JP2008088741A - Flooring and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flooring which is excellent in caster resistance and impact resistance and also excellent in design. <P>SOLUTION: After impregnating paper with a thermosetting resin of which the main ingredient is a melamine based resin, a phenolic resin, or a diallyl phthalate resin, the resin-impregnated paper 2 obtained by being hardened is connected to one surface of a wooden-based substrate 3 with an adhesive. Then a design layer 4 predominantly composed of a natural wood veneer or decorative paper is provided on a surface opposed to the wood based substrate 3 side of the resin-impregnated paper 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flooring and a manufacturing method thereof.

Natural wood veneer decorative veneer used for high-quality musical instruments such as pianos and organs, with thermosetting resin impregnated paper sandwiched between the core and natural wood veneer to keep the surface coating beautiful and mirror-like ( Patent Document 1).
The first object of the invention described in Patent Document 1 is to simplify a painting process that requires careful consideration and a great deal of time. The second purpose is to prevent the movement of the core material due to changes in temperature and humidity, and the expansion and contraction of the core material due to the migration and diffusion of adhesive moisture from deteriorating the coating film smoothness. A third object is to prevent moisture from entering and diffusing from the plane of the coating to the inside of the core, thereby maintaining the smoothness of the coating.

  Also, as a flooring material, MDF (medium specific gravity fiber board [JIS A5905]) is pasted on both sides of the substrate plywood and a natural wood veneer is pasted on one side in order to harden the surface of the flooring material and prevent various scratches. Some of them have a thin MDF sandwiched between plywood and natural wood veneer. This is because the MDF surface is generally harder than the plywood surface (for example, Patent Document 2).

JP 58-47347 JP 2003-27731 A

  A flooring material in which a natural wood veneer or decorative paper is directly attached to a plywood has a problem in that it is easy to have a scratch on a caster wheel or a fall wound with small items dropped.

  The plywood has a variety of red, brown, yellow, and white colors, creating an integrated pattern. When a light-colored natural wood veneer such as China, white oak, maple, or light-colored decorative paper is directly attached to this plywood, the color of the plywood is reflected and a flooring of different colors is obtained. In the case of decorative paper, since the thickness is thin (thickness is about 100 μm), the plywood rule, in particular, the conduit groove is raised on the decorative paper surface and becomes unsightly.

  In recent years, the wood resources have been depleted, and the quality of the wood used for plywood has also decreased. The surface of the plywood has many open cracks, wormholes, cutouts, etc., and is carefully repaired with a putty and then sanded. It is desired to reduce the burden of this putty repair and increase the production work efficiency.

  In recent years, softwood plywood has become widely used. However, softwood has a large difference in hardness between the early and late lumber parts of the annual rings, and after it is made into flooring, the surface is reflected, or the early lumber part is particularly susceptible to scratches and scratches. It is rare.

In order to increase the hardness of the flooring material, there is one in which a fiberboard is further inserted between a natural wood veneer and a base material plywood. MDF is often used for the fiberboard. There are some which stuck MDF of the same thickness on both sides of plywood and took the balance of warpage, and those which stuck one sheet of thin (1mm to 1.3mm) MDF.
MDF has a water absorption thickness expansion coefficient (JIS A5905) that is at least twice as high as that of plywood. When the MDF of the floor material female upper protrusion and the male protrusion absorbs water, the warp deforms and the female and male fittings do not fit well. Further, even after the flooring construction, if water is absorbed, a difference in level may occur at the abutting portion between the flooring materials, and an improvement is desired.

  Comparing the plywood flooring with the MDF on the top and bottom surfaces with the same thickness, the latter has a problem that the bending strength (JIS A5905) decreases as the proportion of MDF on the top and bottom surfaces of the plywood increases. In order to compensate, the thickness of the flooring is increased, but it becomes heavy.

  In the case of a thin MDF, a large plate having a thickness of 2.5 mm to 3.0 mm is divided into two pieces at the top and bottom to obtain two pieces. For example, the thickness of 2,5 mm is made into two sheets to be 1.2 mm, and the sander is made a plurality of times to make an MDF with a thickness of 1.0 mm. This work requires advanced production techniques, and is economically expensive.

