JPH0784583B2 - Urethane adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a urethane-based adhesive composition.

[Conventional technology]

In general, urethane-based adhesive compositions can be cured at room temperature, and are therefore widely used for the purpose of adhering and fixing various materials to be adhered made of resin, metal, glass and the like.

However, in general, the urethane-based adhesive composition has a problem that foaming occurs when the pot life at room temperature is lengthened or the heat curing rate is increased.

On the other hand, in order to suppress foaming during curing of polyurethane,
It is known to add zeolites to uncured compositions, as described in JP-B-48-37331.

[Problems to be solved by the invention]

However, when the conventionally known zeolite is added to the urethane-based adhesive composition, foaming during curing is suppressed, but there is a problem that the cured product of the adhesive composition has reduced elongation and peel strength. It was

Therefore, the object of the present invention is to improve the elongation and peel strength of the cured product while suppressing foaming during curing of the urethane-based adhesive composition, and further, the pot life at room temperature is long and the heat curing rate is large. Moreover, it is to provide a urethane-based adhesive composition having good storage stability.

[Means for solving problems]

That is, the present invention provides a first liquid containing a polyisocyanate compound and an inorganic filler made of zeolite containing 80% by weight or more of particles having a particle size of 10 μm or less, and a second liquid containing an active hydrogen compound and a catalyst. A urethane-based adhesive composition comprising:

The first liquid of the urethane adhesive composition of the present invention contains a polyisocyanate compound and a specific zeolite.

The inorganic filler used in the present invention has a particle size of 10 μm.
Hereinafter, the zeolite preferably contains particles of 2 to 10 μm in a proportion of 80% by weight or more, preferably 90% by weight or more, and the average particle diameter is preferably 1 to 5 μm.

If zeolite having a particle size of more than 10 μm and more than 20% by weight is used, the cured product of the obtained adhesive composition will have a small elongation, and sufficient peel strength cannot be obtained.

As a specific example of the zeolite used in the present invention, for example, zeolite "4A" represented by Na ₂ Al ₂ Si ₃ O ₁₀
And zeolite "13X", zeolite "10X", zeolite "4A" about 70 mol% of sodium was replaced by potassium zeolite "3A", zeolite "4A" about 70 mol% of sodium was replaced by calcium Mention may be made of uncalcined or calcined synthetic zeolites such as zeolite "5A".

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, preferably 5 to 30% by weight in the whole adhesive composition. The ratio of this zeolite is 1
If it is less than wt%, it is difficult to suppress foaming during curing of the adhesive composition, and it is difficult to sufficiently increase the curing rate when heat curing, and if it exceeds 50 wt%, it is obtained. The elongation of the cured product of the adhesive composition becomes small, and the peel strength easily decreases.

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

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

The polyisocyanate compound used in the adhesive composition of the present invention is a compound having a plurality of, preferably 2-3, isocyanate groups in the molecule. As the polyisocyanate compound, various polyisocyanate compounds such as aliphatic, aromatic, and alicyclic compounds can be used.

Examples of such polyisocyanate compounds include xylylene diisocyanate, polyphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate. Examples thereof include diisocyanate compounds such as dicyclohexylmethane diisocyanate, and polymers thereof. Further, compounds containing an allophanate bond, an isocyanate bond, a carbodiimide bond, etc. in the molecule and having a plurality of isocyanate groups in the molecule, for example, phenyl Use of condensates of methane diisocyanate as polyisocyanate compounds It can be.

Furthermore, the polyisocyanate compound used in the present invention is preferably an aromatic polyisocyanate compound in an amount of 50% by weight or more of the total polyisocyanate compound, in order to further increase the adhesive strength of the obtained adhesive composition, It is particularly preferably 80% by weight or more.

Furthermore, in the polyisocyanate compound, all the isocyanate groups are 5 to 5% of the total polyisocyanate compound.
It is preferably 20% by weight, especially 8 to 1% by weight. When this proportion is less than 5% by weight, sufficient adhesive strength may not be obtained, while when this proportion exceeds 20% by weight, the cured product of the adhesive composition tends to have high rigidity and tend to have low elongation.

