JPH04275385A - Two-component urethane adhesive - Google Patents

Abstract

PURPOSE:To provide the subject adhesive composed of a composition containing a polyisocyanate compound and a composition containing a polyol compound and an aliphatic polyamine compound, having high thixotropy and capable of firmly bonding metals, PVC, FRP, plywood, etc. CONSTITUTION:The objective adhesive is composed of (A) a composition containing a polyisocyanate compound composed of preferably an aromatic polyisocyanate compound having an isocyanate content of >=25% and (B) a composition containing (i) 100 pts.wt. of a polyol compound having a hydroxyl value of 70-600 and composed of preferably castor oil (derivative), polyether polyol, etc., and (ii) 0.01-4.0 pts.wt. of an aliphatic polyamine having a molecular weight of 100-600.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a two-component urethane adhesive with high thixotropy. More specifically, it is used in the fields of building materials, vehicles, ships, automobiles, etc. for plastics, metals,
This invention relates to a gap-filling semi-rigid to hard thixotropic two-component urethane adhesive useful for bonding inorganic boards, wood materials, etc.

0002

[Prior Art] Two-component urethane adhesives have superior low-temperature curing properties compared to epoxy resins, etc.
It has good adhesion to metals, etc., and can be easily obtained in a wide range of cured products, from hard to highly flexible soft materials.It also has excellent gap-filling properties, making it suitable for building materials,
Widely used in fields such as vehicles, ships, and automobiles.

[0003] In such applications, adhesive may be applied to a ceiling or vertical surface to a thickness of 1 to 20 mm depending on the assembly work and the shape of the adherend. In addition, even if the adhesive is applied to a horizontal surface, the surface to be coated may be a ceiling or vertical surface in the next process due to operational needs before the adhesive has sufficiently hardened to stop flowing. It will be done. It is essential that two-component urethane adhesives used in such applications have high thixotropy; for example,
By incorporating inorganic thixotropy agents such as fumed silica, asbestos, and surface treatment fillers, or organic thixotropy agents such as hydrogenated castor oil, the adhesive will not drip or drip until it hardens. Attempts have been made to provide sufficient thixotropy to prevent flow.

0004

[Problems to be Solved by the Invention] However, in thixotropic two-component urethane adhesives that can form semi-hard to hard cured products, each composition called the main agent or curing agent is usually Even if it has sufficient thixotropy, there are drawbacks such as a marked decrease in thixotropy during mixing, especially:
A thixotropic two-component urethane adhesive that can form a hard cured product has a strong tendency to do so, and in consideration of the reduction in thixotropy during mixing, excessive thixotropy imparting agent is added to the main ingredient or curing agent. Then, the viscosity of the composition becomes significantly higher,
Mixing tended to be extremely difficult. Therefore, the viscosity before mixing is low, the sag after mixing is sufficient, and
There has been a need for a two-component urethane adhesive whose cured product is semi-hard or hard.

[0005] The inventors of the present invention have conducted intensive research and studies to solve the drawbacks of conventional adhesives as described above, and as a result, they have discovered the two-component urethane adhesive of the present invention.

[0006]

[Means for Solving the Problems] The present invention provides a composition (I) comprising a polyisocyanate compound and a hydroxyl value of 7.
0 to 400 polyol compound (a) and a molecular weight of 100 to 50 per 100 parts by weight of the polyol compound (a)
A two-component urethane adhesive characterized by comprising a composition (II) containing 0.01 to 4.0 parts by weight of an aliphatic polyamine (b) of 0.0 to 4.0 parts by weight.

The polyisocyanate compounds used in the present invention include 2,4- or 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, and isophorone diisocyanate. polyisocyanates such as hexamethylene diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, xylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; cyclized trimers of, for example, addition reaction products of low molecular weight polyol compounds such as ethylene glycol and trimethylolpropane with the above polyisocyanates, or polyether polyols, polymer polyols, polyester polyols. Addition reaction products of polyol compounds such as polyols and castor oil-based polyols with the above-mentioned polyisocyanates are used.

Among these polyisocyanate compounds, aromatic polyisocyanate compounds having an isocyanate content of 25% or more are preferred. In particular, aromatic polyisocyanate compounds such as diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, carbodiimide-modified diphenylmethane diisocyanate, and derivatives thereof are preferably used. In the present invention, the composition (I) is prepared by mixing the polyisocyanate compound with various reagents described below, if necessary.

Next, as the polyol compound (a) used in the preparation of the composition (II) of the present invention, polyesters such as polyoxyethylene glycol, polypropylene glycol, and polytetramethylene glycol are used. - polyester polyols, polyols that are castor oil or its derivatives, such as polyester polyols obtained by condensation of adipic acid and 1,4-butanediol, and liquid diene polymers containing hydroxyl groups. , polycaprolactone polyol, polycarbonate polyol, and other known polyols with a hydroxyl value (mgKOH/g) of 70 to
600 polyol compounds are used.

