JPH0791525B2 - Urethane adhesive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a urethane-based adhesive composition, and more particularly to a urethane-based adhesive composition useful when adhesively fixing a resin plate, a metal plate, or the like. is there.

[Conventional technology]

The urethane-based adhesive composition is widely used to bond and fix materials to be bonded such as resin plates and metal plates, but in bonding and fixing materials to be bonded, sufficient adhesive strength is obtained, and In some cases, it is required that the material to be bonded at the bonding portion does not deform.

For example, a fiber reinforced resin (SMC) plate used as an outer plate of an automobile door, an engine hood, a bonnet or the like is required to be thin from the viewpoint of reducing the weight of the automobile. However, since the strength as an outer panel of an automobile is insufficient with only a thin outer panel, a reinforcing member is usually bonded and fixed to the thin outer panel for reinforcement. In the adhesive composition used for adhesively fixing the reinforcing member to such a thin outer plate, firstly, an adhesive strength larger than the material breaking strength of the fiber reinforced resin (SMC) plate used as the outer plate, That is, it is necessary that the adhesive layer after curing has a cohesive force that does not cause cohesive failure before the material of the skin is destroyed, and second, it does not impair the external appearance of the automobile. As described above, it is required that the so-called "sink" deformation does not occur in the bonding portion of the outer plate with the reinforcing member.

[Problems to be solved by the invention]

Then, in order to increase the cohesive force of the adhesive layer after curing, it is considered to use a hard adhesive composition,
The hard adhesive composition has a high rigidity and a small elongation after being hardened, and therefore the material to be adhered in the adhesive portion is likely to be deformed. As a result, there is a problem that the appearance of the adherend material is poor. For example, when a thin and light fiber reinforced resin (SMC) plate that is useful as an outer panel of an automobile is used as a material to be adhered and a reinforcing member or the like is adhered and fixed to this, the fiber reinforced resin (SMC) plate is usually press molded. Since it is formed by, since some kind of distortion is likely to occur at the time of molding, after the reinforcing member is adhered and fixed to the outer plate, the outer plate is coated. Since the paint is baked at a temperature of about 160 ° C., this tends to cause sink marks at the bonding portion of the outer plate with the reinforcing member, and as a result, there is a problem that the outer appearance of the automobile is impaired.

On the other hand, in order to prevent the deformation of the adhesive portion of the material to be adhered, it is considered to use a soft adhesive composition having a large elongation after curing, but the soft adhesive composition is In the subsequent adhesive layer, the rigidity is low, and as a result, sufficient cohesive force cannot be obtained, and there is a problem that the adhesive layer is cohesively broken before the service life of the material to be adhered expires.

In addition, in order to prevent sink marks, the clamp pressure is generally reduced to reduce the strain applied to the wearer at the time of clamping, but with the conventional urethane adhesive,
When the clamp pressure is reduced, there is a problem that the adhesive foams due to the reaction with the surface moisture of the adherend and the strength of the adhesive after curing is lowered.

Another method to reduce the strain applied to the garment is to raise the temperature during clamping to cure it in a short time, but in the method of curing at high temperature, the adhesive composition foams during curing. There is a problem that it is easy to do.

The present invention has been made under the circumstances as described above, and an object thereof is to prevent deformation of the adherend material at the adhesive portion even when the adherend material is thin, and at the same time, in the adhesive portion. Adhesive strength can be made sufficient, strength does not decrease due to foaming even when the clamping pressure is low or curing at high temperature, the cured product has good elongation and peeling strength, and at room temperature An object is to provide a urethane-based adhesive composition having a long pot life and a high heat curing rate.

[Means for solving problems]

The present invention comprises a first component consisting of a polyisocyanate compound (A) having two or more isocyanate groups at the terminal and a zeolite, and a second component consisting of a polyol compound (B) and a catalyst, and the following (a) The present invention provides a urethane-based adhesive composition characterized by satisfying the requirements (1) to (3).

(A) In the polyisocyanate compound (A), the proportion of isocyanate groups in the diisocyanate compound is 80 equivalent% or more of all isocyanate groups.

(B) In the polyol compound (B), the molecular weight is 300
The proportion of hydroxyl groups contained in the following low molecular weight polyol compounds should be 40 to 80 equivalent% of all hydroxyl groups.

(C) In the polyol compound (B), the proportion of hydroxyl groups contained in the high molecular weight polyol compound having a molecular weight of 1000 or more is 20 to 60 equivalent% of all hydroxyl groups.

Hereinafter, the present invention will be specifically described.

Examples of the polyisocyanate compound (A) that can be used in the present invention include aliphatic, aromatic, and alicyclic polyisocyanate compounds.

