JP2012111898A - Bonding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding method enabling short-time movement of a bonded structure, and heating of the bonded structure.SOLUTION: This method includes: a warming step in which at least either of a main agent containing a crystallizable polymer and a curing agent is allowed to contain a crystallizing agent having a melting point of M, and at least either of the main agent and the curing agent is warmed up to a temperature of ≥(melting point M-10)°C; a mixing step in which the main agent and the curing agent are mixed together; a bonded structure forming step in which an adhesive is applied onto at least one of a plurality of adhesion objects, and a bonded structure is formed by laminating the adhesion objects; and a bonded structure heating step in which the bonded structure is heated.

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. It is an object of the present invention to provide a bonding method that enables 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 (4).
(1) Crystallization in which at least one of the main agent and the curing agent contains a crystallization agent having a melting point M, and at least one of the main agent and the curing agent is heated to a temperature of (melting point M-10) ° C. or higher. A heating step of the main agent and the curing agent containing the agent,
A mixing step of mixing the main agent and the curing agent;
An adhesive structure forming step of applying the adhesive 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 adhesion structure heating step of heating the adhesion structure.
(2) The bonding method according to (1), wherein the crystallization agent has a melting point M of 50 ° C. or higher and 80 ° C. or lower.
(3) The adhesion method according to (1) or (2), wherein a compound having at least one of a hydroxy group, an imino group, and an amino group is contained as the curing agent.
(4) The bonding method according to any one of (1) to (3), wherein a polyester resin having an isocyanate group is contained as the crystallization agent.

  The bonding method of the present invention has an effect that the bonding 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 of the present embodiment.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following description. The constituent elements in the following description 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 configurations disclosed below can be combined as appropriate.

  FIG. 1 is a diagram showing the procedure of the bonding method of the present embodiment. In the bonding method of the present embodiment, a crystallization agent having a melting point M is contained in a main agent containing a crystallizable polymer, and the main agent containing the crystallization agent is heated to a temperature of (melting point M-10) ° C. or higher. A heating step (step S1) of the main agent containing a crystallization agent to be heated, and a mixing step (step S2) in which the main agent heated to a temperature of (melting point M-10) ° C. or higher is mixed to obtain a mixture (step S2) An adhesive structure forming step (step S3) of applying the adhesive to at least one of a plurality of objects to be bonded, and bonding the objects to be bonded to form an adhesive structure, and moving the adhesive structure An adhesion structure moving process (step S4) and an adhesion structure heating process (step S5) for heating the adhesion structure are included.

  In the heating step of the main agent containing the crystallization agent (step S1), a crystallization agent having a melting point M is added to the main agent containing a crystallizable polymer, and the main agent containing the crystallization agent is added (melting point M). -10) A step of heating to a temperature of not lower than ° C.

  The crystallizable polymer means a polymer that hardens to a hardness of at least about 20% of the final hardness in 10 minutes or less after completion of the mixing step (step S2) described later. Curing of the polymer is achieved by crystallizing the polymer by cooling the adhesive.

  Examples of the crystallization agent include polyester resins having an isocyanate group.

  The polyester resin 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 resin having an isocyanate group can be obtained by reacting a polyester polyol with a compound having an isocyanate group.

  As the compound having an isocyanate group, conventionally known polyisocyanates used for the synthesis of urethane resins and the like can be used. Specifically, paraphenylene diisocyanate, tolylene diisocyanate (TDI), tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), octadecyl diisocyanate, naphthalene diisocyanate (NDI), 4,4'-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.

  The main agent can contain carbon black, a catalyst, a plasticizer, calcium carbonate, clay and the like in addition to the crystallizable polymer. 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. As the catalyst, a curing catalyst such as a tertiary amine or an organic tin compound, or a mixture thereof can be used.

  As a hardening | curing agent, the compound which has an active hydrogen group which can react with an isocyanate group, or those mixtures are mentioned, for example. Examples of the active hydrogen group that can react with the isocyanate group include a hydroxy group, an imino group, and an amino group. Examples of the compound having these active hydrogen groups include a polyol, an amine compound, and water.

  Examples of the polyol include polyether polyol, polyester polyol, and polymer polyol. Examples of the polyether polyol include polyether polyols such as polypropylene polyol (PPG) and polyethylene polyol (PEG). As the polyester polyol, a condensate of an alcohol exemplified in the above polyether polyol and a polybasic carboxylic acid such as adipic acid, fumaric acid, maleic acid, phthalic acid; castor oil, reaction product of castor oil and ethylene glycol A condensate of a hydroxycarboxylic acid such as a product with the polyhydric alcohol; a polymer of a lactone obtained by ring-opening polymerization of caprolactone, valerolactone, or the like with an appropriate polymerization initiator.

