JPS5887174A - Aqueous polyisocyanate adhesive - Google Patents

Abstract

PURPOSE:To provide an adhesive having excellent water resistance and useful for the processing and fabrication of plywood, etc., by mixing a water-soluble polyol or an aq. polyol dispersion with a self-dispersible polyisocyanate compd. or an aq. polyisocyanate dispersion, and dispersing the mixture in water. CONSTITUTION:The titled adhesive is obtd. by mixing a water-soluble polyol or a water-dispersible polyol such as ethylene glycol with a self-dispersible polyisocyanate compd. such as a nonionic surfactant-contg. polyisocyanate of the formula (wherein R is a 1-4C alkyl; n is an average of 5; X is a polyisocyanate residue contg. at least one free isocyanate group) or a conventional polyisocyanate in such a proportion as to give a molar ratio of NCO/OH of 2/1 or above, and then dispersing the mixture in water in a weight ratio of the mixture to water of 1/2. This adhesive has excellent water resistance and is suitable for use in the processing and fabrication of plywood.

Description

[Detailed description of the invention] be.

Conventionally, plywood and their secondary processing are made from wood.

Formalin-based water-based adhesives used in fields such as particle board manufacturing are easy to handle.

It is widely used because it is relatively inexpensive.

There are problems such as the generation of 1-1-formalin, which worsens the environment, and poor water resistance, adhesive strength, etc.

Currently, in order to compensate for these drawbacks, for example, a self-emulsifying polyisocyanate compound described in Japanese Patent Publication No. 7472/1983 or a normal polyisonanate compound as a particle board binder is used as a polyisocyanate compound using a forced dispersant. An emulsion is used.

This adhesive or binder is ultimately an adhesive or binder whose main component is a polyurea compound produced by a reaction between water and in/anate, and is desired to have improved physical properties in terms of water resistance, adhesive strength, etc. ing.

As a result of intensive research to improve the above-mentioned drawbacks, the present inventors have succeeded in obtaining an adhesive or binder with excellent mechanical strength by introducing a urethane structure into the structure of the final polyurea compound. It was a success.

That is, the present invention provides a self-emulsifying polyisonne-1 compound or a normal polyisonane-1 aqueous z-mulsion with a water-soluble polyol or a water emulsion polyol, NC0.
An aqueous polyisocyanate characterized in that it is obtained by mixing the mixture so that the molar ratio of 10H is 2/ or more, and dispersing the mixture in water so that the weight ratio of the mixture (g) to water is 8/A>%. This relates to adhesives.

Any known self-emulsifying polyisocyanate compound can be used as the self-emulsifying polyisocyanate compound used in the present invention, but preferably one with a high effective NGO content, low viscosity, and good water dispersibility. Kosho 55-7472 +
c RO(CH2CH20)nCONHX as described
(In the formula, R is an alkyl group having 1 to 4 carbon atoms,
n is an integer such that the compound contains on average at least 5 oxyneethylene groups, and X is a residue of di- or polyisocyanate containing at least one free incyanate. Aqueous emulsions such as those containing ionic surfactants or two commonly used polyisocyanate compounds are used. One kind or a mixture of two or more kinds selected from these polyisocyanate compounds can be used.

Further, as a stabilizer for these polyisocyanate water emulsions, molecular sieving agents such as calcium chloride and sodium aluminum silicate can be used.

Examples of water-soluble polyols or water emulsion polyols that can be used in the present invention include ethylene glyfur,
Diethylene glycol, polyethylene glycol, glycerin, resin.

lactose, polyoxine ethylene polyol, polyoxyethylene propylene polyol, polyoxine propylene polyol, polytetramethylene ether glycol (hereinafter referred to as PTG), polyethylene adipate, polybutylene adipate, etc.

Includes polyester polyols, aqueous alkyd condensation polymers + grouted polymer polyols with vinyl, acrylic, styrene, etc., starch, polyurethane prepolymers containing terminal hydroxyl groups, and the like. During the preparation of these polyols, known surfactants having water emulsification properties are used, such as those with the general formula RO(CH2CH20) n H(
In the formula, R is a methyl group, and a substance derived from n-5 to n-20) can be used.