Examples of such polyisocyanate compound (A) include xylylene diisocyanate, polyphenyl metadiisocyanate, 4,4′-diphenyl metadiisocyanate, isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, and water. Examples thereof include isocyanate compounds such as added xylylene diisocyanate and dicyclohexylmethane diisocyanate, and polymers thereof.
These compounds may be used alone or 2
You may use it in combination of 2 or more types.

The polyisocyanate compound (A) can also be used in the form of a prepolymer having an isocyanate group at the terminal, which is obtained by reacting the above-mentioned isocyanate compound with an active hydrogen compound such as a polyamine compound. Such a prepolymer is an isocyanate compound,
It can be obtained by reacting with an active hydrogen compound such as a polyamine compound at a usual reaction temperature of 20 to 90 ° C. for 1 to 6 hours. Here, examples of the polyamine compound include ethylenediamine and hexamethylenediamine.

Furthermore, a compound containing an allophanate bond, an isocyanurate bond, a carbodiimide bond, etc. in the molecule and having an isocyanate group at the terminal, such as a condensate of diphenylmethane diisocyanate, can be used as the polyisocyanate compound (A).

Furthermore, a part of the polyisocyanate compound (A) is previously reacted with the polyol compound (B) to give a prepolymer having a hydroxyl group at the terminal (hereinafter, referred to as “prepolymer I”).
Is written. ) Form can also be used.

In the present invention, in (a) the polyisocyanate compound (A), the proportion of isocyanate groups in the diisocyanate compound is 80 equivalent% of all isocyanate groups.
The above is required. When this ratio is less than 80 equivalent%, the elongation of the adhesive composition is small after curing, and as a result, the material to be bonded is likely to be deformed at the bonded portion of the material to be bonded.

Furthermore, in the polyisocyanate compound (A), in order to further increase the adhesive strength of the resulting urethane-based adhesive composition, the aromatic polyisocyanate compound is preferably 50% by weight or more of all polyisocyanate compounds, and particularly preferably It is preferably 80% by weight or more.

Furthermore, in the polyisocyanate compound (A), the total isocyanate group content is preferably 10 to 20% by weight, more preferably 13 to 17% by weight, based on the total polyisocyanate compound. When this proportion is less than 10% by weight, sufficient adhesive strength may not be obtained, while when this proportion exceeds 20% by weight, the adhesive composition has high rigidity and low elongation after curing, and as a result Deformation of the adherend material is likely to occur at the adhesion portion of the adhesion material.

In the present invention, all or some of the isocyanate groups of the polyisocyanate compound may be blocked.

Examples of blocking agents for this block include alcohols such as ethanol, propanol, butanol, isoprotanol, phenols such as phenol, cresol, xylenol, p-nitrophenol, ethyl malonates, ethyl acetoacetate, acetylacetone, etc. Carbonyl compounds, acid amides such as acetamide and acrylamide, acid imides such as succinimide and maleic acid imide, imidazoles such as 2-ethylimidazole and 2-ethyl-4-methylimidazole, 2
-Pyrrolidone, lactams such as ε-caprolactam,
Examples thereof include oximes such as acetoxime, methylethylketoxime, diacetylmonooxime, cyclohexanone oxime, and the like.

These blocking agents are polyisocyanate compounds,
In a conventional method, for example, in a solvent containing no active hydrogen atom that dissolves the blocking agent or without a solvent, the temperature is from room temperature to 80.
The reaction may be performed at a temperature of 0.5 ° C. for about 0.5 to 5 hours.

These blocked polyisocyanate compounds are those which generate isocyanate groups when the adhesive composition is cured.

Examples of the polyol compound (B) that can be used in the present invention include ethylene glycol, propylene glycol, polypropylene glycol, trimethylolpropane, diethylene glycol, triethylene glycol, hexamethylene glycol, glycerin, 1,
3-butylene glycol, 1,4-butanediol, hexanetriol, pentaerythritol, sorbitol,
Polyhydric alcohols such as neopentyl glycol; polyether polyols such as compounds obtained by addition polymerization of the above-mentioned polyhydric alcohols with alkylene oxides such as ethylene oxide and propylene oxide; maleic acid, amber and the above polyhydric alcohols Polyester polyol compounds obtained by condensation reaction with polybasic acids such as acids, madipic acid, sebacic acid, tartaric acid, terephthalic acid, and isophthalic acid; obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone Polyester polyol; a polymerizable monomer having a hydroxyl group such as hydroxyethyl acrylate, hydroxybutyl acrylate, and trimethylolpropane acrylic acid monoester, which can be polymerized alone or copolymerized with them, such as acrylic acid, Acrylic polyol compound obtained by copolymerization with tacrylic acid, styrene, acrylonitrile, α-methylstyrene, etc .; castor oil or its derivative; epoxy resin having epoxy groups at both ends reacted with monoethanolamine, diethanolamine, etc. An epoxy polyol compound; etc. can be mentioned.

