JPH0331384A - Resorcinol-based resin adhesive of two-pack type - Google Patents

Abstract

PURPOSE:To obtain the subject adhesive making possible to automatically mix and coat without generating mixing mistake, insufficient curing nor insufficient adhesion by mixing a solution containing liquid resorcinol-based resin as principal ingredient and a solution containing liquid phenolic resin as principal ingredient in a specific ratio. CONSTITUTION:(A) A principal agent component containing liquid resorcinol (initial condensate obtained by reacting resorcin and formaldehyde, etc., in a molar ratio of 1:0.6-0.9 in the presence of acidic catalyst and neutralizing) as principal ingredient is mixed with (B) a hardener component containing liquid phenolic resin preferably containing 2-20wt.% free formaldehyde in a weight ratio of 70/30-30/70 to afford the aimed adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a two-component resorcinol adhesive that enables automatic mixing and application.

<Prior art and problems> Resorcinol-based resin adhesives are used as adhesives for structural laminated timber, etc., but usually liquid resin and powdered curing agents (e.g., a mixture of rose formaldehyde and walnut powder) are used. ) were accurately measured and used at a blending ratio of 100:150 by weight. Therefore, since the curing agent is in powder form, it easily scatters, and is difficult to handle as it causes the inhalation of the harmful substance formaldehyde, and also causes poor adhesion due to insufficient curing due to insufficient dissolution at low temperatures. Furthermore, it was also impossible to perform bonding work using an automatic mixing and coating method.

Means for Solving the Problems> In order to solve the above problems, as a result of studies, the present invention has been completed. That is, the present invention consists of a liquid A containing a liquid resorcinol resin as a main component and a liquid B containing a liquid phenol resin as a main component. It is a two-component resorcinol resin adhesive having a ratio of 30 to 30/70.

The liquid resorcinol resin of liquid A, which is the main ingredient in the present invention, is a mixture of resol jy and formaldehyde (formalin, paraformaldehyde, etc.) under an acidic catalyst (para-toluenesulfonic acid (PTS), etc.) in a molar ratio. 1 to 0
．． It is a well-known resorcinol-based resin adhesive that is an initial condensate obtained by reacting at a F/R ratio of 6 to 0.9 and neutralized with an alkali (caustic soda, etc.).

In addition, the liquid phenolic resin of the curing agent Totoru B liquid is made by combining phenol [F] and formaldehyde [F] under an alkali catalyst (such as caustic soda) in a molar ratio of 1:1 to 5.
(F/P) and neutralized with acid (para-toluenesulfonic acid, etc.) to remove free formaldehyde.
It is characterized by containing more than usual by ~20% by weight.

Both A and B solutions, resins that are collinear or compatible with these resins, such as normal phenol, cresol, xylenol, reaction products of bisphenol A and aldehydes, urea, melamine, acedoguanaquine, benzoguanamine, etc. It also includes formaldehyde-based condensation resins such as reaction products of and aldehydes, water-soluble resins such as polyvinyl alcohol and methyl cellulose, and synthetic resin emulsions or synthetic rubber latexes such as vinyl acetate emulsion and chloroprene latex. Pressurization Known additives, such as wheat flour, barley flour, soybean glue, casein, blood meal, wood flour, kuru flour, coconut husk flour,
Also included are mixtures containing fillers such as charcoal and crushed stone powder, and plasticizers such as glycols such as ethylene glycol and polyhydric alcohols such as 7-lyl alcohol.

The above-mentioned resin, modifier, and extender are blended so that the blending ratio of liquid A and liquid B is 70/30 to 30/70, preferably 60/40 to 40/60 by weight. .

In the present invention, 2 to 20% of free formaldehyde is added to liquid B.
Weight It is an essential requirement that it be heavy, but this is A.
This is because it is necessary to contain an aldehyde group as a curing agent for the liquid resorcinol resin, that is, an addition condensation agent. Therefore, depending on the amount of free formaldehyde added, A
The curing speed of the adhesive made of a mixture of liquid and liquid B can be adjusted. However, the higher the content of free formaldehyde, the faster the curing will take place.9 A small amount will result in insufficient curing, so a minimum of 2 weight is required, and if it is more than 201, the pot life will be too short or the formalin odor will be odor. It is undesirable because it is strong and has poor workability. Therefore, the optimum content is more preferably 7 to 12% by weight.

<Operations and Effects of the Invention> The present invention is characterized by using liquid formaldehyde as the curing agent, which is easier to handle and has better mixing compatibility than the conventional powdered curing agent. (method in which the base resin and hardener are applied separately), static t-kissing system (method in which the base resin and hardener are statically mixed and applied), and mixing machine system (method in which the base resin and hardener are mixed statically and applied); An automatic application system such as a method in which the agent is forcibly stirred and applied in front of a nozzle can be adopted. In addition, conventional spreader systems (
It is also possible to adopt a method in which the main agent and the curing agent are mixed in advance and then applied.

