JPH06238854A - Wear resistant decorative laminate made from abrasive particle-containing paper and its production - Google Patents

Abstract

PURPOSE: To produce a decorative panel having NEMA abrasion and an initial wearing point of definite values or more by preventing that particles in pulp accumulated during the secondary molding process in a papermaking process are carried out. CONSTITUTION: A compsn. containing abrasive particles and a retention aid means for retaining a considerable amt. of abrasive particles in formed paper is accumulated on the upper layer of the papermaking compsn. on the secondary molding wire in the wet section of a papermaking machine and the accumulated pulp for producing formed paper is pressed and dried and a plurality of sheets comprising paper impregnated with a compsn. for molding a synthetic resin are stacked so that paper of a surface layer sheet becomes formed paper in order to produce a stack. A formed stack is compressed into an integrated structure to produce an abrasion-resistant decorative panel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a paper containing abrasive particles and a method for producing a wear-resistant decorative board produced therefrom. In another aspect, the present invention provides a retention aid to improve retention of aluminum oxide particles in the paper during the papermaking process.
id) and the abrasion-resistant veneer laminated with the produced paper. In yet another aspect,
The present invention relates to a wear resistant decorative plate having high wear resistance and a high initial abrasion point. In still yet another aspect, the present invention uses a retention enhancer to improve retention of aluminum oxide particles having an average particle size of 10 microns or less in the paper during the papermaking process. And a veneer having a high abrasion resistance and a high initial abrasion point, which has the produced paper as a surface layer of the veneer.

[0002]

BACKGROUND OF THE INVENTION Laminates generally include multiple layers of synthetic resin impregnated sheets of paper that are compressed or bonded into a unitary structure under heat and pressure. In normal practice, the process from the beginning of the veneer consists of a core of one or more sheets of paper impregnated with phenolic resin, on which a decorative sheet of paper impregnated with melamine resin is applied. Will be placed. Prior to lamination, the paper used as core is impregnated with a hydroalcoholic solution of phenol formaldehyde, dried and
It is partially cured in a hot air oven and cut into sheets. 90-150 pounds ream impregnated with a solution of phenol formaldehyde in aqueous alcohol, dried and partially cured in a hot air oven.
am) Kraft paper can be used as a core. Decorative sheets generally function to give the veneer an attractive appearance. The decorative sheet may be solid or may include a cosmetic design, and may also include a gravure reproduction of a natural material such as a wood grain pattern or leather.

The surface layer of the decorative sheet, which can be a decorative sheet or an overlay sheet, gives the panel its surface properties (ie chemical resistance, heat resistance, light resistance, impact resistance and abrasion resistance). The surface of the veneer is a high quality 50-125 ream weight paper impregnated with a hydroalcoholic solution of melamine-formaldehyde resin, dried, partially cured and cut into sheets. obtain. The high quality paper may contain a high concentration of α-cellulose. The veneer is made by placing a resin impregnated sheet between steel caul plates and allowing the laminate to have sufficient time (generally about 25%) to compress the laminate and cure the resin.
Minute to 1 hour) About 110 to 171 ° C (230 to about 340 °
F) temperature and about 56.2-112.5 kg / cm ² (800-
Subject to a pressure of 1600 psi). This is believed to cause the resin to flow into a sheet of paper which cures and compresses the sheet into a monolithic mass referred to in the art as a high pressure veneer. Veneer is the surface of the counter or table,
Widely used in building and furniture industries such as bathroom and kitchen work surfaces, wall panels, partitions and doors. For many of these applications, especially for highly exposed surfaces such as dining room furniture surfaces, check-out counters, etc., the veneer must have a high degree of wear resistance.

The Standard National Electrical Manufacturers Association (NEMA) test for wear resistance is NEMA test LD 3.1. In this test, the laminated sample was fixed on a rotating disc on which two rubber wheels for loading were mounted and directed to a calibrated sandpaper specimen.
NEMA Standard for Class I Laminates is 4
More than 50% of the pattern of the laminate must not be destroyed after 00 cycles. The 50% endpoint is estimated by averaging the number of cycles the pattern shows initial wear (initial point or IP) and the number of cycles the pattern is completely destroyed (end point or FP). High IP in addition to 400 cycle minimum
It is commercially preferred to have a value. Abrasion resistance would be only about 50-75 cycles if the veneer was made in the conventional manner, but without the overlay sheet, at the usual 35-40% resin content in the print or pattern sheet. . With a specially formulated resin and with a resin content of about 50-55%, abrasion resistance can be extended up to about 150-300 cycles in some cases, but such laminates crack on the surface. They have a tendency, and yet they are extremely difficult to manufacture because they are difficult to impregnate print sheets in a consistent manner. However, more importantly, such laminates are required by the NEMA standard 40
The 0 cycle minimum value is not satisfied.

Prior art methods of imparting abrasion resistance include the use of translucent overlay sheets as the top structural member in a laminate or abrasion resistant particles on either the overlay sheet or the decorative sheet. It includes the use of. It has long been practiced to place resin-impregnated high quality paper as an overlay on top of a decorative sheet to impart abrasion and / or abrasion resistance to the veneer. During the stacking of the laminate, the overlay sheet becomes transparent and the decorative color of the decorative sheet, the pattern or design of the decorative sheet becomes visible. While the use of overlay sheets improves the wear resistance of veneers, it has long been desired to omit overlay sheets for several reasons. Overlay sheets add substantial unrefined raw material costs to laminate manufacture. That is, both the cost of the overlay paper itself, the cost of the resin used to impregnate the overlay paper and the loss of these raw materials during processing and handling.

