JPS6296578A - Adhesive - Google Patents

Abstract

PURPOSE:To obtain an adhesive suitable for use in adhesion of woods, paper, and cloths and having low toxicity and long pot life in the form of a latex, by incorporating a particular isocyanate. CONSTITUTION:An isocyanate compd. of formula I (wherein n is an integer of 0-8) in which the proportion of isocyanate groups attached at the o-position of the benzene ring against a methylene group attached to the benzene ring is 5mol% or more based on the total of the isocyanate groups, or a product prepared by reacting 100pts.wt. aforesaid isocyanate compd. with 0.3-10pts.wt. compd. of formula II (wherein m is 8-35 and R is a hydrocarbon residue of an unsatd. monofunctional alcohol having a molecular weight of 100 or less when l is null; and m is 10-25 and R is a hydrocarbon residue of a monofunctional alcohol having a molecular weight of 100 or less when l is 1-10) at a temp. of 50-150 deg.C in the presence of a urethane forming catalyst. An adhesive is obtd. by incorporating the product.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to isocyanate-based adhesive compositions. More specifically, the present invention relates to an adhesive for bonding wood, paper, polyurethane elastomer, cloth, etc.

[Conventional technology]

In recent years, polyisocyanate compounds, especially methylene-crosslinked polyphenyl polyisocyanate, have been used to produce wood, paper,
Attempts have been made to bond polyurethane elastomers, cloth, etc.

The adhesion mechanism of isocyanate compounds is based on the isocyanate group forming bonds with active hydrogen of the adherend or reacting with water to produce polyuria. When polyphenyl polyisocyanate is used, extremely excellent adhesiveness is exhibited. Furthermore, methylene crosslinked polyphenyl polyisocyanate has a low vapor pressure and is characterized by low toxicity due to steam during handling and heat curing process.

[Problem that the invention seeks to solve]

However, when such an isocyanate compound is used as an adhesive, after contact with moisture or after being applied to the adherend, it reacts with the adherend and coexisting moisture, etc. and cures before the set curing process. There are problems in that it tends to harden and does not exhibit sufficient adhesive performance. These problems become more pronounced the higher the temperature after application to the adherend, and the more pronounced the problem becomes.Also, when a compound having an isocyanate group is modified to be emulsifiable with water and used after being emulsified with water. The precuring phenomenon becomes significant and the so-called pot life becomes short.

[Means for solving problems]

As a result of intensive studies aimed at solving the above-mentioned problems, the present inventor found that the position of the isocyanate group in the polyisocyanate compound is extremely important for solving these problems.
Furthermore, it was discovered that a specific polyalkylene compound is effective when emulsified with water, and the present invention was achieved.

That is, the present invention provides (1) an adhesive comprising an isocyanate compound represented by the following general formula CI) and in which the isocyanate group bonded at the ortho position to the methylene group bonded to the benzene ring accounts for 5 moles or more of the total isocyanate groups. (where n is an integer of 0 or 1 to 8) (2) The isocyanate group represented by general formula (1) and bonded to the ortho position to the methylene group bonded to the benzene ring accounts for 5 of the total isocyanate groups. It is an adhesive formed by containing an isocyanate compound having a molten or higher molecular weight and one or more kinds of compounds represented by the general formula (It).

CH3 RO+CH, CH, O dirt → CH, CHO÷FH (II)
(However, when t=a, 1 is an integer of 8 to 65, R is a hydrocarbon residue of an unsaturated monofunctional alcohol with a molecular weight of 100 or less, and when l is 1 to 10, m is an integer of 10 to 25, R is a hydrocarbon residue of a monofunctional alcohol having a molecular weight of 100 or less.] The isocyanate compound referred to in the present invention is an isocyanate compound represented by the general formula (Il),
If the isocyanate groups bonded at the ortho position to the methylene group bonded to the benzene ring account for 5 or more moles of the total isocyanate groups, and the isocyanated groups account for less than 5% of the total isocyanate groups, so-called pre-curing is likely to occur.
Problems arise when used as an adhesive and in the adhesive itself. When n exceeds 8 in a compound represented by the general formula (()), the viscosity of the compound becomes extremely high, causing problems in handling.

