JP5340754B2 - Decorative board base paper and decorative board - Google Patents

Description

The present invention relates to a decorative board base paper and a decorative board.

A decorative board used for a table, furniture, flooring or the like is manufactured by bonding a decorative board base paper impregnated with melamine resin to a wooden board represented by particle board or plywood. Among the melamine decorative boards, in recent years, it has been particularly desired to increase productivity in the production of low-pressure melamine decorative boards (Patent Document 1).

In the process of impregnating the decorative sheet base paper with melamine resin, the impregnation processing speed is determined by the degree of penetration of the melamine resin into the paper, so if the decorative board base paper has better permeability, the impregnation processing speed can be increased accordingly. Productivity can be improved.

In addition, for cost reduction, a resin-saving decorative base paper that can reduce the cost by suppressing the amount of melamine resin impregnated is desired.

However, a decorative board base paper having two contradictory properties of improving the permeability of the melamine resin and suppressing the amount of impregnation of the resin is awaited.

In order to improve the permeability of paper, it is generally known that it can be improved by lowering the density. As a method, it is common to suppress the beating of the pulp, weaken the wet press, or weaken the consolidation treatment with the calendar. However, these treatments improve the permeability and at the same time increase the amount of resin impregnation, resulting in an increase in cost.

As a method for improving the permeability of the melamine resin of the decorative board base paper, a method of adding powdered silica, aluminosilicate or seed shell, which is a filler excellent in water absorption of the papermaking raw material, has been devised.
However, since a filler that further improves the permeability is added to the filler of the shielding agent, the ratio of the filler constituting the paper becomes high, and it may be difficult to obtain sufficient strength (Patent Document 2).

In addition, a method of adding a surfactant or starch in advance to the decorative board base paper is disclosed, but this may cause trouble when the penetration aid dissolves into the impregnation processing machine during melamine impregnation processing. (Patent Document 3).

Moreover, although it is not a decorative board base paper, a laminated board base paper with good permeability has been raised by specifying the density after wet press and the density after calendering, but this density is compatible with resin saving properties. The impregnation rate increases and the cost increases (Patent Document 4).

In addition, it has been proposed to improve the permeability by increasing the porosity of paper, but it cannot be compatible with the resin saving property (Patent Document 5).

In addition, there is a method of achieving both paper smoothness and impregnation without increasing the density by heat calendering. There is no description of resin saving properties (Patent Document 6).

In addition, a method has been devised in which fine fibers in the circulation system are removed during paper making to improve the impregnation property. There was a problem that a new filtration facility was required and the capital investment cost was increased (Patent Document 7).

Japanese Patent Laid-Open No. 2000-265652 JP-A-51-23303, JP-A-51-026304, JP-A-06-166998 JP 2008-081897 A, JP 2002-201588 A Japanese Patent Laid-Open No. 3-899 Japanese Unexamined Patent Publication No. 03-890 JP 05-263391 A Japanese Unexamined Patent Publication No. 07-26497

The present invention is a process for impregnating decorative board base paper, particularly in a low-pressure melamine manufacturing process, in which the base board of melamine is impregnated with melamine resin. The challenge is to suppress it.

The present inventors have found that in order to solve the above problems, to adjust the freeness of wood pulp is the main raw material for reduction粧板base paper, and the density adjusted by wet pressing, by further density adjusted calender, melamine We found that it was possible to increase the productivity and reduce the cost in the impregnation process by uniformly and rapidly penetrating the resin into the paper and suppressing the amount of the impregnated resin. That is, the present invention is (1) adjusting the freeness of wood pulp as a main component to 450 to 550 ml CSF and adjusting the density of paper after drying with a wet press to be 0.63 to 0.73 g / cm ^3. and, and calibration by the render process the density is adjusted to 0.74~0.96g / cm ^3, a manufacturing method of a good melamine resin penetration and resin saving of the obtained Ru of粧板sheet Is to provide.

According to the present invention, the freeness of the main component wood pulp is adjusted to 450 to 550 ml CSF, the density of the dried paper after wet pressing is adjusted to 0.63 to 0.73 g / cm ³ , and the calender is used. by adjusting the density of 0.74~0.96g / cm ^3, it can be manufactured粧板sheet of could both permeability and resin saving of melamine resin.

Hereinafter, the present invention will be described in detail. The base paper used in the present invention is based on wood pulp. The usable pulp is NBKP, NBSP, LBKP, LB.
SP and the like can be mentioned, but it is particularly preferable to use LBKP alone or a mixture of NBKP and LBKP.

The pulp is beaten to a freeness of 450-550 ml CSF. The beating method is not particularly limited as long as it is known, and examples include a beater, a double disc refiner, a conical refiner, and a cinder refiner.

If the freeness of the wood pulp is less than 450 ml CSF, the permeability of the resin is poor, and if it exceeds 550 ml CSF , the resin saving property may be deteriorated.

Titanium dioxide, which is a shielding agent, is added to give the paper properties as a decorative base paper. Further, it is desirable to add a known pigment, dye or design material in order to impart design properties. An example of the pigment is a petrol (iron oxide).

