JPH08197511A - Ligneous structure for building material - Google Patents

Abstract

PURPOSE: To obtain a ligneous structure for a building material which is excellent in water resistance, primer-impregnating property, and crack resistance by a method wherein a primer containing at least a polyoxyalkylene di(meth) acrylate is applied to a ligneous material, and paint for woodworking is applied thereto after curing. CONSTITUTION: A primer (I) containing a polyoxyalkylene di(meth)acrylate (A) as given in the formula I or polyoxyalkylene mono(meth)acrylate (B) as given in the formula II is applied to a ligneous material. After the primer (I) is cured, paint for woodworking is applied onto the primer (I) to obtain a required ligneous structure for a building material. Herein, R represents a hydrogen atom or a methyl group, R' represents a 2-4C alkylene group, and n represents the number of 2-15 means.

Description

Detailed Description of the Invention

[0001]

The present invention relates to water resistance, primer impregnability, and resistance to heat cracking due to repeated cold heat,
TECHNICAL FIELD The present invention relates to a building material having excellent abrasiveness and the like and excellent adhesion between a woodworking coating applied on the primer and a primer, and particularly to a wooden structure for building material suitable for flooring. Furthermore, it is a wooden structure suitable for a flooring material, which has good adhesion to a coating film for woodwork such as urethane resin of the surface layer.

[0002]

2. Description of the Related Art Conventionally, as a wooden structure for building materials, there is an untreated wood coated with a thermosetting resin. This is because the wood undergoes dimensional changes due to moisture release over time. There was a problem that a crack was generated in the layer. As a means for preventing this crack, (1) wood impregnated with polyoxyalkylene glycol monoacrylate or the like (JP-A-55-25324, JP-A-58-39403), (2) melamine resin Those impregnated with (Japanese Patent Laid-Open No. 1-247106) have been proposed.

[0003]

However, in the case of (1), the water resistance is insufficient, and in the case of flooring materials, the adhesion of the surface layer to a crosslinkable curable resin such as urethane resin is not good. or,
The method (2) requires a reduced pressure impregnation method or a reduced pressure and pressure impregnation method of press-fitting after depressurization, and thus has problems such as poor workability.

[0004]

The present inventors have arrived at the present invention as a result of intensive studies to overcome the above-mentioned drawbacks. That is, the present invention contains a polyoxyalkylene di (meth) acrylate (A) represented by the following general formula (1) or (A) and a polyoxyalkylene mono ((a) represented by the following general formula (2). A wooden structure for a building material, in which a primer (I) containing a (meth) acrylate (B) is applied to a wood material and cured, and then a paint for woodworking is applied. [In each formula, R is a hydrogen atom or a methyl group, and R'is a carbon atom of 2
~ 4 alkylene group, n represents a number of 2 to 15 on average. ]

The primer (I) may be only polyoxyalkylene di (meth) acrylate (A),
It may contain polyoxyalkylene mono (meth) acrylate (B) together with (A). The wooden structure treated with the primer containing only (B) has a high water absorption of the cured product, resulting in poor water resistance. For it,
The wooden structure treated with the primer containing (A) is
The water absorption rate is lower than that of (B) alone, and the water resistance is improved. Moreover, the impregnation property of the primer is superior to that of (B) alone, and the dimensional stability of the wooden structure is also excellent. Although (A) and (B) may be either acrylate or methacrylate, acrylate is suitable for ultraviolet curing.

In the general formulas (1) and (2), the oxyalkylene group may be one kind of oxyethylene group, oxypropylene group and oxybutylene group, or may be a combination of two or more kinds. The content of the oxyethylene skeleton in the polyoxyalkylene skeleton is preferably 50 to 100% by weight. When there are two or more kinds of oxyalkylene groups, block addition or random addition may be performed. General formula (1), (2)
In the above, n is an average number of 2 to 15. If n is less than 2 on average, cracks are likely to occur (dimension stability is poor), and if it exceeds 15 on average, the impregnated layer or coating layer of the cured resin is too soft, and clogging is likely to occur in sandpaper polishing as a post-treatment. Of the primer, and the viscosity of the primer increases, making impregnation difficult.

