JP5467889B2 - Woodwork paint - Google Patents

Description

  The present invention relates to a two-component woodworking paint using a paint base and a curing agent mixed.

  Wood such as oak, zelkova, tochi, cedar and cypress is widely used for furniture and building members. However, wood generally has a low hardness and the surface is easily scratched. For this reason, the surface is painted particularly in applications such as furniture. In addition, the coating also has an effect that the unevenness of the wood surface can be reduced.

  As a paint for wood, there is a two-pack type woodwork paint used by mixing a paint main agent and its curing agent at the time of use. Specifically, for example, there is a coating composition composed of a coating agent containing a polyol resin and a curing agent containing a polyisocyanate resin (see Patent Document 1).

  When such a paint main ingredient and a curing agent are mixed, the hydroxyl (OH) group of the polyol resin and the isocyanate (NCO) group of the polyisocyanate resin react to form a urethane bond and cure. Since the reaction proceeds at room temperature and forms a stable urethane bond, a coating film having excellent hardness can be formed.

  However, when soft wood such as cedar is applied to uses such as furniture, a paint for woodwork having higher hardness is desired. Therefore, a wood coating material in which natural fiber is added to the coating material has been developed (see Patent Document 2).

JP-A-5-32759 JP 2009-209237 A

As described above, in order to apply soft wood to uses such as furniture, a woodworking paint having a higher hardness equal to or higher than that of Patent Document 2 is required.
However, when natural fibers are used for the paint as in Patent Document 2, the surface roughness of the coating film surface after drying tends to increase. Therefore, the unevenness of the surface is conspicuous, and it becomes difficult to use it for applications such as furniture that requires design. In addition, there is a problem in that it cannot be applied to a table, a desk, or the like, particularly requiring smoothness on the surface.
Therefore, in order to apply the soft wood in applications furniture or the like, not only indicates to the higher hardness, the development of superior wood coatings in smoothness has been desired.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a woodworking paint that exhibits excellent hardness after curing and can form a smooth coating film.

The present invention relates to a two-component woodworking paint using a mixture of a paint base containing a polyol resin and a curing agent containing a polyisocyanate resin.
The paint base contains 10 to 70 parts by mass of synthetic fiber with respect to 100 parts by mass of the polyol resin ,
The synthetic fiber is in a woodworking paint having a fiber length of 80 to 200 μm (Claim 1).

The most notable point in the woodwork paint of the present invention is that the paint base contains the specific amount of the synthetic fiber.
Therefore, the above-mentioned paint for woodwork can exhibit excellent hardness after curing, and can form a smooth coating film as compared with the case where, for example, natural fibers are added.
Synthetic fibers have a constant shape compared to natural fibers, so when used in the above-mentioned paint for woodwork, they have the effect of increasing the hardness of the coating film as described above, and prevent unevenness that may occur on the surface. Can do.

  Since the paint base contains a polyol resin having a hydroxyl group, and the curing agent contains a polyisocyanate resin having an isocyanate group, when the paint base and the curing agent are mixed when the woodwork paint is used, the hydroxyl group and The isocyanate group reacts to form a urethane bond and is cured to form a coating film made of a polyurethane resin.

  Since the coating film contains synthetic fibers as described above, the coating film can exhibit high hardness and hardly forms irregularities on the surface. That is, if the woodworking paint is used, a coating film having high hardness and excellent surface smoothness can be formed.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the cross-section of the cedar veneer which formed the undercoat coating film, the intermediate coating film, and the topcoat film concerning Example 1 on the surface. Explanatory drawing which shows the roughness curve measured about arbitrary site | parts A of the coating film formed with the coating material for woodwork (sample X17) concerning Example 2. FIG. Explanatory drawing which shows the roughness curve measured about the arbitrary site | parts B of the coating film formed with the coating material for woodwork (sample X17) concerning Example 2. FIG. Explanatory drawing which shows the roughness curve measured about the arbitrary site | parts C of the coating film formed with the woodwork coating material (sample X17) concerning Example 2. FIG. Explanatory drawing which shows the roughness curve measured about arbitrary site | parts A of the coating film formed with the coating material for woodwork (sample X18) concerning Example 2. FIG. Explanatory drawing which shows the roughness curve measured about arbitrary site | parts B of the coating film formed with the woodwork coating material (sample X18) concerning Example 2. FIG. Explanatory drawing which shows the roughness curve measured about arbitrary site | parts C of the coating film formed with the coating material for woodwork (sample X18) concerning Example 2. FIG. Explanatory drawing which shows the roughness curve measured about arbitrary site | parts A of the coating film formed with the coating material for woodwork (sample X19) concerning Example 2. FIG. Explanatory drawing which shows the roughness curve measured about the arbitrary site | parts B of the coating film formed with the coating material for woodwork (sample X19) concerning Example 2. FIG. Explanatory drawing which shows the roughness curve measured about the arbitrary site | parts C of the coating film formed with the woodwork coating material (sample X19) concerning Example 2. FIG.