In addition to the cost of the overlay, the substantial thickness of the intermediate layer between the decorative sheet and the viewer's eye significantly reduces the desired visual clarity of the decorative sheet. The cellulose fibers used to make the overlay paper have a refractive index close to that of the cured melanin-formaldehyde resin. Thus, the fibers are barely visible in the cured laminate, making the printed pattern visible with little attenuation. However, today's printing technology makes readily available natural raw materials, especially very dense reproductions of various wood veneer species. Because these printed reproductions are close in appearance to natural veneers, even the slight cloudiness or stains introduced by overlay papers are visually disturbing and destroy many of the photorealisms desired by the user. Furthermore, overlays increase the failure rate of manufactured laminated products. The impregnated dry overlay sheet tends to attract small dust particles as it enhances the electrostatic charge during drying. This dust is difficult to detect and remove prior to lamination, resulting in a ruined laminated sheet that cannot be put back into the process. Moreover, the impregnated and dried overlay is brittle and hard to handle without breaking. Such "dust" is accidentally trapped on the surface of the overlay, resulting in a more visually defective sheet.

Finally, overlay-containing laminates, especially those with a relatively high surface gloss, tend to tarnish very rapidly, even when subjected to normal attrition. It can be seen that this is unacceptable if a glossy laminate is desired. It is well known that small hard inorganic particles dispersed in overlay paper or in a resin mixture coating impregnated pattern sheets can promote the wear resistance of veneers. For example, U.S. Pat. No. 3,135,643 to Mihil, U.S. Pat. No. 3,3 to Fuerst.
See 73,070 and 3,373,071. However, while techniques such as those disclosed by the Mihil and Ferst patents above do not omit overlays, they either increase the abrasion resistance of the overlay or provide another type of overlay and combined resin. It is important to keep in mind. GB disclosing electrostatic spray abrasion resistance process on wet resin impregnated decorative sheet
No. 1,348,272 is a prior art method for further omitting overlay sheets of hard wear resistant particles incorporated into the pulp during the papermaking process and hard wear resistant particles adhered to the surface of the paper during the laminating process. It is disclosed to have both.

US Pat. No. 3,798,111, issued Mar. 19, 1974 to Lane et al., Discloses the use of abrasive particles, preferably alumina, during their manufacture in the surface layer of multilayer decorative paper. Is taken into. In order to produce a decorative paper, the surface of the produced paper can be printed. This decorative paper can then be utilized in the laminate without overlay to make a laminate that meets the 400 cycle minimum. In the manufacture of paper, the pulp is generally laminated in one or more subforming sections, through a pressing process (recognized as paper at this point) and then through a drying section. Pulp from one or more headboxes can lie on the secondary forming wire of a papermaking machine. As the pulp moves along the secondary forming section, the vacuum dryer reduces the liquid content from a high content of about 85-95% to a low content of about 10-40%. As the liquid is removed from the pulp, particles that are small enough to pass between the pulp fibers are carried away with the liquid. Lanes are 10-75 microns,
Particle size and particle size distribution is "extremely important", with a useful range of mean particle size, preferably at 40 microns.
Is taught. Layne et al.'S laminates have been criticized in the prior art as meeting the 400 cycle NEMA abrasion test minimum but having an unacceptable initial wear point, which is related to U.S. Pat. No. 4,255,480, 4,305,987 to Sher et al. No. 4,395,452 No. 4,43
Nos. 0,375 and 4,400,423 are said to have less than 100 cycles.

Shear et al. Disclose a coating for a printing paper containing particles having an average size of 20 to 50 microns which is coated without resin on unimpregnated decorative paper. Overlay produced veneer made from such coated veneer is reported to meet the 400 cycle NEMA abrasion test minimum and have an initial abrasion point of up to 500 cycles. Shear and others are 20
Teaches poor wear resistance with submicron particles. U.S. Pat. No. 4,971,855, issued to Rex et al. On November 20, 1990, uses alumina or silica particles of 9 microns or larger to gloss the laminate, such as in the Shear et al. Coating composition. It is disclosed that scratches are created on the highly polished caul plate used to do so.
Such damage is wasteful in terms of production downtime, repair and replacement costs.

In an effort to prevent such damage to caul plates, Rex et al. Disclose the use of 0.5-9 micron sized particles for use in Shear et al. Coating compositions. The composition is applied to unimpregnated decorative paper. Rex et al. Disclose a method of coating 0.5-9 micron abrasion resistant particles onto the surface of an already formed unimpregnated decorative paper, but how Rex et al. No mention is made of whether it is incorporated into the decorative paper during the paper manufacturing process. During the manufacture of paper, small particles in the pulp that are deposited during the secondary molding stage of the papermaking process are carried away with the liquid. Therefore, NEMA wear of 400 cycles or more and 5
There is a need for a papermaking process that is useful for producing veneer having an initial abrasion point of 00 cycles or more. There is also a need for a method of incorporating such small particles into the paper during the papermaking process without having to carry them with the liquid.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent the particles in the pulp accumulated during the secondary forming step during the papermaking process from being carried away, and to prevent NEMA abrasion above a certain level. It is an object of the present invention to provide a method for manufacturing a decorative board having an initial wear point.