In addition, since liquid B is an initial condensate in a liquid state and in an active state,
It has high reactivity, can be bonded for a short time, and has extremely good curing properties at low temperatures. Furthermore, the blending ratio of % A liquid (base ingredient component) and B liquid (curing agent component) = 70/30 to 30 by weight
/70, and the width is wider than the conventional Kitamoto such as 100/15, so there is no mixing, and no insufficient curing or poor adhesion occurs.

Next, an example will be explained. Parts indicate parts by weight.

Example 1 Production of OA liquid 450 parts of resorcin, 265 parts of formalin (371 formaldehyde) (molar ratio F/R = 0.8), 130 parts of ethanol, and 40 parts of glycerin were placed in a flask: IIc, and stirred at 70°C. However, para-toluenesulfonic acid (P
Add 6 parts of TS) to adjust 1) H to 1.2 or less, and
The reaction was stirred for a period of time, and the pH was adjusted to 7 by adding 20 parts of 49% sodium chloride, the non-volatile content was 65%, and the viscosity was 15 poise/2.
A resorcinol resin was obtained at 5° C. and used as a liquid A.

Production of OB liquid 310 parts of phenol, 670 parts of formalin (molar ratio F/
P=2.5), 49-Pour 5 parts of caustic soda into a flask, stir and react at 70°C for 1 hour, and after cooling, add 5 parts of PTS to adjust the pH to 7, add 5 parts of HECl, and 200 parts of coconut husk powder. 50% of non-volatile content, stirred for 1 hour,
A phenolic resin having a viscosity of 12 poise/25° C. and a free formaldehyde of 84 was obtained, which was designated as Example 10B solution.

Example 2 In Example IK, liquid B was produced in the same manner as above, except that the amount of forlin was changed to 1070 parts (molar ratio F/P = 4.0), the non-volatile content was 45, the viscosity was 8 poise/25°C, A phenolic resin containing 13% free formaldehyde was obtained and used as Solution B of Example 2.

Example 3 In Example 1, 535 parts of formalin (
A phenolic resin having a nonvolatile content of 54%, a viscosity of 15 poise/25°C, and a free formaldehyde of 5% was obtained in the same manner except that the molar ratio F/P = 2.0).
It was made into a liquid.

Comparative Example 1 In Example 1, paraformaldehyde 5 was used instead of liquid B.
1 part and 10 parts of coconut shell powder were mixed to prepare a hardening agent. In addition, 15 parts of the curing agent was added to 100 parts of the human liquid of Example 1 to prepare an adhesive for Comparative Example 1. Next, liquids A and B of Examples 1 and 2.3 were added to −
Using an automatic mixing and coating machine as shown in Publication No. 23186, the workability of the mixed Kofu was measured in a total of 9 ways, 4:6°, 5:5.6:4, for each Kitamoto mixture, and all were good. there were. However, the adhesive of Comparative Example 1 could not be applied to an automatic mixing and coating machine because the curing agent was in powder form. Therefore,
The adhesive was mixed with a conventional ink mixer and applied with a roll sprayer.

In addition, in order to measure the curing performance and adhesion performance at room temperature (curing at 20°C) and at low temperature (curing at 5°C), test pieces were prepared under the following bonding conditions, and the adhesive strength was simply measured according to JIS K-6851. The results are shown in Table 1.

In addition, for the purpose of measuring the relationship between free formaldehyde content and pot life, the blending ratio of liquid A/liquid B in each example was 50.
The measured values of the pot life at 40° C. of the adhesive consisting of the mixture of No. 150 and the adhesive of Comparative Example 1 are shown in the No. 10 Adhesion Condition Adherent Mixing Ratio (A/B) Application Table.

: Yonematsu : 4/6, 515, 6/4 : Automatic mixing and coating machine (example) Roll Spreg (Comparative Example 1) : 60 j*/min :310f/a (single side coating) : 10 to 9/cd ・20 hr Normal condition (20℃), low temperature (5℃).

3 days Pro 1 shear strength at 20℃ : Shear strength after repeated boiling Table 1 Material feeding speed Application amount Pressure tightening Nurturing life: normally adhesive crab Boiling resistant adhesive strength

Claims (2)

[Claims] (1) Consists of liquid A, which has liquid resorcinol resin as its main component, and liquid B, which has liquid phenolic resin as its main component, and the blending ratio of liquid A and B is 70/30 to 30 by weight.
A two-component resorcinol resin adhesive characterized in that: /70. (2) The two-component resorcinol resin adhesive according to claim 1, wherein the B solution contains 2 to 20% by weight of free formaldehyde.