Also, known papermaking chemicals are internally added. For example, there is polyacrylamide epichlorohydrin which is a wet paper strength enhancer.

The stock prepared by the above method is made into paper by a known papermaking method. Specifically, there is a paper making method using a standard square sheet machine or a long net paper machine.

The wet press is a device for dehydrating to some extent after forming a web on a wire, and specifically includes a square automatic sheet press or a wet press roll for passing a web between two rolls. By appropriately adjusting the wet press pressure, a base paper having the density can be obtained. The wet press pressure needs to be adjusted appropriately in relation to the freeness,
When a square automatic sheet press is used, the density of the present application can be obtained by setting it to approximately ² to 6 kgf / cm ² .

After the wet press, the density of the dried paper is adjusted to 0.63 to 0.73 g / cm ³ . When the density of the paper after the wet press is less than 0.63 g / cm ³ , the resin saving property is deteriorated, and when it exceeds 0.73 g / cm ³ , the resin permeability is deteriorated.

The calender is a device for consolidating the paper after drying with a dryer, and is a device that applies pressure by passing the paper between a plurality of rolls. Examples of the roll include a metal roll, a resin roll, and a heat roll. The one that comes with the paper machine is called the machine calendar, and the offline one is the super calendar. A base paper having the density can be obtained by appropriately adjusting the compaction by the hot roll temperature and the linear pressure. The degree of compaction needs to be adjusted appropriately depending on the relationship between the freeness and the dry density after wet pressing. However, when a hot roll and a resin roll are used, the hot roll temperature is generally 20 to 80 ° C., and the linear pressure is The density of this application can be obtained by setting it as 8-32 kgf / cm.

The density after the calendar process is adjusted to 0.74 to 0.96 g / cm ³ . If the density of the paper after the calendar process is less than 0.74 g / cm ³ , the resin saving property is deteriorated. If it exceeds 0.96 g / cm ³ , it may be difficult to balance resin permeability and resin saving.

Hereinafter, the present invention will be described in detail with reference to examples. Evaluation in this example and the comparative example was based on the following method.
(1) Freeness was measured based on JIS P8121.
(2) Measured based on JIS P8124.
(3) Thickness and density Measured based on JIS P 8118.
(4) Permeability of melamine resin Use a 55% aqueous solution of melamine resin (melamine formaldehyde resin) and adjust to 20 ° C. The time taken was measured with a stopwatch. The lower the value, the better the resin permeability.
(5) Amount of impregnation of melamine resin The decorative board base paper was immersed in a 55% aqueous solution of melamine resin for 1 minute, the excess resin was scraped off with a glass rod, dried at 140 ° C. for 3 hours, and the impregnation rate was measured. The impregnation rate was calculated by the following formula. The lower the impregnation rate, the better the resin saving property.
Impregnation rate (%) = {(absolute dry weight of impregnated paper) − (absolute dry weight of decorative board base paper)} / (absolute dry weight of decorative board base paper) × 100

(Example 1) Hardwood bleached kraft pulp (LBKP) 100 parts by weight was beaten with a double disc refiner to make 500 ml CSF. To this was added 25 parts by weight of titanium dioxide, 2 parts by weight of petite, 1 part by weight of polyacrylamide epichlorohydrin and 2 parts by weight of aluminum sulfate, and the pH was adjusted to neutral with sodium aluminate. . This was formed into a 100 g / m ² web using a hand machine, dehydrated with a wet press machine (manufactured by Kumagai Riki, square automatic sheet press) for 4 kgf / cm ² × ³ minutes, and dried with a cylinder dryer. Further, a decorative calender board was prepared by a compacting process using a test calender (Kojin homemade, heat roll and resin roll) at a linear pressure of 8 kgf / cm and a calen temperature of 20 ° C.

(Example 2) 100 parts by weight of hardwood bleached kraft pulp (LBKP) was beaten with a double disc refiner to make 545 ml CSF. A decorative base paper was prepared in the same manner as in Example 1.

(Example 3) 10 parts by weight of softwood kraft pulp (NBKP) and 90 parts by weight of hardwood bleached kraft pulp (LBKP) were beaten with a double disc refiner to obtain 545 ml CSF. 25 parts by weight of titanium dioxide, wet paper strength agent: 1 part by weight of polyacrylamide epichlorohydrin and 2 parts by weight of aluminum sulfate were added thereto, and PH was adjusted to neutrality with sodium aluminate. This was formed into a 100 g / m ² web using a hand machine, dehydrated by 4 kgf / cm ² × ³ minutes using a wet press machine, and dried using a cylinder dryer. Further, a decorative sheet base paper was prepared by performing a consolidation treatment with a test calender set to a linear pressure of 32 kgf / cm and a calen temperature of 60 ° C.

