JPS6362364B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing reinforced wood using an air-drying unsaturated polyester resin copolymerizable monomer solution. It is known to treat wood with a vinyl monomer solution of unsaturated polyester resin to obtain reinforced wood with improved appearance, mechanical strength, and dimensional stability compared to that of wood. When the unsaturated polyester resin conventionally used for reinforced wood is cured in the air, it remains sticky due to incomplete curing on the surface in contact with the air, so it must be cured under a nitrogen gas atmosphere. The unsaturated polyester resin and its vinyl monomer solution have insufficient permeability into wood, and the resulting reinforced wood has insufficient dimensional stability, making it unsuitable for molded products. It was hot. However, the present inventors conducted extensive studies to solve these problems, and found that (a) a specific compound was used as the air-drying component, and (b) polyethylene glycol or polypropylene glycol having a specific molecular weight was used as the glycol component. The present invention was completed by discovering that the above-mentioned problem could be solved for the first time by using a copolymerizable monomer solution of an air-drying unsaturated polyester resin containing as an essential component. According to the present invention, the following remarkable effects can be achieved. (1) Since polyethylene glycol or polypropylene glycol of a specific molecular weight is contained as a glycol component, the permeability of the resin into the wood conduit is improved, thereby significantly improving the dimensional stability of the reinforced wood. (2) Therefore, it is particularly suitable for molded wood products. (3) Since the resin solution can be cured in an air atmosphere, it is economically very advantageous. (4) The mechanical strength of reinforced wood is also improved. Examples of the polyhydric alcohol partial allyl ether compound (a) which is the air-drying component of the air-drying unsaturated polyester resin in the present invention include mono- and diallyl ethers of trihydric alcohols such as trimethylolpropane and glycerin, pentaerythritol, diglycerin, Examples include mono-, di-, and triallyl ethers of tetrahydric alcohols such as ditrimethylolpropane, and mono-, di-, tri-, tetra-, and pentaallyl ethers of hexahydric alcohols such as dipentaerythritol and sorbitol. Such a polyhydric alcohol partial allyl ether compound is introduced into the molecular chain of the polyester (when there are two or more hydroxyl groups remaining) or at the end of the molecule (when there is one hydroxyl group remaining) during the reaction between polybasic acid and glycol. , exhibits air-drying effect. The allyl ether compound is used in a proportion of 0.01 to 0.5 mol per mol of the polybasic acid. Examples of tetrahydrophthalic anhydride and its derivatives include tetrahydrophthalic anhydride, entomethylenetetrahydrophthalic anhydride, and the like. Polybasic acid components of unsaturated polyester resin include maleic anhydride, maleic acid, fumaric acid,
Examples include itaconic acid, adipic acid, sebacic acid, isophthalic acid, and terephthalic acid. (b) As the glycol component, polyethylene glycol, polypropylene glycol, etc. having a molecular weight of 200 to 800 are used alone or in combination with other glycol components. If the molecular weight of the glycol is less than 200, the impregnation of the resin liquid into the wood will be insufficient, and there is a tendency for foaming to occur on the wood surface during curing, which is undesirable.If it exceeds 800, the viscosity of the resin liquid will be It is unsuitable because it tends to become too high and impregnate the wood. When a glycol component within the above molecular weight range and a glycol component outside the above molecular weight range are used together, it is appropriate to use the glycol component outside the range at a ratio of 80 mol % or less. Glycol components outside this range include ethylene glycol, propylene glycol, 14-butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, 1.6
-hexanediol, neopentyl glycol,
Examples include glycerin, pentaerythritol, etc. Furthermore, when tertiary alkanolamines such as dihydroxyethyl-P-toluidine, dihydroxypropyl-P-toluidine, etc. are used as a glycol component in a range of 0.01 to 0.1 mol%, impregnating properties into wood can be improved. Its use is desirable because it provides a significantly improved and tighter curing state. In addition, linseed oil, soybean oil, cottonseed oil, peanut oil,
