Next, the bonding method according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, a heating step (step S1) of a curing agent containing a main agent containing a crystallizing agent having a melting point M and a crystallizing agent having a polyester skeleton with both ends being carboxyl groups is a crystallization of the melting point M. A crystallizing agent comprising a main component containing a crystallizable polymer, a crystallization agent having a polyester skeleton having both carboxyl groups and a polyether polyol, and having both polyester terminals having a carboxyl group A curing agent having a content of 1 to 10% by mass with respect to the total amount of the polyether polyol and the crystallization agent having both ends of the polyester skeleton having a carboxyl group (melting point M -10) A step of heating to a temperature of not lower than ° C.

  The crystallizable polymer contained in the main agent of the present embodiment is a polymer that cures to a hardness of at least about 20% of the final hardness in about 10 minutes or less after the mixing step (step S2) described later is completed. Means. Curing of the polymer is achieved by crystallization of the polymer by cooling of the adhesive composition.

  In the heating step (step S1) of the main agent containing the crystallization agent and the hardening agent containing the crystallization agent having both ends of the polyester skeleton having a carboxyl group, the crystallization agent is included in the main agent and the hardening agent described above. Warm the food. The method for mixing the crystallization agent into the main agent and the curing agent is not particularly limited. For example, it can mix using a static mixer etc.

  After the crystallization agent is mixed with the main agent and the curing agent, the main agent and the curing agent including the crystallization agent are heated. The heating condition is set to a temperature that is 10 ° C. lower than the melting point M of the crystallization agent. Thereby, a crystallizing agent dissolves. In consideration of sufficiently dissolving the crystallization agent, the heating condition is preferably 5 ° C. lower than the melting point M of the crystallization agent. In addition, the upper limit value of the heating condition is not theoretically limited, but it is preferable to set the temperature as low as possible in consideration of work efficiency.

  In this embodiment, by including a crystallization agent in the main agent and the curing agent, in a very short time after the adhesion structure forming process (step S3) described later, that is, an adhesion structure moving process (step S4) described later. ), The adhesive composition can be cured to such a strength that the bonded shape of the bonded structure can be maintained during movement. As described above, this curing is achieved by crystallization of the main agent and the curing agent in the adhesive composition by cooling the adhesive composition containing the heated crystallization agent. Thereby, after completion | finish of an adhesion structure formation process (step S3), an adhesion structure can be moved in a very short time (around 5 minutes). After heating the main agent and the curing agent including the crystallization agent, the process proceeds to the mixing step (step S2).

  In the present embodiment, a case has been described in which a crystallization agent is mixed in both the main agent and the curing agent, and both the main agent and the curing agent are heated. However, the present embodiment is not limited to this. Alternatively, the crystallization agent may be mixed and heated only in the main agent, or the crystallization agent may be mixed and heated only in the curing agent. Moreover, you may heat the main agent which does not mix | blend a crystallizing agent, and the hardening | curing agent which does not mix | blend a crystallizing agent.

  The mixing step (step S2) is a step of forming an adhesive composition by mixing the main agent and the curing agent using the heated main agent and the curing agent. The mixing method of the main agent and the curing agent is not particularly limited. For example, it can mix using a static mixer etc. When the main agent and the curing agent are mixed, the process proceeds to the bonded structure forming step (step S3).

  The bonded structure forming step (step S3) is a step of applying the mixed adhesive composition to at least one of a plurality of bonded objects and bonding the bonded objects to form an bonded structure. The objects to be bonded in the present embodiment are mainly vehicle parts, and examples thereof include plastic parts, FRP (fiber reinforced resin), metal, and a coated surface. Step S3 can be started within a period of 5 seconds to 30 minutes after the end of the mixing step (step S2). The method for applying the adhesive composition to the bonding object and bonding the bonding object is not particularly limited. For example, a method of applying the adhesive composition to the object to be bonded with a brush or the like, or a method of applying with an gun can be appropriately selected, and the object to be bonded can be bonded. If the adhesion target object is bonded to form the adhesion structure, the process proceeds to the adhesion structure moving step (step S4).

  The bonded structure moving step (step S4) is a step of moving the bonded structure. Step S4 can be performed after the lapse of time since the adhesive composition is cured to a hardness of at least 20% of the final hardness as described above after the lapse of 2 minutes or more after the mixing step (Step S2). . The bonded structure is moved in a room temperature atmosphere. In moving the bonded structure, at least one of the bonding objects constituting the bonded structure is gripped by the transport device and moved to a predetermined location.

