Method for manufacturing laminated lumber

Abstract

To provide a method for rationally obtaining a laminated lumber without requiring the mixing and preparation work of putty.SOLUTION: Laminas are stacked to obtain a laminated lumber substrate. Meanwhile, a one-component curable putty is prepared, consisting of modified silicone resin, a curing catalyst for the modified silicone resin, inorganic filler, silane coupling agent, and hydrophilic diluent. After filling a missing portion of the laminated lumber substrate with this one-component curable putty, it is cured by curing the one-component curable putty. After curing, a surface of the laminated lumber substrate is cut to obtain a laminated lumber. Alternatively, after cutting the surface of the laminated lumber substrate, the missing portion is filled with the one-component curable putty, then cured to cure the one-component curable putty and obtain a laminated lumber. Using an amino silane coupling agent as the silane coupling agent results in strong adhesion between the cured putty and the wood material.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a laminated lumber, and more particularly to a method for manufacturing a laminated lumber without defects from a laminated lumber substrate with defects on the surface. [Background technology]

[0002] Laminating and gluing lamina (sawn boards) to produce structural or joinery laminated lumber has long been practiced. However, defects caused by the lamina sometimes appear on the surface of the laminated lumber. For this reason, defects on the surface of the laminated lumber are typically filled with a putty based on acrylic resin, epoxy resin, urethane resin, or the like. However, because the hardening of the putty is primarily due to the evaporation of water or organic solvents, the putty shrinks (also known as "thinning"), reducing its adhesion to the defects and making the putty prone to falling off from the defects.

[0003] To overcome these drawbacks, Patent Document 1 proposes the use of a two-component curing putty consisting of a base agent containing a formaldehyde-based resin and a curing agent. Such two-component curing putty is preferable because it has good adhesion to wood materials. However, two-component curing putty requires mixing the base agent and the curing agent to obtain the putty. Therefore, there are drawbacks, such as the cumbersome mixing process and the inability to obtain a good putty due to mixing failure.

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-64769 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a method for obtaining laminated lumber in a rational manner without the need for mixing and preparing putty. [Means for solving the problem]

[0006] That is, the present invention relates to a method for manufacturing laminated timber, which includes a step of stacking lamina to obtain a laminated timber substrate, a repair step of filling defects in the laminated timber substrate with a one-component curing putty containing a modified silicone resin, an inorganic filler, and an aminosilane coupling agent, and then curing the one-component curing putty, and a cutting step of cutting the surface of the laminated timber substrate.

[0007] First, lamina are stacked to obtain a laminated wood substrate. The manufacturing process for such a laminated wood substrate is carried out by a conventionally known method. That is, the laminated wood substrate is obtained by stacking and bonding lamina in each of the length, width, and thickness directions.

[0008] The surface of a laminated wood substrate may have defects such as knotholes or cracks originating from the lamina. If defects exist, they are filled with a one-component curing putty. The one-component curing putty is then cured to repair the defects. The one-component curing putty is cured by curing for several hours to several tens of hours in a humid atmosphere. In the present invention, the one-component curing putty used contains a modified silicone resin, an inorganic filler, and an aminosilane coupling agent.

[0009] The modified silicone resin, which is a component of one-component curing putty, is a moisture-curing resin that has a main chain of polyoxyalkylene or polyacrylic, etc., and hydrolyzable silyl groups attached to the end of the main chain and / or the side chain. Here, the hydrolyzable silyl group is -SiR 1 a (OR 2 ) 3-a (However, R 1 represents an alkyl group having 1 to 10 carbon atoms, and R 2 represents an alkyl group having 1 to 6 carbon atoms, and a is 0, 1, or 2. The main chain may be a straight chain or a branched chain. In the present invention, it is preferable to use a branched chain. This is because a branched chain increases the crosslink density and makes cutting easier. The molecular weight of the modified silicone resin is optional, but a number average molecular weight of about 1,000 to 15,000 is preferred.

