JP3283429B2 - Soft wood coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a protective material for soft wood such as Japanese cedar, Japanese red pine, larch, Japanese black pine, Abies sachalinensis, Scots pine, Japanese cypress and the like, and a function as a surface material utilizing the texture. It is intended to provide a paint for the purpose.

[0002]

[Prior Art] The foundation of Japan's forest resources (soft wood) is
It was built mainly by restoration afforestation after World War II and expanded afforestation in the 1955s, and is now in the harvesting season. Artificial forests made of soft wood, for example, cedar, have been planted mainly with a view to supplying pillars and the like used in conventional framing methods as shaft materials for houses.

In recent years, with the advent of various construction methods and the progress of rationalization, it has become necessary to use soft woods to exploit demand for various housing members and to aim for new uses. In response to such needs, it is urgently required to develop a system for production, processing and distribution of soft wood, and to develop technology and commercialize it.

At present, Iwate Prefecture is the second largest forest prefecture in Japan with the timber material production volume.
Demand is sluggish due to interruption of supply and competition with external timber, and cedar is in the process of cutting thinned timber.However, large use is not expected for the reasons mentioned above. .

However, softwoods such as Japanese red pine are characteristic in that the difference (color / hardness) between the early wood portion and the late wood portion is clear, the color tone is bright, and the softness is felt visually. And warmth and gentleness not found in inorganic materials
If these characteristics are utilized, various applications can be considered, which will lead to an increase in demand.

[0006]

SUMMARY OF THE INVENTION The present invention focuses on three characteristics: (1) light reflection characteristics of a soft wood coating surface; (2) thermal characteristics of a soft wood coating surface; and (3) scratch resistance of a soft wood coating surface. (1) and (2) are intended to enhance the protection function of the material surface by utilizing characteristics of the material by having characteristics similar to the same characteristics of the material surface.

[0007] Paints generally used for wood at present are mostly nitrified cotton lacquers, unsaturated polyester resin paints, UV-curable unsaturated resin paints, acid-curable amino resin paints, and polyurethane resin paints. I have. Among them, two-component acrylic resin-based polyurethane resin paints are mainly used.
However, since the coating film formed by the acrylic resin-based polyurethane resin paint has a high glass transition point and lacks elasticity, there is a problem in impact resistance when used for soft wood.

The acrylic-modified hydrogenated 1, used in the present invention,
2-Polybutadiene is an improved version of 1,2-polybutadiene polyol, which is known to exhibit very good performance in terms of elasticity. Since carbon-carbon double bonds that do not participate in urethane crosslinking affect the coloration of the coating over time, they are hydrogenated to eliminate the double bonds and then modified with acrylic to obtain elasticity and silicone resin. It is a resin with weatherability comparable to that of urethane-based urethane paints and fluorine resin-based urethane paints, and is most suitable for soft wood, and can also be used as an outdoor woodworking resin. Acrylic modified hydrogenation 1,
2-polybutadiene 40, toluene 30, butyl acetate 3
A vehicle consisting of 0 parts by weight has the appearance: a colorless transparent liquid, specific gravity: 0.950 to 0.960, viscosity (cp / 25 ° C.)
500-700, hydroxyl value 40 ± 1.

As the matte transparent type paint for fabric color finishing of wood, fine silica having a large oil absorption is mainly used as a matting agent, and other examples include aluminum stearate, polyethylene wax, polypropylene wax and the like. The light reflected on the surface of the wood painted with such a paint has almost a regular reflection component, which impairs the texture of the wood.

The present invention has been made in view of the above problems, and as a result of intensive studies on matting of a painted surface, the use of solvent-insoluble spherical synthetic resin beads as a matting agent impairs the feel of wood. The inventors have found that an excellent and excellent coating film can be obtained and completed the invention.

As the solvent-insoluble spherical synthetic resin beads used in the present invention, there are polyurethane type, acrylic copolymer type, acrylic urethane crosslinked type, polymethyl methacrylate coating type, polystyrene type, polyacrylonitrile type and the like.

The smaller the particle size of the spherical synthetic resin beads used in the present invention, the better the smoothness of the coating film.
If it is too small, the matte effect is poor and the reflected light from the coating film has a large specular reflection component. The particle size of the spherical synthetic resin beads is preferably 10 to 20 μm.

[0013] It has also been found that polyurethane beads which give a soft touch and texture to the formed coating film are suitable. Further, acrylic copolymer beads giving a hard feeling can be used in combination.