The conditions for mixing incyanate and polyol in the adhesive of the present invention are such that the NC%H molar ratio is at least 100%.

The mixture of these resin components (6) and water (5) is % by weight>
%.

If the weight ratio of (5) to 00 to (A)2 is less than 01, the viscosity increases when used as a water-based adhesive or binder, and moreover, there are many residual bubbles, making it difficult to use. Become. These water-based polyisocyanate adhesives contain catalysts used in ordinary urethanization reactions, such as amine catalysts or strong acids, benzoyl chloride, dimethyl sulfate, etc.
Therefore, it is easy to control the reaction, but the amount added may be smaller than in a normal urethanization reaction.

In order to adjust the hardness of these adhesive layers, it is possible to add inorganic fillers such as mica, charcoal, bone powder, starch, etc., but care must be taken to avoid thickening of the liquid. No.

Or DBP as a flow control agent for these adhesives.

DOP, acrylic ester, vinyl acetate, etc. can be added, but it is preferable to emulsify the polyol by mixing them into the polyol in advance.

A further notable feature of the present invention is that the polyisocyanate and the polyol can be mixed in an aqueous system and used in the presence of a large excess of water, without forming foams, and by adjusting the amount of water to a small extent, the polyisocyanate and the polyol can be used as adhesives or binders. It is possible to obtain appropriate viscosity, flowability, etc.

This adhesive does not emit formalin like formalin-based water-based adhesives, and can be used to modify formalin-based adhesives such as urea tree 1] L7 el resin and urea melamine resin to reduce formalin release. You can also do that. Furthermore, it can also be used to modify latex-based aqueous adhesives.

This adhesive is particularly suitable for plywood or secondary plywood processing, but it is also effective for single-stage poles for chipboards, metal foils, paper, and fiber processing.

Next, the present invention will be explained in more detail by examples.The present invention is not limited to these examples. Note that parts and % in the examples indicate parts by weight and % by weight, respectively.

Example 1 Alcoronate 3053 (trade name manufactured by Nippon Polyurethane Industries) 1 part with self-emulsifying polyisonanate in 200 parts of water
After adding 18 parts, the mixture was stirred and mixed using a stirrer at 100 Orpm to obtain polyinsyanate emulsion A liquid.

Next, 4 parts of an emulsifier (Emazol 130 manufactured by Kako Atlas Co., Ltd.) was added to 200 parts of water, and polyethylene glycol (
Kochu Kasei Kogyo Mw = 400) 82 parts, dimethylcyclohexylamine lt (referred to as DMCA) 01 parts,
7 parts of DOP was added and mixed by stirring at 1100 rpm using a stirrer to obtain emulsion B liquid.

After adding and mixing 100 parts of polyisocyanate emulsion A liquid to 92 parts of emulsion B liquid while stirring with a stirrer Nite 1100 Orp, the mixture was aged for about 10 minutes and used as an adhesive to form a 3-ply lauan plywood (1 + 1 + 1
Plywood was prepared under the following conditions as an adhesive for veneer construction.

Adhesive application amount: 27g/30 x 30cm cold press: pressure 10 to 7,4. Time 600 seconds Horado breath: Pressure 10Kg/cA, temperature 130℃ 2 hours 12
0 seconds.

Adhesive strength Normal adhesive strength 1) 18.7 Kr, water wave rate 88% Hot and cold water adhesive strength 1) 12 Kg/lJ, water wave rate 64%
The adhesion strength obtained by changing the hot press conditions is as follows.

Hot press: Pressure 12 to 9/CIA, temperature 150
℃ 2 hours 180 seconds.

Other conditions are as described above.

1) Normal adhesive strength 21.2 Water wave rate 92%Kq/
c4 Hot and cold water adhesive strength 1) 15 Kr/metre, water wave factor 69
2% Example 2 Emulsifier (Emercy/L, manufactured by Kako Atlas Co., Ltd.) in 200 parts of water
130) and 4 parts of polyethylene glycol (
Kochu Kasei Kogyo MW=2000) 135 parts, chrycerin 14 parts, vinegar vinegar emulsion (Oshika Shinko Co., Ltd., N090)
．． Add 20 parts (solid content 35%).