The polyoxyalkylene di (meth) acrylate (A), the polyoxyalkylene mono (meth) acrylate (B), and the mixture of (A) and (B) are, for example, (meth) acrylic acid and polyethylene glycol. It can be obtained by esterification reaction with polyalkylene glycol such as polypropylene glycol, polytetramethylene glycol, polyoxyethylene / oxypropylene glycol, or transesterification of (meth) acrylic ester such as methyl methacrylate with polyalkylene glycol.

The primer of the present invention comprises the above-mentioned (A),
In addition to (B), it further contains a pigment (C), a filler (D), a preservative (E), a radical initiator (F), an antioxidant (G), and an ultraviolet protective agent (H). May be. As the pigment (C), usual inorganic pigments and organic pigments used in paints for woodwork can be used. As the filler (D), usual inorganic powders / particles, organic powders / particles, inorganic / organic composite particles, inorganic fibers, and organic fibers used in paints for woodwork can be used. As the preservative (E), a conventional organic quaternary ammonium salt, organic iodine-based, bromine-based, sulfur-based, nitrogen-sulfur-based antiseptic / antifungal agent can be used.

The radical initiator (F) is an azo compound such as 2,2'-azobis (2,4-dimethylvaleronitrile) or azobisisobutyronitrile; ditertiary butyl hydroperoxide, ditertiary butyl. Peroxides, peroxides such as benzoyl peroxide; radical initiators for thermal polymerization such as redox type such as persulfate-sodium sulfite, 2-hydroxy-2-methyl-1-phenylpropan-1-one,
Examples thereof include photopolymerization initiators such as 1-hydroxycyclohexyl phenyl ketone. Antioxidants (G) include commonly used hindered phenols (2,6-di-tert-butyl-p-cresol etc.), aromatic amines (diphenylamine etc.), phosphorus-based antioxidants (triphenyl phosphite etc.). ) And the like. The ultraviolet absorber (H) is a commonly used benzophenone (2,4-dihydroxybenzophenone, etc.), benzotriazole [2 (2'hydroxy-3,5'-methylphenyl) benzotriazole, etc.), salicyl ester Examples thereof include phenyl salicinate and the like. In addition to these, an additive for a wooden structure may be optionally blended, and examples thereof include insecticides such as pentachlorophenol sodium salt, boric acid, and borax.

The wooden structure for a building material of the present invention is manufactured by applying the primer (I) to a wooden material and then curing it. Since the primer (I) has a very low viscosity, the wood material can be sufficiently impregnated not only in the time-consuming impregnation step but also in the coating step. The coating method includes coating with various coaters (rolls, knives), brush coating, and spraying.
You may perform the impregnation process that is usually performed other than the application,
As the impregnation method, in addition to a normal reduced pressure impregnation method, a reduced pressure and pressure impregnation method of applying pressure after depressurization is also possible. As a curing method by polymerization, not only thermal polymerization by a dryer but also photopolymerization by a mercury lamp or polymerization by electron beam irradiation is possible.

The woody structure of the present invention comprises primer (I).
After that, the surface is finished by applying a coating material for woodwork on the surface. When polyoxyalkylene glycol mono (meth) acrylate, which has been traditionally said to have good dimensional stability, is used as a primer, the adhesion to the paint coating for woodwork applied on it may not be perfect, Since the primer (I) has good adhesion to a coating film of urethane resin or the like, the wood structure of the present invention is particularly useful when used in a wood building material for floors where abrasion resistance of the surface is important. . The paint for woodworking used in the present invention may be a usual paint, for example, a polyurethane-based paint,
(Ultraviolet curing type) Acrylic-based, alkyd-based synthetic resin paints; natural resin paints such as cashew and lacquer are used.