In the present invention, the polyisocyanate compound may be used alone or in combination of two or more kinds.

Furthermore, the polyisocyanate compound in the present invention is a prepolymer form having a plurality of isocyanate groups in the molecule, which is obtained by reacting with a polyol compound described later, an active hydrogen compound containing an active hydrogen atom such as a polyamid compound. It can also be used. Such a prepolymer is, for example, an isocyanate compound as described above,
It can be obtained by reacting with an active hydrogen compound at 20 to 90 ° C. for 1 to 6 hours.

At this time, a polyol compound is preferable as the active hydrogen compound used for forming the prepolymer having a plurality of isocyanate groups in the molecule. The molecular weight of the active hydrogen compound is preferably 5,000 or less, particularly preferably 500 to 5,
It is 000. When the molecular weight of the active hydrogen compound exceeds 5,000, the strength of the cured product of the obtained adhesive composition tends to be low, and the peel strength tends to be low.

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, isobutanol, phenols such as phenol, cresol, xylenol, p-nitrophenol, ethyl malonate, ethyl acetoacetate, acetylacetone, etc. Carbonyl compounds, acetamide, acid amides such as acrylamide, succinimide, acid imides such as maleic imide, 2-ethylimidazole, imidazoles such as 2-ethyl-4-methylimidazole, 2-
Pyrrolidone, lactams such as ε-caprolactam, oximes such as acetoxime, methylethylketoxime, diacetylmonooxime and cyclohexanone oxime,
Others can be mentioned.

These blocking agents are polyisocyanate compounds,
In a usual method, for example, in a solvent that does not contain active hydrogen atoms that dissolves the blocking agent or in the absence of a solvent, room temperature to 80 ° C
The reaction may be performed at the temperature of about 0.5 to 5 hours.

These blocked polyisocyanate compounds are
An isocyanate group is generated when the adhesive composition is cured.

The second liquid of the urethane adhesive composition of the present invention contains an active hydrogen compound and a catalyst.

Examples of the active hydrogen compound used in the present invention include a polyol compound and a polyamine compound. Specific examples of the polyol compound include, for example, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, trimethylolpropane, diethylene glycol, triethylene glycol, hexamethylene glycol, glycerin,
Polyhydric alcohols such as 1,3-butylene glycol, 1,4-butanediol, hexanetriol, pentaerythritol, sorbitol and neopentyl glycol;
Polyether polyol obtained by addition polymerization of the polyhydric alcohols and alkylene oxides such as ethylene oxide and propylene oxide; the polyhydric alcohols and maleic acid, succinic acid, adipic acid, sebacic acid, tartaric acid, terephthalic acid , A polyester polyol obtained by a condensation reaction with a polybasic acid such as isophthalic acid; a polyester polyol obtained by ring-opening polymerization of a lactone such as ε-caprolactone and γ-valerolactone; hydroxyethyl acrylate, hydroxybutyl acrylate, Monomers obtained by homopolymerizing or copolymerizing a polymerizable monomer having a hydroxyl group such as trimethylolpropane acrylic acid monoester, such as acrylic acid, methacrylic acid, styrene, acrylonitrile, α-meth Acrylic polyols obtained by copolymerization with styrene etc .; castor oil or its derivatives; epoxy polyols obtained by reacting epoxy resins having epoxy groups at both ends with monoethanolamine, diethanolamine, etc .; You can

Further, specific examples of the polyamine compound which is an active hydrogen compound include, for example, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, cyclohexylenediamine, isophorone. Diamine,
Aliphatic polyamine compounds such as dicyandiamide, acid hydrazide, amine imide, melamine and its derivatives,
And o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 4,
Aromatic polyamine compounds such as 4'-diaminodiphenyl ether, 2,4-diaminodiphenylamine, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene and 2,4-diaminotoluene can be mentioned.

Further, a part of the polyol compound may be reacted with the polyisocyanate compound in advance and used in the form of a prepolymer having a hydroxyl group or an amino group at the terminal.

In the present invention, the molecular weight of the active hydrogen compound is usually 90
~ 5,000.

