CS221525B2 - Mixture on the base of organic polyisokyanate - Google Patents

Abstract

The use of polyisocyanates as binders in the preparation of particle boards is subject to the drawback that the boards exhibit a tendency to adhere to the face of the platens used in their formation. This problem is minimized by incorporating minor amounts of a mixture of certain mono- and di- (saturated or unsaturated aliphatic) acid phosphates or the corresponding pyrophosphates, into the polyisocyanate to be used as binder. The polyisocyanates and the acid phosphates and or pyrophosphates, are applied to the particles separately, or after preblending one with the other. Whether the components are applied separately or in combination one with the other, they can each be applied either neat or in the form of an emulsion or emulsions.

Description

The present invention relates to a storage stable composition comprising a polyisocyanate as the basic binder component for bonded particle boards.

It is now generally accepted that organic polyisocyanates, and in particular toluene diisocyanate, methylene bisphenyl isocyanate) and poly (methylene polyphenyl polyisocyanates) may be used as binders or as constituents thereof for the production of bonded particle boards, see for example U.S. Patents 3,428,592, 3,401013, 3,557,263, 3,636,263 , 3,870,665, 3,919,017 and 3,930,110.

In a conventional process, binder resins, particularly in the form of a solution or aqueous suspension or emulsion, are applied to or blended with particles of cellulosic material or other types of material capable of forming bonded particle boards using a drum or mixer or other forms of mixing. The mixture of particles and binder is then shaped in a mat and heated using heated plates under pressure. The process can be carried out either by the Sarda process or continuously. In order to avoid adherence of the resulting plates to heated plates, it has hitherto been necessary to attach an isocyanate-impermeable sheet between the surface of the bonded particle plate and the heated plate during the molding process or to coat the surface of the heating plates before each pressing operation with suitable means to release or coat the surfaces of the particles themselves , which is not adhering to the heating plates. Each of these alternatives, especially when the process is carried out on a continuous basis, is difficult and disadvantageous in an otherwise very satisfactory method of manufacturing bonded particle boards having very advantageous properties and structural strength.

The above disadvantages of using organic isocyanates, such as bonded particle binder plates, can be minimized in a very satisfactory manner when certain phosphorus compounds are used as internal release agents in the isocyanate mixtures used. The authors are aware of U.S. Pat. No. 4,024,088, which discloses the introduction of phosphorus-containing compounds as internal release agents for the production of polyetherblyurethanes. However, the phosphorus compounds disclosed in this publication are generally not suitable for use in the present invention.

An improved process for producing bonded particle boards is based on contacting the particles of organic material capable of binding with the polyisocyanate, and the treated particles are then formed into the panels by heat treatment under pressure, the improvement being achieved by contacting the particles with the polyisocyanate. treatment with 0.1 to 20 parts by weight of the phosphate defined below per 100 parts by weight of the polyisocyanate. The basic condition for achieving an improved process for producing bonded particle boards is that the treated particles are contacted with a polyisocyanate-phosphate mixture that is at least post-diobic, which elapses between its preparation and its curing under the effect of heat under pressure in the shaped plates . However, for operational reasons, especially with a view to reducing labor, it is desirable that the polyisocyanate and phosphate mixtures be stored for an extended period of time.

The authors have resolved the described problem with a storage stable mixture. This mixture forms an object of the present invention. According to the invention, the composition comprises an organic polyisocyanate based composition for the production of bonded particle boards, stable in storage,

(a) polymethylene polyphenyl polyisocyanate containing 25 to 90% by weight of methylenebis (phenylistocyanate), the remainder of the mixture being oligomeric polymethylene polyphenyl polyisocyanates having a functionality greater than 2; and b) 0.1 to 20 parts by weight, per 100 parts by weight of polyisocyanate, pyriophosphate one phosphate selected from the group consisting of acid phosphates of the formula I

O t

RO - P - OH

OH (I) and formula (II)

O t (Rf-OH (II) where

R is independently selected from the group consisting of C 8 -C 35 alkyl, inclusive C 8 -C 35 alkenyl, and the radical of formula

II ⁿ

А in which

R ‘denotes alkyl having 8 to 35 carbon atoms inclusive, one of A and V being hydrogen and the other selected from the group consisting of hydrogen and methyl, and n is an average number of 1 to 5, and mixtures of at least two of these acid phosphates.