Among these polyol compounds, particularly preferred are castor oil or its derivatives.
It is a class. More specifically, castor oil is a product obtained by modifying castor oil, that is, triglycerides of fatty acids mainly composed of ricinoleic acid, and/or its hydrogenated product by a known method such as transesterification, Specific examples include derivatives), hydrogenated castor oil (hydrogenated castor oil), and ordinary castor oil.

Another preferred polyol compound of the present invention is polyether polyol. Polyether polyols include, for example, ethylene oxide,
Oxirane compounds such as propylene oxide, butylene oxide, and tetrahydrofuran are mixed with water, ethylene glycol, propylene glycol, trimethyl
It is obtained by polymerizing a low molecular weight polyol such as propane or glycerin as an initiator. Polyether polio
More preferred as the alcohol is polypropylene glycol.

As the polyol compound (a) of the present invention, the above-mentioned polyols made of castor oil or its derivatives and the above-mentioned polyether polyols can be used in combination, and if necessary, the above-mentioned polyols can also be used in combination. It is also possible to use other polyols in combination. A specific example of this case is, for example, the use of an appropriate amount of polycaprolactone polyol or polycarbonate polyol in order to improve adhesion to hard vinyl chloride resin.

The aliphatic polyamine (b) used in the preparation of the composition (II) of the present invention includes hexamethylene diamine, 2-methylpentyl diamine, 1,12-dodecane diamine, 2,5-diethylhexamethylene diamine. (DMHDA), 2,2,4-trimethylhexamethylenediamine (TMD), isophoronediamine, bis(aminomethyl)cyclohexane, 3,9-bis(3-
Examples include aliphatic polyamines having a molecular weight of 100 to 600, such as 2,4,8,10-tetraoxaspiro(5,5)undecane and diaminodicyclohexylmethane. When the molecular weight is larger than this range, it tends to be difficult to obtain the thixotropy that is the objective of the present invention, and when the molecular weight is smaller than this range, the stability of the resulting composition (II) becomes worse, and When using the composition (
This is not preferable because the miscibility of I) and (II) is reduced and poor mixing is likely to occur.

The amount of this aliphatic polyamine used is as follows:
0.01 to 4.0% per 100 parts by weight of polyol compound.
A range of 0 parts is preferred. No amount of aliphatic polyamine used
．． If it is less than 0.01 parts by weight, the thixotropy will be insufficient and the adhesive will flow easily;
If the amount is more than 1 part by weight, the viscosity becomes extremely high and workability becomes poor, which is not preferable.

In the two-component urethane adhesive of the present invention, the mixing ratio of composition (I) and composition (II) is such that the equivalent ratio of isocyanate groups (-NCO) to hydroxyl groups (-OH) is Usually in the range of 0.7 to 10:1, more preferably 0
．． It is in the range of 8 to 5:1. If the number of isocyanate groups is too small, the obtained cured product will not have sufficient strength, and if it is too large, the obtained cured product will tend to be hard and brittle.

The two-component urethane adhesive of the present invention can be further blended with a known thixotropy imparting agent if necessary.
It is also possible to exhibit even more excellent thixotropy. As such a thixotropy imparting agent, fumed silica, fatty acid amide, etc. are preferable. The amount of the thixotropy imparting agent added is preferably 20 parts by weight or less, more preferably 0.1 to 10 parts by weight, per 100 parts by weight of the polyisocyanate compound or polyol compound. Such a thixotropy imparting agent is
It is blended into either or both of composition (I) and composition (II).

The two-component urethane adhesive of the present invention may further contain a filler. Fillers preferably used in the present invention include fillers such as calcium carbonate, alumina, silica, talc, clay, and iron oxide. The filler content is 10 to 80% by weight of the two-component urethane adhesive, preferably 20 to 80% by weight.
A range of 75% by weight is used. Such fillers are incorporated into composition (I) and/or composition (II).

Composition (II) used in the present invention includes:
Furthermore, by adding a known dehydrating agent, foaming prevention and long-term stability can be improved. Such dehydrating agents include zeolites, quicklime, and hydrolyzable ester compounds. Hydrolyzable ester compounds include ethyl orthoformate, methyl orthoformate, ethyl orthoacetate, methyl orthoacetate, methyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, methyl silicate, and ethyl silicate. etc.

The two-component urethane adhesive of the present invention may further contain a known curing accelerator, if necessary. Examples of the curing accelerator include tertiary amines such as triethylamine, dimethylaniline and hexamethylenetetramine, and organic metal salts such as dibutyltin dilaurate and diethyltin dilaurate.