  Examples of the polymer polyol include those obtained by graft polymerization of an ethylenically unsaturated compound such as acrylonitrile, styrene, or methyl (meth) acrylate on the polyether polyol or polyester polyol.

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

  Examples of the amine compound include aliphatic amine compounds and alicyclic amine compounds. The aliphatic amine compound is not particularly limited as long as it is an aliphatic amine compound having at least one amino group or imino group. Specifically, for example, n-propylamine, n-butylamine, s-butylamine, tert-butylamine, polyoxypropyleneamine, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, dimethylaminopropylamine, 2-diethylaminoethylamine, 3-diethylaminopropylamine, 2-butyl-2-ethylpentane-1,5-diamine, 3- (2-aminoethyl) aminopropylamine, 3-amino-1-methylaminopropane, 3- Aminopropanol, 4,7-dioxadecane-1,10-diamine, 4,9-dioxadecane-1,12-diamine, dipropylenetriamine, 2-ethylhexylamine, n-hexylamine, 2-methoxyethylamine, 3-methoxypropyl Amine, 3 Methylaminopropylamine, neopentanediamine, n-octylamine, tridecylamine, 4,7,10-trioxatridecane-1,13-diamine, 2,2,4-trimethylhexamethylenediamine, 1,6- Hexamethylenediamine, 1,12-dodecanediamine, 1,10-decanediamine, 1,8-octanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, etc. An aliphatic ring compound such as xylylenediamine; and a modified product thereof.

  The alicyclic amine compound is not particularly limited as long as it is an alicyclic amine compound having at least one amino group or imino group. Specifically, for example, cyclohexylamine, 3-amino-1-cyclohexylaminopropane, 4,4′-diaminodicyclohexylmethane, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, cyclohexylaminopropylamine, 1,3-bis (aminomethyl) cyclohexane, 2,5 (2,6) -bis (aminomethyl) bicyclo [2.2.1] heptane, aminocaprolactam, 1,3-bisaminomethylcyclohexane (1,3 -BAC), norbornane diamine (NBDA), alicyclic amine compounds such as isophorone diamine (IPDA); and modified products thereof.

  The average functionality of the compound having an active hydrogen group (the number of active hydrogens that can be reacted with an isocyanate group 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.

  As a hardening | curing agent, it is preferable to mix so that the number of active hydrogen groups may be 70 to 100% with respect to the number of isocyanate groups of a main ingredient (including the polyester resin which has an isocyanate group). By setting the number of active hydrogen groups with respect to the isocyanate group within the above range, it is possible to obtain a cured product having excellent adhesion and no tack remaining.

  The crystallizing agent is preferably a compound having a melting point M of 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 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.

  In the step of heating the main agent containing the crystallization agent (step S1), the above-mentioned main agent containing the crystallization agent is heated. The method for mixing the crystallization agent into the main agent is not particularly limited. For example, it can mix using a static mixer.

  After mixing the crystallization agent with the main agent, the main agent containing the crystallization agent is 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 the present embodiment, by using a crystallization agent, a short time after the adhesion structure forming step (step S3) described later (step S3), that is, before the start of the adhesion structure moving step (step S4) described later, The adhesive 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 the main agent in the adhesive crystallizing by cooling the adhesive 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 short time. After warming the main ingredient containing a crystallization agent, it progresses to a mixing process (step S2).

  In this embodiment, the case where the crystallization agent is mixed with only the main agent and heated is described, but this embodiment is not limited to this, and the crystallization agent is mixed and added to the curing agent. It may be warmed, or both the main agent and the curing agent may be heated by mixing a crystallization agent in both the main agent and 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 the adhesive by mixing the main agent and the curing agent using the heated main 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. 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 adhesive to at least one of a plurality of bonded objects and bonding the bonded objects to form an bonded structure. The adhesion target object in the present embodiment is mainly a vehicle part, and examples thereof include a plastic part, FRP (fiber reinforced resin), metal, and the like. 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 to the bonding object and bonding the bonding object is not particularly limited. For example, it is possible to appropriately select a method of applying an adhesive to a bonding target with a brush or the like, or a method of applying with a gun, and bond the bonding target. 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 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 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 misalignment. 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 is further cured by the cross-linking 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 conditions may be 5 minutes or more and 90 minutes or less, and 100 ° C or more and 200 ° C or less.

  In the past, the adhesive was cured in another curing furnace before heating the bonded structure. However, according to the bonding method of this embodiment, a curing furnace used only for curing the adhesive is used. Workability can be improved without preparing separately. Further, in the present embodiment, since the adhesive is cured at the time of heating the bonded structure, it is not necessary to temporarily fix the bonding objects in advance to prevent the positional deviation between the bonding objects.