In addition, a part of the polyol compound (B) is previously reacted with the polyisocyanate compound (A) to prepare a prepolymer having an isocyanate group at the terminal (hereinafter, referred to as “prepolymer I
I ". ) Form can also be used.

In the present invention, in the (b) polyol compound (B), the proportion of hydroxyl groups contained in the low molecular weight polyol compound having a molecular weight of 300 or less is 40 to 80 equivalent%, preferably 50 to 70 equivalent% of all hydroxyl groups, And (c) In the polyol compound (B), the proportion of hydroxyl groups in the high molecular weight polyol compound having a molecular weight of 1000 or more is 20% of all hydroxyl groups.
It is necessary to be -60 equivalent%, preferably 30-50 equivalent%.

In addition, in the polyol compound (B), it exceeds 300,
Further, the hydroxyl groups contained in the polyol compound having a molecular weight of less than 1000 may be contained in less than 40 equivalent% of all hydroxyl groups.

In this polyol compound (B), when the proportion of hydroxyl groups in the low molecular weight polyol compound having a molecular weight of 300 or less is less than 40 equivalent% of all hydroxyl groups, sufficient adhesive strength is obtained after curing the adhesive composition. On the other hand, when this ratio exceeds 80 equivalent%, the adhesive composition has a large rigidity and a small elongation after curing, and as a result, the material to be bonded is likely to be deformed at the bonded portion of the material to be bonded.

In addition, in the polyol compound (B), the molecular weight is 1000
When the ratio of the hydroxyl groups contained in the above high molecular weight polyol compound is less than 20 equivalent% of all the hydroxyl groups, the adhesive composition has a large rigidity and a small elongation after curing, and as a result, the adhesive portion of the adhered material is not covered. Deformation of the adhesive material is likely to occur. On the other hand, when this ratio exceeds 60 equivalent%, sufficient adhesive strength cannot be obtained after the adhesive composition is cured.

The zeolite used in the present invention is usually a particle system.
It is a zeolite containing particles of 10 μm or less, preferably 2 to 10 μm in a proportion of 80% by weight or more, preferably 90% by weight or more, and an average particle diameter of 1 to 5 μm.

As a specific example of the zeolite used in the present invention, for example, a zeolite "4 represented by Na ₂ Al ₂ Si ₃ O ₁₀
"A", zeolite "13X", zeolite "10X", zeolite "4A" about 70 mol% of sodium is replaced with potassium "3A", zeolite "4A" about 70 mol% of sodium is replaced with calcium The zeolite "5A" and the like may be a synthetic zeolite that has not been calcined or calcined.

Among these zeolites, in order to suppress the foaming of the obtained adhesive composition even better, zeolite "5A",
It is preferable to use zeolite "4A" or the like.

These zeolites can be used alone or in combination of two or more. The proportion of this zeolite is usually 1 to 50% by weight in the whole adhesive composition,
It is preferably 5 to 30% by weight. If the proportion of this zeolite is less than 1% by weight, it is difficult to suppress foaming during curing of the adhesive composition, and it is difficult for the curing rate to be sufficiently high when heat curing, and more than 50% by weight. In that case, the elongation of the cured product of the obtained adhesive composition becomes small, and the peel strength tends to decrease.

In addition to zeolite, other inorganic fillers can be added to the adhesive composition of the present invention as needed, as long as the curing of the present invention is not impaired. Examples of other inorganic fillers include dry carbon black, platelet silica, spherical glass particles, talc, clay, calcium carbonate, zinc oxide, titanium dioxide and the like.

The ratio of the total amount of zeolite and inorganic filler is usually 1 to 60% by weight, preferably 5 in the adhesive composition.
~ 40% by weight.