  Since the MDF raw material used for flooring is mostly Lauan, the color is dark brown. When a natural wood veneer is pale, such as maple, or a light-colored decorative paper is used, the dark brown color of the underlying MDF appears and gives a sense of discomfort to the design when the V-groove is processed. Improvement of the above problems is desired.

An object of the present invention is to provide a flooring material that is excellent in caster resistance and impact resistance and also excellent in design properties.
Moreover, the objective of this invention is providing the manufacturing method of the flooring which can manufacture such a flooring efficiently and economically, suppressing peeling between layers.

  In the present invention, a resin-impregnated paper obtained by impregnating a paper with a thermosetting resin containing a melamine resin, a phenol resin or a diallyl phthalate resin as a main component and then curing the resin is at least one of the woody base materials. A floor which is bonded to a surface via an adhesive and has a design layer mainly composed of natural wood veneer or decorative paper on the surface of the resin-impregnated paper opposite to the wood-based substrate side By providing the material, the above object is achieved.

  According to the present invention, the resin-impregnated paper according to claim 1 and the wood-based substrate are pressed with an adhesive interposed between the wood-based substrate and the resin-impregnated paper, and the impregnated paper-integrated substrate A first joining step of obtaining the impregnated paper integrated base material and the natural wood veneer or decorative paper, between the resin impregnated paper and the natural wood veneer or the decorative paper in the impregnated paper integrated base material A method for producing a flooring material, comprising: a second joining step of pressing with an adhesive interposed therebetween, wherein the second joining step is performed after the first joining step or simultaneously with the first joining step. It is to provide.

The flooring of the present invention is excellent in caster resistance and impact resistance, and is excellent in design.
According to the floor material manufacturing method of the present invention, such a floor material can be efficiently manufactured while suppressing delamination between layers.

Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
FIG. 1 is a cross-sectional view showing a flooring 1 for flooring, which is an embodiment of the flooring of the present invention.
In the flooring 1 of the present embodiment, the resin-impregnated paper 2 obtained by impregnating a paper with a thermosetting resin containing a melamine resin, a phenol resin, or a diallyl phthalate resin as a main component and then curing the resin is a woody material. It is joined to one surface of the base material 3 via an adhesive, and a natural wood veneer or decorative paper is mainly used on the surface of the resin impregnated paper 2 opposite to the wood base material 3 side. A design layer 4 is provided.

The resin-impregnated paper used in the flooring of the present invention is obtained by impregnating a paper with a thermosetting resin and then curing it.
As the paper impregnated with the thermosetting resin, kraft paper, titanium paper, printing base paper for building materials, and the like can be used, and the basis weight is preferably 60 to 280 g / m ² . Among these papers, kraft paper is preferred, and in particular, impregnated kraft paper in which resin has penetrated and air in the paper is easily removed is preferred.
The impregnated kraft paper has increased paper strength by increasing the amount of long-fiber pulp, and does not use a sizing agent to facilitate water penetration. The impregnated kraft paper has air permeability resistance (Gurley, JIS P8117: 1998, hereinafter referred to as air permeability resistance), which varies depending on the thickness, but air easily escapes around 10 seconds / 100 ml.

  The resin-impregnated paper used in the present invention should not cause delamination between the resin-impregnated paper and the woody base material and / or between the impregnated paper integrated base material and the natural wood veneer or decorative paper. From the viewpoint of achieving both excellent caster resistance and impact resistance, the air permeability resistance is preferably 10 to 500 seconds / 100 ml, more preferably 10 to 50 seconds / 100 ml, and still more preferably. Is 10 to 20 seconds / 100 ml.