The active hydrogen compounds in the present invention may be used alone or in combination of two or more kinds, and when two or more kinds are combined, a low molecular weight active hydrogen compound having a molecular weight of 300 or less and a molecular weight of 1,000 or less are used.
It is preferable to combine the above active hydrogen compounds.

In this case, in the active hydrogen compound, the ratio of active hydrogen having a low molecular weight active hydrogen compound having a molecular weight of 300 or less,
It is preferably 40 to 95 equivalent%, particularly preferably 50 to 80 equivalent% of the total active hydrogen, and the ratio of active hydrogen contained in the high molecular weight active hydrogen compound having a molecular weight of 1,000 or more is 15% of the total active hydrogen.
It is preferably -60 equivalent%, particularly 20-50 equivalent%.

In the adhesive composition of the present invention, the equivalent number of total active hydrogen contained in the active hydrogen compound is 0.8 to 1.3 with respect to 1 equivalent of all isocyanate groups contained in the polyisocyanate compound.
It is preferable to select within the range of (NCO / active hydrogen (equivalent ratio)).

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 of the cured product of the adhesive composition is large and the elongation is small. In some cases, sufficient peel strength may not be obtained.

Examples of the catalyst used in the present invention include 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-
Diaza-bicycloalkenes such as 7,1.8-diaza-bicyclo (7.5.0) tetradecene-8 and 1.14-diaza-bicyclo (11.4.0) heptadecene-13; With phenols such as phenol, cresol, xylenol, naphthol, salts of adipic acid, formic acid, acetic acid, propionic acid, octylic acid, butyric acid, oleic acid, stearic acid, and other fatty acids, benzoic acid, orthophthalic acid Acid, salt with p-toluenesulfonic acid, salt with salicylic acid, salt with parbital acid, salt with carbonic acid, salt with phosphoric acid; stannous acetate, stannous octanoate, stannous laurate, Stannous carboxylic acid such as stannous oleate; dibutyltin acetate, dibutyltin dilaurate, dibutyltin maleate, dibutyltin di -2-ethyl-
Dialkyltin salts of carboxylic acids such as hexoate, dilauryltin diacetate and dioctyltin diacetate; trialkyltin hydroxides such as trimethyltin hydroxide, tributyltin hydroxide, trioctyltin hydroxide;
Dialkyltin oxides such as dibutyltin oxide, dioctyltin oxide and dilauryltin oxide, dialkyltin chlorides such as dibutyltin dichloride and dioctyltin dichloride;
Examples include tertiary amines such as triethylamine, benzyldimethylamine, triethylenediamine, tetramethylbutanediamine, and 2-methyltriethylenediamine, and the like.

Further, these catalysts can also be obtained as commercial products, for example, "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 81
0 "," U-CAT SA 821 "," U-CAT SA 831 "," U
-CAT SA 841 "," U-CAT SA 106 "(above, manufactured by San-Apro Co., Ltd.)," methyl DABCO "(manufactured by Sankyo Air Products Co., Ltd.) and the like can be mentioned.

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 adhesive composition of the present invention, if necessary, anti-sagging agent,
Colorants, stabilizers, plasticizers and the like can be added.

In the present invention, it is composed of a first liquid containing a polyisocyanate compound and an inorganic filler made of the above-mentioned zeolite, and a second liquid containing an active hydrogen compound and a catalyst. The two liquids are mixed, the mixed liquid is applied to the material to be adhered, and then cured to bond and fix the material to be adhered.

Examples of the present invention will be described below, but the present invention is not limited thereto.

In addition, "part" shows a weight part and "%" shows a weight%.

〔Example〕

Example 1 35 parts of a polyether polyol “EXCENOL 2020” having an average molecular weight of 2,000 (manufactured by Asahi Glass Co., Ltd.) and 4,4′-diphenylmethane diisocyanate polymer “SUMIDUL 44”
V-20 "(average functionality 2.5, Sumitomo Bayer Urethane Co., Ltd.)
35 parts) and reacted at a temperature of 80 ° C. for 2 hours. To this, 30 parts of synthetic zeolite “4A” having an average particle size of 4 μm containing 90% or more of particles having a particle size of 10 μm or less was added, and an isocyanate group was added.
A first liquid containing 38% was obtained.