  As a result, even if the bonded structure is moved in a room temperature atmosphere in a short time, the bonding objects constituting the bonded structure are not shifted from each other, and the bonded structure is maintained in the same shape as at the time of bonding. Can do. In this embodiment, the adhesive composition is cured to a hardness of at least 20% of the final hardness when the bonded structure is moved. There is no need to prevent positional displacement between objects. When the bonded structure is moved, the process proceeds to the bonded structure heating step (step S5).

  The bonded structure heating step (step S5) is a step of heating the bonded structure. Step S5 can be performed after the lapse of time since the adhesive composition is further cured by the crosslinking reaction between the main agent and the curing agent as described above after the lapse of 1 hour or more after the mixing step (Step S2). The bonded structure is heated in a high temperature atmosphere. In heating the bonded structure, the bonded structure is placed in a heating furnace. The heating temperature is preferably 40 ° C. or higher and 100 ° C. or lower, and more preferably 40 ° C. or higher and 80 ° C. or lower. When the heating temperature exceeds the above range, foaming occurs in the bonded portion, which is not preferable. If the heating temperature is below the above range, sufficient adhesive strength cannot be obtained. The heating time is preferably 10 minutes to 30 minutes. When the heating time is shorter than the above range, sufficient adhesive strength cannot be obtained when the heating time is taken out from the heating furnace.

  In the past, the adhesive composition was cured in a separate curing furnace before heating the bonded structure, but according to the bonding method of the present embodiment, the adhesive composition is only cured. Workability can be improved without separately preparing a curing furnace to be used. Further, in the present embodiment, since the adhesive composition is cured when the bonded structure is heated, it is not necessary to temporarily fix the bonded objects in advance to prevent the positional shift between the bonded objects.

  As described above, according to the bonding method of the present embodiment, the bonded structure obtained by bonding the objects to be bonded develops the initial bonding strength in a short time. Therefore, the bonding structure can be bonded in a very short time after the bonded structure is formed. The structure can be moved, and the bonded state can be maintained even when the bonded structure is heated.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these.

<Preparation of main agent and curing agent>
The components shown in Table 1 below were blended in the mass ratio (parts by mass) shown in Table 1, and these were sufficiently mixed in a vacuum using an electric stirrer or the like to obtain a main agent and a curing agent. The amount of each component in Table 1 is the amount when each urethane prepolymer is 100 parts by mass.

<Preparation of adhesive structure>
A plurality of 100 mm × 100 mm × 5 mm plastic plates were prepared and used as bonding objects. The main agents and curing agents of Examples 1 to 3 and Comparative Examples 1 to 3 shown in Table 1 were heated at 63 ° C. and sufficiently mixed using an electric stirrer or the like to obtain an adhesive composition. Each adhesive composition was applied to one side of the plastic plate at room temperature in a triangular shape having a width of 8 mm and a height of 12 mm on four sides of the plastic plate. Within 5 minutes after the formation of the adhesive composition, the two plastic plates are bonded together, and both the plastic plates are pressed until the thickness of the adhesive composition reaches 5 mm, thereby producing an adhesive structure in each example and each comparative example. did.

<Evaluation>
After bonding two plastic plates together using the adhesive composition to form an adhesive structure, the adhesiveness of each adhesive structure after a predetermined time was evaluated as follows. The evaluation results are shown in Table 1. Evaluation 1 is for evaluating crystallinity, Evaluation 2 is for evaluating curability and foamability, and Evaluation 3 is workability (re-bonding: is it possible to correct when deviation occurs? ).
[Evaluation 1 (Crystallinity): 10 minutes after the formation of the adhesive composition]
10 g after the formation of the adhesive composition applied before bonding the two plastic plates, 50 g / cm in the direction in which the two objects to be bonded are separated from the bonded structures of the examples and comparative examples. A load per length of the adhesive composition was applied, and the distance (displacement) between the two plastic plates was measured. In Table 1, “◯” and “x” indicate the following states, respectively.
○: When the displacement is less than 0.1 mm ×: When the displacement is 0.1 mm or more