  The woodworking paint of the present invention is a two-component woodworking paint used by mixing a paint base containing a polyol resin and a curing agent containing a polyisocyanate resin. The wood paint is used by mixing the paint main agent and the curing agent at the time of use. When the coating agent and the curing agent are mixed and applied to wood, curing proceeds at room temperature, and a coating film having high hardness can be formed on the surface of the wood.

The woodworking paint can be applied to wood such as oak, zelkova, tochi, cedar and hinoki.
Preferably, it is good to apply to soft wood, such as cedar. In this case, the effect of improving the hardness by the woodworking paint becomes more remarkable.

  The woodwork paint comprising the paint base and the curing agent can be used as an undercoat paint for forming an undercoat film. Further, by adding silica, talc, zinc stearate and the like to the woodworking paint as appropriate, it can be used as an intermediate coating and a top coating to form an intermediate coating film and a top coating film.

Examples of the polyol resin in the coating material include a polyester resin having a hydroxyl group, an acrylic resin, a polyether resin, and an epoxy resin.
Preferably, the polyol resin may be at least one selected from a polyester polyol resin, an acrylic polyol resin, and an alkyd polyol resin.
In general, when a coating film having high hardness is formed, the usable time of the coating is shortened, the strain at the time of curing is increased, the coating film is discolored, and the coating film is easily cracked. By employing one or more selected from the above-mentioned polyester polyol resins, acrylic polyol resins, and alkyd polyol resins, it is possible to form a coating film with high hardness while avoiding these problems.
Moreover, as said polyol resin, it is preferable to employ | adopt the thing of OH values 100-300.

Examples of the polyisocyanate resin include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (MDI), and the like.
In the woodworking paint, the paint base and the curing agent are mixed and the polyol resin and the polyisocyanate resin are reacted to form a urethane bond to form a polyurethane resin, which can be cured.

The said coating material main ingredient contains 10-70 mass parts of synthetic fibers with respect to 100 mass parts of said polyol resins. When the content of the synthetic fiber is less than 10 parts by mass with respect to 100 parts by mass of the polyol resin, the hardness may not be sufficiently improved. On the other hand, even if added in excess of 70 parts by mass, the effect of improving hardness is almost lost and the cost may increase.
More preferably, the content of the synthetic fiber is preferably 20 parts by mass or more, and more preferably 25 parts by mass or more with respect to 100 parts by mass of the polyol resin.

The synthetic fiber is preferably at least one selected from vinylon fiber, polyamide synthetic fiber, polyester synthetic fiber, polyolefin synthetic fiber, rock wool, and glass wool.
In this case, the improvement effect of hardness and surface smoothness can be made more remarkable. Particularly preferred is vinylon fiber.
As the polyamide-based synthetic fiber, for example, nylon fiber, as the polyester-based synthetic fiber, for example, polyethylene terephthalate fiber, and as the polyolefin-based synthetic fiber, for example, polyethylene fiber, polypropylene fiber, or the like can be used.

As said synthetic fiber, it is preferable to employ | adopt a fiber length of 80-200 micrometers.
In this case, the above-mentioned effect that the hardness and the surface smoothness can be improved becomes more remarkable. When the fiber length is less than 80 μm, the fibers cannot be sufficiently entangled with each other, and the effect of improving the hardness may not be sufficiently obtained. Further, the amount of synthetic fiber added to sufficiently increase the hardness is increased, which may increase the cost. On the other hand, when it exceeds 200 μm, unevenness on the surface of the coated film after curing becomes violent, and the surface smoothness may be lowered.

The coating agent and the curing agent can contain an appropriate amount of an organic solvent so that the viscosity and the like can be adjusted and mixing and coating can be easily performed.
Preferably, the coating agent contains 100 to 250 parts by mass of an organic solvent with respect to 100 parts by mass of the polyol resin.
When the content of the organic solvent is less than 100 parts by mass, the viscosity becomes high, and it may be difficult to mix with a curing agent or to be applied to wood after mixing. On the other hand, when the amount exceeds 250 parts by mass, the paint components are easily separated, the composition becomes non-uniform, and the paint tends to accumulate around the object to be coated, making it difficult to apply with a uniform thickness. There is. More preferably, the content of the organic solvent is 150 to 200 parts by mass with respect to 100 parts by mass of the polyol resin.