[0010] Conventional inorganic fillers can be used. Examples include calcium carbonate, such as heavy calcium carbonate and surface-treated calcium carbonate; glass balloons or fumed silica; finely powdered silica; and silica, such as surface-treated finely powdered silica. Adding an inorganic filler improves cutting performance. The aminosilane coupling agent is a silane coupling agent having an amino group as a functional group, and conventionally known aminosilane coupling agents can be used. For example, functional groups include those having an ethylenediamine structure, a primary amine, an aniline structure, or a primary amino group. Specifically, Shin-Etsu Chemical Co., Ltd.'s "KBM603," "KBM602," "KBE903," "KBM573," and "KBM903" can be used. Such aminosilane coupling agents strengthen the bond between the cured modified silicone resin and wood, making the cured modified silicone resin less likely to fall off during cutting.

[0011] The blending ratio of the modified silicone resin, inorganic filler, and aminosilane coupling agent is preferably as follows: That is, the inorganic filler is preferably 200 to 800 parts by mass per 100 parts by mass of the modified silicone resin. If the blending amount of the inorganic filler is less than 200 parts by mass, cutting tends to be difficult. On the other hand, if the blending amount of the inorganic filler is more than 800 parts by mass, the filler powder tends to scatter during cutting, and the viscosity becomes high, making it difficult to apply to the defect area.

[0012] The amount of aminosilane coupling agent is preferably 0.1 to 3 parts by mass per 100 parts by mass of modified silicone resin. If the amount of aminosilane coupling agent is less than 0.1 part by mass, the adhesive strength between the cured modified silicone resin and wood tends to decrease. On the other hand, if the amount of aminosilane coupling agent is more than 3 parts by mass, it tends to be difficult to further improve the adhesive strength between the cured modified silicone resin and wood.

[0013] The one-component curing putty preferably further contains a hydrophilic diluent and / or a curing catalyst. Conventional known hydrophilic diluents and curing catalysts are used. For example, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, etc. are used as hydrophilic diluents. Tin-based catalysts, titanium-based catalysts, etc. are used as curing catalysts. The inclusion of a hydrophilic diluent is preferred because it facilitates the absorption of atmospheric moisture during use of the one-component curing putty, facilitating the curing of the modified silicone resin. The inclusion of a curing catalyst is also preferred because it accelerates the curing of the modified silicone resin.

[0014] The amount of hydrophilic diluent blended is preferably 5 to 50 parts by mass per 100 parts by mass of modified silicone resin. If the amount of hydrophilic diluent blended is less than 5 parts by mass, the modified silicone resin tends to be difficult to cure. On the other hand, if the amount of hydrophilic diluent blended is more than 50 parts by mass, the viscosity of the one-component curing putty decreases, making it difficult to work with. The amount of curing catalyst blended is preferably 0.5 to 10 parts by mass, more preferably 4 to 8 parts by mass, per 100 parts by mass of modified silicone resin. If the amount of curing catalyst blended is less than 0.5 parts by mass, the curing of the modified silicone resin tends to be slow, and internal curing tends to require a long time. Even if the amount of curing catalyst blended is more than 10 parts by mass, the effect of promoting the curing of the modified silicone resin tends not to improve. Various conventional additives may be blended into the one-component curing putty. For example, dehydrating agents, colorants such as dyes and pigments, weathering agents, UV absorbers, anti-aging agents, etc. may be blended.

[0015] After a repair process in which defects in a laminated wood substrate are filled with a one-component hardening putty and the one-component hardening putty is hardened, a cutting process is carried out in which the surface of the laminated wood substrate is cut. The cutting process may also be carried out before the repair process. Furthermore, a preliminary cutting process may be followed by a repair process, and then a further cutting process may be carried out. Cutting of the surface is carried out by a conventionally known method, and is generally carried out using a molder. Cutting by sanding using a file is also used. In this cutting process, the surface of the laminated wood substrate is cut by about 1 to 3 mm.

