CA1083026A - Rapid curing melamine-formaldehyde resin mar- resistant laminate - Google Patents

Abstract

TITLE OF THE INVENTION

RAPID CURING MELAMINE-FORMALDEHYDE
RESIN MAR-RESISTANT LAMINATE

ABSTRACT OF THE DISCLOSURE
A heat and pressure consolidated structure compris-ing, in superimposed relationship, (1) a self-supporting substrate and (2) a decorative, .alpha.-cellulose paper sheet impreg-nated with a resin composition comprising, before consolidation, A. The resinous reaction product of mela-mine formaldehyde and diethylethano-lamine, B. an ortho- or para-toluene sulfonamide, C. ethyleneglycol phenyl ether, D. a catalyst, E. water and F. andalusite, pyrophyllite or mixtures thereof and a method for the production thereof, are disclosed.

Description

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Because of their excellent color, hardness and sol-vent and chemical resistance~ aminoplast resinous compositions, particularly melamine-formaldehyde resinous compositions, have found many uses in the plastics, molding, coating and laminat-ing fields. These resins give a thorough impregnation and thereby insure a co~lplete bond when employed in the production of laminates. Resiskance to discoloration due to heat and light is also realized.
For ma~ny years, these resinous compositions have been used in the production of decorative, high pressure lami-nates wherein a plurality of phenolic resin impregnated kraft paper sheets have been used as a laminate core to which is bonded, at 310F, and 1600 psi, melamine-formaldehyde resin ~mpregnated decorative and overlay sheets. These lamina~es are then bonded to a rigid substrate and used as parkitions, walls, doors, table and counter tops, etc.
More recently, there has been a growing demand for a laminated panel which may be readily fabricated into furni-ture, kitchen cabinets and the like. These panels are pro-duced by applying a single melamine-formaldehy~e resinous composition impregnated decorative sheet to a particleboard substrate at much lower pressure and temperature, i.e., 160C.
and 325 psi. Consequently, these laminate panels have been designated "low pressure" panels as distinguished from the "high pressure" laminates discussed above. ' Low pressure panels have been very ~avorably accept-ed by the industry, and as a result, extensive research has been recently ~.dertaken to improve these panels. One area in which the panels have not proven to be as successful as ' 3Q would be dès~red resides in the area'of abra~slon resi~t~ance~
a property necessary when the panels are to be used'in verti-cle applications. That is to say, when'the panels are fabri- '~