As the thermosetting resin impregnated into the paper, a thermosetting resin containing melamine resin, phenol resin or diallyl phthalate resin as a main component is used. As the thermosetting resin, one having an epoxy resin as a main component can also be used.
As the thermosetting resin mainly composed of melamine resin, melamine resin alone, melamine / urea co-condensation resin, a mixture of melamine resin liquid and urea resin liquid, various modified products of these resins, and the like can be used. .
As the impregnation machine used for impregnation of the thermosetting resin, a dipping method, a squeeze method, or a combination of both can be used.
The paper impregnated with the thermosetting resin is heated by a heating means to cure the thermosetting resin, whereby a resin-impregnated paper is obtained.

A method for manufacturing a resin-impregnated paper, a curable resin mainly comprising melamine resin from a basis weight 60 g / m ² kraft paper 280 g / m ^2, dry weight was 300 g / m ² impregnated from 60 g / m ^2, the This will be described more specifically by taking as an example the case of obtaining resin-impregnated paper by curing. According to this method, a resin-impregnated paper having a thickness of 120 μm to 750 μm can be obtained.
The resin concentration used in the impregnation machine is about 30 to 50%, preferably about pH 4.5 to about pH 5.5. If the pH is too low, the impregnated paper may be deteriorated, and if it is too neutral, the resin will be insufficiently cured.
The amount of impregnating resin is preferably 50% to 120% (converted to dry weight) of the weight of the base paper, and if it is 50% or less, the hardness is not sufficient, and if it exceeds 120%, the impregnated paper becomes gradually harder and more easily cracked. Alternatively, the surface of the impregnated paper is clogged with resin, the adhesive penetration is insufficient, and problems such as poor adhesion occur.

  After impregnating the resin, it is dried with hot air at 70 ° C. to 130 ° C. for 2 to 15 minutes, and then cut into a predetermined size to form a single sheet or roll. The Barcol hardness of the impregnated paper itself can be 25 to 45 degrees when measured by overlapping several sheets. If it is less than 25 degrees, there is a possibility that the hardness of the flooring material cannot be sufficiently obtained, and if it exceeds 45 degrees, it tends to break and the workability is deteriorated. The Barcol hardness is a value measured with a Barcol hardness meter GYZJ-936 type manufactured by Barber-Colman Company of the United States.

In the flooring of the present invention, the resin-impregnated paper obtained as described above is bonded to at least one surface of the wood-based substrate via an adhesive, and the wood-based paper in the resin-impregnated paper A design layer mainly made of natural wood veneer or decorative paper is provided on the surface opposite to the substrate side.
For example, the production of the impregnated paper integrated base and the formation of the design layer on the impregnated paper integrated base by joining the resin impregnated paper and the wood base material are performed as follows, for example.

The resin-impregnated paper is pressed by a hot press method or a cold press method together with the wood base material in a state where an adhesive is interposed between the resin base paper and the wood base material to be integrated with the wood base material. For convenience, the composite material in which the resin-impregnated paper and the woody base material are integrated is referred to as an impregnated paper-integrated base material or an impregnated paper-laminated board.
As the wooden base material integrated with the resin-impregnated paper, various materials conventionally used for interior building materials such as flooring can be used, for example, plywood (one where the fiber orientation directions of a single plate intersect) , Single board laminate (LVL, single board with aligned fiber orientation), particle board (OSB), monolithic composite board with a three-layer structure with MDF on the surface and OSB in the core layer (for example, trade name “ For example, commercially available as “Triboad”), PSL (parellel Strand Lumber), LSL (Laminated Strand Lumber, for example, commercially available under the trade name “Timber Strand”), and the like. Among these, plywood and LVL are preferable.

The Barcol hardness of the impregnated paper integrated substrate is, for example, 30 to 48 degrees. The Barcol hardness of the plywood base plate varies widely depending on the tree species, but is about 10 to 30 degrees.
As plywood or LVL used as a woody base material, there are hardwood and coniferous systems. As hardwood plywood, Lauan, Sina, Eucalyptus, Falkata, etc. can be used, and as a coniferous plywood, Radiata pine Wood, cedar, larch, etc. can be used. In addition, there are composites of lauan and softwood, accompanying plywood. Although the number of laminated single plates of the plywood increases with the thickness, it can be used without particular limitation such as 3 ply, 5 ply and 7 ply.
Note that the surface of the plywood has open cracks, chips, bugs, etc., and it is preferable to smooth the surface with sandpaper or a wide belt sander after performing putty repair multiple times.