When l is 1 to 10, the metal compound represented by the general formula (II) is produced by the usual method of adding ethylene oxide and propylene oxide to a monofunctional alcohol in the presence of a basic catalyst using a monofunctional alcohol as an initiator. Ru. Although the rigidity of addition of ethylene oxide and propylene oxide or the form of their addition (random, block, etc.) may be any, it is preferable to first add ethylene oxide and then add propylene oxide in a relatively evening view.

The above-mentioned monofunctional alcohol preferably has a molecular weight of 100 or less, and typical examples thereof include methyl alcohol, ethyl alcohol, n7' alcohol, isopropyl alcohol, sn-butyl alcohol, 5ec-butyl alcohol, and isobutyl alcohol. , tert −
7'tyl alcohol, n-amyl alcohol, isoamyl alcohol, 5eC-butyl carbinol, neopentyl alcohol, diethyl carbinol, 2-pentanol, methylisopropyl carbinol, tert
- Saturated monofunctional alcohols such as amyl alcohol, allyl alcohol, crotyl alcohol, methylvinyl carbinol, 71J carbinol, methylpropenyl carbinol, 4-penten-1-ol, 4-penten-
2-ol, 2-methyl-4-penten-2-ol,
1,4-pentadien-6-ol, 2,4-pentadien-1-ol, 1,4-hexadien-3-ol, 6,5-hexadien-2-ol, 2,4-hexadien-1 -ol, propargyl alcohol, 2-butyn-1-ol, 3-butyn-2-ol, 3-butyn-1-ol, 2-pentyl-1-ol, 2-methyl-3-butyn-2-ol , 2-hexyn-1-ol, 3-methyl-1-pentyn-3-ol, 4-hexen-1-yn-3-ol, 3-hexen-5-yn-2-ol, and the like.

The molecular weight of the monofunctional alcohol exceeds 100, or m in the compound represented by the above general formula (IN)
When m is less than 10, or when j exceeds 10, it becomes difficult to emulsify the product of the compound represented by the general formula (Il) and the organic polyisocyanate in water;
When l is more than 5 or less than 1, the pot life of the aqueous emulsion of the above compound and organic polyisocyanate is shortened, which tends to cause problems in practical use.

When 1 is O, the compound represented by the above general formula (II) is produced by the usual method of adding ethylene oxide to an unsaturated monofunctional alcohol in the presence of a basic catalyst using an unsaturated monofunctional alcohol as an initiator.

The unsaturated monofunctional alcohol preferably has a molecular weight of 100.
These include allyl alcohol, crotyl alcohol, methylvinylcarbinol, allylcarbinol, methylpropenylcarbinol, 4-pentene-
1-ol, 4-penten-2-ol, 2-methyl-
4-penten-2-ol, 1,4-pentadiene-6
-ol, 2,4-pentadien-1-ol, 1,4
-Hexadien-3-ol, 6,5-hexadiene-
2-ol, 2,4-hexadien-1-ol, phlopargyl alcohol, 2-butyn-1-ol, 6-butyn-2-ol, 3-butyn-1-ol, 2-pentyn-1-ol , 2-methyl-3-butyn-2-ol, 2-hexyn-1-ol, 6-methyl-1-pentyn-3-ol, 4-hexen-1-yn-6-ol, 6-hexen-5 -in-2-ol and the like.

In the compound represented by the above general formula (n), J=0
In this case, if m is less than 8, it will be difficult to emulsify the product from this and the organic polyinocyanate in water.
If the number exceeds 35, the stability of the aqueous emulsion of the product often deteriorates.

Based on 100 parts by weight of an isocyanate compound of general formula (1) (n = 0 to 8) in which the isocyanate group bonded at the ortho position to the methylene group bonded to the benzene ring accounts for 5 moles or more of the total isocyanate groups. , the compound represented by general formula (II) is 0.3 to
Preferably, 10 parts by weight are used.

