FR2586023A1 - RAPID-CURING CONDENSATION PRODUCT BASED ON FORMOL AND THIOUREE AMINOPLAST FORMAT FORMAT - Google Patents

Abstract

A. QUICK-SETTING CONDENSING PRODUCT BASED ON AMINOPLAST FORMATORS, FORMOLA AND THIOUREE. B. PRODUCT CHARACTERIZED IN THAT IT CONTAINS A SEPARATING OR RELEASING AGENT, AS WELL AS A PLASTICIZER, A GUANAMINE, A WETTING AGENT AND A HARDENER, AND METHOD OF MANUFACTURING. C. THE INVENTION RELATES TO A QUICK CURING CONDENSATION PRODUCT USED FOR THE MANUFACTURE OF LAMINATES AND OR OF WOOD DERIVATIVES, AND TO A PROCESS FOR ITS MANUFACTURE.

Description

25860.23

  "Rapid hardening condensation product based.

  of aminoplast, formalin and thiourea formers.

  Decorative laminates, such as those used especially for kitchen furniture,

  especially as work surfaces, have so far been

  exclusively by parts in multi-stage presses.

  In this process, improper papers are used.

  resinous: it is used, for the upper face, a paper, often colored or printed, impregnated with melamine resin, and for the intermediate beds and the back,

  kraft paper with soda, impregnated with phenolic resin

  that, which are pressed into laminates for a period of up to 40 minutes, under

  800 to 1000 Newton / cm2, and under temperatures that may

  up to 160 C. This type of laminate manufacturing consumes a lot of energy because it takes

  cool the press before removing the

  hardened, and warm it up again for

  following statement. Another important factor in the increase

  costs in the manufacture of these strati-

  high pressure process is the high investment of a multi-stage press, the heating boiler and

  cooling as well as the numerous sheets and padding

  rages. It is already known, from DE-OS 20 27 085, a thermosetting resin modified with thiourea, which makes it possible to press resin-impregnated particle boards in the space of 45 to 120 seconds, where the cooling may be removed before removing the plates from the press, the resulting products having resistance to acids and coloring

  more important, as well as an improvement in the resistance

  this to the water in the boiling water test.

It has also been done many

  tests to make these decorative laminates, in

  tinu, with simpler presses and without cooling

  is lying. A result was obtained by gluing together decorative papers impregnated with resin with a material

  of support, which is called a dou-

  ble, with a width of about 50 cm.

With double band presses

  of this kind, it was initially

  only 100 to 200 Newton / cm, so that the possibilities of changing the condensation products to be used were very limited. It was possible to work on these presses only with very fluid resins that were not enough for all

  requirements that were put to them. As a result, the strati-

  made in this way could be used only, essentially, for the

laminated particle board.

  The pressures achieved with the double belt presses could finally be increased to 350 to 400 Newton / cm2, and the working width could be widened to more than one meter. With appropriate resin compositions it has thus been possible to obtain laminates of very high quality with pass rates of 30 seconds or more. The advantages of this process lie in the significant savings in energy and personnel compared to batch-operated presses, as well as in the suppression of

falls thanks to the endless format.

  The continuous manufacture became economically all the more interesting for the strati- fied as the speed of passage of the material to be squeezed

could be increased.

By further increasing the speed of

  passage, that is to say with lower pressing surfaces

  less than 30 sec, there was formation of

  flures in the laminate, and a separation of the layers in the boiling water test. Attempts to speed up the curing rate of the melamine resin by increasing the proportion of hardener did not reach their goal because, already because of the heat radiation from the pressing plates before the pressing zone, it occurred. too much condensation of the resin, so that it did not spread completely

  and that the surfaces were consequently no longer complete

closed.

  There was then the problem of developing a resin that provides, in a very short time

  short press, in a pass press, strati-

  or coated particle board of a high quality

  which satisfies the most severe requirements.

  This problem is solved by means of a rapid cure condensation product based on aminoplast, formalin and thiourea formers, having a certain content of separating or demolding agent, as well as possibly plasticizers, guanamine , in

wetting agent and hardener.