[0012]

SUMMARY OF THE INVENTION Abrasive particles useful in making abrasion resistant laminates include an upper layer of a paper composition on a secondary forming wire of a papermaking machine, wherein an aqueous slurry of the abrasive particles and a retention enhancer is used. By depositing on it is retained in the paper during the papermaking process. Paper made with retention enhancers for retaining abrasive particles has commercially desirable abrasion resistance. Moreover, the use of retention enhancers allows the incorporation of sufficiently small abrasive particles, minimizing damage to the backing plate during veneer manufacture. The aqueous slurry of abrasive particles and retention enhancer may contain a paper composition. Aluminum oxide provides a commercially available and commercially desirable abrasion resistant laminate. Cationic high molecular weight polyacrylamide retention promoters have been found to retain greater than about 80-90% by weight of the aluminum oxide deposited on the paper composition during the papermaking process. In the paper of the present invention, NE for abrasion resistance
Veneer that exceeds MA standard can be manufactured.

The veneer of the present invention has abrasion resistance properties not hitherto achieved by incorporating abrasive particles into the paper. This is accomplished by using a retention enhancing means to retain a substantial amount of abrasive particles deposited on the pulp in the resulting paper. The retention-enhancing means also allow the uptake of abrasive particles having a particle size that minimizes damage to the caul plate used to apply pressure during the laminating process. Retention promoters have traditionally been
It is believed that it has never been used to hold abrasive particles in paper pulp during the papermaking process. The paper produced by the method of the present invention can be used as an overlay sheet or a decorative sheet. If additional abrasion resistance is required, the paper is produced by the method of the present invention as an overlay sheet and a decorative sheet. Solid and printed decorative sheets can be made from the paper produced by the method of the present invention. In the present invention, it is desirable to use abrasive particles that are sufficiently small that they do not cause significant damage to the backing plate used to make the veneer. About 1-10
It has been found that abrasive particles having an average particle size of micron result in a laminate having desirable abrasion resistance without causing significant damage to the caul plates used in making the laminate. It is believed that particles larger than 10 microns can cause damage to the caul plates used to make veneer. It is believed that particles less than about 1 micron cannot impart substantial wear resistance to the veneer.

Commercially available aluminum oxide abrasive particles that can be used in the present invention include Aluchem AC-9.
There is 9. Table I below shows particle size distributions suitable for the present invention. Less than about 1% by volume of the product, aluminum oxide, has a particle size greater than about 10 microns. Less than about 10% by volume abrasive particles should have a particle size greater than about 10 microns. More than about 60% by volume of this product is about 1% aluminum oxide.
Has a particle size of about 10 microns. The particle size distributions shown in Table I were measured using a Horiba CAPA-700 model particle size analyzer. It should be noted that the particle size may vary depending on the equipment and method used to measure the particle size distribution.

[0015]

[Table 1] Table I: Distribution table (capacity) (K [D] = 1) ─────────────────────────────── ────── D [Pa] F [%] U [%] ───────────────────────────────── ──── 40 <0.0 100.0 40.0-30.0 0.0 100.0 30.0-20.0 0.0 100.0 20.0-10.0 1.0 100. 0 10.0-9.00 5.0 99.0 9.00-8.00 7.0 94.0 8.00-7.00 6.0 87.0 7.00-6.00 7.6 81.0 6.00-5.00 7.2 73.4 5.00-4.00 8.1 66.2 4.00-3.00 8.6 58.1 3.00-2.00 13 0.0 49.5 2.00-1.00 24.0 36.5 1.0 0-0.90 2.2 12.5 0.90-0.80 2.1 10.3 0.80-0.70 1.9 8.2 0.70-0.60 2.1 6.3 0.60-0.50 1.7 4.2 0.50-0.00 2.5 2.5 ───────────────────────── ─────────────

The particles used in the present invention must have sufficient hardness for the particular application for which the veneer will be used. In general for most applications the particles used in the present invention have a hardness of at least 6 on the Moh scale. The preferred particles used in the present invention have a hardness of about 7 on the Moh scale, and most preferably the hardness is Mo.
It is in the range of about 7 to about 10 on the h scale. Materials suitable for use in the present invention having a hardness of at least 6 on the Moh scale include aluminum oxide and silicon dioxide. Other polishing materials that are considered useful in the present invention are aluminum boride, beryllium carbide, boron carbide, silicon carbide, tantalum carbide, titanium carbide, zirconium carbide, boron nitride, titanium nitride, spinel, diamond and mixtures thereof. There is. The abrasive particles to be used to achieve the objects of the present invention depend on such factors as economics, particle size, availability, color and end use. For example, for very light or white backgrounds, it is usually desirable to use essentially inorganic particles having an index of refraction similar to that of the cured melamine-formaldehyde resin, such as aluminum oxide.