The catalyst used in the present invention includes 1,5-diaza-bicyclo (4,2,0) octene-5,1,5-diaza-bicyclo (4,3,0) nonene-5,1,4-diaza. -Bicyclo (3,3,0) octene-4,3-methyl-1,4-diaza-bicyclo (3,3,0) octene-4,1,8-diaza-bicyclo (5,3,0) decene -7,1.6-diaza-bicyclo (7.3.0) dodecene-5,1.5-diaza-bicyclo (4.4.0) decene-5,10-methyl-1-8-diaza-bicyclo (5.
3.0) decene-7,1.8-diaza-bicyclo (5.
4,0) undecene-7,1,8-diaza-bicyclo (7.5.0) tetradecene-8,1.14-diaza-bicyclo (11.4.0) heptadecene-13 and other diaza-
Bicycloalkenes; salts of the above diaza-bicycloalkenes with phenols such as phenol, cresol, xylenol, naphthol, fatty acids such as adipic acid, formic acid, acetic acid, propionic acid, octylic acid, butyric acid, oleic acid, stearic acid Salts with benzoic acid, orthophthalic acid, salts with p-toluenesulfonic acid, salts with salicylic acid, salts with parbital acid, salts with carbonic acid, salts with phosphoric acid; stannous acetate, octanoic acid Stannous acid, stannous laurate, stannous carboxylic acid such as stannous oleate; dibutyltin acetate, dibutyltin dilaurate, dibutyltin maleate, dibutyltin di-2-ethyl-hexoate, dilauryltin diacetate, dioctyltin diacetate Dialkyltin salts of carboxylic acids such as acetate; trihydroxide Trialkyl tin with trityl tin, tributyl tin hydroxide, trioctyl tin hydroxide; dialkyl tin oxide such as dibutyl tin oxide, dioctyl tin oxide, dilauryl tin oxide; dialkyl tin chloride such as dibutyl tin dichloride and dioctyl tin dichloride. Tin; triethylamine, benzyldimethylamine, triethylenediamine, tetramethylbutanediamine, 2-
Mention may be made of tertiary amines such as methyl-triethylenediamine, and others.

In addition, these catalysts can be obtained as commercial products, for example, "DBU", "U-CAT SA 1", "U-CAT SA".
102 "," U-CAT SA 103 "," U-CAT SA 506 ",
"U-CAT SA 603", "U-CAT SA 610-50", "U-
CAT SA 810 "," U-CAT SA 821 "," U-CAT SA 83
1 "," U-CAT SA 841 "," U-CAT SA 106 "(above, San-Apro Co., Ltd.)," DABCO "," methyl DABC "
O ”(above, manufactured by Sankyo Air Products Co., Ltd.) and the like.

These catalysts are preferably used in an amount of about 0.001 to 5% by weight of the adhesive composition.

When the adhesive composition of the present invention is heat-cured, by combining it with zeolite, a curing rate that is 2 to 3 times the curing rate of an adhesive composition containing no zeolite can be obtained. It is preferable to use bicycloalkenes and / or salts thereof.

The urethane-based adhesive composition of the present invention is a two-component type composed of a first component composed of a polyisocyanate compound (A) and zeolite and a second component composed of a polyol compound (B) and a catalyst.

Here, when using the prepolymers I and II,
Prepolymer I is included in the second component, and prepolymer II is included in the first component.

In the urethane-based adhesive composition of the present invention, the equivalent number of all hydroxyl groups OH of the polyol compound (B) is the total isocyanate group NC of the polyisocyanate compound (A).
It is preferable to select within a range of 0.8 to 1.3 (NCO / OH (equivalent ratio)) with respect to 1 equivalent of O. When the value of this ratio is less than 0.8, the water resistance may decrease after curing the adhesive composition, while when the value of this ratio exceeds 1.3, the rigidity is high and the elongation after curing of the adhesive composition increases. It is small, and as a result, deformation of the adhered material may occur in the bonded portion of the adhered material.

The urethane-based adhesive composition of the present invention contains a primary or secondary amine compound in order to prevent sagging of the adhesive composition when the adhesive composition is applied to a material to be adhered. May be added. The primary or secondary amine compound is usually added to the second component containing the polyol compound (B) as a main component. Examples of such primary or secondary amine compounds include ethylenediamine, diethylenetriamine, triethylenetetramine,
Aliphatic polyamines such as tetraethylenehexamine and pentaethylenehexamine; cycloaliphatic polyamines such as cyclohexylenediamine, dicyclohexasilmethanediamine and isophoronediamine; phenylenediamine, tolylenediamine, xylylenediamine, diphenylmethanediamine, polyphenylmethane Aromatic polyamines such as polyamines; heterocyclic polyamines such as piperazine and aminoethylenepiperazine; and the like can be used. The addition ratio of these amine compounds is 10% of that of the polyol compound (B).
It is preferably 5 parts by weight or less with respect to 0 parts by weight.

If necessary, a colorant, a stabilizer, a plasticizer, etc. can be added to the adhesive composition of the present invention.