The two-component urethane adhesive of the present invention may further contain other known additives, if necessary. Examples of such additives include tackifiers such as petroleum resins, plasticizers such as dioctyl adipate, coloring pigments such as red iron and titanium oxide, antioxidants, dispersion stabilizers, antifoaming agents, etc. .

Compositions (I) and (II) used in the present invention
) can be easily manufactured by a known method. That is, when producing composition (I), it is preferable to carry out the production in a nitrogen stream to avoid the reaction between isocyanate groups and moisture (water), and when producing composition (II), it is preferable to carry out the production in a nitrogen stream. Methods are adopted to avoid contamination with water).

The two-component urethane adhesive of the present invention is mixed with a stirring rod, hand mixer, disperser, etc.
The coating is applied to the adherend manually using a spatula, brush, hand roller, etc., or by an automatic coating machine equipped with a static mixer or a power mixer.

[0023]

Effects of the Invention The two-component urethane adhesive of the present invention has high thixotropy and can be used with metals such as iron and zinc, vinyl chloride, fiber reinforced plastics (FRP), synthetic resins such as ABS resin, and particleboard. Adheres well to wood-based materials such as wood and plywood. The two-component urethane adhesive of the present invention is useful in fields such as building materials, vehicles, ships, and automobiles. Furthermore, since it has excellent gap-filling properties, it is useful as a filling and fixing agent between porous substrates such as inorganic boards and wood materials and artificial marble.

[0024]

EXAMPLES Next, the present invention will be explained more specifically and in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Here, "parts" represent parts by weight.

Example 1 Preparation of Composition (I-1) 100 parts of polymethylene polyphenylene polyisocyanate (Sumidur 44V20; manufactured by Sumitomo Bayer Urethane Co., Ltd., isocyanate content 31%), Disparon #6
500 (fatty acid amide type thixotropy imparting agent, manufactured by Kusumoto Kasei Co., Ltd.) was stirred at 80° C. for 1 hour under a nitrogen stream. Calcium carbonate (charcoal N) was added to 504 parts of the obtained uniform composition.
S-100, Nitto Funka Kogyo Co., Ltd.) 100 copies distributed.
Stir vigorously to mix uniformly. After stirring for 1 hour, the mixture was allowed to cool at room temperature for 24 hours. The composition (I) thus obtained is in the form of a paste with high thixotropy, and its viscosity is 4500 poise/2 rpm at 25°C and 120
It was 0 poise/20 rpm.

Preparation of composition (II-1) Average molecular weight: 40
0 polypropylene glycol (hydroxyl value 280) 49
2 parts and 13 parts of Disparon #6500 (above) at 80°C.
The mixture was stirred for 1 hour. To 505 parts of the obtained composition, 468 parts of calcium carbonate (above), 5 parts of 1,12-dodecanediamine, 22 parts of zeolite, and dibutyltin dilaure were added.
1 part of the mixture was added and stirred vigorously with a disperser to mix uniformly. After stirring for 1 hour, the mixture was allowed to cool at room temperature for 24 hours. The thus obtained composition (II) was in the form of a paste with high thixotropy, and its viscosity was 3600 poise/2 rpm and 470 poise/20 rpm at 25°C using a BH type viscometer.

[0027] Vertical sag test according to JIS A5758-1979 Composition (
Weigh out 100 parts of I) and 100 parts of composition (II),
Stir vigorously with a stirring bar to mix uniformly. JISA57
In a vertical sag test conducted in accordance with 58-1979, no sagging was observed and the measured value was 0 mm.

Comparative Example 1, Preparation of Composition (I-2) Composition (I-2) was prepared by preparing composition (I-2) in Example 1.
1) was used.

Preparation of composition (II-2) Average molecular weight: 40
0 polypropylene glycol (hydroxyl value 280) 49
2 parts and 13 parts of Disparon #6500 (above) at 80°C.
The mixture was stirred for 1 hour. To 505 parts of the resulting homogeneous composition were added 473 parts of calcium carbonate (as described above), 22 parts of zeolite, and 1 part of dibutyltin dilaurate, and the mixture was vigorously stirred with a disburser to mix uniformly. After stirring for 1 hour, the mixture was allowed to cool at room temperature for 24 hours. The composition thus obtained (II-2
) is a paste with high thixotropy, and its viscosity is 3540 poise/2 rpm at 25°C and 4
It was 20 poise/20 rpm.

Vertical sag test composition (I-2) 100 parts and composition (II-2) 1
00 parts were weighed out and stirred vigorously with a stirring rod to mix uniformly. In a vertical sag test conducted in accordance with JIS A5758-1979, there was significant sagging, and the measured value was 50 m.
It was m.