In the present invention, the amount of inorganic particles used in the production of the paper of the present invention must be sufficient for the laminate formed from the produced paper to have the desired abrasion resistance and initial abrasion properties. . Generally, the inorganic particles comprise from about 1% to about 25% by weight of the paper. Preferably, the abrasive particles comprise about 2 to about 20% by weight of the paper, most preferably about 3 to 15%. Cationic, anionic and nonionic polymers may be used as a retention enhancing means to retain a substantial amount of abrasive particles deposited on the resulting paper. It has been found that commercially available anionic and cationic retention enhancers can be used to substantially improve the retention of abrasive particles in paper and the abrasion resistance of laminates made from the paper. . Examples of commercially available retention promoters that have been found to result in papers with incorporated abrasive particles, which papers have been found to result in veneers with good abrasion resistance, include American Cyanamid's Acurac. (Accur
ac) 130, 171, and 181. Acurac 1
30, 171 and 181 are high molecular weight (about 5-10 million) polyacrylamide polymers. Acurac 130 and 171 are anionic and Acurac 181 is cationic.

Abrasion resistance was measured by performing the rubbing test described in Table II of the present application. Aluminum oxide is
It was incorporated into paper using a TAPPI standard sheet machine. The abrasion resistance of the laminates made with Accurac 181 was superior to the laminates made with Accurac 130 and 171. However, the abrasion resistance of the laminates produced with Acurac 130 and 171 was also very good. The retention enhancer may be mixed in an aqueous slurry containing abrasive particles and may be deposited on the secondary forming wire in the wet section of the papermaking machine on top of the papermaking composition. The retention enhancer may also be mixed into an aqueous slurry containing wear particles and paper pulp and deposited on top of the paper on the secondary forming wire in the wet section of the papermaking machine.

The amount of retention promoter used is such that it retains a suitable amount of abrasive particles in the composition during the secondary molding process, so that the laminate formed from the produced decorative paper is The amount required to have sufficient wear resistance and initial wear properties. Generally, retention enhancers are used in the range of about 0.01% to about 25% by weight abrasive particles, based on the weight of the abrasive particles. Preferably, the retention enhancer is from about 0.02 to about 1.
Used in the range of 0% by weight, most preferably about 0.02
Used in the range of about 5% by weight. The wear resistant decorative sheet of the present invention is manufactured by a conventional method well known in the art. The lamination resistance is manufactured by first forming a laminated stack comprising a core of one or more resin impregnated sheets and a surface resin impregnated decorative sheet. Here, the decorative sheet before resin impregnation includes one or more paper layers, and at least the surface layer of the one or more paper layers is about 0.01 to about 25 weight based on the weight of abrasive particles. % Particle retention promoter. Then, based on the weight of the produced paper, about 1 to
Containing about 75% by weight of abrasion resistant inorganic particles. Here, substantially all particles have a particle size of less than 10 microns and the surface layer is a decorative layer. The laminated stack is then compressed into a veneer using heat and pressure.

[0020]

EXAMPLES Examples 1-8 shown below used the following standard procedures to obtain the results shown in Table II. Makeup type base layer, for Examples 1-6, 30.4 kg / 278.7 m ²
It was formed on a 33 inch wide paper machine having a basis weight of (67 pounds / 3000 square feet) (dry basis), and for Examples 7 and 8 was formed on a 60 inch wide paper machine. This base sheet for Examples 1-6 was bleached softwood pulp (500 ml Canadian Standard.
Freeness refined Procter & Gamble Grand Prily), titanium dioxide, melamine-formaldehyde wet strength resin (American Cyanamide Paramel HE), aluminum sulphate and colorant (Ciba Geigy Irgalite GL) It consists of standard components such as These ingredients were compounded and added to a paper machine under standard papermaking conditions and then held constant throughout Examples 1-6. For example, the basis weight was controlled by adjusting the flow rate of pulp from the storage chamber.
Standard pulpers were used to disperse and mix these ingredients.

The wear resistant layer was applied on the surface of the wet pulp on the secondary forming wire using a second headbox located on the secondary forming wire and in front of the wet press section press. This double layer pulp thus formed on the secondary forming wire is then passed through a wet press section press, a drying section with steam heating rolls, then a calender section and wound up on a winder. It was These rolls of dual-ply paper were later treated with a melamine-formaldehyde resin, assembled with a phenolic resin impregnated kraft core and then laminated into a press under standard veneer lamination conditions. The surface layer of the abrasion resistant raw material on the decorative paper was always on the surface of the finished laminate. Alumina having the distribution shown in Table I above was used as the abrasive particles. A paper control was made on the same machine without using any raw material from the second headbox.

Example 1 In this example, Procter & Gamble Grade 5
05 Cotton linter was added to a pulper with 0.35% consistency, transferred to a second headbox and applied to the surface of the base pulp layer on the secondary forming wire. Cotton linters this level was adjusted to provide a basis weight of 6.8kg / 278.7m ² (15 lbs / 3000 square feet) by controlling the flow rate of the pump to the second headbox. Example 2 Aluminum oxide (Alhem AC-99,9 micron average size) was added to a pulper along with the cotton linter, then transferred and applied to the surface of the base pulp. The depressurized white water was centrifuged from the secondary forming wire and found to contain aluminum oxide. This shows the passage of this raw material through cotton linters, base pulp and secondary forming wire. Also, aluminum oxide collected on the metal surface of the second headbox.