Further, it is preferable that the urethane-based adhesive composition of the present invention has a Young's modulus after curing, for example, 100 to 450 kg / cm ² . If this Young's modulus exceeds 450 kg / cm ² , the bonded portion of the material to be bonded may be deformed, resulting in poor appearance. On the other hand, when the Young's modulus is less than 100 kg / cm ² , the adhesive strength becomes insufficient, and for example, when it is used to bond and fix a reinforcing member to a fiber reinforced resin (SMC) plate used as an automobile outer plate, There is a problem that the cohesive force of the adhesive layer after curing the adhesive composition is smaller than the material breaking strength of the fiber reinforced resin (SMC) plate.

Further, the urethane-based adhesive composition of the present invention preferably has a limit elongation of 100% or more before breaking after curing. If the limit elongation is too small, the bonded portion of the material to be bonded may be deformed, resulting in poor appearance.

The reason why the urethane-based adhesive composition of the present invention exerts an excellent effect is not always clear, but it is speculated that the following is part of the reason.

That is, 2 in the polyisocyanate compound (A)
The ratio of the isocyanate group of the functional diisocyanate compound is not less than a specified value, and the ratio of the hydroxyl group of the low molecular weight polyol compound having a molecular weight of not more than the specified value in the polyol compound (B) and the high molecular weight polyol compound having a molecular weight of the specified value or more Since the ratio of the hydroxyl group to have is defined in a specific range, respectively, in the adhesive layer after curing, the end portion of the long-chain soft segment, which has a property of being soft and easy to stretch, has a property of increasing hardness and adhesive strength. In other words, it has a structure in which hard segments are connected, and as a result, as will be understood from the description of the examples described later in detail, the adhesive layer after curing is flexible and has a large elongation and the adhesive layer is Before the breaking limit is reached, the breaking strength of the adhesive layer increases rapidly. It can eventually be bonded with sufficient bonding strength without causing any deformation of the adherend material be one the bonded material is thin in the adhesive portion.

Furthermore, in the present invention, by using zeolite as the inorganic filler, foaming at the time of curing can be suppressed without deteriorating the physical properties of the adhesive composition.

〔Example〕

Examples of the present invention will be described below, but the present invention is not limited to these examples. In addition, "part" represents a weight part below.

<Example 1> (1) Preparation of first component 29 parts of polyether polyol "EXCENOL 2020" (Asahi Glass Co., Ltd.) having an average molecular weight of 2000 and 4,4 'of the following structure
-9 parts of diphenylmethane diisocyanate polymer "Sumijour 44V-20" (Sumitomo Bayer Urethane Co., Ltd., average functionality 2.5) and carbodiimide-modified 4,4'-diphenylmethane diisocyanate "Isonate 143 L" ) Manufactured by Sumitomo Bayer Urethane Co., Ltd., which has an average functionality of 2) 16 parts, and is a bifunctional urethane prepolymer "Sumijour PF" obtained by the reaction of a low molecular weight diol compound and 4,4'-diphenylmethane diisocyanate.
22 parts) was reacted at 80 ° C for 2 hours, and the particle size was 10 μm.
First, 24 parts of synthetic zeolite "4A" (manufactured by Nippon Kagaku Kogyo Co., Ltd.) containing 90% or more of the following particles and having an average particle diameter of 4 μm was added.
The ingredients were prepared.

(2) Preparation of the second component 62 parts of polyether polyol "EXCENOL 3030" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 3000 and 10 parts of polyether polyol "EXCENOL 890MP" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 200 And 1,8-diaza-bicyclo (5.4 ・
0) Undecene-7 (0.3 parts) was mixed to prepare a second component.

In the polyisocyanate compound (A), the proportion of isocyanate groups contained in the diisocyanate compound is
It is 95 equivalent% of all isocyanate groups.

Further, in the polyol compound (B), the molecular weight is 300
The proportion of hydroxyl groups contained in the following low molecular weight polyol compound is 60 equivalent% of all hydroxyl groups (including the hydroxyl group of the polyol compound of the first component), and the proportion of hydroxyl groups contained in the molecular weight polyol compound having a molecular weight of 1000 or more is 30 of hydroxyl groups
Equivalent%.

The first component and the second component thus obtained are 1.3:
A weight ratio of 1 (NCO / OH = 1 (equivalent ratio)) was mixed with a dispenser and a dynamic gun (all manufactured by Nippon Synthetic Rubber Co., Ltd.) to obtain a urethane adhesive composition.

