JP2801306B2 - Method for producing surface-treated plywood or concrete formwork plywood - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing surface-treated plywood, and particularly to a method for producing plywood requiring surface smoothness. The present invention relates to a method for producing a surface-treated plywood or a concrete formwork plywood which avoids an adverse effect of a base treatment resin and improves surface smoothness.

(Prior art)

The following methods are known as prior art, but have various problems as described below.

(1) A method in which an aqueous resin is used as the resin for the base treatment, and a polyurethane-based fat layer is applied to the overcoat resin (Japanese Patent Laid-Open No. Sho 62)
-133252), by the moisture from the base resin and the base plate,
Since the groups of the isotonate in the overcoat resin react with moisture and are cured while foaming occurs, they cause deterioration of the surface smoothness.

To prevent this, as a method of minimizing the effect of moisture after applying the undercoating resin, take a long drying time to disperse the moisture, or raise the drying temperature to a high temperature (60 ° C to 100 ° C). ) And evaporating the water.

However, in consideration of restrictions due to the manufacturing time, the processing must be performed at a high processing temperature.

In this case, as a problem, distortion occurs in the plywood of the base plate due to drying shrinkage of the woody portion, and it is very difficult to apply the coating so that the film thickness of the top coating resin is constant.

Also, from the viewpoint of product dimensional stability, high-temperature treatment of the base plate should be avoided.

(2) The method of producing a surface-treated plywood or a concrete formwork plywood in which a water-based resin is applied to a base-coating resin, and a solvent-based polyurethane coating resin is applied to a top-coating resin. However, it reacts with the isocyanate groups in the overcoat resin to cause foaming, which degrades the quality of the product in terms of surface smoothness after coating.

In order to prevent this, at present, after a coating resin for base treatment is applied, a high-temperature drying treatment is performed to evaporate moisture, and then an overcoat resin is applied.

Further, in order to obtain surface smoothness, a large amount of a coating resin is applied, so that internal foaming of a solvent in the resin occurs.

To prevent this, as a method of minimizing the effect of moisture after applying the undercoating resin, take a long drying time to disperse the moisture, or raise the drying temperature to a high temperature (60 ° C to 100 ° C). ) And evaporating the water.

However, in consideration of restrictions due to the manufacturing time, the processing must be performed at a high processing temperature.

As a problem in this case, due to drying shrinkage of the wooden part,
Distortion occurs in the plywood base plate, and it is very difficult to apply the coating to keep the thickness of the overcoat resin layer constant.

Also, from the viewpoint of product dimensional stability, high-temperature treatment of the base plate should be avoided.

[Problems to be solved by the invention]

At present, in the production of surface-treated plywood or concrete-painted formwork plywood, organic solvent-based paint resin is often used as a coating resin for coating. The problem of contamination of the working environment is becoming a serious factor, and non-organic solvent-based paint resins are attracting attention.

Above all, when an aqueous resin and an isocyanate resin are used together, it has been found that the water in the resin reacts with the isocyanate to cause foaming and adversely affect the quality of the product. It is an important issue to establish a technology that can easily and easily produce high quality surface treated plywood or concrete formwork plywood.

[Means for solving the problem]

The present inventors have found that the room temperature curability of the aqueous polyurethane resin,
By focusing on the shielding property of the formed coating film and finding that the above-mentioned problems can be solved by forming the intermediate treatment resin layer, the present invention has finally been reached.

That is, the present invention provides (1) a surface treatment plywood and a method for producing a concrete formwork plywood, wherein an intermediate treatment resin layer is formed between an undercoat resin layer and an overcoat resin layer. A method for producing a plywood and / or a concrete formwork plywood, wherein the resin for the base treatment is formed by using a curable aqueous resin.
The method for producing a surface-treated plywood and / or a concrete formwork plywood, wherein the resin is cured at a temperature of not more than 0 ° C. and the intermediate layer treatment resin is an aqueous polyurethane resin. Polyurethane paint resin,
(1) The method for producing a surface-treated plywood and / or a concrete formwork plywood according to (1), wherein an isocyanate-polyol-based two-pack paint resin is used; (3) a urea-formaldehyde resin;
Melamine / formaldehyde resin, phenol / formaldehyde resin, phenol melamine / formaldehyde resin, phenol melamine / urea / formaldehyde resin, and / or aqueous polyurethane resin, aqueous emulsion resin, aqueous polymer / isocyanate resin,
(1) The method for producing a surface-treated plywood and / or concrete formwork plywood according to (1), wherein the base treatment is performed with a resin obtained by mixing 80% of a filler and a curing agent.