[0016] The laminated lumber obtained in this manner is used as structural laminated lumber for beams, pillars, etc., or as joinery laminated lumber for furniture applications such as tables, etc. The one-component hardening putty used in the present invention is not only used in the manufacturing method of laminated lumber, but is also employed to fill and repair defects in wood materials. [Effects of the Invention]

[0017] The method of the present invention uses a specific one-component hardening putty, which eliminates the need for mixing and preparing the putty, resulting in the streamlined production of laminated timber. Furthermore, the putty has good adhesion to the wood material after hardening, which means that the putty is less likely to fall off during the cutting process of the laminated timber substrate. [Example]

[0018] [Production of one-component hardening putty 1] The raw materials having the following composition were uniformly mixed to obtain a one-component hardening putty 1. Modified silicone resin 240 parts by mass (Kaneka Corporation "SAX015") Surface-treated calcium carbonate 500 parts by mass (Maruo Co., Ltd. "Kalfain 200M") Heavy calcium carbonate 800 parts by mass (Maruo Co., Ltd. "08 Heavy Coal") Dipropylene glycol dimethyl ether 80 parts by mass ("Proglide DMM" manufactured by Ando Parachemie Co., Ltd.) Aminosilane coupling agent 1 part by mass ("KBM603" manufactured by Shin-Etsu Chemical Co., Ltd.) Vinyl silane coupling agent 5 parts by mass ("KBM1003" manufactured by Shin-Etsu Chemical Co., Ltd.) Tin-based catalyst 15 parts by mass ("Neostan U220H" manufactured by Nitto Kasei Co., Ltd.)

[0019] [Production of one-component hardening putty 2] One-component curing putty 2 was obtained in the same manner as one-component curing putty 1, except that the amount of surface-treated calcium carbonate ("Calfine 200M" manufactured by Maruo Co., Ltd.) was reduced to 400 parts by mass and 100 parts by mass of glass bubbles ("Glass Bubbles S38" manufactured by 3M Corporation) was added.

[0020] [Production of one-component hardening putty 3] The raw materials having the following composition were uniformly mixed to obtain a one-component hardening putty 3. Modified silicone resin 260 parts by mass (Kaneka Corporation "SAX730") Surface-treated calcium carbonate 200 parts by mass (Maruo Co., Ltd. "Kalfain 200M") Heavy calcium carbonate 400 parts by mass (Maruo Co., Ltd. "08 Heavy Coal") Glass balloons 50 parts by mass (3M Glass Bubbles S38) Dipropylene glycol dimethyl ether 17.5 parts by mass ("Proglide DMM" manufactured by Ando Parachemie Co., Ltd.) Aminosilane coupling agent 1 part by mass ("KBM603" manufactured by Shin-Etsu Chemical Co., Ltd.) Vinyl silane coupling agent 5 parts by mass ("KBM1003" manufactured by Shin-Etsu Chemical Co., Ltd.) Tin-based catalyst 15 parts by mass ("Neostan U220H" manufactured by Nitto Kasei Co., Ltd.)

[0021] [Production of one-component hardening putty 4] One-component curable putty 4 was obtained in the same manner as one-component curable putty 3, except that dipropylene glycol dimethyl ether ("Hisorb MPM" manufactured by Toyo Kasei Kogyo Co., Ltd.) was used instead of dipropylene glycol dimethyl ether ("Proglide DMM" manufactured by Ando Parachemie Co., Ltd.).

[0022] [Production of one-component hardening putty 5] One-component curable putty 5 was obtained in the same manner as one-component curable putty 3, except that an isoparaffin-based hydrophobic diluent ("Isopar H" manufactured by ExxonMobil Corporation) was used instead of dipropylene glycol dimethyl ether ("Proglide DMM" manufactured by Ando Parachemie Co., Ltd.).

[0023] [Production of one-component hardening putty 6] The raw materials having the following composition were uniformly mixed to obtain a one-component hardening putty 6. Modified silicone resin 230 parts by mass (Kaneka Corporation "SAX730") Surface-treated calcium carbonate 230 parts by mass (Maruo Co., Ltd. "Kalfain 200M") Heavy calcium carbonate 400 parts by mass (Maruo Co., Ltd. "08 Heavy Coal") Glass balloons 50 parts by mass (3M Glass Bubbles S38) Aminosilane coupling agent 1 part by mass ("KBM603" manufactured by Shin-Etsu Chemical Co., Ltd.) Vinyl silane coupling agent 5 parts by mass ("KBM1003" manufactured by Shin-Etsu Chemical Co., Ltd.) Tin-based catalyst 15 parts by mass ("Neostan U220H" manufactured by Nitto Kasei Co., Ltd.)