  From the same viewpoint, the curing agent preferably contains 100 to 200 parts by mass of an organic solvent with respect to 100 parts by mass of the polyisocyanate resin. More preferably, 120-170 mass parts is good.

Solvents used for the paint base and the curing agent can be appropriately selected according to the types of the polyol resin and the polyisocyanate resin, respectively.
Specific examples of the organic solvent include ester solvents such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate (PGA).

  The coating material base and the curing agent can be used by being appropriately mixed at an optimal mixing ratio depending on the contents of the polyol resin and the polyisocyanate resin.

Example 1
Next, examples and comparative examples of the woodwork paint according to the present invention will be described.
The woodworking paint according to the example is a two-component woodworking paint used by mixing a paint base containing a polyol resin and a curing agent containing a polyisocyanate resin. The paint base contains 10 to 70 parts by mass of synthetic fiber with respect to 100 parts by mass of the polyol resin.

  In this example, as shown in Tables 1 to 3 below, a paint base containing an additive composed of synthetic fibers, natural fibers, or inorganic compounds is prepared, and these properties are compared and evaluated. That is, in this example, as shown in Tables 1 to 3, 31 types of woodworking paints were produced by changing the types and amounts of additives in the paint main agent.

  In this example, the coating agent is added to synthetic resin, natural fiber, or an inorganic compound and a solvent at a ratio shown in Tables 1 to 3 described below with respect to 100 parts by mass of the polyol resin, and stirred with a desper. Produced. In addition, a paint base material (sample X1) to which any of synthetic fibers, natural fibers, and inorganic compounds was not added was also prepared for comparison (see Table 1).

In this example, as the polyol resin, polyester resin PO265-78 manufactured by Thai Do No Gen Gen, which is an isocyanate curable polyester resin, was used.
As synthetic fibers, vinylon fibers ("Vinylon fiber" manufactured by Unitika Ltd., fiber length 80 to 150 [mu] m), or rock wool ("Lappinas fiber" manufactured by Lapinus, fiber length 100 to 150 [mu] m) are used. did.

As natural fibers, wood powder (fiber length 100 to 300 μm) obtained by cutting and sizing cedar with a saw, or cellulose powder (KC Flock manufactured by Nippon Paper Chemicals Co., Ltd., average fiber length 28 μm) was employed.
As an inorganic compound additive, a foamed glass sphere (Taisetsu balloon manufactured by Biei Shirachi Kogyo Co., Ltd., average particle size of 120 μm) was employed.
Moreover, butyl acetate was used as a solvent.

Next, the curing agent was prepared by mixing 122 parts by mass of the solvent with respect to 100 parts by mass of the polyisocyanate resin.
As the polyisocyanate resin, “Takenate D204” manufactured by Mitsui Chemicals, Inc., which is a TDI type polyisocyanate, was employed. As the solvent, butyl acetate was used in the same manner as the coating material.

  Next, as shown in FIG. 1, using the woodworking paints of Sample X1 to Sample X31 prepared in this example, the surface of the wood (cedar veneer) 1 is coated with an undercoat coating 2, an intermediate coating 3, A top coat film 4 was formed.

  In forming the undercoat coating film 2, first, for each sample, a paint main agent and a curing agent were mixed to prepare an undercoat paint. This paint was applied to the surface of the cedar veneer 1 with a spray gun at a coating amount of 20 g / scale. Then, it dried at room temperature for 1 hour, the coating material was hardened, and the coating film was formed in the surface of a cedar veneer. Next, the same coating material was further applied onto the cured coating film in the same manner as the first coating, and dried at room temperature for 4 hours. Thus, as shown in FIG. 1, the undercoat coating film 2 was formed on the surface of the cedar veneer 1. The film thickness of the undercoat film 2 after drying is about 160 μm.

Next, the intermediate coating film 3 was formed on the undercoating film 2 as follows.
First, 5% by mass of talc and 3% by mass of zinc stearate were added to the mixture of the main coating material and the curing agent used for forming the undercoat coating film 2 to prepare an intermediate coating material. This intermediate coating material was applied onto the undercoat coating film 2 with a spray gun at an application amount of 10 g / scale and dried at room temperature for 30 minutes to cure the coating material. Next, the same paint was further applied in the same manner as in the first coating, and dried at room temperature for 4 hours. Thus, as shown in FIG. 1, an intermediate coating film 3 was formed on the undercoating film 2. The film thickness of the intermediate coating film 2 after drying is about 60 μm.