[0012]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. Production Example 1 200 g of 144 g (2 mol) of acrylic acid and polyethylene glycol (PEG-200) having a number average molecular weight of 200
(1 mol) as a catalyst, p-toluenesulfonic acid 3 g
After reacting in a toluene solvent at 120 ° C. for 8 hours, toluene was distilled off to obtain PEG-200 diacrylate. To 100 g of this diacrylate, 2 g of 2,2′-azobis (2,4-dimethylvaleronitrile) (azo V) was added as a radical initiator, and the primer (I-
1) was obtained.

Production Example 2 130 g (1.8 mol) of acrylic acid and a number average molecular weight of 40
0 polyethylene glycol (PEG-400) 400
After reacting g in the presence of 5 g of p-toluenesulfonic acid in a toluene solvent at 120 ° C. for 8 hours, toluene was distilled off to obtain a PEG-400 dimethacrylate / monoacrylate mixture. 2 g of azo V was added to this di / monoacrylate to obtain a primer (I-2).

Production Example 3 172 g (2 mol) of methacrylic acid and a number average molecular weight of 200
Polyethylene glycol (PEG-200) 200g
(1 mol) was reacted in the presence of 4 g of p-toluenesulfonic acid in a toluene solvent at 120 ° C. for 8 hours, and then toluene was distilled off to obtain PEG-200 dimethacrylate. 2 g of azo V was added to this dimethacrylate to obtain a primer (I-3).

Production Example 4 PEG-200 diacrylate synthesized in Production Example 1
Darocur 117 as a photopolymerization initiator instead of Azo V
5 g of 3 (manufactured by Ciba-Geigy Co., Ltd.) was added to obtain a primer (I-4).

Comparative Production Example An autoclave having a stirring and temperature controlling function was charged with 130 g (1 mol) of hydroxyethyl methacrylate and tin tetrachloride as a catalyst, and 396 g of ethylene oxide.
It was reacted with (9 mol) for 6 hours to obtain PEG-400 monomethacrylate. 2 g of Azo V was added to this monomethacrylate to obtain a primer (II) for comparison.

Examples and Comparative Examples The methods for evaluating impregnability, water resistance and dimensional stability and the results thereof are shown below. The curing conditions for the primer are as follows. Thermal Polymerization Curing: In the case of Azo V blending (Primer I-1 to 3
And II) The test piece was cured at 120 ° C for 15 minutes in a circulating air dryer. Ultraviolet polymerization curing: In the case of Darocur 1173 blending (primer I-4), the test piece was irradiated with a high pressure mercury lamp of 80 w / cm and was irradiated while being passed at a speed of 5 m / min at a distance of 8 cm directly below the lamp to cure. [Impregnating Property] Table 1 shows the results of measuring the viscosities of the primers (I-1), (I-2) and (I-3) and the primer (II) at 25 ° C.

[0018]

[Table 1]

Next, the primers (I-1) and (II)
5.0 g was cast on a 10 cm × 10 cm plate with oak which was weighed in advance, and the whole was spread with a 100 μm thick bar coater. Thirty seconds after the casting and coating, the primer whose surface was not completely impregnated was immediately wiped off with a cloth and removed. Furthermore, separately from this, 60 seconds after coating,
The same observation and wiping operation after 120 seconds were performed using another plate with oak. The weight after coating and wiping was weighed, and the impregnated weight of the primer was calculated from the weight increase before and after this coating step. Time to wipe off after application (30 seconds,
After 60 seconds and 120 seconds) and the impregnated weight of the primer (g / 1
The relationship of 00 cm ² ) is shown in FIG. As shown in FIG. 1, the test piece coated with the primer (I-1) had a larger amount of the impregnated primer attached than the test piece (II).