According to the method of the present invention, in the production of surface-treated plywood, particularly in the method of producing plywood requiring surface smoothness, by forming an intermediate treatment resin layer, to the overcoat resin, from the base treatment resin Since adverse effects can be avoided, the above-described problems as in the prior art can be solved, and the surface smoothness can be significantly improved.

About the aqueous polyurethane resin used in the present invention,
To give a more detailed description, for example, it is manufactured from the following raw materials.

That is, the following diassocyanate is reacted with the following glycol and a glycol having a carboxylic acid group to cause a urethanation reaction.

As the diassocyanate used at this time, a known aliphatic, alicyclic or aromatic diisocyanate can be used.

Such diisocyanates include, for example, 2,4-
Tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, m-
Phenylene diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 1,4-
Cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4 '
-Biphenylenediisocyanate, 3,3'-methoxy-4,
Known isocyanate-modified products such as 4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, garbodiimide-modified products, biuret-modified products, and urethane-modified products of these diisocyanates. .

These diisocyanates may be used in a mixture of two or more.

Examples of the glycols include glycol ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, trimethylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, bisphenol A, and ethylene of bisphenol A. Polyethers such as low molecular weight glycols such as oxide adducts, or polyols such as polyethylene glycol and polypropylene glycol, ethylene glycol and adipic acid,
Polyesters and polycaprolactone, which are condensates of hexanediol and adipic acid, ethylene glycol and phthalic acid, and a mixture of two or more of these glycols are used.

Examples of the glycols having a carboxylic acid group include, for example, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, and the like, or two or more glycols having these carboxylic acid groups. Is used.

The aqueous polyurethane resin composed of the above-mentioned raw materials can form a film having excellent adhesion, water resistance, and shielding properties. By forming this film between the undercoat resin layer and the overcoat resin layer, the undercoat is performed. Prevents the transfer of moisture from the resin layer and the base plate, suppresses the foaming phenomenon of the overcoating resin caused by moisture, and uses a low-temperature curing type resin to dry the synthetic material that has conventionally been generated by heating. The generation of distortion due to shrinkage can be prevented, and quality with excellent surface smoothness can be obtained.

The method of the present invention, top coat resin may conventionally coated amount was applied to obtain the surface smoothness does not need, in conventional approximately 2/3 (150gr / 3 × 6 feet ^2), and, overcoat The resin is also 1/2 (50 gr / 3 × 6 shaku ² ) of the conventional resin, and it is possible to obtain excellent surface smoothness.

As the manufacturing equipment, a conventional roll coater or knife coater can be used, and no special coating equipment is required.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 The undercoat resin was an aqueous polymer resin (Mitsui Toatsu Chemical Co., Ltd.)
100 parts by weight of MR-113) and 5 parts by weight of a crosslinking agent isocyanate (SB-225H manufactured by Mitsui Toatsu Chemicals, Inc.) were used. 4-5g
After r / scale ² coating, those dried for 3 minutes at 40 ° C. was used as a base plate.

Intermediate coating resin, (HU-101 manufactured by Mitsui Toatsu Chemicals Inc.) aqueous polyurethane resin relative to 10 parts by weight, a material obtained by adding a crosslinking agent 1 part by weight, after the treatment 2～3Gr / rod ² after coating ,
Dried at 40 ° C. for 3 minutes.

As the crosslinking agent, a compound containing at least one aziridine group was used.

The top coating resin is a polyol (Mitsui Toatsu Chemical Co., Ltd.)
To 100 parts by weight of (NM-450), 120 parts by weight of a curing agent isocyanate (CR-200 manufactured by Mitsui Toatsu Chemicals, Inc.) was added, and 5 parts by weight of a dissolving agent was further added.

After applying the above-mentioned overcoating resin at ² to 3 gr / scale ² , it was heated at 90 ° C. for 5 minutes, and further cooled in an atmosphere of 25 ° C. for 20 minutes.

As the resin used for the intermediate forming layer, the aqueous polyurethane resin is most excellent in workability and film properties.