More preferably, it is 1 to 5 parts by weight. The amount used is 03
If it is less than 10 parts, it will be difficult to emulsify the obtained isocyanate base with water, and if it exceeds 10 parts, the content of isocyanate groups will be too low, which will limit the use of the product, for example, when used as a binder. This tends to lead to disadvantages such as increased water absorption.

The reaction between the compound represented by the general formula (1) and the compound represented by the general formula (II) is carried out by a conventional method. That is, the reaction is generally carried out at 50 to 150°C for a predetermined period of time in the presence of a conventional urethanization catalyst if necessary.

The adhesive according to the present invention can be used to bond wood, paper, cloth, etc., but of course it can also be used alone, or if it has been modified to be water-dispersible, it can also be used after being dispersed in water. In addition, aqueous formaldehyde resin solutions, aqueous polymer compound solutions such as polyvinyl alcohol aqueous solutions, latexes made by copolymerizing conjugated dienes such as butadiene and isoprene with monomers that can be copolymerized with these, aqueous chloroprene latexes, butyl rubber latexes, polybutadiene latexes, etc. It is also possible to use it by mixing it with latexes, aqueous emulsions such as ethylene acetate heel copolymer emulsions, pol) acetic acid Ml vinyl emulsions, and acrylic resin emulsions, emulsions of synthetic waxes, petroleum waxes, and animal and vegetable waxes. Further, it may be used in combination with a mold release agent for the purpose of preventing adhesion to molding iron plates, metal molds, etc. used in the bonding process. When the isocyanate adhesive composition of the present invention which has been modified by water emulsion is emulsified and used, a surfactant may be used in combination. As the surfactant, silicon-containing substances such as dimethylpolysiloxane and dimethylpolysiloxane-polyoxyalkylene block copolymers are desirable.

The adhesive of the present invention has a milder reactivity after being applied to an adherend at low temperatures than an isocyanate compound having an isocyanate group at the para position of the benzene ring relative to the methyl group, and after being applied, There are fewer restrictions on deposition time up to the curing process. Furthermore, when the adhesive composition of the present invention modified to be emulsifiable in water is emulsified with water, the so-called bot life is also extended.

〔Example〕

The effects of the present invention will be explained by examples, but the present invention is not limited by these in any way.

Parts in the examples are heavy parts and weight % unless otherwise specified.

Reference Example 1 2190 parts of diethylene glycol monomethyl ether and 4.45 parts of potassium hydroxide were placed in an autoclave, the temperature was raised to 90°C after purging with nitrogen gas, and 1052 parts of ethylene oxide was reacted under pressure, followed by 211 parts of propylene oxide. .4 parts were reacted. Thereafter, one reaction product was neutralized with a theoretical amount of phosphoric acid, and a product was obtained after filtration. This product (hereinafter referred to as A) had an OH value of 67.

Reference Example 2 116 parts of allyl alcohol and 4.50 parts of potassium hydroxide were placed in an autoclave, the autoclave was purged with nitrogen gas, the temperature was raised to 90°C, and 1,350 parts of ethylene oxide was reacted under pressure. Thereafter, the reaction product was neutralized with a theoretical amount of phosphoric acid, and the product was obtained after filtration.

This product (hereinafter referred to as B) had a 08 valence of 748. Reference Example 5: 90 parts of 3-butyn-1-ol, 4.5 parts of potassium hydroxide
Reference Example 1 except that 849 parts of ethylene oxide were used.
Product C was obtained by processing in the same manner as above. The OH value of C is 75.8
Met.

Reference Example 4 The compound A2S part obtained in Reference Example 1 was charged into a reaction vessel, and UR-4005 (manufactured by Mitsui Toatsu Chemical Co., Ltd., crude diphenylmethane diisocyanate, NC
Total O content 32.2%, ortho NCO content 16.8
%) was added, and after mixing, the temperature was raised to 80 ° C.
The mixture was mixed and stirred at 80°C for 2 hours. The obtained reaction product (hereinafter abbreviated as E-nee 1) had an NCO content of 299%.