On the other hand, 1.8 parts were added to 77 parts of polyether polyol "EXCENOL 450NE" (made by Asahi Glass Co., Ltd.) having an average molecular weight of 500.
-Diaza-bicyclo (5,4,0) undecene-7 (hereinafter abbreviated as "DBU") formate 50% dipropylene glycol solution "U-CAT SA 610-50" (San Apro Co., Ltd. 3 Part, and calcium carbonate "NS # 60
0 ”(manufactured by Nitto Koka Kogyo Co., Ltd.) was added to add 10.
A second liquid containing 52% was obtained.

The first liquid and the second liquid obtained as described above were mixed at a weight ratio of 100: 36 to obtain an adhesive composition of the present invention. The proportion of zeolite in this adhesive composition is about 22.1% and the proportion of catalyst is about 0.8%.

In addition, NCO / OH in the mixed liquid of the above-mentioned first liquid and second liquid
The value of (equivalent ratio) is 1.

Example 2 46 parts of polyether polyol "Excelnol 2020" having an average molecular weight of 2,000, and 25 parts of 4,4'-diphenylmethane diisocyanate polymer "Sumijour 44V-20",
Hydrogenated xylylene diisocyanate "Takenate 600"
(Takeda Pharmaceutical Co., Ltd.) 8 parts were reacted at a temperature of 80 ° C. for 2 hours, and 90% or more of 15 parts of synthetic zeolite “4A” having the same particle size as in Example 1 and particles having a particle size of 10 μm or less were used. Add 6 parts of talc “Kunimine Talc TF” (manufactured by Kunimine Industries Co., Ltd.) having an average particle size of 4 μm to add isocyanate groups to 9.
A first liquid containing 4% was obtained.

On the other hand, 59 parts of polyether polyol "EXCENOL 3030" (made by Asahi Glass Co., Ltd.) having an average molecular weight of 3,000 and 16 parts of polyether polyol "EXCENOL 330" (made by Asahi Glass Co., Ltd.) having an average molecular weight of 300 were used. DB similar to 1
U2 part and 25 parts of calcium carbonate "NS # 600" were added to obtain a second liquid containing 3.72% of hydroxyl groups.

The first liquid and the second liquid obtained as described above were mixed at 100: 100.
To obtain an adhesive composition of the present invention. The proportion of zeolite in this urethane adhesive composition is about
7.4%, the proportion of catalyst is about 1.0%.

In addition, NCO / OH in the mixed liquid of the above-mentioned first liquid and second liquid
The value of (equivalent ratio) is 1.

Comparative Example 3 40.2 parts of polyether polyol "EXCENOL 2020" having an average molecular weight of 2,000 and 33.0 parts of 4,4'-diphenylmethane diisocyanate polymer "SUMIDUR 44V-20" were reacted at a temperature of 80 ° C for 1 hour, and 10 parts of synthetic zeolite "5A" having the same particle size as in Example 1 was added. Then, this was reacted with 16.8 parts of 2-butanone oxime to block all the isocyanate groups, and 59.3 parts of polyether polyol "Exenol 1030" having an average molecular weight of 1,000 and DBU adipic acid monosalt "U-CAT SA 821" were used. 3 parts (manufactured by San-Apro Co., Ltd.) was added to obtain a comparative adhesive composition. The proportion of zeolite in this adhesive composition is about 6.3% and the proportion of catalyst is about 1.9%.

The value of NCO / OH (equivalent ratio) in this adhesive composition is 1.2.

Example 3 An adhesive was prepared in the same manner as in Example 1 except that 0.5 part of 2-methyltriethylenediamine was used in place of 3 parts of a 50% solution of the DBU formate dipropylene glycol in the second liquid of Example 1. A composition was obtained.

The proportion of zeolite in this adhesive composition is about 22.1.
%, The proportion of catalyst is about 0.1%.

Comparative Example 1 Instead of 30 parts of the synthetic zeolite in the first liquid of Example 1, the same talc “Kunimine Talc TF” 30 as in Example 2 was used.
An adhesive composition was obtained in the same manner as in Example 1 except that parts were used.