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

<Formation of adhesive structure>
A plurality of 100 mm × 100 mm × 5 mm plastic plates were prepared and used as bonding objects. When these plastic plates were bonded two by two, a main agent and a curing agent containing the components shown in Table 1 were prepared.

  Table 1 shows each component of the main agent and the curing agent and the blending amount thereof. The amount of each component in Table 1 is the amount when each urethane prepolymer is 100 parts by mass. In Table 1, the main catalyst or the like consists of dioctyl dilaurate (U-810, manufactured by Nitto Kasei Co., Ltd.) and bis (dimethylaminoethyl) ether (BL19, manufactured by Air Products). The crystallizing agent is a compound in which hexamethylene diisocyanate (HDI) is bonded to the terminal of a polyester polyol formed from sebacic acid and 1,6 hexanediol. The melting point of the crystallization agent is indicated by the symbol M. The amount of the curing agent in Table 1 is the total amount of polypropylene diol, polypropylene glycol, calcium carbonate, and catalyst.

Each component shown in Table 1 below 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.-Calcium carbonate used as curing agent: Trade name "Super S", manufactured by Maruo Calcium Co., Ltd.-Catalyst used as curing agent: Triethylenediamine product name : "DABCO", manufactured by Air Products

  The main agents and curing agents of Example 1 and Comparative Examples 1 to 3 shown in Table 1 were heated at 63 ° C. and mixed. Each adhesive 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. The two plastic plates were bonded together within 5 minutes after the formation of the adhesive, and both the plastic plates were pressed until the thickness of the adhesive reached 5 mm, thereby producing an adhesive structure in each example.

<Evaluation>
Table 1 shows the evaluation results regarding the adhesiveness of the adhesive after a predetermined time has elapsed after two plastic plates are bonded together using an adhesive to form an adhesive structure.
(Evaluation 1: 10 minutes after the formation of the adhesive)
10 minutes after the formation of the adhesive formed before the two plastic plates are bonded together, the adhesive structure of each example has a length of 30 g / cm of adhesive in the direction in which the two objects to be bonded are separated. The distance (displacement) at which the two plastic plates were separated was measured. In Table 1, o 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: After heating for 2 hours from the formation of the adhesive)
Two hours after the application of the adhesive formed before bonding the two plastic plates, the bonded structures of each example were placed in a heating furnace and left at 140 ° C. for 20 minutes. At that time, a load of 30 g / cm ² was applied in the direction in which the two objects to be bonded were separated from each other in the heating furnace, and the distance (displacement) between the two plastic plates was measured. In Table 1, o 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 results)
As is clear from Table 1, the adhesion of Example 1 using an adhesive formed by mixing a main component with a crystallization agent and heating the mixture to a predetermined temperature, and mixing the main agent and the curing agent after this heating. About the method, it was confirmed that the distance (displacement amount) which both the plastic plates left | separated was less than 0.1 mm about any of Evaluation 1 and Evaluation 2.

  On the other hand, for the bonding method of Comparative Examples 1 and 2 in which the crystallization agent was not mixed with the main component containing a crystallizable polymer (urethane prepolymer), and the bonding method of Comparative Example 3 in which no curing agent was used. For at least one of Evaluation 1 and Evaluation 2, it was confirmed that the distance (displacement amount) between the two plastic plates was 0.1 mm or more.

  Therefore, according to the present invention, it is possible to achieve both the maintenance of the adhesion state of the adhesion structure obtained by adhering the adhesion object in a short time and the maintenance of the adhesion state when the adhesion structure is heated. found. Therefore, the present invention can be suitably used for adhesion of vehicle parts.

  As described above, the bonding method of the present invention is useful for enabling the bonding structure obtained by bonding the objects to be bonded to move in a short time and heating the bonding structure. .

Claims (4)

A crystallization agent is included that includes a crystallization agent having a melting point M in at least one of the main agent and the curing agent, and warms at least one of the main agent and the curing agent to a temperature of (melting point M-10) ° C. or higher. A heating step for the main agent and the curing agent;
A mixing step of mixing the main agent and the curing agent;
An adhesive structure forming step of applying the adhesive 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 adhesion structure heating step of heating the adhesion structure.   The bonding method according to claim 1, wherein the melting point M of the crystallization agent is 50 ° C. or higher and 80 ° C. or lower.   The adhesion method according to claim 1 or 2, wherein a compound having at least one of a hydroxy group, an imino group, and an amino group is contained as the curing agent.   The adhesion method according to any one of claims 1 to 3, wherein at least one polyester polyol having an isocyanate group is contained as the crystallization agent.

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