JPS6055070A - Adhesive composition - Google Patents

Abstract

PURPOSE:To provide an adhesive compsn. having good workability and suitable for use in bonding wood having a high water content, by blending further a nonionic surfactant with a formaldehyde condensation resin adhesive compsn. CONSTITUTION:0.1-10wt% (based on the total quantity of solids in compsn. B described below) nonionic surfactant (A) such as polyoxymethylene alkyl ether is blended with a compsn. (B) consisting of an aq. latex (a) (e.g. SBR Latex PL-750, a product of Mitsui Toatsu Kagaku K.K.), a formalin condensation resin (b) (e.g. urea/formalin resin, urea/melamine/formalin resin or phenol/formalin resin) and an isocyanate compd. (C) (e.g. tolylene diisocyanate) in such a proportion that the weight ratio of component (a) to component (b) is 3:7-7:3 and the quantity of component (c) is 0.1-10wt% based on the combined quantity of components (a) and (b).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention &:j,' is suitable for bonding wood with high moisture content.
The present invention relates to an adhesive composition that is easy to work with.

Currently, DL and Polmarine-based condensation resins are used in the production of plywood, but in order to achieve sufficient adhesion performance, it is necessary to dry the veneer sufficiently. 10 City t7t: It is safe to control to %, 1 [°]. However, there is a range of moisture that logs can retain.1. -! Since the ease of drying differs between the two species, it causes many problems related to drying1; therefore, productivity may be adversely affected, and in some cases, over-drying may cause tI.
There was also the problem that cracks occurred in the T-plate, making it unusable.

Therefore, JP-A-50-69438 provides an adhesive comprising an aqueous emulsion, a compound having an isocyanate group dissolved in a hydrophobic organic solvent, and a surfactant, and optionally containing a polymeric acid. A vehicle that can be used in conjunction with a condensation resin has been disclosed.

However, there is no mention of the formalin-based condensed Kawagishi, which is said to be able to be used in this case, nor is there any mention of its blending amount or its effects; It is considered suitable. For example, high water content to solve Tsukasa: Tsukasa? When using F-board, increase the amount of flour, etc. added to the adhesive, reduce the amount of juice and water, use soybean flour, blood meal, corn starch, etc. at the same time, or extend the heat-pressing time. has been adopted, but no method has been found to achieve satisfaction 1-2.

As a result of various studies to achieve this objective, the inventor of the present invention discovered that the use of a nonionic surfactant in a specified proportion of aqueous latex, formalin-based condensed resin, and incyanate compound can be applied to a sheet. The inventors have discovered that the problems described above can be solved and have arrived at the present invention.

That is, the present invention contains (1) an aqueous latex, (2) a formalin-based condensation resin, and (2) an isocyanate compound; 1 to 20% by weight of Kishu of ■ and said ■, and 01 to 10% of the total solid content of said ■, ■, and nonionic surfactant.
This is an adhesive composition characterized by containing a heavy weight compound.

The aqueous latex used in the present invention is a product obtained by copolymerizing conjugated dienes such as butadiene and isoprene with monomers copolymerizable with these, such as various vinyl monomers such as styrene, methyl methacrylate, and acrylonitrile. Chloroprene latex, butyl rubber latex, polyvinyritine latex, polyvinyl chloride emulsion, polyphthane latex, ethylene-vinyl acetate copolymer, polyvinyl acetate emul/yon, or these emulsions contain carphogycyl groups, H - A crosslinkable reactive group selected from the group consisting of -J tyrol group, N-alcogysimethyl group, glutinyl group, β-methylgrindyl group, hydroxyl group, amino group, amide group, and acid anhydride group. at least 1 [XI
It is a so-called modified latex obtained by emulsion copolymerization of at least 1 liter of reactive monomers on the side.

The formalin-based condensation resin in the present invention includes urea-formalin-based condensation resin, urea-melamine-formalin condensation resin,
Examples include melamine-formalin condensation resin, melamine phenol-formalin condensation flIff, phenol-formalin condensation resin.

The ratio of formalin-based condensed resin to the total amount of (1) aqueous latex and O-formalin-based condensed resin in the adhesive in the present invention must be 60-70% by weight, preferably 1-70%.
1 is 35 to 65 weight; it is in the range of a frog. If the proportion of the formalin-based condensation resin is less than 30 g, the stability of the blended paste is poor and there are problems in workability, and the performance also deteriorates rapidly over time. If it exceeds 70% by weight, it cannot be said that the tolerance to high moisture content wood is sufficient and punctures occur during the production of plywood, and at an extremely low level, practical adhesion strength cannot be expected.

^ The incyanate compound in the present invention may be any compound containing two or more incyanate groups in the molecule, such as tolylene diisocyanate (TDI),
4-41-diphenylmethane isocyanate (MD■)
, hexamethylene diisocyanate (HMDT), xylylene diisocyanate (XI) (■), isophorone diisocyanate) (more ■) polymethylene polyphenyl polyisocyanate (polymeric MDI), and the like.

Compounds having isocyanate groups include their polymers, such as mixtures of polyisocyanate and polyol, prepolymers, i.e., NCO-terminated prepolymers prepolymerized with polyol and excess polyinsyanate, or prepolymerization with excess polyol. It is also possible to use a polymer in which an excess of polyisocyanate is added to the terminal prepolymer at the time of use.

The incyane-1 compound group in the present invention is 1 to 20% by weight of the total amount of the aqueous latex and formalin condensation resin.
It should be preferably in the range of 6 to 15% by weight. The amount of isocyanate compound is less than 1 [trap], which is sufficient for tolerance to high moisture content wood as referred to in the present invention.
: , 1tII cannot be used, and if it exceeds 20w/3h, the adhesive after compounding will increase in viscosity over time, making it impractical.