The mixture was stirred and mixed with a stirrer e and a trowel at 11,000 rpm to obtain an emulsion C solution.

Coro*-to 3 (153,251 parts and 13 m of molecular lubricant (manufactured by Toyo Soda, Zeolum A-4); 200 parts of water was added to the mixture, and the mixture was heated to 1,100 O with a stirrer.
Mix well with rp and add polyisocyanate emulsion D.
I got the liquid.

124 parts of polyisocyanate emulsion solution O was stirred at 1100 rpm using a stirrer, 100 parts of emulsion solution C was added and mixed, and the mixture was aged for about 10 minutes. Using the mixture as an adhesive, plywood was prepared in the same manner as in Example 1. .

However, adhesive application amount: 30g/30x30cm real press: temperature 120℃ Adhesive strength 1) Normal adhesive strength 226%, water wave rate 90%1) Hot and cold water adhesive strength 17 K9/ctfi, water wave rate 622% Hot press conditions The adhesive strength was as follows: Hot press: pressure 10 to 9/d, temperature 150°C for 2 hours and 180 seconds, other conditions as described above.

1) Normal adhesive strength 23. I K C, water wave coefficient 93%1) Hot and cold water adhesive strength 18.9 If/d, water wave coefficient
68.1% Example 3 10 parts of an emulsifier (Emazol 130 manufactured by Kako Atlas Co., Ltd.) was added to 200 parts of warm water (60° C.), and polyethylene adipate (manufactured by Nippon Polyurethane Industries Co., Ltd.) was added.

Product name 1f-4002, MW=1.000. Hydroxyl value 1
12.3) 253 parts were thoroughly mixed with a stirrer at looOrpm, and the temperature was lowered to room temperature. DB for this
20 parts of P were added and mixed well with a stirrer at 1100 rpm to obtain an emulsion GW.

After adding 3053,147 parts of Coronae to 200 parts of water, the mixture was thoroughly mixed with a stirrer at 1100 rpm to obtain a polyisocyanate emulsion H solution.

While stirring 72 parts of polyincyanate emulsion H solution with a stirrer at 1100 Orp, the emulsion G number is 100.
plywood was prepared in the same manner as in Example 1 using the adhesive as an adhesive.

However, adhesive application amount: 26g/30 x 30 cm Hot press: Temperature 120℃ 1 hour 180 seconds Adhesive strength ■) Normal adhesive strength 15.6 Kf/r4, Water wave rate 6
85%1) Hot and cold water adhesive strength IQ, 6 Kg/cA, water wave rate 49.3% The adhesive strength with different hot press conditions is as follows Hot press: Pressure 10 Kg/cjR, Temperature 160'C
, time 300 seconds, other conditions as described above.

1) Normal adhesive strength 18.7 K9/cJ, Kiki ratio 9
0%1) Hot and cold water adhesive strength 15.2Ky/d, water wave coefficient 61
2% Example 4 In a glass four-necked flask equipped with a thermometer, stirrer, condenser and dropping funnel.

PTG (manufactured by Nippon Polyurethane Industries, PTG -
200° molecular weight 1000. Hydroxyl value 110) 5
Tolylene diisocyanate (manufactured by Nippon Polyurethane Industries, Desmodur T)
17.4 parts of -10(1) was added dropwise, the temperature was raised to 45°C, and the mixture was reacted for 3 hours in a nitrogen stream while maintaining the same temperature to obtain a prepolymer.

As a result of analysis of this prepolymer, the hydroxyl value was 85. This prepolymer is referred to as liquid I. 88 parts of polyethylene glycol (manufactured by Kochu Kasei Kogyo, MW=6oo), 35 parts of prepolymer solution (2), and 0.02 part of DMCA.

5 parts of emulsifier (Emazol 130 manufactured by Kao Atlas).

As in Example 2, an emulsion prepared by dispersing in 200 parts of water is designated as J. After mixing 100 parts of the water-dispersed polyison anate emulsion D solution of Example 2 with 88.4 parts of emulsion J solution, the mixture was aged for about 10 minutes and used as an adhesive to prepare plywood in the same manner as in Example 2. did.