Example 4 100 parts by weight of hardwood bleached kraft pulp (LBKP) was beaten with a disc refiner to make 545 ml CSF. To this, 25 parts by weight of titanium dioxide, wet paper strength agent: polyacrylamide epichlorohydrin 1
Part by weight and 2 parts by weight of aluminum sulfate were added, and the pH was adjusted to neutral with sodium aluminate. A web of 100 g / m ² is formed by a hand milling machine, and 4 by a wet press machine.
It dehydrated kgf / cm ² × 3 minutes and dried with a cylinder dryer. Further, a decorative sheet base paper was prepared by a consolidation process with a test calender set to a linear pressure of 32 kgf / cm and a calen temperature of 80 ° C.

(Comparative Example 1) 100 parts by weight of hardwood bleached kraft pulp (LBKP) was beaten with a disc refiner to obtain 400 ml CSF. A decorative board base paper of 100 g / m ² was prepared in the same procedure as in Example 1.

Comparative Example 2 Hardwood bleached kraft pulp (LBKP) 100 parts by weight was beaten with a disc refiner to make 564 ml CSF. To this was added 25 parts by weight of titanium dioxide, wet paper strength agent: 1 part by weight of polyacrylamide epichlorohydrin, 2 parts by weight of aluminum sulfate,
The pH was adjusted to neutral with sodium aluminate. This was formed into a 100 g / m ² web using a hand machine, dehydrated by 4 kgf / cm ² × ³ minutes using a wet press machine, and dried using a cylinder dryer. Furthermore, with a test calender, the linear pressure is 8 kgf / cm and the calender temperature is 20 ° C.
A decorative board base paper was prepared by compaction treatment.

(Comparative Example 3) 10 parts by weight of softwood kraft pulp (NBKP) and 90 parts by weight of hardwood bleached kraft pulp (LBKP) were beaten with a disc refiner to obtain 550 ml CSF. 25 parts by weight of titanium dioxide, wet paper strength agent: 1 part by weight of polyacrylamide epichlorohydrin and 2 parts by weight of aluminum sulfate were added thereto, and PH was adjusted to neutral with sodium aluminate. A 100 g / m ² web is formed with a hand-rolling machine and 2 k with a wet press machine.
It dehydrated gf / cm ² × 3 minutes and dried with a cylinder dryer. Further, a decorative sheet base paper was prepared by a consolidation process with a test calender set to a linear pressure of 32 kgf / cm and a calen temperature of 80 ° C.

(Comparative Example 4) 100 parts by weight of hardwood bleached kraft pulp (LBKP) was beaten with a disc refiner to make 500 ml CSF. To this, 25 parts by weight of titanium dioxide, 2 parts by weight of the petal,
Wet paper strength agent: 1 part by weight of polyacrylamide epichlorohydrin and 2 parts by weight of aluminum sulfate were added, and the pH was adjusted to neutral with sodium aluminate. 1 with a handmade machine
A web of 00 g / m ² was formed and dehydrated with a wet press machine for 6 kgf / cm ² × ³ minutes,
It dried with the cylinder dryer. Further, a decorative sheet base paper was prepared by a consolidation process with a test calender set to a linear pressure of 8 kgf / cm and a calen temperature of 20 ° C.

(Comparative Example 5) 100 parts by weight of hardwood bleached kraft pulp (LBKP) was beaten with a disc refiner to obtain 485 ml CSF. To this, 25 parts by weight of titanium dioxide, 2 parts by weight of the petal,
Wet paper strength agent: 1 part by weight of polyacrylamide epichlorohydrin and 2 parts of aluminum sulfate were added, and the pH was adjusted to neutral with sodium aluminate. 100 with a hand machine
A web of g / m ² was formed, dehydrated with a wet press machine at 2 kgf / cm ² × 3 minutes, and dried with a cylinder dryer. Further, a decorative sheet base paper was prepared by a consolidation process with a test calender set to a linear pressure of 8 kgf / cm and a calen temperature of 20 ° C.

(Example 5) 55% melamine resin was applied to the decorative board base paper produced in Examples 1-4 and Comparative Examples 1-5.
Each solution was impregnated. This is commercially available MDF (medium density fiberboard, thickness 10 mm)
A low pressure melamine decorative board was obtained by molding using a hot press machine. Hot pressure condition is 185 ℃ ・ 2
The test was performed at 0 kgf / cm ² · 1 minute.

The surface finish of the decorative board produced in Example 5 was visually observed and evaluated. Excellent surface finish without fading: ◯, with partial fading: Δ, with fading over the entire surface: X

As described above, according to the present invention, by providing a decorative board base paper that has good melamine resin permeability and can suppress the resin impregnation rate, it is possible to increase the productivity of the step of impregnating the melamine resin in the low-pressure melamine molding step. Cost can be reduced.

Claims (2)

A decorative board base paper made of wood pulp and internally impregnated with titanium dioxide , which is used for a melamine decorative board used by impregnating a melamine resin, the freeness of the wood pulp is 450 to 550 ml CSF By adjusting the wet press, the density of the paper after drying is adjusted to 0.63 to 0.73 g / cm ³ , and the density after the calendar process is adjusted to 0.74 to 0.96 g / cm ³ . A method for producing decorative base paper, characterized by being prepared. A method for producing a decorative melamine board, comprising impregnating a decorative base paper obtained by the production method according to claim 1 with a melamine resin.