Example 2, Preparation of Composition (I-3) Composition (I-3) was obtained by preparing the composition (I-3) prepared in Example 1.
1) was used.

Preparation of composition (II-3) 428 parts of castor oil (hydroxyl value: 160 mgKOH/g), Disparon #
6500 (above) was stirred at 80° C. for 1 hour. Calcium carbonate (as described above) was added to 441 parts of the obtained homogeneous composition.
540 parts of 1,12-dodecanediamine and 22 parts of zeolite were added and stirred vigorously with a disper to mix uniformly. After stirring for 1 hour, the mixture was allowed to cool at room temperature for 24 hours. The composition (II-3) thus obtained was in the form of a paste with high thixotropy, and its viscosity was measured at 25°C using a BH type viscometer.
at 6460 poise/2rpm and 1150 poise/2
It was 0 rpm.

Vertical sag test composition (I-3) 100 parts and composition (II-3) 2
00 parts were weighed out and stirred vigorously with a stirring bar to obtain a homogeneous mixture. The viscosity of this product is 4500 poise/2rpm and 845 poise/20r at 25°C using a BH type viscometer.
It was pm. In a vertical sag test conducted in accordance with JIS A5758-1979, there was no sagging, and the measured value was 0 m.
It was m.

[0034] Also, ABS resin is bonded and JIS K6
In a tensile shear test conducted in accordance with 850-1976, it was 121 kgf/cm2.

Comparative Example 2, Preparation of Composition (I-4) Composition (I-4) was prepared using the composition (I-4) prepared in Example 1.
1) was used.

Preparation of composition (II-4) 428 parts of castor oil (hydroxyl value: 160 mgKOH/g), Disparon #
6500 (above) was stirred at 80° C. for 1 hour. Calcium carbonate (as described above) was added to 441 parts of the obtained homogeneous composition.
540 parts of zeolite and 22 parts of zeolite were added and stirred vigorously with a disper to mix uniformly. After stirring for 1 hour, the mixture was allowed to cool at room temperature for 24 hours. The composition thus obtained (II
-4) is a paste with high thixotropy, and its viscosity is B
On an H-type viscometer, the values were 4600 poise/2 rpm and 1030 poise/20 rpm at 25°C.

Vertical sag test composition (I-4) 100 parts and composition (II-4) 2
00 parts were weighed out and stirred vigorously with a stirring bar to obtain a homogeneous mixture. The viscosity of this product is 3900 poise/2rpm and 780 poise/20r at 25°C using a BH type viscometer.
It was pm. In a vertical sag test conducted in accordance with JIS A5758-1979, there was sag, and the measured value was 47 mm.

Example 3, Preparation of Composition (I-5) Composition (I-5) was obtained by preparing the composition (I-5) prepared in Example 1.
1) was used.

Preparation of composition (II-5) 1,12-dodecanediamine 5 used in composition (II-3) of Example 2
A paste-like composition (II-5) was obtained in the same manner as in the preparation of composition (II-3), except that 1 part was replaced with 5 parts of 2-methylpentanediamine. The viscosity was 4300 poise/2 rpm and 970 poise/20 rpm at 25° C. using a BH viscometer.

Vertical sag test composition (I-5) 100 parts and composition (II-5) 2
00 parts were weighed out and stirred vigorously with a stirring bar to obtain a homogeneous mixture. The viscosity of this product is 4100 poise/2rpm and 890 poise/20r at 25°C using a BH type viscometer.
It was pm. In a vertical sag test conducted in accordance with JIS A5758-1979, there was no sagging and the measured value was 0 m.
It was m.

[0040] Furthermore, in a tensile shear test conducted using hard vinyl chloride resin (manufactured by Nippon Test Panel Co., Ltd.) in accordance with JIS K6850-1976, the adhesive strength was 91k.
gf/cm2.

Claims (5)

[Claims] 1. Composition (I) comprising a polyisocyanate compound, a polyol compound (a) having a hydroxyl value of 70 to 600, and a molecular weight of 100 to 100 parts by weight per 100 parts by weight of the polyol compound (a). 600 aliphatic polyamines (
b) Composition (II) comprising 0.01 to 4.0 parts by weight
) A two-component urethane adhesive. 2. The two-component urethane adhesive according to claim 1, wherein the polyol compound (a) is castor oil or a derivative thereof. 3. The polyol compound (a) is a polyether
The two-component urethane adhesive according to claim 1, which is terpolyol. 4. The two-component urethane according to claim 1, wherein the polyisocyanate compound is an aromatic polyisocyanate compound having an isocyanate content of 25% or more. adhesive. 5. The two-component urethane adhesive according to claim 1, wherein the adhesive contains 10 to 80% by weight of filler.