However, adhesive application amount: 24.8g/30X30cm Cold press: 100 seconds Hot press: Temperature 120℃ 2 hours 240 Adhesion strength
Adhesion strength: Normal adhesive strength 1)], 9 to 9/cIl, Water wave rate 70% warm water supply adhesive strength 1) 91Kg/c, Wood breakage rate 2
Mizunami Hoso!・Adhesive strength with different pressing conditions is as follows: hot press pressure 10Kg/aR, temperature 160℃, l
Other conditions are as mentioned above: normal adhesive strength 1) 19.6 Kr/cIR, water wave rate 85% hot and cold water adhesive strength], 5.7 Kq/cm + water wave rate 38% Example 5 16 parts of starch Gradually add 200 parts of water and mix well to suspend.To this, 5.1 parts of molecular lubricant (Zeolam A-4 manufactured by Toyo Soda Kogyo Co., Ltd.) and Coronate 3053 are added.
264 parts of a polyisocyanate solution consisting of 0.00 parts were added and mixed well with a stirrer at 1.00 rpm to obtain a polyisocyanate emulsion Kl.

Plywood was prepared in the same manner as in Example 1 by mixing 100 parts of the polyisocyanate emulsion with 71 parts of Emulsion J solution prepared in Example 4 and aging it for about 10 minutes, using the mixture as an adhesive.

However, adhesive application amount: 27.2 g/30 x 30 cm cold press for 2 hours 100 seconds.

Hono Dobress: Temperature: 120°C, time: 240 seconds Adhesive strength: Normal adhesive strength 1) 12. ], Kg/Water wave rate 68%1
) Hot and cold water adhesive strength 8.5Kp/cJ, water wave coefficient 4
The adhesive strength with different 3% hot press conditions is as follows: Hot press: Pressure 10 K9/crn + Temperature 160
°C, time 300 seconds, and other conditions as described above.

Normal adhesive strength 1)] 4. I Kp/cJ, water wave rate 80%.

Hot and cold water adhesive strength 1) 1.0.1 Kg/cJ, water wave rate 75%.

1) Comparative example 1 of JAS (normal board) method 200 parts of water Emulsifier (Emazol 1 manufactured by Kao Atlas Co., Ltd.
30) Add 4 parts and mix, first polyethylene glycol (manufactured by Kochu Kasei Kogyo MW = 2000) 1122fi,
Add 90 parts of polyethylene glycol 7-methyl ether (MW 2800 manufactured by Kochu Kasei Tagyo Co., Ltd.) and mix with a stirrer to 1,100 parts.
The mixture was thoroughly mixed at 0 rpm to obtain emulsion E liquid.

388 parts of Coronet 1-3053 were added to 200 parts of water and mixed well at 1.00 rpm using a stirrer to obtain a polyisocyanate emulsion F solution.

Polyisonoanate emulsion F solution] 00 parts was stirred with a stirrer at loooorpm while emulsion/E solution 24
After adding and mixing 0 parts, the product that was aged for about 10 minutes had a high viscosity and foamed violently, making it difficult to use as an adhesive for practical use.

Comparative Example 2 4 parts of an emulsifier (Emulsol 130 manufactured by Kako 7 Truss) was added to 700 parts of water, and polyethylene glycol (
Kochu Kasei Kogyo MW=400) 523 copies, DMCA
Add 0.1 part and 7 parts of DOP to 11,000 ml with a stirrer.
The emulsion M solution was prepared by stirring and mixing using RP.

100 parts of polyison anate emulsion A solution of Example 1 was added to 350 parts of Solution M and mixed while stirring at 11,000 rpm using a stirrer and a trowel.The mixture was aged for about 10 minutes and used as an adhesive. Plywood was prepared in a similar manner.

This was carried out using an NC010H molar ratio 'V of 2.89.

Favorable results were obtained for both normal adhesive strength and hot and cold water adhesive strength.

Claims (1)

[Claims] A self-emulsifying polyisocyanate-1 compound or a normal polyisocyanate aqueous emulsion is mixed with a water-soluble polyol or a water emulsion polyol so that the N% molar ratio is V1 or more, and the weight ratio of the mixture (g) to water is 0. fart>
A water-based polyisoneate adhesive, characterized in that it is obtained by dispersing the mixture in water to a ratio of 1/2.