[0024] [Production of one-component hardening comparative putty 1] A one-component curable comparative putty 1 was obtained in the same manner as one-component curable putty 3, except that an aminosilane coupling agent (KBM603 manufactured by Shin-Etsu Chemical Co., Ltd.) was not added.

[0025] [Production of one-component hardening comparative putty 2] A one-component curable comparative putty 2 was obtained in the same manner as one-component curable putty 6, except that an aminosilane coupling agent (KBM603 manufactured by Shin-Etsu Chemical Co., Ltd.) was not added.

[0026] [Measurement of viscosity (Pa s)] The viscosities of the one-component curable putties 1 to 6 and the one-component curable comparative putties 1 and 2 were measured using a TVB35H (S Resin) B-type viscometer manufactured by Toki Sangyo Co., Ltd. under the following conditions: a temperature of 23°C, humidity of 50%, and a No. 7 rotor were used to measure the viscosities at rotational speeds of 1 rpm and 10 rpm. The viscosity (Pa·s) at a rotational speed of 1 rpm was designated "viscosity 1," and the viscosity (Pa·s) at a rotational speed of 10 rpm was designated "viscosity 10," and these are shown in Table 1. The specific gravities of the one-component curable putties 1 to 6 and the one-component curable comparative putties 1 and 2 are also shown in Table 1.

[0027] [Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Viscosity 1 Viscosity 10 Specific gravity ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ One-component hardening putty 1 4760 860 1.85 One-component hardening putty 2 3630 750 1.55 One-component hardening putty 3 3100 555 1.40 One-component hardening putty 4 3430 600 1.40 One-component hardening putty 5 3110 565 1.40 One-component hardening putty 6 3820 740 1.50 1-component hardening comparative putty 1 3200 610 1.40 1-component hardening comparison putty 2 4000 750 1.40 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0028] [Evaluation of adhesion to wood materials] Each of the one-component hardening putties 1 to 6 and the one-component hardening comparative putties 1 and 2 was applied to the surface of one Douglas fir lamina to a thickness of 1 mm, and another Douglas fir lamina was laminated and bonded to the applied surface. After curing for 24 hours at 23°C, each Douglas fir lamina was grasped with the fingers and peeled off. Observation of the state of peeling revealed that the one-component hardening putties 1 to 6 had peeled off due to cohesive failure. On the other hand, the one-component hardening comparative putties 1 and 2 had peeled off at the interface between the wood and the putty. This demonstrates that the one-component hardening putties 1 to 6 have good adhesion to wood.

[0029] [Evaluation of workability and machinability] When one-component hardening putties 1 to 6 were used with a spatula to fill a defect (a cylindrical shape with a diameter of 40 mm and a depth of 12 mm) in a laminated timber substrate at 10°C, the spread, release, and shape retention of each putty were excellent. After filling the defect with each putty and allowing it to harden for 16 hours, the surface of the laminated timber substrate was cut five times, each at 0.4 mm intervals (a total of 2 mm), using an automatic planer (Yuki Kogyo Co., Ltd.'s "SP-200"). The hardened putty did not adhere to the blade of the automatic planer, and the surface of the defect filled with each putty was smooth, resulting in a smooth-surfaced laminated timber. Furthermore, one month after filling with each putty, no thinning of the hardened putty was observed.

Claims

1. A step of stacking the laminas to obtain a laminated wood substrate; A repair process in which the defective portion of the laminated wood substrate is filled with a one-component hardening putty containing a modified silicone resin, an inorganic filler, and an aminosilane coupling agent, and then the one-component hardening putty is hardened; A cutting step of cutting the surface of the laminated wood substrate A method for manufacturing laminated wood, comprising:

2. 2. The method for manufacturing a laminated lumber according to claim 1, wherein the cutting step is carried out after the repairing step.

3. The method for manufacturing a laminated lumber according to claim 1, wherein a repairing step is carried out after the cutting step.

4. 2. The method for producing laminated wood according to claim 1, wherein the one-component hardening putty further contains a hydrophilic diluent and / or a hardening catalyst.

5. A one-component hardening putty for filling defects in wood materials, comprising a modified silicone resin, an inorganic filler, and an aminosilane coupling agent.

6. 6. The one-component curable putty according to claim 5, further comprising a hydrophilic diluent and / or a curing catalyst.