  Whereas the technique has long called for condensation products that harden more rapidly for the production of laminates, coated particle boards, coated hard trays

258'02!

  and others, it was surprisingly found, however, that no products had yet been found which could give the final products the necessary properties in terms of surface quality, gloss, hardness, resistance staining and boiling resistance. It is only by finding the composition according to the invention that the properties which make them suitable for

  stratigraphic manufacturing facilities

bound in fast walking bands.

  These condensation products consist of formaldehyde, melamine, and thiourea with a certain content of separating or demolding agents,

  as well as possibly plasticizers, and small

  portions of a guanamine with 1 to 12 carbon atoms in the chain. Before the impregnation operation, it is added

  to the solution again, a wetting agent and a hardener.

  The following condensation products

  the fast-curing invention are obtained by hand-

  keeping as much as possible the following recommended molar ratios between constituent parts: 1.5 to 2.5 moles formalin 1 mole melamine 0.1 to 1 mole glycol 0.02 to 1 mole thiourea 0.00005 to 0.0015 mole stearate guanidine 0.00010 to 0.005 mole of substituted aliphatic guanamine. The condensation product has a viscosity number of 12 to 25 sec in the beaker

  Ford-DIN with a nozzle of 4 mm at 20 C.

  In condensation products intended to impregnate the papers of the lower layers,

  it can be replaced up to 100% by weight of the melamine

  mine with urea, the proportion of thiourea being

  same time increased. Condensate products have

  Then the following recommended composition: 1.5 to 2.5 moles formalin 0.01 to 0.5 mole melamine 0.1 to 0.9 mole thiourea 0.00005 to 0.005 mole guanidine stearate The three aminoplast formers taken together require a proportion of 1.5 to 2.5 moles of formaldehyde to provide a suitable suitable resin composition. Guanadine stearate in small proportion also serves here as release agent. The conditions of the concentration must be maintained

  such that clear resin solutions occur.

  Examples of suitable plasticisers

  which can be introduced into the product of

  densification according to the invention and which are combined after pressing, there may be mentioned, for example, glycols, such as dipropyleneglycol, dibutyleneglycol, but also sugar, sorbite, caprolactam, sulphonamide,

  toluene; diethylene glycol is preferably used.

  Formalin will be introduced into the process according to the invention, preferably in the form of its 30% aqueous solution or a higher percentage. As guanamine, an alkyl-substituted guanamine, preferably caprinoguanamine, will preferably be used. We can also use,

  with the same advantage, dodecyl- or butyroguanamine.

  As the release agent, salts of long chain fatty acids with more than 10 carbon atoms or fatty acid esters, such as

  that, for example, glycerin stearate. It is recommended

  It is recommended that guanidine salts of long-chain fatty acids be used, the steroid or guanidine palmitate being particularly recommended. A sufficient effect

  is obtained with already relatively small quantities.

  The finished resin solutions are provided with a wetting agent, which may be a nonionic or anionic wetting agent, to wet the support materials (paper webs) better.

  A nonionic wetting agent based on ethylene phenols

  xylated alcohols or amines will be used preferably.

  To accelerate the hardening, it is necessary to add to the resin, before using it, to

  low levels of a common hardener in the

  merce, with latent action, such as, for example,

  amines of para-toluenesulfonic acid.

  The resin solutions are prepared by pooling all the components in an aqueous medium at pH 6.5 to 10.5 and condensing at a temperature of 80 to 100 ° C to a dilutability at 10 to 50 ° C. % with water. It is however recommended to

  prepare a precondensate of formalin,

  amino-plasters and a part of the plasticizer at a pH of 8.5 to 10, and to condense the thiourea at 80 to 100 C, only after reaching the hydrophobic point, and after adjusted the pH again. When the condensation is complete, the mold release agent and the plasticizer ester are added to the cooled resin solution. By later addition

  thiourea and plasticizer, stable stability.

  ckage of the very large resin solution, is obtained

  can reach many weeks.