Comparative Example 2 Instead of 15 parts of the synthetic zeolite in the first liquid of Example 2, 90% or more of particles having a particle size of 10 μm or less were included, and an average particle size of 3.5.
An adhesive composition was obtained in the same manner as in Example 2 except that 15 parts of calcium carbonate “NS # 600” having a diameter of μm was used.

Comparative Example 4 Instead of the synthetic zeolite in the first liquid of Example 1,
53% of particles with a particle size of more than 10 μm are included, and the average particle size is 8 μ
An adhesive composition was obtained in the same manner as in Example 1 except that the synthetic zeolite "4A" of m was used.

Test Example 1 [Measurement of pot life at room temperature] Each of the adhesive compositions obtained in Examples 1 and 2 and Comparative Examples 1 to 3 was applied in a bead shape having a width of 20 mm and a thickness of 7 mm, and the temperature was applied. The pot life was measured at 25 ° C until the adhesive did not cause stringing. The results are shown in Table 1.

Comparative Example 2 [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 to 2 and Comparative Examples 1 to 3, adhesives at various temperatures were used. Measuring device torque (Kg · cm) of composition “JSR Curastometer III”
(Manufactured by Nigo Shoji Co., Ltd.) and measured according to the following measurement conditions, the adhesive hardens and the measured torque value is 1.0 kg · c.
The time to reach m was measured. This torque value is
The state of the cured product showing 1.0 kg / cm usually reached a state in which the adhesive has reached a strength sufficient to withstand an external force applied to the bonded portion, that is, a strength capable of being clamped off. It is a state that can be regarded as.

Measurement conditions: Amplitude angle 1/4 degree, Frequency 100 cycles / minute The results are shown in Table 1.

Test Example 3 [Measurement of Physical Properties of Cured Product Sheet] Each of the adhesive compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was sandwiched between polyethylene sheets to have a thickness of 2 mm at 60 ° C. for 1 hour. A sheet of a cured product of the adhesive composition was produced by press molding with, and JIS No. 2 dumbbell-shaped test pieces were punched out. After peeling the polyethylene sheet from the dumbbell-shaped test piece, a tensile test was performed at a tensile speed of 200 mm / min to measure the strength and elongation at break. Second result
Shown in the table.

Test Example 4 [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 “MIGHTY GRIP 9025” (manufactured by Japan Synthetic Rubber Co., Ltd.), and Examples 1 to 3 were performed. And each of the adhesive compositions obtained in Comparative Examples 1 to 4 was heat-cured at 60 ° C. for 1 hour in a constant temperature bath to prepare a T-type peel test piece. Using this test piece, a T-type peel test was performed at a pulling speed of 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 2.

Comparative Example 5 In the preparation of the first liquid of Example 1, 30 parts of zeolite "4A" was not added, and in the preparation of the second liquid, the zeolite "4A" was prepared.
An adhesive composition was obtained in the same manner as in Example 1 except that 30 parts were added.

Experimental Example Each of the adhesive compositions obtained in Example 1 and Comparative Example 5 was stored in an environment of a temperature of 40 ° C. for 30 days, and the viscosity of each adhesive composition before and after the storage was measured. For each adhesive composition after the storage period, the strength and elongation at break and the T-type peel strength were measured in the same manner as described above. The results are shown in Table 3.

[Effects of the Invention] The urethane-based adhesive composition of the present invention can suppress foaming at the time of curing, and can keep the elongation and peel strength of the cured product large. Furthermore, it has a long pot life at room temperature, a high heat curing rate, and good storage stability.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazunori Iwadate 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd. (56) Reference JP-A-62-280278 (JP, A) Kai 62-223286 (JP, A) JP 62-280277 (JP, A) JP-B 48-37331 (JP, B1)

Claims (1)

[Claims] 1. A polyisocyanate compound and a particle size of 10 μm.
A urethane adhesive comprising a first liquid containing an inorganic filler made of zeolite containing 80% by weight or more of particles of m or less, and a second liquid containing an active hydrogen compound and a catalyst. Composition.