Examples 3-6 In this example, 0.5% of a cationic polyacrylamide (Acurac 181 from American Cyanamide) was added.
It was diluted in solution and then pumped into the transfer line between the pulper and the second headbox. The approximate residence time of the polyacrylamide with cotton linter and aluminum oxide was about 10-30 seconds. The amount of polyacrylamide is reported as the weight percent of cotton linter fiber. Polyacrylamide impregnation amount 0.02%, 0.0
Levels of 2%, 0.3%, 0.75% were achieved by increasing the flow rate of the aqueous acrylamide solution into the transfer line. A negligible amount of aluminum oxide was found in the centrifuged sample of white water from the reshaped wire. No aluminum oxide was found to collect on the walls of the second headbox, indicating the binding of aluminum oxide to the cotton linter fibers.

Examples 7 and 8 In this example, the retention promoter and aluminum oxide were mixed and deposited via the second headbox. No fiber is used. In Table II, scuff resistance was measured according to the following method. The method measures the ability of the surface of a laminate to resist scuff wear from 100 grit aluminum oxide sandpaper that rubs across the surface. The test includes: 1. Straight line washing machine and friction machine (Gardner Laboratory) 2.100 Grit Aluminum Oxide 3M Company Three-M-ite (registered trademark) Elek-Tro-Cut (registered trademark) Cross Cloth roll 3-inch wide 100J double flex 7.6 cm (3 inches) x 25.4 cm (10 inches) specimen 3. Steel block 3-1 covered with foamed weatherstrip chips (1 inch x 7/16 inch, Champ Sheave Item # 9-1494, Standard Motor Products branch, St. Louis, MO 63130) on the bottom and edges. / 2 inch x 2-11 / 16 inch 4. Sponge holder for washing machines (Gardner Laboratory)

The laminate test piece was cut into a 4 inch × 8 inch rectangle so that it could be placed on the base of a washing machine, and held with a masking tape. Then, a polishing cloth (sanding c
Blocks with steel applied in loth) (steel / padded blo
ck) was wrapped around, bound with masking tape, inserted into a holder and bound to the machine. The stroke counter was set to 0 and the machine was started. Fifty
The machine stopped on a stroke. The test piece was removed and washed with a sponge soaked with clean water and soapy water. It was dried and examined for surface scratches. The sample is 1 (worst) to 1
Graded using a modified grading scale ranging from 0 (best). The modified grade scales 1 and 10 correspond to the ISO scales 1 and 6, respectively, and have a linear relationship between the scales.

[0026]

[Table 2] Table II: Paper line test (lbs / 3000 square feet) ────────────────────────────────── ─── Comparison Rubbing resistant decorative paper Example Wilsonart laminated control D369 + A1203 Object roll overlay 1 2 3 ──────────────────────────── ───────── 1st headbox base sheet 67 67 67 67 67 2nd headbox Cotton linter 0 15 15 15 A1203 (9 micron) 0 0 7 7 Polyacrylamide (%) 0 0 0 0.02 A1203 Has Overlay 2200 0 0 (40 micron) Rubbing test 9 7 1 1 5 8 (10-best, A1203 sandpaper, 50 cycles) NEMA test Friction test (NEMA) 4424 1327 602 628 2715 2949 Initial point (IP) 3600 1100 253 292 694 1425 End point (FP) 4670 1380 873 873 4380 4087 Ball impact (in J) 46 58 47 78 Drop dart impact (inch) 16 30 24 24 Blot (6-best) 6 4 6 6 ───────────────────────── ─────────────

[0027]

[Table 3] Table II: Paper Line Test (Continued) (pounds / 3000 square feet) ─────────────────────────────── ────── 4 5 6 7 8 ─────────────────────────────────── 1st headbox 67 67 67 67 67 Base sheet 2nd head box 15 15 15 0 0 Koton linter A1203 7 7 7 5 7 (9 micron) Polyacrylamide (%) 0.2 0.3 0.75 0.02 0.05 Overlay with A1203 0 0 0 0 0 (40 micron ) Rub test 8 10 8 8 8 (10-best, A1203 sandpaper, 50 cycles) NEMA test Friction test (NEMA) 3265 3602 3732 1995 6869 Initial point 1910 2376 2459 1710 6042 End point 4193 4357 4517 2019 6797 Ball impact (inch) 56 52 Drop dart impact (inch) 30 15 Blot (6-best) 6 6 ───────────────────── ───────────────

Example 9 In this example, damage to a press plate by a laminate containing four types of alumina particles was measured. Plate preparation The plate size used in the experiments was limited by the dimensions of the press platen and the maximum load of the press. The platen has a maximum dimension of 24 inches and the press load limit is 75 tons. The longest plate (which will result in the longest scratches) has the greatest expansion, so
Twenty-four inches was chosen as one of the dimensions. The press is 73.1 kg / cm ² (1040 psi) to cure the laminate.
Pressures of up to 6 inches need to be achieved, but due to the 75 ton load limit, other dimensions are up to 6 inches. Thus, the set of 6 plates was 24 inches long and 6 inches wide, which provided sufficient length and various shapes of scratches. Since it is not practical to monitor continuous scratch build-up across a 24 inch long by 6 inch wide plate, three representative areas for each plate are roughly the same: the center and two opposite edges. Selected in position. Each area is approximately 1 cm ² , and Violes reagent (Vio
ll's reagent; stainless steel etchant containing glycerol, hydrochloric acid and nitric acid) to mark the outer circumference of the stainless steel. Each plate was labeled by etching to identify the type of alumina particles that were pressed. Thus, three 1 cm ² areas would be monitored for each of the 5 vertical 24 inch by 6 inch plates facing 10 consecutive press cycles.