Preferred embodiments of the composition of the invention include the case where the pyrophosphate is derived from a mixture of lauryl dihydrogen phosphate and dilauryl monohydrogen phosphate, the pyrophosphate is derived from a mixture of oleyl dihydrogen phosphate and dioleyl monohydrogen phosphate, and the composition also comprises an emulsifying agent.

The polyisocyanate component of the binder system generally may be any organic polyisocyanate containing at least two isocyanate groups per molecule. Illustrations of organic polyisocyanates are didenyl methanediisocyanate, m- and p-phenylenediisocyanates, chlorophenylenediisocyanate, α, n-xylenediisocyanate, 2,4- and 2,6-toluene diisocyanate, and mixtures of these two isomers, which are commercially available, triphenylmethane diisocyanates, diisocyanates, diisocyanates, and diisocyanates. and polymethylene polyphenyl polyisocyanates. The latter polyisocyanates are mixtures comprising from about 25 to about 90% by weight of methylenebis ^{(fenylisiokyaná:} ty) and the remainder of the mixture are polymethylenpolyfenylpioilyisioikyanáty a functionality higher than 2.0. These polyisocyanates and methods for their preparation are well known in the art. See, for example, U.S. Patent Nos. 2,683,730, 2,950,263, 3,012,008 and 3,097,191. These polyisocyanates are also available by a variety of modified processes. One such process is to subject the polymethylene polyphenyl polyisocyanate as described above to a heat treatment, typically at a temperature of about 150 ° C to about 300 ° C, unless the viscosity (at 25 ° C) rises to a value in the range of about 800 to 1500 mPa. Another modified polymethylene polyphenyl polyisocyanate is a substance obtained by treatment with a minor amount of epoxide to reduce acidity, according to U.S. Patent No. 3,793,362.

Polymethylene polyphenyl polyisocyanates are preferred polyisocyanates which are used in a storage-stable mixture according to the invention. Particularly preferred polymethylene polyphenyl polyisocyanates are those containing from about 35 to about 65% by weight of methylenebis (phenyl isocyanate).

The term "alkyl of 8 to 35 carbon atoms" means a saturated, linear or branched, monovalent aliphatic radical having the specified number of carbon atoms in the molecule. Illustrations of these groups are octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, docioisyl, tricoisyl, pentacosyl, hexaciosyl, octakecyl, non-heptacosyl, tri-heptacosyl, tri-decyl, penitatriacontyl and the like, including isomeric forms thereof.

The term "C 8 -C 35 alkenyl" means a monovailent straight or branched aliphatic radical containing at least one double bond having the specified number of carbon atoms per molecule. Illustrative of such groups are octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, eicosenyl, HeNe ^J ikiosenyl, dekosenyl tricosenyl, pentaklosenyl, triacontenyl, pentatriakontenyl and the like, including isomeric forms thereof .

The term "pyrophosphates derived from the removal of condensation water from at least one mono phosphate expelled from the group consisting of the acid phosphates of the general formula I and of the general formula II ^" has the following meaning:

The acid phosphates of the formulas I and II are usually produced in the form of mixtures of the mionohydrogen phosphate of the formula II and the dihydrogen phosphate of the formula I. The mixtures are prepared by reacting the corresponding alcohol of the formula