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~3~6 cated into vertical surfaces of furnlt-ure etc. which are used in a domicile or business office, the surfaces thereof tend to wear more readily then desired. I~he worn surface obvious-ly affects the attractiveness of the article of furniture and thereby renders it undesirable.
Accordingly, if a new panel could be devised which had an increased resistance to surface deterioration by abra-sion, a long felt need would be satisfied.
I have now discovered a novel heat and pressure con-solidated decorative panel which has an increased abrasion resistance over those panels now commercially available.
I~his abrasion resistance is imparted to the panels by incorp-orating small amounts of andalusite, pyrophyllite or mixtures - -thereof into the resin composition which is impregnated into the decorative layer of the panel. Although minerals of this type have previously been added to high pressure laminates to increase their abras~on resistance, I employ much smaller amounts of material of a specific particle size to obtain acceptable abrasion re~stance without deleteriously a~fect~
ing the other essential properties o~ the ultimate panel. As examples o~ the prior art, please consider United States Patent Nos. 3,135,643; 3,373,070; 3,373,071; 3,798,111; British Patent Nos. 1,139,183; 1,321,473. It should be noted that each of these references teaches adding a mineral material either to the paper making fibers used to fcrm the decorative sheet or in con~unction with another additive such as cellulosic flock, microcrystalline cellulose etc. I add the minerals alone directly to the resin composition which is -Lmpregnated into the decorative sheet without experienc-ing the decrease in craze resistance, poor print clarit~,-bri~tle surface~ mottle and uneYen glos~
exper~enced b~ those ~1 the ~rior ~rt in thë high pressure : ' ':
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laminate field.
~ccordingl~, the present invent-~on provides a heat and pressure consolidated article comprising (1) a self-supporting substrate and (2~ a decorative a-cellulose paper sheet i~,pregnated with a resin composit-lon comprising, before consolidation, (a) the resinous reaction product of melamine, formaldehyde and from about 0.07 to about 0.16%, by weight, of diethylethanolamine, havlng a ratio of formaldehyde to melamine of from about 1.7 to about 1.9 to 1, respectively, (b) at least about 1.0%, by weight, of ortho- or para- or mixtures of ortho- and para-toluene sulfonal~ide, (c~ from about 1.0% to about 5.0%, by weight, of ethylene-glycol phenyl ether, (d) from about 0.04% to about o.o8% by weight, of a catalyst (e) from about 40% to about 45%, by weight, of water, the remainder being melamineformaldehyde resin, all percentages being based on the total weight of the co~lposition and ~;
(f) from about 0.5% to about 4.5%, by weight, based on the solids ~eight of (a), of andalusite, pyrophyllite or mixtures thereof.
In another aspect, the present invention provides a method for -the production of the article descr~bed above which comprises heat and pressure consolidating, in superi~,posed relationship ; (a) a self-supporting substrate and (b) a decorative a-cellulose paper sheet i~,pregnated with a resin composition comprising, before consolidating, (a) the resinous reaction product of melamine, forn~aldehyde and from about 0.07 to about 0.16%, by weight, of diethylethanolamdne, having a ratio of formaldehyde to melamine of from about 1.7 to about 1.9 to 1, respecti~el~
(b) at least about 1~0%, by we-l~ght, of ortho- or para- or m~xtures of ortho- and para-toluene sulfonam~de, ~3 ~

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(c) from about 1.0% to about 5.0%, by weight, of ethylene-glycol phenyl ether, (d) from about 0.04% to about o.o8%, by weight, o~ a catalyst, (e) from about 40% to about 45%, by weight, of water, the remainder being melamine-formaldehyde resin, all percentages being based on the total weight of the composition and (f) from about 0.5% to about 4.5%, by weight, based on the solids weight of (a), of andalusite, pyrophyllite or mixtures thereof, and recovering the resultant article.
Thus, the heat and pressure consolidated structure of the instant invention comprises, in superimposed relationship, 1. a self-supporting substrate and

2. a decorative ~-cellulose paper sheet impreg~ated with a resin composltion comprising, before consolidation, (A) the resinous reaction product of melamine, formaldehyde and diethylethanolamine, (B) an ortho- or para-toluene sul~onamide, (C) ethyleneglycol phenylether, (D) water and (~) andalusite, pyrophyllite or mixtures thereof.
These ingredients are all critical in the formation o~ the compositions used to produce my novel laminates, as are the specific ; concentrations of each component in said compositions.
me melamine and formaldehyde comprise the maJor portion of the solids, as resin, of the composition. These components æe reacted under the stringent reaction conditions mentioned hereinbelow, at a formaldehyde to melamine ratio of from about 1.7 to about 1.9 to 1, respectively, with from about 0.07 to about 0.16%, by weight, based on the total weight of the composition, of diethylethanolamine. -The ratio o~ formaldehyde to;melamine is critical and when the ratio is about 1.6 to 1, poor melamine dissolution results and an inferior a ~33~;2~;i composition is produced while at ratios above about 2.2 to 1, the crack resistance o~ the panels, i.e~, laminates, produced ~rom the resinous compositions is poor.
Similarly, the amount of diethylethanolamine is . ``! ~ 3b - .