Manufacture of Laminates For each press cycle, 2 for each of the following:
Two laminates were pressed: control (no alumina), 1.1 micron diameter alumina, 325 mesh alumina, spherical alumina, and alumina overlay (822).
The side facing the plate is labeled "TO
Labeled P "). The stack forms a single stack using both the four sides of the plate and one of the two sides at the top and bottom of the stack. Each laminate had a decorative B-stage paper top coating side (dec) facing the plate.
orativeb-staged paper top-coated side), two layers of phenolic, and one layer of a release sheet that allows the two laminates to be pressed back to back without sticking together. The finished stack was placed in a press using four layers of kraft paper to cushion the impact and a foil layer between the brass platen and the outer steel plate of the stack. The same stacking arrangement was repeated throughout the experiment. The press presses 75 to cure the laminate.
It was a ton load. This load is 73.1 kg / cm ² (1040 psi) for a plate 24 inches long and 6 inches wide.
Bring the pressure of. The platen heater was then activated for 1 hour. The temperature was measured at the ends of the two plates in the center of the stack using a thermocouple located between the release layers. The temperature usually reaches 133.8 ° C (280 ° F) after 45 minutes,
Maintain the remaining heating time at 280 ° F (133.8 ° C).
At this point, the heater was turned off and cooling water was circulated through the platen. The thermocouple takes 37.8 to 48.9 ° C (100
C. to 120.degree. F.), at which point the load was released and the laminate removed from the press. In this experiment 10 press cycles were performed.

Plate Testing After each press cycle, the plates were brought to the metallography laboratory for testing. For the overlay plate, 15x magnification pictures were taken in each of the three areas for each cycle. For 1.1 micron, 325 mesh, and spherical plates, 40X photographs were taken in the central region for each cycle only. First,
After the 5th and 10th cycles, for the 1.1 micron, 325 mesh, and spherical plates, 12.
I made a 5x magnification photo. Scratch density varies throughout the plate. There was an area that appeared to be scratched on each press cycle, and the other area was scratched only on one or two press cycles.
The size and shape of the scratches will vary with the position of the plate. Scratches generally appear to be longer at points away from the center of the plate.

The method of surface reproduction was used to obtain a permanent record of wear damage from each press cycle in the three areas of the five plates. This method can be used to obtain a negative or inverse image of a plate with very fineness. This process also makes it possible to see the abrasion damage with a scanning electron microscope. A thin film of acetobutyrate was softened with solvent and applied to the areas to be copied. The thin film flows into the scratches of the plate. When the solvent dries, the film retains the detailed surface condition of the plate. In this experiment, Ted Pella, Reding, CA (cat.no.448)
48) 100 micron thick thoria hole (T
A riafol) copy sheet was used with a few drops of acetone to obtain a copy. In order to prepare visible copies, they tended to curl on drying, so they were first applied flat to glass slides. A thin layer of silver was then deposited on the copy using a Denton Vacuum Desk-1A Cold Sputter-Etch unit.
The copy was then viewed under a bright microscope. The fineness of the copy is so good that even a few mechanical flaws from the plate and the etched perimeter are apparent. 32 for the first, fifth and tenth cycles
Assembled photographs at 12.5 magnification were made from copies of circular areas from 5 mesh alumina and diamond areas of spherical alumina.

Damage determination Scratch quantification: Quantitative by quantifying the number of scratches observed on duplicates of the etched areas from the respective plates for 1, 5 and 10 press cycles. Each copy was visible on the metallograph at a magnification of 50 and the image was viewed on a monitor. The number of scratches on the monitor screen was counted using image analysis software. At 50x the scratches were clearly visible but the entire area to be observed had to be divided into smaller boxes. The number of scratches in each frame was added to obtain the number of scratches in the area. The total number of scratches in each area was divided by the area of that area to obtain the scratch density or number of scratches per unit area.

[0033]

[Table 4] Table III ──────────────────────────────────── Cycle number Alumina -325 mesh Spherical 1 .1 micron diameter Overlay alumina Alumina Alumina ───────────────────────────────────── 16.9 / mm ² 4.9 1.4 0.4 5 10.8 7.7 3.0 0.6 10 14.4 9.1 5.5 1.9 ─────────────── ──────────────────────

Scratch Observations: Scratch accumulation after each press cycle was observed using 1.1 micron, 325 mesh, and 40 × photographs from the central area of the spherical plate. At 40 times, a photograph of 3.5 inches in height and 4.5 inches in width corresponds to the actual plate observation area of 6.35 mm ² (3.48 mm ² for a spherical plate due to the bad connection of consecutive photographs). Observed). The number and size of the scratches in the photographs were recorded for each press cycle.
Thus, the number and size of new scratches after each press cycle was determined:

[0035]

[Table 5] Table IV ──────────────────────────────────── Cycle number -325 mesh Spherical 1. 1 micron diameter ^{(6.35mm 2) (3.48mm 2)} (6.35mm 2) ──────────────────────────────── ──── 1 18 new scratches 47 6 2 8 0 0 3 0 5 5 10 4 4 0 0 5 5 0 0 0 6 6 0 0 0 7 7 0 3 0 8 8 0 9 1 9 0 0 0 10 10 3 0 0 total 33 ( 5.2 / mm ² ) 64 (18.4 / mm ² ) 7 (1.1 / mm ² ) ──────────────────────────────── ─────

Although the invention has been disclosed in connection with many specific embodiments, it is contemplated that many different additional geometries can be used without departing from the spirit of the invention. Further shapes can be obtained by varying the shape, size, thickness, etc. of the various structural members. Moreover, in view of the present teachings, many combinations of various features can be made without testing the invention.