Coconut oil, castor oil, etc., or reaction products of these fatty oils with polyhydric alcohols such as glycerin, are also used as the unsaturated polyester resin component. When obtaining an air-drying unsaturated polyester using each of the above-mentioned components, no special equipment is required, and the process may be carried out in a conventional manner using an ordinary polyester manufacturing apparatus. The molecular weight of the obtained air-drying unsaturated polyester resin is suitably in the range of 500 to 2,000. Copolymerizable monomers used when the air-drying unsaturated polyester resin is dissolved and used include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, vinylpyrrolidone, carbitol acrylate, ethylene glycol diacrylate, and diethylene glycol diacrylate. , triethylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, etc. Among them, those having a boiling point of 200° C. or higher are preferred because they are less likely to foam. Also, epoxy monomers (e.g. hydrogenated bisphenol A), diphenylmethane-4,4' disocyanate (MDI), polyisocyanates (Desmodyur L, Coronate L, Desmodyur VL,
When a small amount of Desmodyur HL, Coronate HL), resol type phenolic resin, etc. is blended into the resin solution of the present invention, the effect of improving the toughness and dimensional stability of reinforced wood by improving the impregnating property of the wood is observed, so it is desirable to use it. Furthermore, a small amount of a surfactant may be added in order to uniformly impregnate the wood with the resin solution. The curing catalyst for curing the resin solution in the present invention is a high temperature curing catalyst, and the catalyst includes:
Examples include benzoyl peroxide, dicumyl peroxide, tertiary butyl peroxide, etc., and as air drying accelerators, metal soaps such as cobalt naphthenate, cobalt octoate, manganese naphthenate, vanadyl octoate, etc. Examples include sulfides such as n-butyl sulfide, diphenyl sulfide, and tetramethylthiuram sulfide. When producing reinforced wood using the resin solution of the present invention, the wood or wood processed product is placed in a pressurized reaction can, and the pressure of the reaction can is reduced (50 mmHg to 2 mmHg) to remove moisture and air in the wood. . Next, the prepared resin liquid is gradually introduced into the wood or the wood product to completely immerse it in the resin liquid. Next, after maintaining the air pressure at 2 to 10 kg/cm ² for about 120 minutes using a compressor, the resin liquid is discharged from the system, and then maintained at 60 to 90° C. for about 1 to 4 hours. The reinforced wood thus obtained is suitable for a wide variety of applications such as furniture, musical instruments, baseball bats, golf club heads, textile shuttles, buttons, flooring, and interior decoration. Next, the present invention will be specifically explained with reference to Examples. In the examples, "parts" and "%" are based on weight. Example 1 1.0 mol of maleic anhydride, 0.3 mol of propylene glycol, polyethylene glycol (molecular weight
200) 0.8 mol, soybean oil fatty acid 0.1 mol and trimethylolpropane diallyl ether 0.4 mol, and the molecular weight was
1260 unsaturated polyester resin (Resin-A) was obtained. Resin - 40 parts of A, 20 parts of 2-hydroxyethyl methacrylate, ethylene glycol diacrylate
After adding 40 parts and stirring, 2 parts of benzoyl peroxide (50% paste) and 0.5 parts of cobalt octenoate (metal component 8%) were added to prepare a resin solution (solution-A) with a viscosity of 180 cps. Next, in a 1-volume autoclave, length 7.0 cm, diameter 4.0
Add several centimeters of egg-shaped ash wood and use a vacuum pump to
The wood was kept under reduced pressure of mmHg for 1 hour to remove moisture and air from the wood. Next, Solution-A was gradually introduced under the reduced pressure to completely immerse the wood in the resin solution. Next, the air pressure was maintained at 5 kg/cm ² for 30 minutes using a compressor, and the liquid was discharged from the system. After that, the air pressure was maintained at 80° C. for 2 hours, the pressure was reduced, and the ash wood was taken out. The surface of the ash wood was smooth and photosensitive, and its performance was excellent as shown in Table 1. Example 2 A resin with a molecular weight of 1300 was prepared in the same manner as in Example 1 except that 0.4 mol of tetrahydrophthalic anhydride and 0.6 mol of maleic anhydride were used in place of trimethylolpropane diallyl ether in Resin-A of Example 1.