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26,068 critical. This material is needed to adjust the pH of the initlal melamine-water-formaldehyde slurry to its proper value. Amounts lower than about 0.02~ produce a drastically low pH which makes control of the end point of the composi-tion very difficult as well as producing a compositlon which has a stability of less than about 3 days and laminates therefrom which have poor stress-crack resistance. Concen-trations of diethylethanolamine of about 0~2% cause elevated pH ~alues and materially extend the cook time.
The constituent of the composition which consti-tutes the second largest ingredlent is water. This compon-ent is generally present in amounts CO as ~o result in an ulti~ate composition containing from about S5~ to about 60~ -solids. The water therefore comprises from about 40% to ~bout 45% of the composition, the other component~ of the inal composition, of course, constituting the solids there-of, the majority being melamine-Eonmaldehyde resin. The solids content of the composition, when less than about S0~, causes poor treatability when the composition is impregnated into the cellulosic decorative sheet. High ~urface resin oontent on the sheet is very difficult to achieve and longer drying time is needed to obtain a dried ~-staged impregnated sheet suitable for storage. A solids content of greater than about 65~ causes poor melamine dissolution during the resin manufacture and therefore poor quality panels.
The sulfonamide component of the composition can constitute ortho-toluene sulfonamide, para~toluene sulfon-amide or mixtures of ortho- and para-toluene sulfon~amide~
the latter mixtures being preferred since normal commercial production of these compounds results in the formation of such a mixture. These mixtures usually contain Erom about 5~ to about 40~ ortho and, correspondingly, ~rom about 60~ to about 95% para of the isomers. The toluene sulfon-_ ~ _ .... ., :
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8~2l6 26,068 amide is incorporated into the resinous composition in order to increase the stability thereof and also to plasticize the melamine-formaldehyde resin. Compositions containing no toluene sulfonamide exhibit a stability of less than 3 days and panels produced therefrom show unacceptable crackin~ at low humldity. At least about 1.0~ of ~e toluene sulfonamide ~ust therefore be used. Preferred amounts range from about 1.0% to about 4.0~, higher concentrations there'having no detrimental efect on'the compositions or the panel produced therefrom but adding materially to the economic considera- -, tions involved in the productia~ thereofO
~nother critical component of the composition is e~hylene glycol phenyl ether. This material is also known as phenyl cellosolve or ~henoxyethanol. It is also added to ~he composition in or~er to assis~ in plastici2ing the mela-mine-formaldehyde resin. It also produces opti~um flow in the composition during the heat and pressure consolidation ' of the panel. Absence of the ether causes the panel produc-ed from the resultant composition to exhibit very poor crack xesistance and very poor appearance due to a lack of resin flow`. When the ether is incorporated into the composition at levels of 10~ and above, excessive flow occurs during panel production and unslghtly products result~ The preerr-ed concentration of ethylene gly'col phenyl ether ranges rom about 1.0% to about 5.0%, by weight. The ether can b~ re-placed, in whole or in part, by an equivalent amount of di-glycolamine.
All the percentages of the components of the compo-sition'ment'ioned'herein are by weight, based on the total weight o the composition, if not otherwis~ indicated.
As mentioned above, the final critical component of the composition used to form my novel laminates is andalusite, ' pyrophyllite or mixtures thereof. These materials are incorp-_ 5 _ , .::