Example 10 A test was conducted to determine the retention properties of four commercially available cationic polymers. Retention properties were measured by depositing a paper composition containing aluminum oxide on the screen of a TAPPI Standard Sheet Machine Model S-50-4 handsheet machine with a 6.25 inch diameter screen. About 48% by weight aluminum oxide was retained in the produced paper without the use of retention enhancers. Acurac 181 cationic (10%) high molecular weight (5-10 million) polyacrylamide retention promoter, available from American Cyanamide, Inc., retained about 82% by weight aluminum oxide in the produced paper. . Betz Paperchem
DPP-1813 cationic (15
%) High molecular weight (6-8 million) polyacrylamide retention promoter, about 83% by weight aluminum oxide was retained in the produced paper. Polyplus 695 cationic (10 available from Bets Paperchem)
%) High molecular weight (6-8 million) polyacrylamide retention promoter, about 94% by weight aluminum oxide was retained in the produced paper. DPP-1878 cationic (40%) high molecular weight (6-8 million) polyacrylamide retention promoter available from Betts Paperchem.
About 52% by weight aluminum oxide was retained in the produced paper.

These tests were performed by depositing enough composition with enough water to fill the TAPPI handsheet machine to the 6800 ml level to produce a 67 lb sheet. When the liquid level in the handsheet machine reached the 2200 ml level, an aqueous slurry of aluminum oxide particles and retention promoter was added. The paper produced was weighed to determine the amount of aluminum oxide retained in the produced sheet. The invention and its embodiments disclosed herein are well adapted to attain its ends and obtain the advantages initially mentioned. Certain changes can be made in the method and apparatus without departing from the spirit and scope of the invention. Modifications are possible, and each element drawn in any of the claims is
It is further intended to be understood as referring to all equivalent elements, transformations or combinations of elements to achieve substantially the same result in substantially the same or equivalent manner. It is intended to broadly cover the invention in any way that its principles may be used. Thus, the present invention is well adapted to attain the ends and other ends mentioned, as well as obtain the ends and advantages.

Front Page Continued (72) Inventor Richard Earl Hotara United States Texas 76502 Temple Chelsea Place (No Street) (72) Inventor Jerry El Marina United States Texas 76502 Temple Spanish Oak 4101 (72) Inventor Melvin Pitts United States Texas 76504 Temple Brazos Street 703 (72) Inventor Clyde El Witham United States California 94037 Montara Birch Street 1294 (72) Inventor Nancy Jay Annor United States California 94065 Redwood City 209 Evoset Drive 1

Claims (44)