Adhesives used for joining resin-impregnated paper and wood-based substrates include vinyl acetate resin adhesives, vinyl acetate resins added with isocyanate crosslinking agents or urea resins, acrylic-modified vinyl acetate resins or ethylene vinyl acetate co-polymers. Condensation resins and the like can be used, but any of those that give water resistance of JAS standard type I is preferable.
Although the hot press method has good productivity, there is a risk of warping when it becomes a flooring material when it is applied at a high temperature, but the hot platen temperature is 100 ° C. or less, the pressing time is 40 seconds to 90 seconds, and the pressing pressure is 3 kgf / This danger can be avoided by sticking at _cm ² to 4.5 kgf / _cm ² .
The cold press method is disadvantageous in that it takes time to stick, but there is an advantage that there is less risk of warping after it becomes a flooring material.

For example, a natural wood veneer or floor decorative paper having a thickness of 0.2 mm to 2.0 mm is attached to the base material integrated with impregnated paper through an adhesive, and further coated. And a design layer is provided. The natural wood veneer is preferably stuck by a hot press method, and the decorative paper for floor is preferably stuck by a hot press method or a laminator method.
As the adhesive used for joining the impregnated paper integrated base and the natural wood veneer or decorative paper, the same adhesive as that used when sticking the resin impregnated paper to plywood or the like can be used, but the water resistance is JAS. Those that pass the standard type I are preferred.
Furthermore, when sticking a natural wood veneer, the adhesive may ooze on the veneer, so that it is possible to mix 20 to 30% by weight of flour.

If the design layer is laminated with natural wood veneer or decorative paper without top coat, it is painted and used as a flooring.
The painting of piano organs places importance on aesthetics and is to keep the smoothness close to the mirror surface forever. However, the floor coating is practically easy to remove stains when wiped with a dust cloth, and shoes and slippers. This is performed in order to make it difficult to cause scratches due to the like. The paint is preferably a urethane paint or polyester paint, and a water paint is also used. Applicable by UV curing method, hot air drying method or electron beam curing method, and the coating thickness is suitably about 30 μm to 100 μm.

As the decorative paper for floors used for the design layer, it is preferable to use a surface top coat layer in which an anti-friction agent, ceramic or the like is mixed to improve wear resistance. As the decorative paper base paper, a resin-incorporated paper or a resin-impregnated paper can be used, and a basis weight of 30 g / m ² to 45 g / m ² is suitable. When the basis weight exceeds 45 g / m ² , it may be peeled from between the base papers in the floor material production construction work process. The appropriate thickness of the decorative paper for flooring is 60 μm to 100 μm including the top coat.

In addition, it is preferable that the flooring of this invention is provided with the actual process for connecting flooring to the side. As actual processing, for example, as shown in FIG. 1, a convex portion (male) 5 is formed on one of a pair of opposite side surfaces of a flooring, and a groove (female) corresponding to the convex portion is formed on the other side. Actually, 6 is formed. As the cross-sectional shapes of the male and female berries, various known ones can be employed without particular limitation. As actual processing, only one of male fruit and female fruit may be provided on one floor material.
Further, the first joining pressure for integrating the wood base material and the resin impregnation and the second joining step for integrating the impregnated paper integrated base material and the natural wood veneer or decorative paper are sequentially performed. Can be performed simultaneously.