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2~ ,8 or~ted in an a~ount of no mor~ than about 4.5%, by weight, based on the weight of the resin solids in the composition~
A preferred amount of these minerals ranges from about 0.7%
to about 4.0%, by weight, same basis.
Andalusite is a well known mineral aluminum silicate having the generic formula (,A10)Al[Si04~ or A12Si05 and is a naturally occurring mineral~ although it is preferred that it be purified before being used herein so that it does not de.leteriously affect the, aesthetic values of the laminates.
1~ P~rophy-lli.te is also a naturally occurring mineral which is- best employed herein in its purified form, It has th.e formula A12~si40lo/(oH)2~ or A1203 4si2 H2~
Both the andalusite and pyrophyllite should be used~
alone or as mixtures~ as particles having a size ranging from 15 about 10~ to a~out lQ0 microns, prefera~ly from about 30-60 microns. Smaller sized particles: do not materially increase the a~rasion resistance at the percent incorporation expressed : ' above and laryer sized particles tend to interfere with the `
other desired properties of the laminate.
When mixtures of andalusite and pyrophyllite are em-; ployed~ the mixture can contain from about 5% to about 95% of ei,ther component~ pre~erably from about 20~ to about 80%, and more preferably a majority of pyrophyllite~ Suitable materials may ~e obtained commexcially from Piedmont Minerals Co. Inc, : ~ 25 ~reens~oro~ N.C~ undex the tradenames Pyrotrol* and Alkatrol*~
Other ingredients may alsQ ~e. incorporated into the com~ositIons in order to render them even more useful~ For example:~, lecithin has heen found to ~e effective. in increas~ , ' ~ng the'release characteristics of the composition wh.en press~
,~. 3~ ing a panel. H~drolyzed lecithin ;s preferred for the pur~
p~e~' Us~ful a,~ounts ran~e fro~ a~out ~1% to ab.out 1~5%r by ,'' ~eigh.t~ ~ased on the'total wei~h.t of the composition. Wetting `"' `
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-6- :' : ' 3i~26 25,068 agents, such as arylalkylpolyethers, may also be added.
Before impregnatioh of the resinous composition into the cellulosic decorati~e sheet, it is al90 necessary to in-corporate a catalyst therein in order to produce a sheet con-tainin~ ~-staged resin which will cure to a thermoset state during heat and pressure consolidation. Catalytic amounts of ammonium sulfate are useful for this purpose. Amounts rang-ing from about 0.04~ to about 0.08~ have proven satisfactory.
Thiourea dioxide, thiourea, etc. can also be used at similar concentrations. The Sunshine Gel time should be 7-8 minutes at 136C. after the catalyst addition. ~
The low pressure melamine-formaldehyde resin formu-lation is produced by adding the water ~o the reaction ves-sel and charging the formalin, diethylethanolamine and mela-15 mine crystal thereto. The charged materiaIs are thoroughly admixed for about 5 minutes and the pH is then determined.
It should range from about 9.0 to about 9.8 at 25C~ A high pH can be lowered by adding small, successive increments o~
90~ formic acid and continually testing the pH or adding 20 more formaldehyde or wa-ter after pèrforming an assay of the, charge and determining that one of these components was mis-charged. A low pH can be corrected by adding additional di-ethylethanolamine in small increments while continually test-ing the pH or again determining if a mischarge of water or 25 formaline was made and adding either depending upon said determination. -Once the pH is found to be within the above-speci-fied range, the reaction media is heated -to 90C. until the melamine crystal is dissolved, but not exceedlng 45 minutes.
30 The ~essel is then cooled to 80C.-88C. and the reaction is ;
allowed to proceed until a water tolerance of about 300~ ;