Next, the top coat film 4 was formed on the intermediate coat film 3 as follows.
First, 2% by mass of a matting agent made of silica was added to a mixture of a main coating material and a curing agent used for forming the undercoat coating film 2 to prepare a top coating material. Next, the surface of the intermediate coating film 3 was polished with sandpaper (# 400) to smooth the coating film surface. Next, the intermediate coating film 3 having a smooth top coating was applied at a coating amount of 80 g / scale with a spray gun and dried at room temperature (20 ° C. to 25 ° C.) for 7 days. Thus, as shown in FIG. 1, the top coat film 3 was further formed on the intermediate coat film 3. The film thickness of the top coat film 2 after drying is about 30 μm.

  Next, the pencil hardness of the coating film formed on the cedar veneer using the paint for woodworking of each sample (sample X1 to sample X31) was measured. The pencil hardness was measured according to “scratch hardness (pencil method)” defined in JIS K5600. The results are shown in Tables 1 to 3.

  As known from Tables 1 to 3, woodworking paints (samples X12 to X15, samples X17 to X20, samples X22 to X25, and samples X27) containing 10 parts by mass or more of synthetic fiber or natural fiber with respect to 100 parts by mass of polyol resin It can be seen that -Sample X30) exhibits a higher hardness than those containing no additive or containing an inorganic compound. Moreover, although the hardness becomes high, so that the addition amount of a synthetic fiber and a natural fiber is enlarged, it turns out that the hardness improvement effect with respect to an addition amount is saturated gradually (refer Table 1-Table 3). Therefore, the upper limit of the addition amount is preferably less than 70 parts by mass.

  Moreover, when the coating agent containing a synthetic fiber is used, it can be seen that excellent hardness can be exhibited as described above. However, among the synthetic fibers, using vinylon (polyvinyl alcohol-based synthetic fiber) can improve the hardness. Recognize.

(Example 2)
In this example, the impact resistance, the surface roughness, and the adhesion were evaluated for the sample X1 prepared in Example 1 and the woodwork paints of Samples X17 to X21.
Sample X1 is a woodworking paint that uses a paint base that does not contain additives (see Table 1).
Sample X17 is a woodworking paint using a paint base containing 29.6 parts by weight of vinylon (synthetic fiber) with respect to 100 parts by weight of a polyol resin (see Table 2).

Sample X18 is a woodworking paint using a paint base containing 29.6 parts by weight of rock wool (synthetic fiber) with respect to 100 parts by weight of polyol resin (see Table 2).
Sample X19 is a woodworking paint using a paint base containing 29.6 parts by weight of wood flour with respect to 100 parts by weight of polyol resin (see Table 2).

Sample X20 is a woodworking paint using a paint base containing 29.6 parts by weight of cellulose powder with respect to 100 parts by weight of polyol resin (see Table 2).
Sample X21 is a woodworking paint using a paint base containing 29.6 parts by mass of foamed glass spheres with respect to 100 parts by mass of polyol resin (see Table 2).

  Using these sample X1 and samples X17 to X21, a coating film was formed on a cedar veneer in the same manner as in Example 1. And about the formed coating film, impact resistance, surface roughness, and adhesiveness were evaluated.

The impact resistance was evaluated according to JIS K5600.
Specifically, on the impact core (tip R dimension: 1/2 inch), which was placed in contact with the coating film, using a DuPont impact tester (DuPont impact tester manufactured by Coating Tester Co., Ltd.). Then, a weight of 300 g was dropped from a predetermined height, and the occurrence of cracks on the coating film surface was visually evaluated. The height of the weight to be dropped was varied from 5 cm to 50 cm at intervals of 5 cm, and the height when cracking occurred in the coating film was examined. The results are shown in Table 4. Table 4 shows the maximum height at which cracking does not occur. When cracks occur even at a height of 5 cm, “−” is shown in the table.