[0020]

[Figure 1]

[Water resistance] The primers (I-1), (I-2) and (II) obtained in the production example and the comparative production example were respectively poured into a mold having a diameter of 5 cm and a depth of 3 mm, and a circulating air drier was used. A test piece of a cured resin was prepared by heating and curing in the inside. This test piece was pre-dried for 24 hours in a thermostat at 50 ° C., then cooled to 20 ° C. in a desiccator, and the weight before water absorption (W ₁ ) was measured. Next, the sample was immersed in a water absorbing container containing distilled water at 23 ° C. for 24 hours, taken out, wiped off the water, and then the weight (W ₂ ) of the water-absorbed test piece was measured. Table 2 shows the result of calculating the water absorption rate A (%) by the following formula. A = (W ₂ −W ₁ ) × 100 / W ₁ The water absorption of the test pieces prepared from the primers (I-1) and (I-2) of the present invention was lower than that of (II), and the water resistance thereof was excellent. It is clear from this.

[0022]

[Table 2]

[Crack resistance] (I-1) and (II)
Apply 100g of the primer of No.3 to a plate with a oak of 150 cm x 150 cm (thickness of the oval part is 0.2 mm).
After 0 seconds, the surface was wiped off with a cloth, and the resin was heat-cured in an air-circulation dryer to prepare two test pieces each. further,
The process of leaving untreated wood chips together with these test pieces in an incubator at 80 ° C. for 2 hours and then in an incubator at −20 ° C. for 2 hours was repeated twice and allowed to reach room temperature. This cycle of cold heat was defined as one cycle, and this step was repeatedly tested for 6 cycles. After reaching room temperature, rub white chalk and wipe it gently with a cloth.
A crack generated at a position separated by not less than cm was confirmed and its length was measured. Table 3 shows the total length. (I-
Both 1) and (II) have smaller crack lengths due to heat shock than the untreated test pieces, and have good dimensional stability.

[0024]

[Table 3]

[Adhesiveness] On the plate with oak coated with the primers (I-1) and (II) prepared in the above [Impregnation] column, polyurethane resin (clear lacquer) Samprene C-810-40 was further applied. (Manufactured by Sanyo Kasei Co., Ltd .; moisture-curable one-liquid type) was coated with 50 μm and left at room temperature for 24 hours. According to the cross-cut tape method (JIS-K5400), make 100 cross-cuts with a cutter knife at 1 mm intervals on the coating film surface, and check the peeling condition with cellophane tape.
Table 4 shows the number of squares that were not peeled off.

[0026]

[Table 4]

[0027]

The wooden structure for building materials of the present invention is water resistant,
Excellent primer impregnation, dimensional stability, and polishing. Further, it has a good adhesion between the primer and the coating film for woodworking such as urethane resin of the surface layer, and is therefore particularly suitable for flooring. It can be suitably used for furniture and wooden structures for walls.

[Brief description of drawings]

FIG. 1 is a diagram comparing the impregnating properties of primers of Examples and Comparative Examples.

[Explanation of symbols]

 (I-1) Primer (I-1) of Example (II) Primer (II) of Comparative Example

Claims (5)

[Claims] 1. A polyoxyalkylene di (meth) acrylate (A) represented by the following general formula (1) or containing (A) and a polyoxyalkylene mono ((a) represented by the following general formula (2): A wooden structure for a building material, which is obtained by applying a primer (I) containing a (meth) acrylate (B) to a wood material, curing the wood material, and then applying a paint for woodworking. [In each formula, R is a hydrogen atom or a methyl group, and R'is a carbon atom of 2
~ 4 alkylene group, n represents a number of 2 to 15 on average. ] 2. (A) / (B) in the primer (I)
The wooden structure according to claim 1, wherein the weight ratio is 100/0 to 50/50. 3. The wood structure according to claim 1, wherein the polyoxyalkylene skeleton of (A) has an oxyethylene skeleton content of 50 to 100% by weight. 4. The primer (I) comprises a pigment (C), a filler (D), a preservative (E), a radical initiator (F), an antioxidant (G) and an ultraviolet absorber (H). The wood structure according to any one of claims 1 to 3, further comprising one or more additives selected from the group consisting of: 5. The wood structure according to claim 1, wherein the primer (I) applied to the wood material is cured by irradiation with ultraviolet rays.