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26,068 wi-th 25C. water is reached, usually in 4 to 5-1/2 hours.
The reaction media is then allowed to cool to 30C.
and the toluene sulfonamide and the ethyleneglycol phenyl ether are added. The resultant composition is then filtered and s-tored for ultimate usage, preferably at 68-77F.
The temperature of the cook governs the properties of the ultimate resin composition and also determines how long the cook must be conducted. At temperatures below about 80~C. the properties of the resin composition are satisfactory but the cook time ls uneconomically increased to from about 8-12 hours. Poor stability of the resin formulation and poar crac~ resistance of panels prepared thereform are exhibited when the cook tèmperature is raised above about 88C.
After recovery from the composition production vessel, the low-pressure resin Eormulation should have the following properties: ~
_ Parameter LimitsMethod ~ -pH at 25C. 9.0 - 9.8ASI~I - E-70-52T
Specific G~avi~y at 25G. 1.24 ~ .015Westphal Balance ~ater Tolerance at 25C. 100 + 20 --ASTM Solids (3 hrs at 105C.) 59 + 1% ASTM - D-1289-64:
APH~ Color S~andard 30 max; clear --Sunshine Gel Time at 136C. 14-18 mins. Sunshine Scien-; tific Gel ~leter Free Formaldehyde 0.5%.max.Sodium Sulfite ; 25 .V~scosity at 25C. ~el RVT 40-6~ cpsBrookfield .
Speed 20 - . Spindle 1 . .
When preparing the decorative sh~eets for impregnation, the above described portion of the resin formulation is modi-fied by adding the catalyst, the alkylaryl polyether, the other desired ingredients, e.g., lecithin, and the fine parti-; cles of the andalusite or pyrophyllite at their approp~iate concentrations. The resin composition is then ready for im-pregnatlon into the cellulosic decorative sheets. ~`
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26,068 The decorative papers from which the novel low-pressure panels of the preseht invention are produced are made from bleached wood pulp whlch is high, at least about 60~, in alpha cellulose content. The papers are pigmented in a known manner to obtain the desired levels of color and opacity. They range in basis weight from about 50-90 pounds per 3,000 square foot ream. The paper has a controlled pH
of about 6.75 ~ 0.5 due to the lnfluence pH has on the re-action rate of the melamine resin after it is applied there-to. Variances in this pH range have adverse effects on the storage life of the treated paper and/or press cycle times when the panel is being producedO
The decorative surface paper porosity (Gurley) is preferably controlled to 15-25 ~econds per 100 c.c. o~ air to assure proper treating of the paper with the resin and pressing of the panel. A paper having too high a porosity will allow too much resin to penetrate and will resul~ in dry spots on the panel produced therefrom. A paper witll ~oo low a porosity will not enable sufficient resin to penetrate and the excessive resin on the surfàce wiIl cause a mottled appearance and surace crazing and/or cracking of the re~ult-ant panel made therefrom.
Impregnation of the paper and drying of the impreg-nated paper may be effected by conventional treaters and Z5 driers known to those skilled in the art. Vits treaters have been found to be particularly useful in this regard and achieve a high resin pick~up and uniform surface coating with sufficient surface resin to achieve an abrasion resistance of 225-275 cycles, NE~ LD 1-2.01. Agitation of the resin ; 30 composition during treatment of the decorative sheet is xecom-mended in order to keep thé mineral particles in suspension.
The resin content of the impregnated paper generally range~
from about 55~ to about 65P6 by weight based on the weight of 9 _ . . . .

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26,068 the impregna-ted paper. Paper volatile levels are maintained at about 5~+0.5. A balance between flow levels and treated weight of the treated paper is maintained to assure proper abrasion levels without reducing craze resistance and other S properties. Treated paper is dried and stored flat in a con-ditioned storage area. It has ~ nominal shelf life of three months at 70-75F. and 40-50% relative humidity.
Core material, i.e., self-supporting substrates useful in producing the decorative low-pressure panels in-clude medium density, mat-formed, wood particleboard and medium density, wood fiberboard. ~seful core material, h~ow-evert merely must enable the production of full-sized, smooth--face~, well-bondedl crack- and craze-resistant panels. Core materials should be stored for a sufficient time at ambient conditions to achieve an equilibrium temperature and an equilibrium moisture content of 7~2Ø
The decorated layer may be placed on both si~es or only on one side of the self-supporting substra~e when panels are being produced. If the decorative sheet is placed only ~ -on one side of the substrate, it is preferred that a so-called balance sheeti i.e., a melamine~ormaldehyde resin impregnat-~d paper sheet! e.g. of Kraft or other paper, sometimes called a cabinet liner, be piaced on the other side in order ~ ;
to prevent the resultant panel from warping during pressing.
Typical release sheets can be applied to both the di~corative layer and t~e balance sheet to prevënt the press plate from sticlsing thereto. A typical press cycle is 325 psi, 150-160C. for 60 ~ S seconds.
Various finishes may be applied to the decorative panels of the present invention. ~or example, the surface - ., may be rendered glossy by using a highly polished press plate, matte by interposing a texturizing release sheet be-tween the press plate and the decoratlve sheet or embossed - 10 - ~, . .. _ . . ... ... ... _ . .. . . .. ... . . , . . . .... ... .. .. ... . . . . _ .. . _ .. ...
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~ 6 26,068 by using an etched press plate.
The following ~xamp~es are ~et forth for purpose~ oE
illustration only and are not to be conskrued as limitations on the present invention except as set forth in the appended claims. ~ll parts and percentages are by weight unless other-wlse specified.