The nonionic surfactant in the present invention can be
It is also effective to use polyoxyethylene alkyl ether, polyoxygotylene alkyl phenol ether, polyoxygotylene alkyl phenol ether, etc.
Norbitane fatty acid ester, holoxyethylene azole ester, etc. are used. The addition of nonionic surfactant 11 is from 1 to 1 o of the total solid content of ■aqueous radenox, formalin-based condensation resin, and ■isocyanate compound.
The weight ratio is appropriate, particularly preferably in the range of 05 to 5 weight ratio. If a nonionic surfactant is added at least 1 to no, problems tend to occur in the stability of the blended paste, and when it is used for plywood production, etc., it becomes a cause of variations in physical properties.

Surfactants include anionic and cationic surfactants, and these may replace the nonionic surfactant used in the present invention, or nonionic, anionic, and/or cationic surfactants may be used in combination. If this happens, the balance of the blended glue will be disrupted, resulting in extremely poor fluidity, which will not only seriously affect the adhesive operation, but also cause a decline in physical properties. In order to avoid such negative effects, anionic surfactants and cationic surfactants must never be used.

In addition, nonionic surfactants play a role in significantly improving the applicability of the blended paste and greatly contribute to stabilizing the physical properties of the paste.

In the present invention, a compound having an isocyanate-1 group is used as an isocyanate-1 compound in a hydrophobic solvent, that is, it has almost no solubility in water, and is mutually soluble with an isocyanate compound or a compound having an isocyanate group. l'If (Although it also includes blending the glue dissolved in a solvent having properties of JIi'F, the blended paste of the present invention is sufficiently stable even when no hydrophobic solvent is used. In terms of performance, it is advantageous not to use a solvent.

In the practice of the present invention, barley flour 1. Rice flour, wood flour, talc, clay, etc. are used, compounds such as polyvinyl alcohol are used to improve temporary adhesion, blood powder, soybean powder, etc. are used to improve the adhesion direction.
;It is prohibited to use corn flour, etc. together.

When using the adhesive composition of the present invention, since the viscosity is close to that of formaldehyde resin, there is no need to modify the gear pump used for transfer within the piping, or to modify the storage tank attached to it during application. , it is possible to use the same equipment currently used for formaldehyde-based resins.Also, the compounded adhesive does not thicken over time and has a long pot life.

Next, the present invention will be explained in more detail with reference to Examples. still,
In the examples, ``part'' means % by weight, and ``part'' means part by weight.

Examples 1 to 6 and Comparative Examples 1 to 12 SBR latex PL-750 (
Mitsui Toatsu Chemical (4'l products), MBR Latex PL
-707 (Mitsui Toatsu Chemical C@ product), NBR latex croslene NA-10 (Narita Pharmaceutical■ product)
, urea formaldehyde resin U-701 (Mitsui Toatsu Chemical Co., Ltd. product), melamine urea formaldehyde resin U-350 (Mitsui Toatsu Chemical Co., Ltd. product) as formalin-based condensation resin.
side product), melamine phenol formaldehyde resin U-'881 (Mitsui Toatsu Chemical (<16 product), as an isocyanate compound MDI-OR-200 (Mitsui Toatsu Chemical (product of (1)), MDr-cR -200 (mentioned above)
and dioctyl phthalate at a weight ratio of 4:1 (this is referred to as AH), clay as a filler,
Talc, cacoz, flour,.

Adhesives were prepared using a surfactant (manufactured by Kako Atlas (1'J)) and water in various proportions as shown in Table 1 of Formulation 17. These adhesives are 1.0-4-2.0
+101 Painted 4mm plywood with veneer composition 1i: 30 f
/900crit, cold pressure 1D Kg/ci at 21
1m1n, heat pressure 9K! 77 crl ”'C115℃
, 60 sec.

The moisture content of all the veneers used was 16 to 20%.

The data on the thickening tendency, applicability, and adhesion strength of the formulation are shown in Table 1. Adhesive strength was evaluated by JAS method.

0 Proceedings Amendment ゛Mr. Kazuo Wakasugi, Commissioner of the Patent Office 1. Indication of the case 1986 4. Y Hu, Application No. 162616 2,
Title of the invention: Adhesive composition 3, amended person Specification 1, "Detailed description of the invention 4, Column 1) Description 2, page 2, line 1, 1. Such" has been replaced with "-""However, the above-mentioned problem has not been solved. 3. It is a moat, as mentioned above."

2) On page 4, line 9, replace "on the 1st type side chain" with "on the 1st type side chain"
I am corrected.

6) On page 4, line 14, "condensation resin" is corrected to "system condensation resin."

4) On page 4, line 16, it includes all the things that say "There are etc." [using formalin as a raw material], but
Considering the physical properties of the pre-cleaned plywood, melaban/phenol-formalin condensation resins are particularly preferred3. ” he corrected.

5) On page 5, line 7, [Adhesive force (-, J, -1 is corrected to read "Adhesive force only" 1. Patent applicant Mitsui Toatsu Kagaku Co., Ltd.)

Claims (1)

[Claims] ■Water-based latex, formalin-based condensation resin details■
Isocyanane 1, including the proboscis] j-7, said ■ and said 0
The weight M°1 of the nonionic surfactant is 3=7 to 7:5, and the amount of σ) is the sum of the 01 of the total solid content of ■, 0 and ■
An adhesive composition characterized in that it contains 1 to 10 parts.