Next, the present invention will be specifically described based on examples and comparative examples, but the present invention is not limited to the following examples.
(Example 1)
A titanium base paper having a basis weight of 60 g / m ² is impregnated with a melamine resin (concentration 45%, pH 3.5) by immersion, and further dried and cured with hot air at 70 ° C. to 130 ° C. for 10 minutes, so that the amount of impregnated resin 60 g / m ² ( Dry weight), a thickness of 143 μm, and an impregnated paper having a Barcol hardness of 30 degrees were obtained. Thickness 5.5 mm, 3-ply plywood ethylene vinyl acetate co-condensation resin adhesive 70 g / m ² coating subjected this impregnated paper was adhered by a hot press Barcol hardness 35 ° of the impregnated paper laminated plywood (impregnated paper integrated Substrate).
Hot press conditions: Hot plate temperature 80 ° C. Clamping pressure 4.0 kgf / cm ² , Clamping time 45 seconds

The impregnated paper-laminated plywood was coated with 80 g / m ² of adhesive (2.5% isocyanate cross-linking agent added to vinyl acetate resin adhesive and 15% flour mixed), and a white oak veneer with a thickness of 0.25 mm was applied. A design layer is formed by adhesion by hot pressing.
Hot press conditions: Hot plate temperature 90 ° C, pressing pressure 5.0 kgf / cm ² , pressing time 90 seconds Urethane resin paint is applied to the design layer with a roll coater, cured by hot air drying, and the coating thickness is 40 μm A flooring was obtained.

(Comparative Example 1)
In Example 1, a flooring was obtained in the same manner as in Example 1 except that the white oak veneer was directly attached to the plywood without attaching the impregnated paper.

(Evaluation)
The obtained flooring was subjected to an evaluation test, and the results are shown in Table 1.
1. Color difference of flooring The color difference (ΔE) of the flooring was measured using a color difference meter CR-200 manufactured by Minolta Co., Ltd.
Specifically, in the L ^* a ^* b ^* color system, the L ^* a ^* b ^* value of each test piece is measured, and the combination showing the maximum color difference (ΔE) among each combination is measured. The color difference (ΔE) of the flooring was selected.

2. Caster test Using a rotating nylon caster, a 200 mm straight line was reciprocated 10,000 times with a load of 20 kg in a straight line in the design layer. The test piece was moved back and forth, and the caster was rotated about once every reciprocation. The largest portion of the dents that were made was measured with a dial depth gauge, and the average value of the six specimen measurements was shown in Table 1 as dents by casters.
Caster: Nylon reinforced phenolic resin single caster (Hammerton part number 420G-MC50)
Specimen dimensions: Width 150mm The length is matched to the tester fixed base.

3. Barcol hardness It measured using the Barcol hardness meter (the product number "GYZJ-936" by BARBERCOLMAN). The floor surface 30 points were measured and the average value was taken (the same applies to the measurement of impregnated paper laminate).
For measurement, a needle supported by a constant force is inserted by a spring. Expresses the depth of the inserted needle.
The Barcol hardness indicates that the smaller the value, the deeper the needle was pierced.

4). Impact resistance Measured according to the JAS impact A test. The dent on the floor material surface made of falling weight was measured with a dial depth gauge, and the average value of the five specimens was taken as the measured value.

As a result of the color difference of the flooring material, in the example, the base color was unified by the resin-impregnated paper, and only the color variation of the white oak square veneer became the maximum color difference ΔE = 0.3.
On the other hand, Comparative Example 1 is affected by variations in the color of the base plywood (dark brown, yellow, red and light colors), and the difference between the one attached to the dark brown plywood and the light color is different. The maximum was ΔE = 1.0.
From the test results of caster test, Barcol hardness and impact resistance, it can be seen that the flooring material of the example is less prone to unevenness and scratches than the flooring material of the comparative example.

(Example 2)
Impregnated resin is impregnated with melamine / urea co-condensation resin (concentration 40%, pH 4.8) by impregnation on impregnated kraft paper with a basis weight of 80 g / m ² and further dried and cured with hot air at 80 ° C. to 120 ° C. for 10 minutes. An impregnated paper having an amount of 90 g / m ² (dry weight), a Barcol hardness of 39 degrees, and a thickness of 206 μm was obtained.
70 g / m ^{2 of} 12 mm thick, 7-ply radialata pine plywood with a vinyl acetate resin adhesive mixed with 2.5% by weight of an isocyanate cross-linking agent was applied, and the impregnated paper was attached with a hot press. An impregnated paper-coated radiata pine plywood having a hardness of 43 degrees is obtained.
Hot press conditions: hot platen temperature 85 ° C, pressing pressure 4.2 kgf / cm ² , pressing time 60 seconds