Next, the surface roughness was measured using a surface roughness measuring instrument.
Specifically, the measurement was performed using “Surfcom 1800” manufactured by Tokyo Seimitsu Co., Ltd. The results are shown in Table 4. The measurement conditions for the surface roughness Ra are as follows.
Calculation standard: JIS B0601 (1994) standard Measurement type: Roughness measurement Measurement length: 4.0 mm
Cut-off wavelength: 0.8mm
Measurement magnification: × 5K
Measurement speed: 0.60 mm / s
Cut-off type: Gaussian Inclination correction: Least square straight line correction

For reference, Samples X17 to 19 show the roughness curves obtained by the surface roughness measuring device in FIGS. 2 to 10, the vertical axis represents the surface roughness (μm), and the horizontal axis represents the measurement length (mm).
2-4 is the surface roughness curve of the coating film produced using the sample X17. 2 to 4 all show the surface roughness curve of the sample X17, which are at different sites. In FIG. 2, the surface roughness (arithmetic average roughness) Ra is 0.40 μm, the maximum height Ry is 2.59 μm, and the ten-point average roughness Rz is 1.88 μm. In FIG. 3, Ra is 0.45 μm, Ry is 3.06 μm, and Rz is 2.18 μm. In FIG. 4, Ra is 0.39 μm, Ry is 3.02 μm, and Rz is 1.91 μm.

  5-7 is the surface roughness curve of the coating film produced using the sample X18. 5 to 7 all show the surface roughness curve of the sample X18, but are at different portions. In FIG. 5, Ra is 0.40 μm, Ry is 3.25 μm, and Rz is 2.23 μm. In FIG. 6, Ra is 0.38 μm, Ry is 3.16 μm, and Rz is 2.08 μm. In FIG. 7, Ra is 0.45 μm, Ry is 4.16 μm, and Rz is 2.43 μm.

  FIGS. 8-10 is the surface roughness curve of the coating film produced using the sample X19. 9 to 10 all show the surface roughness curve of the sample X19, but are at different sites. In FIG. 8, Ra is 0.73 μm, Ry is 4.54 μm, and Rz is 3.15 μm. In FIG. 9, Ra: 1.38 μm, Ry: 6.56 μm, Rz: 5.09 μm. In FIG. 10, Ra is 1.35 μm, Ry is 5.93 μm, and Rz is 4.81 μm.

The evaluation of adhesion was performed according to the “cross-cut method” defined in JIS K5600. Specifically, with a cutter knife, cuts that penetrated the coating film and reached the cedar veneer were made in a grid pattern (100 pieces) with a side of 2 mm. Next, after the cellophane tape was adhered to the coating film, the cellophane tape was peeled off, and the number of grids peeled off after being adhered to the cellophane tape was measured. The results are shown in Table 4. Table 4 shows the number of squares that did not peel in the 100 squares. That is, when it does not peel at all, it becomes “100/100”.
For reference, Table 4 also shows the pencil hardness of each sample measured in Example 1.

As is known from Table 4, it can be seen that Sample X17 and Sample X18 containing synthetic fibers in the coating material exhibit superior impact resistance compared to other samples.
It can also be seen that Sample X17 and Sample X18 not only have excellent impact resistance as described above, but also have a small surface roughness and excellent surface smoothness. And in the adhesiveness, the adhesiveness which was excellent similarly to other samples was shown.
Thus, according to this example, it can be seen that the use of synthetic fibers can provide a woodworking paint that exhibits excellent hardness after curing and can form a smooth coating film.

1 Wood (cedar veneer)
2 Undercoat film 3 Intermediate coat film 4 Topcoat film

Claims (5)

In a two-component woodworking paint using a mixture of a paint base containing a polyol resin and a curing agent containing a polyisocyanate resin,
The paint base contains 10 to 70 parts by mass of synthetic fiber with respect to 100 parts by mass of the polyol resin ,
The synthetic fiber has a fiber length of 80 to 200 μm, and is a wood coating material.   The woodwork paint according to claim 1, wherein the synthetic fiber is at least one selected from vinylon fiber, polyamide synthetic fiber, polyester synthetic fiber, polyolefin synthetic fiber, rock wool, and glass wool. Paint for woodwork.   3. The woodworking paint according to claim 1 or 2, wherein the polyol resin is at least one selected from a polyester polyol resin, an acrylic polyol resin, and an alkyd polyol resin.   The woodworking paint according to any one of claims 1 to 3, wherein the coating material contains 100 to 250 parts by weight of an organic solvent with respect to 100 parts by weight of the polyol resin. paint.   The woodworking paint according to any one of claims 1 to 4, wherein the curing agent contains 100 to 200 parts by mass of an organic solvent with respect to 100 parts by mass of the polyisocyanate resin. Paint.

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