Reference Example 5 825 parts of the compound obtained in Reference Example 2 was charged into a reaction vessel, and 500 parts of UR-4005 and CR-2 were heated under a nitrogen stream at room temperature.
00 (manufactured by Mitsui Toatsu Chemical Co., Ltd., crude diphenylmethane diisocyanate, total NCO content! 11.3%,
Ortho rank 1. After adding and mixing 500 parts of ICO content (2.0%), the mixture was heated to 80'C and mixed and stirred at 80C for 2 hours. The obtained reaction product (hereinafter abbreviated as E-nee 2) is N
The CO content was 295 cm.

Reference Example 6 Using Compound C obtained in Reference Example 3, a reaction product (hereinafter abbreviated as EI-3) was obtained in the same manner as in Reference Example 4.

The NCO content of EI-3 was 297%.

Reference Example Z 25 parts of the compound A obtained in Reference Example 1 was placed in a reaction vessel, and 1000 parts of CR-200 was added at room temperature under a nitrogen stream.
The temperature was raised to 80°C, and the mixture was mixed and stirred at 80°C for 2 hours. The obtained reaction product (hereinafter abbreviated as E-nee 4) had an NCO content of 2
It was 96chi.

Example 1 UR- was added to 1000 parts of lauan chips with a moisture content of 6.2%.
9 parts of 400546 was applied by spraying, and the chip after application was left in a sealed state in an atmosphere of 60° C. for 30 minutes. Scatter the coating chips onto a 30cm square corner of a stainless steel plate coated with a release agent, place the stainless steel plate coated with a release agent, and place it on a 15m+
A particle board was obtained by installing a stopper of 500 m and hot pressing at 150° C. for 5 minutes. The obtained particle board had a thickness of 15.1+i+density of 0.761, and was
The physical property values measured in accordance with A-5908 were as shown in Table 1 and were good.0 Example 2 146.9 parts of the reactant EI-obtained in Reference Example 4 and 46.9 parts of water
The components were mixed to obtain an emulsion. A particle board was obtained in the same manner as in Example 1 except that the emulsion was used. The resulting particle board has a thickness of 15.2 ni and a density of 0.76
5, and the physical property values were good as shown in Table-1. The emulsion was stable at room temperature for 4 hours.Example 3Example 2 except that the reactant EI-2 obtained in Reference Example 5 was used.
Particle board was obtained by the same operation. The obtained particle board had a thickness of 15.1 and a paper rating of 0,766, and its physical properties were good as shown in Table 1. The emulsion was also stable for 3 hours at room temperature.

Example 4 Example 2 except that the reactant EI-3 obtained in Reference Example 6 was used.
I obtained a particle horde with the same operation. The obtained particle board had a thickness of 150 mm and a density of 0.764, and its physical properties were excellent as shown in Table 1. The emulsion was also stable for 4 hours at room temperature.

Example 5 146.9 parts of the reaction product EI obtained in Reference Example 4 and 469 parts of water were mixed to obtain an emulsion. The emulsion was applied to 1000 parts of lauan chips having a moisture content of 6.2%, and the applied chips were left sealed at room temperature for 2 hours. A particle board was produced using the chip after being left in the same manner as in Example 1. The thickness of the obtained board was 151fi, the density was 0.763, and the physical properties were as shown in Table 1.

Example 6 Example 5 except that the reactant gr-2 obtained in Reference Example 5 was used.
Particle board was obtained by the same operation.

The resulting particle board has a thickness of 153 mm and a density of 0.
．． 762, and the physical property values were as shown in Table 1.

Example 7 Example 5 except that the reactant EI-3 obtained in Reference Example 6 was used.
Particle board was obtained by the same operation. The thickness of the obtained particle board was 15.2 fl, the density was 0.765, and the physical properties were as shown in Table 1.

Example 8 Reactant EI-532 obtained in Reference Example 6, 8 parts, SBR latex 5B-1051 (manufactured by Mitsui Toatsu Chemical Co., Ltd.) 4
69 parts and 94 parts of water were mixed to obtain an emulsion.