An antisettling agent is added to the coating composition to prevent the spherical synthetic resin beads used in the present invention from separating from the vehicle and settling at the bottom of the container. Its anti-settling agents include aluminum stearate, zinc stearate, organic bentonite, white carbon, lecithin, amino process clay, ethyl oleate, alkyl sulfonate, alkyl allyl sulfonate,
Colloidal organic esters, fatty acid amide waxes and the like can be used, but it is necessary that the anti-settling agent does not adversely affect the color, gloss, hardness, water resistance and the like of the coating film.
As a result of studying the above points, the antisettling agent used in the present invention is most preferably a fatty acid amide wax.

Acrylic-modified hydrogenation 1, 2 in the present invention
-A compound having two or more isocyanate groups is used as a curing agent for curing polybutadiene. As the curing agent, an adduct type or biuret type polyisocyanate can be used.

Specific examples of the curing agent include an adduct of tolylene diisocyanate, diphenylmethane diisocyanate or isophorone diisocyanate with trimethylpropane, a biuret of hexamethylene diisocyanate and an adduct of trimethylolpropane. When importance is placed on weather resistance, it is preferable to use an aliphatic isocyanate.

In the present invention, acrylic modified hydrogenation 1, 2
-The mixing ratio of the polybutadiene and the polyisocyanate compound is preferably 0.5 to 1.5 mol ratio in NCO / OH, but is not limited thereto.

In the present invention, acrylic modified hydrogenation 1, 2
-As a solvent for dissolving polybutadiene, one or a mixture of two or more selected from organic solvents such as aromatic hydrocarbons and esters is used.

The main component of the soft wood coating composition of the present invention may further contain an auxiliary agent such as a dispersant, a leveling agent, an anti-cissing agent, an antifoaming agent, and an ultraviolet absorber.

The following ratios show the best performance in the mixing ratio of the coating composition of the present invention.

(A) Acrylic-modified hydrogenated 1,2-polybutadiene 68.9-49.0 parts by weight (b) Polyurethane resin beads or a mixing ratio of polyurethane resin beads to acrylic copolymer beads of 1: 1.
~ 2: 1 mixture 31.0-5O. 0 parts by weight (c) Anti-settling agent 0.1-1.0 parts by weight A mixture of a hydrocarbon-based solvent and an ester-based solvent with respect to 100 parts by weight of the mixture of the above (a), (b) and (c) 180-
A mixture prepared in a proportion of 210 parts by weight is used as a main agent, and (d) a polyisocyanate compound is used as a curing agent.

The amount of the synthetic resin beads to be added to the coating composition of the present invention will be described below.
31.0 with respect to 100 parts by weight of the sum of components (b) and (c)
And the upper limit is 50.0 parts by weight from the limit of transparency.

In the present invention, the amount of the anti-settling agent for imparting thixotropic properties to the coating to prevent the sedimentation of the synthetic resin beads is 1.0 to 100 parts by weight of the sum of the components (a), (b) and (c). Not more than parts by weight. If the amount of the antisettling agent exceeds 1.0 part by weight based on 100 parts by weight of the sum of the components (a), (b) and (c), there is a drawback that the flowability at the time of coating deteriorates.
In the present invention, when the amount of the acrylic-modified hydrogenated 1,2-polybutadiene is 68.9 parts by weight or more, the glossiness is higher than the surface gloss of the wood material, and the diametrically opposite component in the reflection characteristics is increased. Feeling is lost. If the content is less than 49.0 parts by weight, the transparency of the coating film becomes poor,
Since the grain becomes unclear, the texture of the wood is impaired.

If the polyurethane resin beads or the mixture of polyurethane resin beads and acrylic copolymer beads in a mixing ratio of 1: 1 to 2: 1 is 31.0 parts by weight or less, the matte effect of the coating film is deteriorated and the surface of the wood material is deteriorated. It shows higher gloss than gloss, and the reflection characteristics have many opposite components,
The texture of wood is impaired. When the content is 50.0 parts by weight or more, the transparency of the coating film becomes poor, and as a result,
The wood grain becomes unclear, and the texture of the wood is impaired.

When the amount of the anti-settling material is 0.1 parts by weight or less, the thixotropic property of the coating material is reduced, and the synthetic resin beads are liable to settle in the container. And the stability of the paint becomes worse. If the amount is more than 1.0 part by weight, the thixotropic property of the paint becomes excessively large, so that the flowability of the applied coating film is deteriorated, so-called yuzu skin occurs, and a smooth coating film cannot be obtained.

When the mixture of the hydrocarbon solvent and the ester solvent is 180 parts by weight or less, the cost is unnecessarily increased. If the amount is more than 210 parts by weight, the viscosity of the composition decreases, and the function of preventing sedimentation is impaired.

[0027]

Next, the present invention will be described in more detail with reference to examples.

[0028]

Examples 1 to 4 are shown in Table 1. Each component was blended to produce a soft wood coating composition.