An adhesive (vinyl acetate resin adhesive mixed with 2.5% by weight of an isocyanate-based crosslinking agent and 20% by weight of wheat) was applied to this impregnated paper laminated board at 80 g / m ² , and a maple plate having a thickness of 0.25 mm was simply applied. A board is stuck with a hot press to form a design layer.
Hot press conditions: hot platen temperature 90 ° C, pressing pressure 5.0 kgf / cm ² , pressing time 90 seconds Polyester paint is applied to the design layer, UV cured, and impregnated paper-coated flooring with a coating thickness of 80μ Got.

(Comparative Example 2)
In Example 2, a flooring was obtained in the same manner as in Example 2 except that only the impregnation paper sticking was omitted from the working process of Example 2.

The flooring materials obtained in Example 2 and Comparative Example 2 were evaluated in the same manner as in Example 1, and the results are shown in Table 2.
In addition, each test method and its measuring instrument in and after Example 2 are the same as those in Example 1. Also, the method of creating the comparative example for each example is the same as that of the example 1.

(Example 3)
Resin (resin) in which melamine resin (concentration: 45%), urea resin (concentration: 50%) and water are mixed in a ratio of 5 parts: 5 parts: 1 part in a kraft paper for impregnation having a basis weight of 140 g / m ^2. Impregnated with a concentration of 43.2%, pH 4.5), and further dried and cured with hot air at 70 ° C. to 120 ° C. for 15 minutes, the amount of impregnated resin 145 g / m ² (dry weight), Barcol hardness 43 degrees, thickness 350 μm, transparent An impregnated paper having a gas resistance of 13 to 16 seconds / 100 mL was obtained. This impregnated paper is coated with 80 g / m ² of type I water-resistant ethylene-vinyl co-condensation resin adhesive on a 12 mm thick, 7-ply lauan plywood, and stuck in a cold press to impregnate with a Barcol hardness of 47 °. A paper-laminated plywood was obtained.
Cold press conditions: room temperature 25 ° C., pressing pressure 4.5 kgf / cm ² , pressing time 45 minutes

This impregnated paper-laminated board was coated with 80 g / m ^{2 of} a mixed adhesive prepared by adding 2.5% by weight of an icyanate-based crosslinking agent and 20% by weight of wheat flour to a vinyl acetate resin adhesive, and a maple board having a thickness of 0.25 mm. A board is stuck with a hot press to form a design layer.
Hot press conditions: Hot plate temperature 90 ° C., pressing pressure 5.5 kgf / cm ² , pressing time 90 seconds Polyester paint is applied to the design layer and UV cured to obtain an impregnated paper flooring material with a coating thickness of 80 μm It was.

(Comparative Example 3)
In Example 3, a flooring was obtained in the same manner as in Example 3 except that only the impregnation paper sticking was omitted from the working process of Example 3.

  The flooring materials obtained in Example 3 and Comparative Example 3 were evaluated in the same manner as in Example 1, and the results are shown in Table 3. The maximum color difference of the flooring material of Comparative Example 3 was the largest when it was attached to dark brown plywood and that applied to light color plywood, which was ΔE = 1.6.

Example 4
Pre-coated decorative paper for floors (basis weight 70 g / m ² , thickness 50 μm, brown cork) by applying 70 g / m ² of type I specification ethylene vinyl acetate co-condensation resin adhesive to the impregnated paper laminated plywood obtained in Example 3 The handle was stuck with a hot press to obtain an impregnated paper-attached flooring material.
Hot press conditions: Hot plate temperature 80 ° C, pressing pressure 3.5 kgf / cm ² , pressing time 60 seconds

(Comparative Example 4)
In Example 4, a flooring material was prepared in the same manner except that only the impregnation paper sticking was omitted from the working process of Example 4. The flooring materials obtained in Example 4 and Comparative Example 4 were evaluated in the same manner as in Example 1, and the results are shown in Table 4.