Example 2 The undercoat resin was an aqueous polymer resin (Mitsui Toatsu Chemical Co., Ltd.)
100 parts by weight of MR-113) and 5 parts by weight of a crosslinking agent isocyanate (SB-225H manufactured by Mitsui Toatsu Chemicals, Inc.) were used. ~ 5gr /
After applying the shaku ^{2 and} drying at 40 ° C. for 3 minutes, it was used as a base plate.

The intermediate coating resin was prepared by adding 1 part by weight of a crosslinking agent to 100 parts by weight of an aqueous polyurethane resin (HU-101 manufactured by Mitsui Toatsu Chemicals Co., Ltd.), and after applying the above treatment, applying ^{2 to 3} gr / shaku2. rear
Dried at 40 ° C. for 3 minutes.

As the crosslinking agent, a compound containing at least one aziridine group was used.

The overcoat resin is a solvent-based urethane paint resin (Q-177 of Mitsui Toatsu Chemical Co., Ltd. layer) per 100 parts by weight of a curing agent urethane prepolymer (MC80-50CX manufactured by Mitsui Toatsu Chemical Co., Ltd.)
120 parts by weight were added, and further, 20 parts by weight of a dissolving agent was used.

After coating the above top coating resin at ² to 3 gr / shaku2, it was heated at 40 ° C. for 5 minutes and further cooled in a 25 ° C. atmosphere for 30 minutes.

As the resin used for the intermediate forming layer, the aqueous polyurethane resin is most excellent in workability and film properties.

Example 3 An undercoat resin was prepared by adding 80 parts by weight of calcium carbonate to 100 parts by weight of a melamine urea-formaldehyde resin (U-777 manufactured by Mitsui Toatsu Chemicals Co., Ltd.) and further adding a crosslinking agent isocyanate (Mitsui Toatsu) After adding 5 parts by weight of VU-6100H manufactured by Chemical Co., Ltd., and adding 1 part by weight of a curing agent,
After applying 4 to 5 gr / size ² to a plywood for a formwork, it was dried at 60 ° C. for 3 minutes and used as a base plate.

The intermediate coating resin was prepared by adding 1 part by weight of a crosslinking agent to 100 parts by weight of an aqueous polyurethane resin (HU-101 manufactured by Mitsui Toatsu Chemicals Co., Ltd.), and after applying the above treatment, after applying ^{2 to 3} gr / shaku2. ,
Dried at 40 ° C. for 3 minutes.

As the crosslinking agent, a compound containing at least one aziridine group was used.

The overcoat resin is 100 parts by weight of a solvent-based urethane paint resin (Q-177 manufactured by Mitsui Toatsu Chemicals, Inc.), and a curing agent urethane prepolymer (MC80-50CM manufactured by Mitsui Toatsu Chemicals, Inc.)
120 parts by weight were added, and further, 20 parts by weight of a dissolving agent was used.

After applying the above-mentioned top coat resin at ² to 3 gr / size ² , it was heated at 40 ° C. for 5 minutes, and further cooled in an atmosphere of 25 ° C. for 30 minutes.

As the resin used for the intermediate forming layer, the aqueous polyurethane resin is most excellent in workability and film properties.

Comparative Example 1 The undercoat resin was an aqueous polymer resin (Mitsui Toatsu Chemical Co., Ltd.)
To MR-113) 100 parts by weight of manufacturing, the crosslinking agent isocyanate (Mitsui Toatsu Chemicals Inc. The material obtained by adding SB-225H) 5 parts by weight made of, 4～5Gr / scale ² coated mold plywood Later, at 40 ℃ 3
The dried product was used as a base plate.

The top coating resin is a polyol (Mitsui Toatsu Chemical Co., Ltd.)
To 100 parts by weight of (NM-450), 120 parts by weight of a curing agent isocyanate (CR-200 manufactured by Mitsui Toatsu Chemicals, Inc.) was added, and 5 parts by weight of a dissolving agent was further added.

After applying the above-mentioned top-coating resin at ² to 3 gr / size ² , it was heated at 90 ° C. for 5 minutes and further cooled in a 25 ° C. atmosphere for 20 minutes.

Comparative Example 2 The undercoat resin was an aqueous polymer resin (Mitsui Toatsu Chemical Co., Ltd.)
To MR-113) 100 parts by weight of manufacturing, the crosslinking agent isocyanate (Mitsui Toatsu Chemicals Inc. The material obtained by adding SB-225H) 5 parts by weight made of, 4～5Gr / scale ² coated mold plywood Later, at 40 ℃ 3
The dried product was used as a base plate.