An unsaturated polyester resin (Resin-B) was obtained. Add 20 parts of 2-hydroxypropyl acrylate and 40 parts of diethylene glycol diacrylate to 40 parts of resin B, stir, and then add 2 parts of benzoyl peroxide (50% paste) and 2 parts of cobalt octenoate (8% metal component) to adjust the viscosity. A 200 cps resin solution (solution-B) was prepared. Next, reinforced wood was obtained in the same manner as in Example 1. The performance is listed in Table 1. Example 3 In Resin-A of Example 1, 0.3 mol of propylene glycol was replaced with 0.28 mol of propylene glycol.
mol, dihydroxyethyl-para-toluidine
An unsaturated polyester resin (resin-C) with a molecular weight of 1500 was prepared in the same manner as in Example 1 except that 0.02 mol was used.
I got it. Add 20 parts of 2-hydroxyethyl acrylate and 40 parts of tetraethylene glycol diacrylate to 40 parts of resin-C and stir, then add 2 parts of benzoyl peroxide (80% paste) and 0.5 parts of cobalt octenoate (8% metal component). A resin solution (solution-C) with a viscosity of 230 cps was prepared. Next, reinforced wood was obtained in the same manner as in Example 1. The performance is listed in Table 1. Control Example 1 An unsaturated polyester resin having a molecular weight of 800 was obtained in the same manner as in Example 1, except that ethylene glycol was used in place of the polyethylene glycol in Example 1. 20 parts of 2-hydroxyethyl acrylate and 40 parts of tetraethylene glycol diacrylate were added to 40 parts of the resin, and after stirring, 2 parts of benzoyl peroxide (50% paste) and 0.5 parts of cobalt octenoate (metal component 8%) were added. viscosity
A resin solution of 250 cps was prepared. Reinforced wood was obtained in the same manner as in Example 1, and its performance is listed in Table 1. Control Example 2 An unsaturated polyester resin with a molecular weight of 2500 was obtained in the same manner as in Example 1, except that polyethylene glycol with a molecular weight of 1200 was used in place of the polyethylene glycol with a molecular weight of 200 in Example 1. 25 parts of 2-hydroxyethyl acrylate to 35 parts of the resin.
Part, tetraethylene glycol diacrylate 40
of benzoyl peroxide (50%
% paste) and 0.5 part of cobalt octenoate (metal component: 8%) were added to prepare a resin liquid with a viscosity of 320 cps. Reinforced wood was obtained in the same manner as in Example 1, and its performance is listed in Table 1. Control Example 3 An unsaturated polyester resin having a molecular weight of 1300 was obtained by baking in a conventional manner in the ratio of 0.7 mol of maleic anhydride, 0.3 mol of phthalic anhydride, 0.5 mol of ethylene glycol, 0.3 mol of propylene glycol, and 0.4 mol of ethylene glycol. 2 to 40 parts of the resin
- Add 20 parts of hydroxy methacrylate and 40 parts of ethylene glycol diacrylate and stir, then add 2 parts of benzoyl peroxide (50% paste) and 0.5 part of cobalt octenoate (metal component 8%),
A resin liquid with a viscosity of 170 cps was prepared. Reinforced wood was obtained in the same manner as in Example 1, and its performance is listed in Table 1. 【table】

Claims (1)

[Claims] 1. When producing reinforced wood by impregnating it with an unsaturated polyester resin liquid, (a) an air-drying component selected from the group consisting of a polyhydric alcohol partial allyl ether compound, tetrahydrophthalic anhydride and its derivatives; (b) a copolymerizable monomer solution of an air-drying unsaturated polyester resin containing polyethylene glycol or polypropylene glycol with a molecular weight of 200 to 800 as the glycol component; A method for producing unsaturated polyester resin-reinforced wood.