(part A) Into a suitable reaction vessel equipped with ther-mometer and stirrer are charged 1482 parts of water, 4303 parts of 37~,aqueous foxmaldehyde, 8 parts o~ diethylethanol-amine, ~.P. 163C., and 36g~ parts of melamine crystal. The charge is mixed at room temperature for 5 minutes and the pH
is then determined to~be 9.3. ~he vassel is heated to 90C.
and maintained until the melamine crystals dissolve ~39 min- , utes). The charge is then cooled to R0C. and reacted at tha~ temperature until a water tolerance o 750~ with, 5C.
water is reached. The temperature is then raised to 83C.
and the reaction is continued until a final water toleranoe of 300% with 25C. water is achieved. A total reaction time~ -of 3-3/4 hours elapses. The vessel is cooled to 30C. while~
continually adding 306 parts of an ortho-, para-toluene sul-fonamide mixture (50/50) and 203 parts of ethyleneglycol phenyl ether. When the solution reaches 30C. it is filter-ed. A water-like resinous composition having a pH of 9.2l a specific gravity of 1.240, a water-tolerance of 100, a Vi5-cosity of 50 cps., a solids content of'59%, a free formalde-hyde content of 0.37~ and a Sunshine Gel time of 16 minutes '~
lS recovered. The composition (formaldehyde to melamine -~ ' ratio of 1.8/1.0) is stored for 35 days without variation.
(Part B) To 1000 parts of the composition, in a suitable mix-ing vessel, are added 20 parts of a 25~ aqueous solution of ~-': ' ~33~2~

26,068 hydroxylated lecithin,- 0.8 part oE a commercially available alkylaryl polyether having a Specific Gravity of 1.04 and a Flash Point of >480F. (open cup), 20.0 parts o pyrophyllite and 0.6 part of ammonium sulfate crystals, dissolved in water at a 1 : 4 ratio, respectively. I'horough agi~ation after each ingredient is charged results in a resin formulation having a Sunshine Gel time of 7 minutes.
(Part C) A 65 pound basis weight,3000 ft.Z ream, absorbent a-cellulose paper having a Gurléy porosity of 20 seconds per 100 cc oE air, a pH o~ 6.72 and a teakwood grain pattern ~ere-on, is fed into an agitated impregnating bath containing th~e resin formulation of Part B, above. The resultant, impreg-nate~ ~aper is then i~me~ia~ely B-staged ~y passing it through a forced air drying oven at 260F. at a line speed of 55.0 ft./n~n.
The resultant dry treated paper has a resin content of 60~, ~ ed on the dried weight, a volatile content of 5.0~ and a 1 of 1.0~. The impregnated paper is stored 3 months at 72F.
and 48~ relative humidity without detrimental effect.
. ~Part D) ~
A 4'x8'x5/8" thick particleboard, weighing 45 $'~ ' .
pounds per cubic foot, with sanded surfaces is sandwiched be-tween two 4'x8' sheets of the impregnated paper of Part C, above. The non-decorative surfaces of the paper sheets are in adjoint contact with the particleboard. The sandwich is placed betwqen a pair of highly polished stainless steel pressure plates having a release coating thereon and is yressed a-t 145C. for 60 seconds under a pressure of 325 psi.
- A decorative faced panel is recovered having an attractive, aesthetically pleasing surface with good wear, impact and craze resistance.
A stainless steel roll which is mounted in the above resin bath undergoes 300 hours of contact at 50 ~t./min. ~eat-. . . .. . .