<Test Example 1> (1) Using the urethane-based adhesive composition obtained in Example 1, an automobile exterior made of a fiber reinforced resin (SMC) plate having a length of 300 mm, a width of 300 mm and a thickness of 2 mm. 2mm long and 2mm wide
A reinforcing member made of a fiber-reinforced resin (SMC) plate having a thickness of 200 mm and a thickness of 2 mm was bonded and fixed. The curing temperature is 150 ° C., the curing time is 1 hour, and the clamping pressure is 0.5 kg / cm ² .

After the adhesive composition was cured, the bonded portions of the outer plate and the reinforcing member were observed. As a result, no sink mark was found on the outer plate at the bonded portion, and the appearance was good. No foaming was observed in the adhesive layer.

Further, when the adhesive strength of the outer plate and the reinforcing member was fixed after adhering and fixing, it was 60 kg / cm ² , and material destruction of the outer plate and the reinforcing member was confirmed.

(2) The urethane-based adhesive composition obtained in Example 1 was sandwiched between polyethylene sheets to give a thickness of 2 mm.
A sheet of a cured product of the adhesive composition was produced by press molding at 0 ° C. for 1 hour, and a JIS No. 2 dumbbell-shaped sample was punched out. After peeling the polyethylene sheet from this dumbbell-shaped sample, a tensile test was performed at a tensile rate of 200 mm / min, and the relationship between the load and the elongation of the cured product of the adhesive was examined. The results shown were obtained.

The Young's modulus at this time was 250 kg / cm ² , and the limit of elongation was 200%.

As can be seen from this curve I, according to the urethane-based adhesive composition of the present invention, after curing, the adhesive layer of the adhesive layer is flexible and has a large elongation, and before the adhesive layer reaches the limit of breaking. It has the property that the cohesive force increases rapidly,
As a result, it is possible to perform adhesive bonding with sufficient adhesive strength and without causing sink marks.

<Example 2> (1) Preparation of first component A first component was prepared in the same manner as in Example 1.

(2) Preparation of the second component 62 parts of polyether polyol "EXCENOL 3030" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 3000 and 10 parts of polyether polyol "EXCENOL 890MP" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 200 And 0.3 parts of triethylenediamine,
A second component was prepared by mixing with 1 part of pentaethylenehexamine.

The first component and the second component thus obtained are 1.3:
A urethane adhesive composition was prepared by mixing in a weight ratio of 1 (NCO / OH = 1 (equivalent ratio)) in the same manner as in Example 1.

<Example 3> (1) Preparation of first component A first component was prepared in the same manner as in Example 1 except that 14 parts of the 4,4'-diphenylmethane diisocyanate polymer of Example 1 was used.

(2) Preparation of second component A second component was prepared in the same manner as in Example 1.

The first component and the second component thus obtained are 1.1:
A urethane adhesive composition was prepared by mixing in a weight ratio of 1 (NCO / OH = 1 (equivalent ratio)) in the same manner as in Example 1.

<Example 4> (1) Preparation of first component A first component was prepared in the same manner as in Example 1.

(2) Preparation of the second component 93 parts of polyether polyol "EXCENOL 3030" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 3000 and 7.5 parts of polyether polyol "EXCENOL 890MP" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 200 And 0.3 part of triethylenediamine were mixed to prepare a second component.

The first component and the second component obtained as described above are 0.8:
A urethane adhesive composition was prepared by mixing in a weight ratio of 1 (NCO / OH = 1 (equivalent ratio)) in the same manner as in Example 1.

<Example 5> (1) Preparation of first component A first component was prepared in the same manner as in Example 1.

(2) Preparation of the second component 31 parts of polyether polyol "EXCENOL 3030" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 3000 and 12.5 parts of polyether polyol "EXCENOL 890MP" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 200 And 0.3 part of triethylenediamine were mixed to prepare a second component.

2.2: the first component and the second component obtained as described above.
A urethane adhesive composition was prepared by mixing in a weight ratio of 1 (NCO / OH = 1 (equivalent ratio)) in the same manner as in Example 1.

<Comparative Example 1> (1) Preparation of first component To 42 parts of polyether polyol "EXENOL 2020",
4.4'-diphenylmethane diisocyanate polymer "Sumijour 44V-20" (Sumitomo Bayer Urethane Co., Ltd.)
35 parts of an average functionality of 2.5) was added, and the mixture was reacted at 80 ° C. for 2 hours, and 90% or more of particles having a particle size of 10 μm or less were added thereto and an average particle size of 4 μm, “4A” (Nippon Kagaku Kogyo Co., Ltd. )) Was added to prepare a first component.

(2) Preparation of second component A second component was prepared in the same manner as in Example 1.