[Claims] 1. A wear resistant decorative sheet produced by compressing a plurality of sheets of paper impregnated with at least one synthetic resin molding composition into a unitary structure at a temperature and pressure of lamination conditions. The surface sheet of paper has abrasive particles incorporated during the step of forming the paper, and the abrasive particles and a retention promoting means for retaining a substantial amount of abrasive particles in the produced paper. Depositing the composition containing on a secondary forming wire in a wet section of a papermaking machine on top of a papermaking composition, and then pressing and drying the deposited pulp to produce a product paper; For producing, stacking a plurality of sheets of paper impregnated with a synthetic resin molding composition such that the surface sheet of paper is the product paper;
And a wear resistant decorative sheet manufactured by compressing the produced stack into a unitary structure at a temperature and a pressure of lamination conditions. 2. The abrasion-resistant decorative board according to claim 1, wherein the produced paper covers the decorative sheet. 3. The wear-resistant decorative board according to claim 1, wherein printing is performed on a surface layer surface of the produced paper. 4. The abrasion resistant decorative board of claim 1 wherein the papermaking composition further comprises sufficient pigment means to produce a product paper having a solid color. 5. The abrasion resistant decorative board according to claim 1, wherein the produced paper and the lower paper in the produced stack are impregnated with different resin molding compositions. 6. The surface sheet paper and the lower paper in the production stack are impregnated with a resin molding composition.
The wear-resistant decorative plate described. 7. The wear resistant decorative sheet of claim 1, wherein the abrasive particles have a hardness of at least about 7 on the Moh scale. 8. The wear resistant decorative board of claim 1, wherein the abrasive particles have a hardness of at least about 7 to about 10 on the Moh scale. 9. The wear resistant decorative sheet of claim 1, wherein the abrasive particles have an average particle size of about 1 to about 10 microns. 10. The wear resistant decorative sheet of claim 1, wherein less than about 10% by volume of the abrasive particles have a particle size greater than about 10 microns. 11. At least about 60% by volume of the abrasive particles.
The wear resistant decorative board of claim 1 having a particle size of about 1 to about 10 microns. 12. The wear-resistant decorative plate according to claim 1, wherein the abrasive particles are aluminum oxide particles. 13. The abrasion-resistant decorative board according to claim 1, wherein the abrasive particles are contained in the produced paper in an amount of about 1 to 25% by weight. 14. The abrasion-resistant decorative board according to claim 1, wherein the abrasive particles are contained in the produced paper in an amount of about 2 to 20% by weight. 15. The wear resistant decorative sheet according to claim 1, wherein the abrasive particles are contained in the produced paper in an amount of about 3 to 15% by weight. 16. The wear-resistant decorative sheet according to claim 1, wherein said retention promoting means retains more than 50% by weight of abrasive particles deposited on the secondary forming wire in the produced paper. 17. The wear resistant decorative board of claim 1, wherein said retention promoting means retains greater than 80% by weight of the abrasive particles deposited on the secondary forming wire in the produced paper. 18. A wear resistant decorative board according to claim 1, wherein said retention promoting means retains greater than 90% by weight of abrasive particles deposited on the secondary forming wire in the produced paper. 19. The wear-resistant decorative board according to claim 1, wherein the retention promoting means comprises a cationic polymer. 20. The abrasion-resistant decorative board according to claim 1, wherein the retention promoting means comprises a cationic high molecular weight polyacrylamide polymer. 21. A wear resistant decorative sheet produced by compressing a plurality of sheets of paper impregnated with at least one synthetic resin molding composition into a unitary structure at a temperature and pressure of lamination conditions. The surface sheet paper has aluminum oxide particles incorporated during the pulp depositing step to form the paper, and about 80% by weight of the aluminum oxide particles in the resulting paper.
A composition comprising a retention-enhancing means for retaining more aluminum oxide particles is deposited on a secondary forming wire in the wetting section of a papermaking machine, onto a top layer of the papermaking composition, followed by production of the resulting paper. Pressing and drying the deposited pulp for stacking; stacking multiple sheets of paper impregnated with a synthetic resin molding composition such that the surface sheet of paper is the product paper to produce a stack; And a wear resistant decorative sheet manufactured by compressing the produced stack into a unitary structure at a temperature and a pressure of lamination conditions. 22. The average particle size of the abrasive particles is about 1 to
22. The wear resistant decorative board of claim 21, which is about 10 microns. 23. The wear resistant decorative board of claim 21, wherein less than about 10% by volume of the abrasive particles have a particle size greater than about 10 microns. 24. At least about 60% by volume of the abrasive particles.
22. The particle size of the is from about 1 to about 10 microns.
The wear-resistant decorative plate described. 25. The wear resistant decorative board according to claim 21, wherein the abrasive particles are contained in the produced paper in an amount of about 1 to 25% by weight. 26. The wear-resistant decorative board according to claim 21, wherein the abrasive particles are contained in the produced paper in an amount of about 2 to 20% by weight. 27. The wear-resistant decorative board according to claim 21, wherein the abrasive particles are contained in the produced paper in an amount of about 3 to 15% by weight. 28. The wear resistant decorative board of claim 21, wherein said retention promoting means retains greater than 90% by weight of the abrasive particles deposited on the secondary forming wire in the produced paper. 29. The wear-resistant decorative board according to claim 21, wherein the retention promoting means comprises a cationic polymer. 30. The wear-resistant decorative board according to claim 21, wherein the retention promoting means comprises a cationic high molecular weight polyacrylamide polymer. 31. A method of making a paper having abrasive particles entrapped during the pulp depositing step for retaining more than about 50% by weight of abrasive particles in the abrasive particles and the resulting paper. And a composition for promoting retention of
On the secondary forming wire in the wet section of the paper machine,
After deposition on a top layer of a papermaking composition, a method comprising pressing and drying the deposited pulp to produce a product paper. 32. The method of claim 31, wherein the abrasive particles have a hardness of at least about 7 on the Moh scale. 33. The method of claim 31, wherein the abrasive particles have a hardness of at least about 7 to about 10 on the Moh scale. 34. The average particle size of the abrasive particles is about 1 to
32. The method of claim 31, which is about 10 microns. 35. The method of claim 31, wherein less than about 10% by volume of the abrasive particles have a particle size greater than about 10 microns. 36. At least about 60% by volume of the abrasive particles.
32. The particle size of the is from about 1 to about 10 microns.
The method described. 37. The method of claim 31, wherein the abrasive particles are aluminum oxide particles. 38. The method of claim 31, wherein said abrasive particles are present in the resulting paper in an amount of about 1-25% by weight. 39. The method of claim 31, wherein said abrasive particles are present in the resulting paper in an amount of about 2-20% by weight. 40. The method of claim 31, wherein said abrasive particles are present in the resulting paper in an amount of about 3-15% by weight. 41. The method of claim 31, wherein said retention enhancing means retains greater than 75% by weight of the abrasive particles deposited on the reformed wire in the produced paper. 42. The method of claim 31, wherein said retention enhancing means retains greater than 90% by weight of the abrasive particles deposited on the reformed wire in the produced paper. 43. The method of claim 31, wherein the retention enhancing means comprises a cationic polymer. 44. The method of claim 31, wherein the retention enhancing means comprises a cationic high molecular weight polyacrylamide polymer.