[0029]

[0030]

[Preparation of test pieces] After adjusting the base of red pine and cedar wood cut into a certain shape using abrasive paper of # 320, Ford cup # 4 was used for holding down the material and stopping suction of the topcoat paint. Using a polyurethane sanding sealer whose viscosity was adjusted with a thinner for 15 seconds, air spray coating was performed. After drying at room temperature for 24 hours, # 360
Medium sharpening was performed with abrasive paper.

Thereafter, each of Examples 1 to 4 shown in Table 1 was adjusted in viscosity with a thinner for 18 seconds using a Ford cup # 4, overcoated twice by air spray coating, and dried at room temperature for 48 hours to obtain test pieces.

The method for measuring the reflection characteristics, thermal characteristics and scratch resistance of the painted wood surface is described below.

Measurement of Reflection Characteristics of Painted Surface of Wood Regarding the red pine material, the cedar material and their reflection characteristics on the painted surface, the reflection light distribution was measured by a goniophotometer, and the reflection characteristics of the material surfaces were compared. Gonio Photometer is GP-2 manufactured by Murakami Color Research Laboratory.
A 00 horizontal rotation type was used.

Measurement of Thermal Characteristics of Wood Painted Surface The thermal conductivity of the Japanese red pine material, Japanese cedar material, and the test piece coated with them was measured, and the "warmth" and "heat retention" specific to wood were examined. Was done. The thermal conductivity measuring instrument used was a QTM-MD model manufactured by Showa Denko KK

Measurement of scratch resistance of painted wood surface The scratch resistance of the painted surface of red pine and cedar was determined by JI
S-K5400 8.4 The scratch of the coating film was evaluated using a pencil scratch tester and a pencil having a pencil hardness “H” specified in the pencil scratch value test. The evaluation was performed by removing the carbon powder of the pencil with an eraser so as not to damage the paint film at the tested location, and visually observing the surface of the test piece at a 45 degree angle perpendicular to the scratching direction. The scratches that could be discriminated were defined as "scratches", and the load was evaluated at that time.

[0036]

Comparative Examples 1 and 2 are shown in Table 2. Each component was blended to produce a coating composition. The preparation of the test piece was the same as in the example.

[0037]

[0038]

[Measurement results] The measurement results are shown in FIGS. 1, 2, 3, 4, 5 and 6.

[0039] FIG. 1 shows the measurement result of the reflected light distribution in the red pine wood, and FIG. 2 shows the measurement result of the reflected light distribution in the cedar wood. In each case, the horizontal axis indicates the reflection intensity%, the vertical axis is 0 °, and the horizontal axis is 90 °.

As can be seen from Tables 3 and 4, when the present invention is carried out, the thermal conductivity hardly increases.
It can be seen that the scratching strength is improved as can be seen from FIG.

[0041]

As to the reflection characteristics, the first to fourth embodiments show a wide curve close to the material from FIGS.
In Nos. 2 and 3, the specular reflection component is almost present, and the texture of wood is impaired.

The thermal properties are as shown in Tables 3 and 4. Examples 1 to 4 are close to the thermal conductivity values of the raw materials, but are comparative examples 1-2.
Has a high value, which hinders the feel of the material and makes the player feel cold.

With respect to the scratch resistance, Table 5 and Table 6 show that Comparative Example 1
It shows a value of 6 to 10 times that of ２2, and significant improvement in scratch resistance is recognized.

[Brief description of the drawings]

FIG. 1 is a view showing a reflected light distribution of a Japanese red pine.

FIG. 2 is a diagram showing a reflected light distribution of a cedar material.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhiro Ariga 4-2 Babaino, Shimomainai, Morioka-shi, Iwate Prefecture (72) Inventor Tatsuya Higashi 3078-14 Nakazato Kojoji, Noda-shi, Chiba Saito Saito Co., Ltd. Noda Factory (58) Field surveyed (Int.Cl. ⁷ , DB name) C09D 7/02

Claims (1)

(57) [Claims] 1. A) Acrylic-modified hydrogenated 1,2-polybutadiene 68.9-49.0 parts by weight b) Polyurethane resin beads or a mixture ratio of polyurethane resin beads and acrylic copolymer beads of 1: 1 to 1
2: 1 mixture 31.0 to 50.0 parts by weight c) Antisettling agent 0.1 to 1.0 part by weight A hydrocarbon solvent is used for 100 parts by weight of the mixture of the above a), b) and c), A mixture of ester-based solvents in a proportion of 180 to 210 parts by weight as a main component; d) a matte transparent two-pack type soft material for fabric color finishing characterized by using a polyisocyanate compound as a curing agent. Wood coating composition