The first component and the second component thus obtained are 1.3:
A urethane adhesive composition was prepared by mixing in a weight ratio of 1 (NCO / OH = 1 (equivalent ratio)) in the same manner as in Example 1.

<Comparative column 2> (1) Preparation of first component A first component was prepared in the same manner as in Example 1.

(2) Preparation of Second Component 100 parts of polyether polyol "EXCENOL 450NE" (manufactured by Asahi Glass Co., Ltd.) having an average molecular weight of 500 and 0.3 part of triethylenediamine were mixed to prepare a second component.

The first component and the second component thus obtained are 5: 1.
The weight ratio (NCO / OH = 1 (equivalent ratio)) was mixed in the same manner as in Example 1 to obtain a urethane-based adhesive composition.

<Comparative example 3> (1) Preparation of first component A first component was prepared in the same manner as in Example 1.

(2) Preparation of Second Component 100 parts of a polyether polyol "EXCENOL 3030" (produced by Asahi Glass Co., Ltd.) having an average molecular weight of 3000 and 0.3 part of triethylenediamine were mixed to prepare a second component.

The first component and the second component obtained as described above are 0.6
A urethane adhesive composition was prepared by mixing in a weight ratio of 5: 1 (NCO / OH = 1 (equivalent ratio)) in the same manner as in Example 1.

In the polyisocyanate compound (A) of the urethane-based adhesive compositions obtained in Examples 2 to 5 and Comparative Examples 1 to 3, the ratio of the isocyanate groups of the diisocyanate compound to all the isocyanate groups, and in the polyol compound (B) The ratio of the hydroxyl groups of the low molecular weight polyol compound having a molecular weight of 300 or less to the total hydroxyl groups, and the ratio of the hydroxyl groups of the high molecular weight polyol compound having a molecular weight of 1000 or more in the polyol compound (B) to the total hydroxyl groups are shown in Table 1 below. It is as follows.

<Test Examples 2 to 5 and Comparative Test Examples 1 to 3> (1) Using the urethane-based adhesive compositions obtained in Examples 2 to 5 and Comparative Examples 1 to 3 as Test Example 1 (1), respectively. The test was conducted in the same manner.

Those using the urethane-based adhesive compositions obtained in Examples 2 to 5 were observed after the curing of the composition to observe the bonded portions of the outer plate and the reinforcing member, and the outer plate in the bonded portion had a sink mark. Was not observed, and the appearance was good. No foaming of the adhesive layer was observed.

However, when using the urethane-based adhesive composition obtained in Comparative Examples 1 to 3, after curing the composition, when observing the bonded portion of the outer plate and the reinforcing member, The occurrence of sink marks was recognized and the appearance was poor.

Moreover, about the thing using the urethane type adhesive composition obtained in Examples 2-5, after the adhesive fixation of an outer panel and a reinforcement member, it is investigated like (1) of Test Example 1 in adhesive strength. However, the cohesive strength of the adhesive layer was high, and in all cases, material destruction occurred. The measurement result of the material breaking strength at this time is the second
Shown in the table.

(2) Using the urethane-based adhesive compositions obtained in Examples 2 to 5 and Comparative Examples 1 to 3, the Young's modulus and the elongation limit were measured in the same manner as in (2) of Test Example 1.

The results are shown in Table 3 below.

Further, regarding the products using the urethane-based adhesive compositions obtained in Comparative Examples 2 and 3, the relationship between the load and the elongation of the cured product of the adhesive was examined in the same manner as in (2) of Test Example 1. The results shown in curves II and III in FIG. 1 were obtained.

The curve II is the measurement result of the urethane adhesive composition obtained in Comparative Example 2, and according to this urethane adhesive composition, the cohesive force of the adhesive layer is large after curing. However, the Young's modulus of the adhesive layer is large, and as a result, the adhesive layer cannot be adhesively fixed without causing a sink mark.

Curve III is the measurement result of the urethane adhesive composition obtained in Comparative Example 3. According to this urethane adhesive composition, the adhesive layer breaks after curing. Although the elongation up to the limit is large, the rigidity is small and the cohesive force is small, so that it is difficult to put it to practical use.

<Example 6> (1) Preparation of first component (2) Preparation of second component of catalyst 1,8-diaza-bicyclo (5.4.0) undecene-7 added to the second component of Example 1 A second component was prepared in the same manner as in Example 1 except that 0.3 part of triethylenediamine was added instead.

The first component and the second component thus obtained are 1.3:
A urethane adhesive composition was prepared by mixing in a weight ratio of 1 (NCO / OH = 1 (equivalent ratio)) in the same manner as in Example 1.