The overcoat resin is 100 parts by weight of a solvent-based urethane paint resin (Q-177 manufactured by Mitsui Toatsu Chemicals, Inc.), and a curing agent urethane prepolymer (CM80-50CM manufactured by Mitsui Toatsu Chemicals, Inc.)
120 parts by weight were added, and further, 20 parts by weight of a dissolving agent was used.

After applying the above-mentioned overcoating resin at ² to 3 gr / shaku2, it was heated at 40 ° C. for 5 minutes, and further cooled in a 25 ° C. atmosphere for 30 minutes.

Comparative Example 3 An undercoat resin was prepared by adding 80 parts by weight of calcium carbonate to 100 parts by weight of a melamine urea-formaldehyde resin (U-777 manufactured by Mitsui Toatsu Chemicals, Inc.) and further adding a crosslinking agent isocyanate (Mitsui Toatsu) after addition of chemical Co., Ltd. of VU-6100) 5 parts by weight, a material obtained by adding a curing agent 1 part by weight, after 4～5Gr / scale ² coated plywood formwork, dried for 3 minutes at 60 ° C. The thing was used as a base plate.

The overcoat resin is 100 parts by weight of a solvent-based urethane paint resin (Q-177 manufactured by Mitsui Toatsu Chemicals, Inc.) and a curing agent urethane prepolymer (MC80-50CX manufactured by Mitsui Toatsu Chemicals, Inc.)
120 parts by weight were added, and further, 20 parts by weight of a dissolving agent was used.

After applying the above-mentioned top-coating resin at ² to 3 gr / scale ² , it was heated at 40 ° C. for 5 minutes, and further cooled at 25 ° C. in an atmosphere for 30 minutes.

 Table 1 shows the above results.

In addition, the physical property measuring method of Table 1 measured based on Japanese Agriculture and Forestry standard of the plywood for concrete type frame.

[Effects of the Invention] According to the present invention, a water shielding effect due to the formation of the intermediate treatment coating layer is remarkably exhibited, and a foaming phenomenon due to a reaction between isocyanate groups in the overcoat resin and water is suppressed, so that the surface smoothness is improved. Is good, and the gloss is good is clear from Table 1.

Also, compared to the physical properties of existing concrete formwork plywood,
Since it has the same or better performance, it is possible to improve the quality of the product.

The resin for intermediate treatment used in the present invention is an aqueous resin, and does not cause environmental pollution problems as in the case of a solvent system.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a surface-treated plywood or a concrete form plywood manufactured by the method of the present invention.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code FI E04G 9/05 E04G 9/05 (56) References JP-A-63-83389 (JP, A) JP-A-61-118177 (JP) JP-A-2-43464 (JP, A) JP-A-62-133252 (JP, A) JP-A-62-221474 (JP, A) JP-A-62-75928 (JP, U) (58) Surveyed field (Int.Cl. ⁶ , DB name) B05D 7 / 06,7 / 24 B27D 5/00 E04G 9/05 B32B 7 / 02,7 / 04 B32B 21/00-21 / 08,21 / 14 B32B 27/08

Claims (3)

(57) [Claims] 1. A method for producing a surface-treated plywood and a concrete formwork plywood, wherein an intermediate-treated resin layer is formed between an undercoat resin layer and an overcoat resin layer. A method for producing a concrete formwork plywood, wherein the undercoating resin is cured at a temperature of 60 ° C. or lower using a curable aqueous resin, and the intermediate layer processing resin is an aqueous polyurethane resin. A method for producing a surface-treated plywood and / or a concrete formwork plywood, which is a feature. 2. The production of a surface-treated plywood and / or a concrete formwork plywood according to claim 1, wherein the overcoating resin is a solvent-based polyurethane coating resin or an isocyanate-polyol-based two-pack coating resin. Method. 3. An undercoating resin comprising urea / formaldehyde resin, melamine / formaldehyde resin, phenol / formaldehyde resin.
Formaldehyde resin, phenol melamine / formaldehyde resin, phenol melamine / urea / formaldehyde resin, and / or water-based polyurethane resin, water-based emulsion resin, water-based polymer / isocyanate resin mixed with 20-80% filler and hardener The method for producing a surface-treated plywood and / or a concrete formwork plywood according to claim 1, wherein the base treatment is performed with a resin made of the resin.