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26,068 er speed with no discernable wear as determined by micro-scopic and profilometer examina-tions indicating that the in~
clusion of the pyrophyllite does not materially affect the treater rolls.
A press plate was marked off into two sections and pyrophyllite treated paper was pressed against one section ~hereof while pyrophyllite-free paper was pressed against ~e second section. Profilometer readi,ngs before and after 100 pressings-show,ed that equal wear occurred on each section of the press plate, indicating that no extra wear of the press plate would be expected from using a pyrophyllite contain~ng ~' resin composition. ~ ~
A test sample'is cut from the panel and tested for ~ -' its properties which are set forth in Table I, below.

- , ' The procedure of Example 1 is again followed except that a tidewood patterned decorative 9~ lb. basis weight, 3000 ft. 2 ream a-cell~lose paper of Gurley porosity o lS
seconds, Fer 100 cc of air and a pH o 6.55 is ~sed. Resin pick-up on impregnation is 54~. Paper volatile level is S 5% ' and the flow level is 4.0%. The properties of the resulta~nt panel are similar to those of a panel produced as in Example , 1 but void of pyrophyllite except that the wear resista`nce ~'' is materially increased in the instant panel.
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26,068 - T~ELE I
PHYSICAL PROPERTY RES~LTSNEMA LDI TEST
l. Wear Resistance-cycles 225-275 2.01 Example l Panel 2. Surface Reslstance :
A. Teapot .Slight 2.02 B. High TemperatureNo effect 2.03 i~
3. Cigarette Burn - secs. 575 2.04 Example 1 Panel

4. Stain Resistance Panel not 2.05 affected by any of 29 reagents

5. Color FastnessNo effect2.06 Example 1 Panel ; 6. Scratch - grams 750 Gardner , Example 1 Panel Method ::
- 7. Resistance to ~mpact 21 2.15 (Inches Drop) `.-Example 1 Panel l :
8. Surface Crack Resistance No cracks 28 days, 10%
Example 1 Panel RH;70F.+ 2.0 The Wear Resistance of a panel produced as in . Example 1 but void of any pyrophyllite is 100 cycles. The 20 remaining properties of the panel, as enumerated in Table Ir ~, !: ' ' are substantially identical to those oE the panel of Example :. 1. ' : ~5 ., 1 '' ~` 30 ' ' : . ' '`' `
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26,068 EXAMPLE 3 Example 1 is again followed except that the concen-tration of the following components charged -to the reaction vessel in Part A thereof are varied as follows:
Water 2166 parts 44~ a~. formaldehyde sol. 3619 parts All else remains constant. Again a highly stable resin com-position results. a-cellulose paper impregnated with the composition and dried is storage stable 3 months at 72F. and 48% ~H. Panels pro*uced therefrom have properties substanti-ally conforming to those o the panels set forth in Table 1, ; above.

The procedure of Example 1 is again followed except that the toluene sulfonamide mixture is replaced by para-tolu-ene sulfonamide. 5imilar results are achieved.

The procedure of Examp:Le 1 is again followed except that the ethyleneglycol phenyl ether is replaced by an equiva-lent amount of diglycolamine. 'rhe resin composition, impreg- ;
nated a-cellulose papers and resultant panels all exhibit properties substantlally the same as those of Example 1.

Replacing about one-half of the ethyleneglycol phenyl ether with diglycolamine results in a composition substanti-ally identical to that of Example 5.

The procedure of Example 1 is again followèd except that the hydroxylated lecithin and alkylaryl polyether are omitted and the catalyst is thiourea dioxide. Similar results are achieved, release being effected by spraying the press plates with a commercially available release agent.
The water tolerance of the resins at any particu-. ". ..