Resin solutions for the im-

  Prégnation of the papers of the lower layers will be prepared in the same way. In order to obtain particularly clear and stable resin solutions, it is first necessary to prepare a pre-condensate of formalin and

  urea, and add thiourea, urea and possibly

  melamine. When the dilutability of the condensation product has reached 10 to 50%, thiourea will be added once more and after cooling the methanolic solution of guanidine stearate. In the preparation of these resins too, all the components can be condensed in common.

  Condensation products

  rapid curing according to the invention, the composition and the manufacturing process deviates only slightly

  of known resins suitable for the manufacture of

  laminates, coated wood derivatives or hard coated fiberboard

  has been felt for many years,

  suitable for the impregnation of paper webs for the continuous production of laminates, or coated wood products. in so-called double-band presses. Although the pressing time in these presses is lower

  at 25 seconds, the surfaces of the products manufactured

  valuable properties, such as high gloss, perfectly sealed surface, sufficient hardness, high resistance to steam and boiling water, and outstanding behavior against

the formation of color spots.

  The following examples should explain

  more fully the invention without limiting it

is lying.

  The condensation products according to the invention can naturally also be used for laminates, wood-based laminates, or fiber plates

  in presses working by loads, for example

  in multi-stage presses. So he is

  obtained particularly short pressing cycles.

Example 1

  Resin for surface coating: In a stainless steel tank with a stirrer, and heating and cooling devices, 654.2 parts by weight of 30% formalin, 40.1 parts by weight of diethylene glycol, and 408.9 parts of melamine at room temperature. By introducing 3.545 parts by volume of sodium hydroxide solution I n, the pH of the suspension is adjusted to 9.4 and then heated to 90 ° C.

  the space of 30 minutes. When is reached the hydro-

  phobic (formation of haze when a drop of the condensation product is introduced into clear water), this

  which occurs after a period of condensation of

  after 90 minutes, 0.955 parts by volume of caustic soda lye and 28.6 parts by weight of caustic soda are added

  thiourea. The condensation is then continued

  only at a precipitation index of 1.6; that is to say

  Until the mixture of one part by volume of solu-

  resin with 1.6 parts by volume of water at 20 C makes a cloudy appearance. The contents of the tank are then rapidly cooled to 40 ° C. and at this temperature a solution consisting of 0.119 parts of guanidine stearate in 2.261 parts by weight of methanol and 68.2 parts by weight of diethylene glycol is added.

in the resin, while stirring.

  The clear resin solution pre-

  has a flow time of 17 seconds, measured with

  the Ford beaker with a 4 mm nozzle at 20 C. The visco-

  sity does not change within three weeks.

Example 2

  Resin for Surface Coating: In a stainless steel tank, 480 parts by weight of% formalin are placed and 2.8 parts by volume of 1 n sodium hydroxide solution are added. After addition of 29.4 parts by weight of diethylene glycol, 1.5 parts by weight of capronoguanamine and 300 kg of melamine, a pH of 9.4 is established in the suspension. The contents of the tank are heated to 90 ° C. in the course of 30 minutes, and when the hydrophobic point is reached, 0.7 parts by volume of 1 n sodium hydroxide solution and 21 parts by weight are added. thiourea. The condensation is continued at 90 ° C. to a precipitation index of 1.8, and then cooled rapidly. At 40 ° C., a solution of 0.089 parts by weight of guanidine stearate in 1.681 parts by weight of methanol and 50% by weight is added to the resin while stirring.

  parts by weight of diethylene glycol.

  Resin has a flow time of 18 seconds measured with the Ford beaker

with a nozzle of 4 mm at 20 C.

Example 3

  Resin for the impregnation of the lower layers of paper (core layers): In a stainless steel tank, 620 parts by weight of 30% formalin, 63 parts by weight of paraformaldehyde (95%) are introduced, and the pH at 6.5 with 0.688 parts by volume of caustic soda lye 1 n. After addition of 165 parts by weight of urea, the mixture is heated to 90 ° C. in the course of 40 minutes. We raise the temperature up to

   C and keep it there for 40 minutes. After cooling

  at 90 ° C., 178.7 parts by weight of

  thiourea and 18.3 parts by weight of urea, and the condensation

  tion is continued for 10 minutes at 85 ° C.