  From the results shown in Tables 1 to 4, it can be seen that the floor material of the example has fewer dents due to the caster test, that is, scratches on the caster wheel marks, as compared with the floor material of the comparative example. In addition, the floor material of the example has less dents due to the JAS impact A test, has a higher Barcol hardness, and is less likely to be damaged by falling small items than the floor material of the comparative example.

  In addition, according to the flooring material of the example, by sticking impregnated paper to the plywood surface, the color variation of the wood base material (plywood etc.) is suppressed, and the color of the impregnated paper is unified. It can be seen that the color variation can be suppressed. That is, in the conventional flooring material, the pale pattern of the decorative paper for flooring may cause a different color flooring due to the variation in the color of the plywood used as the wooden base material. In the flooring, this problem is also solved.

  When the design layer was decorative paper as in Example 4, it appeared remarkably when hot-pressing, but it was possible to prevent the plywood texture from being raised on the decorative surface and to make a beautiful surface. In the comparative example, the plywood rule and the conduit groove appeared on the decorative surface, and the beauty was inferior in design.

Repairing cracks, worm holes and break-through putty on plywood is also thick (thickness 120 to 600 μm) and hard (barcol hardness of impregnated paper-laminated plywood 35 ° to 52 °) covered with impregnated paper, reducing work load It was.
The current flooring is made of 2 or more grades of plywood according to the JAS normal plywood standard “surface quality standards”. Typical defects are as follows: open cracks are 4 mm or less in width, insect holes are circular with a diameter of 1.5 mm or less, linear ones with a major axis of 10 mm or less, and missing parts or holes with a major axis with a major axis of 5 mm. And so on. The depth of the above defects is approximately the thickness of the surface layer original plate and is about 1 mm. As a rule, putty repair is performed for all the above-mentioned defects. The major drawback is that it is necessary to put the sander on the repair area after flattening once or twice, even if it is a small defect twice or three times.
According to the present invention, when the thinnest (143 μm) impregnated paper laminated board of Example 1 is used, an open crack with a width of 1 mm and a depth of 1 mm, a linear insect hole with a width of 1 mm and a depth of 1 mm is obtained. The white oak veneer with a thickness of 10 mm and a breakthrough with a major axis of 1.5 mm could be applied smoothly without repairing putty. Moreover, even if it was larger than the above-mentioned defect, the white oak veneer was stuck smoothly without omitting one putty. Even if a caster test and a JAS impact test were performed on this repaired portion, no trace of repair was found and the measured values in the examples were in the range. This is because the adhesive on the impregnated paper (applying amount 70 g / m ² ) flows into the cracks, wormholes and breakthroughs that harden and hardens by narrowing or filling the openings, and the impregnated paper with a thickness of 143 μm covers the openings. It is. Therefore, the work load of putty repair has been reduced.

  In Example 2, the influence of weaving due to the difference between the early and late materials did not appear in the design layer, and the surface hardness of the floor material was not affected, and the measured values in the test result table were obtained. In Comparative Example 2, glossy spots reflecting the reason appeared in the design layer, and the surface hardness of the early lumber part was weak, and the measured value in the test result table was obtained.

There is a flooring with MDF pasted between a base plywood and a natural wood veneer.
When water and moisture are absorbed, the MDF expands, and the female and male mating may not fit well, and even after construction, there will be a difference in the leveling between the flooring materials. (Open 2003-27731, JP-A-10-121707, JP-A-11-50647, JP-A-2005-335204)
In the flooring material of Example 3 (12 mm, 7-ply one plywood), the vertical thickness of the female upper protrusion is 4.5 mm, the length is 6 mm, and the vertical width of the recess (notch) is 4 mm (lower side) The thickness of the protrusion in the vertical direction is 3.5 mm). The male projecting portion has a vertical thickness of 4 mm and a length of 5.5 mm as a fitting portion. Ten pieces of water absorption thickness expansion coefficient (JIS A5905) test pieces including female and male parts are prepared. Similarly, ten test pieces of Comparative Example 3 are prepared. The test results are shown in Table 5.