., ,__ _ .. ._ _ ___ . _ . ._ _ . .. .... . _.. . . . _._ _ .. . ... ..... . .... :. _ . _.: . _ . _. .... .. .
. . ` . : : . : . : . . ,: , :
.: : : . . : . . -26,Q68 lar point in time during the reaction according to this invention is determined by calculating the ratio of the milliliters of water to the milliliters of resin times 100 required to produce a milky, permanent turbidity, see U.S.
3,753,93~.

The procedure of Example 1 is again followed except that 27 parts of andalusite are used in place of the pyro-phyllite. Substantially identical results are recorded.
lQ EXAMPLE 9 Again the procedure of Example 1 is followed except that the pyrophyllite is replaced by 12 parts of a commerci- ~ ' ally available mixture of andalusite and pyrophyllite identi-fied as Refractory Grade Pyrotrol* manufactured by the Pied- -mont Minerals Co. Inc.~ Greensboro, N. C, The resultant panel has an abrasion value of 265. All other properties ~ are excellent.

25 *Trademark - '.

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Claims (9)

1. A heat and pressure consolidated article comprising (1) a self-supporting substrate and (2) a decorative .alpha.-cellulose paper sheet impreg-nated with a resin composition comprising, before consolidation, (a) the resinous reaction product of melamine, formaldehyde and from about 0.07 to about 0.16%, by weight, of diethylethanolamine, having a ratio of formaldehyde to melamine of from about 1.7 to about 1.9 to 1, respectively, (b) at least ahout 1.0%, by weight, of ortho-or para- or mixtures of ortho- and para-toluene sulfonamide, (c) from about 1.0% to about 5.0%, by weight, of ethyleneglycol phenyl ether, (d) from about 0.04% to about 0.08% by weight, of a catalyst (e) from about 40% to about 45%, by weight, of water, the remainder being melamine-formaldehyde resin, all percentages being based on the total weight of the composition and (f) from about 0.5% to about 4.5%, by weight, based on the solids weight of (a), of andal-usite, pyrophyllite or mixtures thereof.

2. An article according to Claim 1 wherein (f) is andalusite.

3. An article according to Claim 1 wherein (f) is pyrophyllite.

4. An article according to Claim 1 wherein (f) is a mixture of andalusite and pyrophyllite.

5. An article according to Claim 1 containing, in addition thereto, (g) from about 0.1% to about 1.5%, by weight, same basis as (a)-(d), of a lecithin.

6. An article according to Claim 1 wherein said reaction product has a pH ranging from about 9.0 to about 9.8, at 25°C.

7. A method for the production of the article of Claim 1 which comprises heat and presssure consolidating, in superimposed relationship (A) a self-supporting substrate and (B) a decorative .alpha.-cellulose paper sheet impregnated with a resin composition comprising, before con-solidating, (a) the resinous reaction product of melamine, formaldehyde and from about 0.07 to about 0.16%, by weight, of diethylethanolamine, having a ratio of formaldehyde to melamine of from about 1.7 to about 1.9 to 1, respectively, (b) at least about 1.0% by weight, of ortho-or para- or mixtures of ortho- and para-toluene sulfonamide, (c) from about 1.0% to about 5.0%, by weight, of ethyleneglycol phenyl ether, (d) from about 0.04% to about 0.08%, by weight, of a catalyst, (e) from about 40% to about 45%, by weight, of water, the remainder being melamine-formaldehyde resin, all percentages being based on the total weight of the composi-tion and (f) from about 0.5% to about 4,5%, by weight, based on the solids weight of (a), of andalusite, pyrophyllite or mixtures thereof, and recovering the resultant article.

8. A method according to Claim 7 wherein said (f) is pyrophyllite.

9. A method according to Claim 7 wherein said (f) is andalusite.