  Then 52.5 parts by weight of melamine are added and continue to condense to a precipitation index of 1.2 to 20 C, which is obtained at 85 C after a condensation time of still about minutes. When this degree of condensation is reached,

  4.6 parts by weight of thiou-

  The mixture is cooled to 40 ° C. and a solution of 0.11 parts by weight of guanidine stearate in 2.09 parts of methanol is introduced into the resin solution with stirring.

Example 4

  Continuous coating of wood derivatives (panels of

  cules): With the resin manufactured according to Example 1 for the surface coating of white paper, decorated is impregnated whose weight is 100 g / m2. Before impregnation, a homogeneous mixture of the resin is prepared with 0.1% by weight of a wetting agent (Triton X 114), nonionic, and 0.1% by weight of a hardener based on sodium salt. ammonium (Melpers RH 4), calculated each time on the liquid resin, the hardener being used in the form of a 25% aqueous solution. Resin

  must, therefore, have a trouble time of 5 minutes.

  at 100 C (cloud time = time after which a resin sample has become completely opaque

  after suspension in boiling water).

With the resin solution as well

  prepared, the decorative paper is impregnated into a

  current impregnation resin, and dried

  in a suspension dryer mounted later, then

  rolled. The dry paper sheet has a weight of 225 g / m2, its humidity is close to 6% (determined by

drying for 5 minutes at 160 ° C).

With these sheets of improper

  The two sides of the 13 mm thick chipboard are coated on a double band press with the Hymmen system. The sheets of the press are at a temperature of 175 C, the speed of advance of the paper is 8 m / min, the pressure of 250 Newton / cm2. The length of the pressing table is 2 m; from where he

  a pressing time of 15 sec.

  decorated plates made in this way, (= coated particle board) have demonstrated outstanding surface properties. The adhesion of the decorative sheet to the particle board

  was excellent. The surface of the plate was complete-

  hermetically sealed. The hardness of the panel surface was good. During the steam test (one-hour action of hot water vapor at 100 ° C on the surface of the panels), no deterioration of the surface of the panel was found. The hardening test, in which

  a sulfuric solution of rhodamine B con-

  200 ml of water, 4 ml of concentrated sulfuric acid,

  and 4 ml of a 2% aqueous solution of rhodamine B,

  two hours at room temperature, on the surface of the plate, showed, from the point of view of the coloring, a value of 1 to 2, which is considered a

hardness of very good, good.

Example 5

  Continuous coating of wood derivatives (panels of

cules):

  A resin solution according to the example

  pl 1 is mixed with 0.1 wt% wetting agent (Triton X 114) and 0.15 wt% hardener (Melpers RH 4) as 25% aqueous solutions. The cloud time of the solution is 4 minutes. A decorative paper weighing 100 g / m 2 is impregnated as in Example 4 with this resin solution. The sheets of dry paper then had a weight of 230 g / m2

  with a moisture content of 6.3%.

  In the installation mentioned in

  example 4, we again put on panels of parti-

  13 mlm thick, under pressure of -

  230 Newton / cm2, and a temperature of 170 C. The forward speed of the belt is set at 10 m / min, so that the pressing time is only 12.5 sec. The laminated sheets showed no sticking phenomenon on the pressing plates. The surfaces of the plates were well sealed. The hardening test showed, according to the staining with rhodamine B, a value of about 2, which corresponds to satisfactory curing.

Example 6

  Continuous manufacture of a laminate: The resin solution manufactured according to Example 2 is completed with 0.1% by weight of wetting agent (Triton X 114) and 0.15% by weight of hardener (Melpers RH 4), after which a clouding time of the resin solution of 4 minutes at 1000C is established. After mechanical impregnation and drying to a moisture content of 6%, the decorative paper which weighed initially 100 g / m reaches the weight of 215 g / m2

  The resin made according to the example

  3 for the papers of the lower beds is completed with 0.4% by weight of hardener (Melpers RH 4), and impregnated with Kraft paper-soda with a weight of g / m2. After drying to a residual moisture content of 5.4%, the weight of this paper amounts to

250 g / m.