  The males and females did not warp, and at the end of the test, all combinations of males and females were smoothly fitted between the examples, and there was no step at the butt. The comparative example had the same result. This means that the resin-impregnated paper containing melamine resin as a main component hardly deforms with respect to water absorption and moisture absorption, and therefore does not have the above-described problems of floor materials using MDF.

There is a flooring with MDF on both sides of the plywood. It is well known that MDF is easy to bend and the strength is weak when the plywood of the same thickness is compared with the bending strength (JIS A5905) of MDF. For example, flooring typical 12mm thickness of plywood (lauan system, conifer system 5-ply plywood) flexural strength is 40N / mm ² ~50N / mm ² in the longitudinal direction, the MDF 20N / mm ² ~30N / mm ^2nd place. Therefore, the floor material is more likely to bend as the composition ratio of the MDF increases in the floor material upper and lower cross sections. To prevent this, the overall thickness increases. For example, there is a 14 mm composite board in which 2.5 mm MDF is attached to the top and bottom of a 9 mm 5 ply plywood. The bending strength is approximately 40 to 50 N / mm ² which is substantially the same as that of plywood, but becomes heavy as a flooring.
The density of Lauan plywood that is often used for flooring is about 0.5 g / cm ³ , and the MDF is about 0.7 g / cm ³ . Lauan plywood with a thickness of 1.2cm, width 30cm, and length 180cm is about 3.3kg, but MDF composite plywood is 1.4cm thick (9mm thickness plywood) It is obvious that the weight of one flooring material having a width of 30 cm and a length of 180 cm is about 4.3 kg, and is heavier.

  A thin MDF of 1 mm to 1.3 mm (many of lauans) may be inserted between the base material plywood and the natural wood veneer. Thin MDF has a limit in hardness, and the Barcol hardness measured by sticking to plywood cannot exceed 40 °. Therefore, it is difficult for the flooring material to have a Barcol hardness exceeding 40 °. The impregnated paper-bonded plywood of the present invention has a Barcol hardness of 35 ° to 47 ° and can produce a hard flooring.

When a natural wood veneer with light color (for example, maple) or a light colored floor decorative paper is pasted on the floor material using MDF, the lower MDF dark brown color appears due to V-groove processing, Gives a sense of incongruity. V-grooves are often about 1.5 mm to 2.5 mm wide and 1 mm to 2 mm deep. The thickness of the natural wood veneer is about 0.25 mm in practical use and the thickness of the decorative paper is about 100 μm at maximum. Therefore, the impregnated paper always appears by the V-groove processing.
The thickness of the impregnated paper is 600 μm at the maximum and is thin and light brown, so even if it appears in the V-groove, the color of the design layer does not give any sense of incongruity to the color of the plywood. In FIG. 1, a V-groove by V-groove processing is indicated by reference numeral 7.

FIG. 1 is a cross-sectional view showing a flooring which is an embodiment of the flooring of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Floor material 2 Resin impregnated paper 3 Wood type base material 4 Design layer 5 Male fruit 6 Female fruit 7 V groove

Claims (2)

  A resin-impregnated paper obtained by impregnating a paper with a thermosetting resin containing melamine resin, phenol resin or diallyl phthalate resin as a main component and then curing the adhesive on at least one surface of the wood base material The floor material is provided with a design layer mainly made of natural wood veneer or decorative paper on the surface of the resin-impregnated paper opposite to the wood-based substrate side. The resin-impregnated paper according to claim 1 and a woody substrate,
A first joining step of obtaining an impregnated paper integrated base by pressing an adhesive between the wood base and the resin impregnated paper, and the impregnated paper integrated base and a natural wood veneer; Or a second joining step of pressing the decorative paper with an adhesive interposed between the resin-impregnated paper and the natural wood veneer or the decorative paper in the impregnated paper integrated base material,
The method for manufacturing a flooring material, wherein the second joining step is performed after the first joining step or simultaneously with the first joining step.

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