Comparative Example 4 (1) Preparation of First Component Instead of the synthetic zeolite added to the first component of Example 1, talc “Kunimine Talc TF” having an average particle size of 4 μm containing 90% or more of particles having a particle size of 10 μm or less. (Manufactured by Kunimine Industry Co., Ltd.)
The first component was prepared as in Example 1 except that 24 parts were added.

(2) Preparation of second component A second component was prepared in the same manner as in Example 1. The first component and the first component obtained as described above were mixed in a weight ratio of 1.3: 1 (N
CO / OH = 1 (equivalent ratio)) and mixed in the same manner as in Example 1 to obtain a urethane-based adhesive composition.

Test Example 6 [Measurement of pot life at room temperature] Each of the adhesive compositions obtained in Examples 1 and 6 and Comparative Example 4 was applied in a bead shape having a width of 20 mm and a thickness of 7 mm at a temperature of 25
The pot life was defined as the time from the application to the time when the adhesive did not cause stringing at ° C. The results are shown in Table 4.

Test Example 7 [Measurement of heat curing time] In order to determine the curing rate at various temperatures for each of the adhesive compositions obtained in Examples 1 and 6 and Comparative Example 4, the adhesive compositions at various temperatures were measured. Torque (kg ・
cm) using a measuring device "JSR Curastometer Type III" (manufactured by Nigo Corporation) according to the following measurement conditions,
The time taken for the adhesive to harden and the measured torque value to reach 1.0 kg · cm was measured. This torque value is 1.0 kg
The state of the cured product showing m is usually regarded as the state where the adhesive has reached a strength sufficient to withstand the external force even when an external force is applied to the adhesive portion, that is, the strength at which clamp-off is possible. It is in a ready state. The results are shown in Table 4.

Measurement conditions: Amplitude angle 1/4 degree, frequency 100 cycles / minute Test Example 8 [Measurement of T-type Peel Strength] A 0.8 mm thick steel plate having an adhesive portion of 150 × 25 mm was pretreated with a primer “MIGHTYGRIP 9025” (manufactured by Japan Synthetic Rubber Co., Ltd.), and Examples 1 and 6 were used. Each of the adhesive compositions obtained in 1. was heat-cured in a constant temperature bath at 60 ° C. for 1 hour to prepare a T-type peel test piece. Using this test piece, pulling speed
A T-type peel test was performed at 100 mm / min. The value of the T-type peel strength was the fracture equilibrium value during the test. The results are shown in Table 5.

With respect to the sheet cured products of the adhesive compositions obtained in Examples 1 and 6 by the method shown in (2) of Test Example 1, the elongation limit was measured by a tensile test, and the results are shown in Table 5. .

[Advantages of the Invention] The urethane-based adhesive composition of the present invention has an adhesive strength greater than the material breaking strength of a fiber reinforced resin (SMC) plate used as an outer panel of an automobile, that is, the adhesive layer after curing is external. It has a cohesive force that does not cause cohesive failure before the material of the board is destroyed, and the so-called "sink" deformation does not occur at the joint between the outer board and the reinforcing member of the outer board, so automobiles, etc. It does not spoil the appearance of the outer plate.

In addition, it is possible to suppress the foaming at the time of curing, and at the same time, it is possible to keep the elongation and peel strength of the cured product large.
Furthermore, the adhesive composition is excellent in that it has a long pot life at room temperature and a large heat curing rate.

Therefore, the urethane-based adhesive composition of the present invention is suitable for adhesion of fiber-reinforced resin used as an outer panel of automobile doors, engine hoods, bonnets, and the like.

[Brief description of drawings]

FIG. 1 is a curve diagram showing the relationship between the load and the elongation of an adhesive cured product in a tensile test performed using the urethane-based adhesive compositions obtained in Example 1, Comparative Example 2 and Comparative Example 3, respectively. Is.

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Claims (1)

[Claims] 1. A first component composed of a polyisocyanate compound (A) having at least two isocyanate groups at the terminal and a zeolite, and a second component composed of a polyol compound (B) and a catalyst, and ) ~ (C)
A urethane-based adhesive composition, characterized in that: (A) In the polyisocyanate compound (A), the proportion of isocyanate groups in the diisocyanate compound is 80 equivalent% or more of all isocyanate groups. (B) In the polyol compound (B), the molecular weight is 300
The proportion of hydroxyl groups contained in the following low molecular weight polyol compounds should be 40 to 80 equivalent% of all hydroxyl groups. (C) In the polyol compound (B), the proportion of hydroxyl groups contained in the high molecular weight polyol compound having a molecular weight of 1000 or more is 20 to 60 equivalent% of all hydroxyl groups.