  Coated impregnated papers are introduced such as in a double-belt press which has to press three papers of lower layers with, placed on them, a decorative paper. With a forward speed of 8 m / min and a length of the pressing table of 2 m, a pressing time of 15 seconds occurs. The pressure is 400 Newton / cm2, the temperature of the pressing plates is 170 C. At the exit of the press, the different

  leaves were connected, without blisters in a laminate.

  Even with the boiling water test in which the samples

  lons of laminate are kept for two hours in

  boiling water there was no disintegration

  fication. After prolonged exposure to water vapor C, no blistering appeared on the decor side of the treated products manufactured according to the invention. The hardening test, which was carried out based on

  staining with a rhodamine B solution containing

  Sulfuric acid (see Example 4) gave values of 1 to 2. The laminate was therefore completely hardened despite the very short duration of pressing. Comparative test: A decorative paper with a weight of

  g / m2 was impregnated with a resin solution

  document DE-OS 20 27 085, dried to a maximum of

  moisture content of 6%, and rolled up, in strip.

  As paper from the lower layers, it was used a kraft paper with soda impregnated with

phenolic resin of commerce.

  Three strips of paper impregnated with phenolic resin were pressed with a strip of the decorative paper, in a double-belt press under the conditions of Example 6, so for 15 seconds, at

  a temperature of 170 C, under 400 Newton / cm2. At the exit

  Already in the press, there were many gaps between the layers. In the boiling water test,

  there has been a nearly complete delamination

  plete. The steam test gave a surface of

inadmissible

R E V E N D I CATI 0 N S

1) Condensation product with durability

  rapid curing based on aminoplast, formalin and thiourea formers, characterized in that it contains a separating or demolding agent, as well as

  a plasticizer, a guanamine, a wetting agent,

lant and a hardener.

  2) Condensation product according to claim 1, characterized in that it has the following composition: 1.5 - 2.5 moles formaldehyde 1.0 mole melamine 0.1 - 1.0 mole glycol 0.02 - 1, 0 mole thiourea 0.00005 - 0.0050 moles guanidine stearate

0.00010 - 0.0050 mole guanamine.

  3) condensation product according to claim 1, characterized in that it has the following composition: 1.5 - 2.5 moles formalin 0.01 - 0.5 mole melamine 0.1 - 0.9 mole urea 0, 1 - 0.9 mole thiourea 0.00005-0.0050 mole guanidine stearate 4) Condensation product next

  any of claims 1 to 3, characterized

  in that, as aminoplast trainers, use is made of

  urea in combination with thiourea.

   Process for the production of a condensation product according to any one of

  Claims 1 to 4, characterized in that it comprises

  the following operational steps: a) condensation of the aminoplast formers, formalin,

  as well as one quarter to one half of the pre-

  plasticizers and guanamine, with a pH value of 6.5 to 10.5, at 80 to 1000C, until either

reaches the point of hydrophobicity.

  b) addition of thiourea, adjustment of pH to values between 8.5 and 10, and condensation at 80 to 100 C to dilutability with water such as 1: 1 to 2. c) cooling to 30 and up to 50 C and addition of the release agent and the remainder of the proportion of plasticizer. d) addition of the wetting agent and the hardener before

the impregnation operation.

  Process for the production of a condensation product according to any one of

  Claims 1 to 5, characterized in that if the melamine

  is replaced by urea and thiourea, the condensation

  This is done with pH values of 6.5 to 8.

) Use of a product of

  Densification according to any one of claims 1

  to 6 for the manufacture of laminates and / or wood products.

  80) Use of a product of con-

  densification according to claim 7, characterized in that the production of laminates and / or

  wood is produced in a double-belt press under a pres-

  at least 200 Newton / cm2, at a temperature of

  150 to 180 C, and a pressing time of less than

seconds.