[Evaluation 2 (Curability and Foaming): Heating Test after 2 Hours from Formation of Adhesive Composition]
Two hours after the formation of the adhesive composition applied before bonding the two plastic plates, the adhesive structures of the examples and comparative examples were placed in a heating furnace and heated and cured in an 80 ° C. atmosphere for 30 minutes. It was. At that time, a load of 50 g / cm ² was applied in the direction in which the two objects to be bonded were separated in the heating furnace, and the distance (displacement) at which the two plastic plates were separated was measured. In Table 1, “◯” and “x” indicate the following states, respectively.
◯: When the displacement is less than 0.1 mm ×: When the displacement is 0.1 mm or more [Evaluation 3 (workability): Test whether it can be reattached after 3 minutes from the formation of the bonded structure]
Three minutes after the two plastic plates are bonded to form the bonded structure, the two bonded objects are peeled off from the bonded structures of the examples and the comparative examples, and then bonded again. After that, a load per length of the adhesive composition of 50 g / cm was applied in the direction in which the two objects to be bonded were separated, and the distance (displacement amount) at which the two plastic plates were separated was measured. In Table 1, “◯” and “x” indicate the following states, respectively.
◯: When the displacement amount is less than 0.1 mm ×: When the displacement amount is 0.1 mm or more, or the adhesive composition is hard and cannot be peeled off, or cannot be bonded again.

Each component shown in Table 1 is as follows.
-Urethane polymer: Polypropylene glycol and 4,4'-diphenylmethane diisocyanate (MDI), a prepolymer having an NCO group at the end-Carbon black: Product name "Niteron N330", manufactured by Nippon Nihon Carbon Co., Ltd. Calcium carbonate used as the main agent: Trade name “Super S”, manufactured by Maruo Calcium Co., Ltd. ・ Catalyst used as the main agent: Dioctyltin dilaurate (U-810, manufactured by Nitto Kasei), bis (2-dimethylaminoethyl) ether (BL -19, manufactured by Air Products Japan Co., Ltd.)-Crystallizing agent used as the main agent: Compound obtained by binding hexamethylene diisocyanate (HDI) to the end of a polyester polyol formed from sebacic acid and 1,6-hexanediol, melting point M = 58 ° C
-Crystallizer-containing polyether polyol used as a curing agent: Mixture in which a compound having a polyester skeleton formed from sebacic acid and 1,6-hexanediol and having both carboxyl groups is dissolved in polyether polyol-Curing agent Calcium carbonate used for product: Trade name “Super S”, manufactured by Maruo Calcium Co., Ltd. ・ Catalyst used for curing agent: Triethylenediamine, product name “DABCO”, manufactured by Air Products

  As is apparent from Table 1, a predetermined amount of a crystallization agent is mixed with the main agent and the curing agent, and the mixture is heated to a predetermined temperature, and then the adhesive composition formed by mixing the heated main agent and the curing agent. For the adhesion methods of Examples 1 to 3 used, the distance (displacement amount) between the two plastic plates is less than 0.1 mm and “◯” for any of the evaluations 1 to 3, and adhesion and crystallization As a result, it was confirmed that it has excellent properties, curability, foamability and workability. That is, it is possible to reattach after 3 minutes from the formation of the adhesive structure, good adhesion after 10 minutes from the formation of the adhesive composition, and heating after 2 hours from the formation of the adhesive composition. It was confirmed that the adhesion was good even when

  On the other hand, about the adhesion method of the comparative example 1 which does not contain a crystallizing agent in a hardening | curing agent, the comparative example 2 which contains a crystallizing agent more than predetermined amount, and the comparative example 3 which uses only a main ingredient and does not contain a hardening | curing agent, evaluation 1 For at least one of the three, the distance (displacement) between the two plastic plates is 0.1 mm or more and “×”, and it is confirmed that the adhesiveness and crystallinity / curability / foamability / workability are poor. It was done.

  Therefore, according to the bonding method of the present embodiment, since the bonding structure obtained by bonding the bonding target object exhibits the bonding strength in a short time, the bonding structure can be moved in a very short time after the bonding structure is formed. It has been found that the adhesive state can be maintained even when the adhesive structure is heated. Therefore, the bonding method of this embodiment can be suitably used for bonding vehicle parts and the like.

Claims (2)

Includes a main agent and a crystallizing agent crystallizable urethane prepolymer and the melting point M, and both ends crystallizing agent and polyether polyol is a carboxyl group having a polyester skeleton, both terminals having a polyester backbone Curing in which the content of the crystallization agent which is a carboxyl group is 1% by mass or more and 10% by mass or less based on the total amount of the polyether polyol and the crystallization agent having both ends of the polyester skeleton having a carboxyl group. A heating step of the main agent and the curing agent, wherein the agent is heated to a temperature of (melting point M-10) ° C. or higher,
A mixing step of mixing the main agent and the curing agent;
An adhesive structure forming step of applying the mixed adhesive composition to at least one of a plurality of objects to be bonded, and bonding the objects to be bonded to form an adhesive structure;
An adhesive structure heating step of heating the adhesive structure;
A bonding method comprising the steps of:   The adhesion method according to claim 1, wherein the melting point M of the crystallization agent contained in the main agent is 50 ° C. or higher and 80 ° C. or lower.

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