A particle board was obtained in the same manner as in Example 4 except that the emulsion was used. The resulting particle board has a thickness of 1
53 mm, density 0.76 B, and physical property values are as shown in Table-1. The emulsion was stable for 3 hours.

Example 9 A mixture was obtained by mixing 118.8 parts of the reactant EI obtained in Reference Example 4, 9125 parts of Melami' formaldehyde resin Nyloid 230 (Mitsui Toatsu Chemical Co., Ltd., 9125 parts of non-volatile content 603%), and 06 parts of ammonium chloride. A particle board was obtained by the same operation as in Example 4 except that the obtained mixture was used.The obtained particle board had a thickness of 15.1 mm.
The density was 0.769, and the physical properties were as shown in Table 1. The mixture was stable for 6 hours.

Example 10 4 parts of the reactant EI-59 obtained in Reference Example 6, 125 parts of melamine formaldehyde resin Niloid 230, 0.6 part of ammonium chloride, SBR latex 5B-105
1 part of 114 were mixed to obtain a mixture. A particle board was obtained in the same manner as in Example 4 except that the obtained mixture was used. The resulting particle board has a thickness of 15.2s.
+m, and the density was 0.771, and the physical property values were as shown in Table 1. The mixture was stable for 6 hours.

Comparative Example 1 A particle board was produced in the same manner as in Example 1 except that CR-200 was used. The resulting hoard has a thickness of 15.
It was 4 mm and the density was 0.756. The physical property values were as shown in Table 2, and the results were inferior to those of Example 1.

Comparative Example 2 Example 2 except that the reactant EI-4 obtained in Reference Example 7 was used.
Particle board was obtained by the same operation.

The resulting particle board had a thickness of 152 toms and a density of 0.759. As shown in Table 2, the physical properties were inferior to those of Example 2. The emulsion was also stable for up to 1.5 hours.

Comparative Example 3 Example 5 except that the reactant EI-4 obtained in Reference Example 7 was used.
Particle board was obtained by the same operation. The resulting particle board has a thickness of 15.3+o+ and a density of 0752.
Met. As shown in Table 2, the physical properties were inferior to those of Example 5.

Comparative Example 4 Example 8 except that the reactant EI-4 obtained in Reference Example 7 was used.
Particle board was manufactured using the same procedure. The thickness of the obtained particle board was 15.5 sn and the density was 0.
．． 749, and the physical property values were as shown in Table 2 (inferior to Example 8). The emulsion was stable for 1.5 hours.

Comparative Example 5 Example 9 except that the reactant EI-4 obtained in Reference Example 7 was used.
Particle board was made using the same procedure. The thickness of the obtained particle board was 15.4n and the density was 0.763.
As shown in Table 2, the physical properties were inferior to those of Example 9. The emulsion was stable for 1.5 hours.

Comparative Example 6 Example 1 except that the reactant EI-4 obtained in Reference Example 7 was used.
Particle board was produced using the same procedure as in Example 0. The resulting particle board has a thickness of 155 mm and a density of 0.770.
As shown in Table 2, the physical properties were inferior to those of Example 10. The emulsion was stable for 1.5 hours.

〔Effect of the invention〕

As is clear from the above Examples and Comparative Examples, the adhesive of the present invention has excellent stability when emulsified, and the physical properties of the particle board using it are also excellent.

Claims (2)

[Claims] (1) An adhesive comprising an isocyanate compound represented by the following general formula (I) and in which the isocyanate group bonded at the ortho position to the methylene group bonded to the benzene ring accounts for 5 mol% or more of the total isocyanate groups. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (where n is 0 or an integer from 1 to 8) (2) An isocyanate compound represented by the general formula (I) in which the isocyanate group bonded at the ortho position to the methylene group bonded to the benzene ring accounts for 5 mol% or more of the total isocyanate groups; An adhesive containing one or more of the compounds shown. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (However, when l = 0, m is an integer from 8 to 35, R is a hydrocarbon residue of an unsaturated monofunctional alcohol with a molecular weight of 100 or less, and l is 1 ~10, m is an integer of 10 to 25, R is a hydrocarbon residue of a monofunctional alcohol with a molecular weight of 100 or less)