ROH where

R is as hereinbefore defined, with phosphorus pentoxide, according to a procedure well known in the art for the production of phosphoric acids, cf. for example, Kosolapoff, Organiophbsphorus Coimpounds., pp. 220 and 221, John Wiley and Sons, Inc. New York, 1950. Mixtures of these phosphates obtained in this manner may optionally be separated, for example, by fractional crystallization of barium and the like, as described in the above references. The individual acid phosphates or mixtures of the two may be used in the process of the invention. Pyrophosphates are readily obtained from the corresponding acidic phosphates of formula II and I. These are reacted with a dehydrating agent such as carbonyl chloride, aryl or alkylthioisocyanates and polyisocyanates, carbodiimides of N, N karb-disubstituted hydrocarbon radicals, and the like, according to procedures well known in the art, see, for example, F. Cr, amera.M. Winter Chem. Ber. 94, 989 (1961); F. Crarner and M. Winter, Chem. Ber. 92, 2761 (1959); M. Smith, JG Moffat and HG Khorana, J. Amer. Chem. Soc., 80, 6204 (1958); and F. Ramirez, JF Marecek, and I. Ugi, J. Amer. Chem. Soc., 97, 3809 (1975) The individual acid phosphates of formulas I and II may be separately converted to the corresponding pyrophosphates or mixtures of both types of acid phosphates. They can be converted into the corresponding mixture of pyrophosphates.

In the case of the hydrogenphosphates of the formula II above, the corresponding pyrlotosphates of the formula III represent ⁰ (R 1 PO 3 -POR), (III) where:

R is as defined above.

In the case of the dlhydriogenphosphates of formula (I) above, the corresponding pyrophosphates form a complex mixture of the average composition of formula (IV)

where

X is an average value of 1 or more; and

R is as defined above.

The acid phosphates of the formulas I and II may also be used in the form of their ammonium salt, alkali metal salt or alkaline earth salt.

The term "alkali metal" has a well-known meaning that includes lithium, sodium, potassium, rubidium and cesium. The term "alkaline earth metal" also has a well-known meaning that includes calcium, sitronium, magnesium and barium.

The actual production of bonded particle boards is essentially carried out according to the methods previously described in the field where organic polyisocyanates are used as a binder resin or a component thereof (See, for example, German Patent Publication No. 2,610,552 and US Patent 3,428,592. ) with the main difference that the phosphate as defined herein is used in admixture with the isocyanate used to process the particles to be bound to each other to form a bonded particle board.

The bonded particle board is made by binding particles of wood or other cellulose or organic material that is capable of being solidified using heat and pressure in the presence of a binder system comprising a mixture of organic piolyisocyanate and phosphate as defined above and hereinafter referred to as a "phosphate-providing agent".

Although the polyisocyanate and the phosphate-providing agent can generally be contacted with the particles as separate, individual components. However, the present invention uses a polyisocyanate / phosphate mixture that is contacted with the particles and the polyisocyanate and phosphate can be used neat, i.e. without diluents or solvents, or at least one or more of the components can be used in the form of aqueous dispersions or emulsions.

When the organic polyisocyanate component of the composition of the invention is used in the form of an aqueous emulsion or dispersion, the aqueous emulsion or dispersion can be prepared using any technique known in the art for making aqueous emulsions or dispersions. By way of illustration, the polyisocyanate is dispersed in water in the presence of an emulsifying agent. Any emulsifying agent known in the art, including ammonium and non-ionic agents, may be used as the composition. Illustrative of non-phenologenic emulsifying agents include poilyoxy.thylene alcohols, polyoxypropylene alcohols and block copolymers of two or more of ethylene oxide, propylene oxide, butylene oxide and styrene, alkoxylated alkylphenols such as nonylphenoxypoly (ethyleneoxy) ethoxylated aliphatic ethoxylates, such as alkoxylated aliphatic ethoxylates; from 4 to 18 carbon atoms, glycerides of saturated and unsaturated fatty acids such as stearic, oleic and rictoooleic acids and the like, polyoxyalkylene esters of fatty acids such as stearic, lauric, oleic and the like, fatty acid amides such as dialkanolamides of fatty acids such as stearic acid , lauras, oleos and mischievous. A detailed listing of these materials is given in Encyclopedia of Chemical Technology, 2nd edition, Vol. 19, pp. 531-554 (1969), Interscience Publishers, New York (Sp. St. A.).

The preparation of the emulsions or dispersions may be carried out at any time prior to use as a storage-stable mixture, but is preferably carried out within about 3 hours prior to use. Any of the conventional methods for preparing aqueous polyisocyanate emulsions can be used to prepare the aqueous polyisocyanate emulsions used in the process of the invention.

The storage stable compositions of the present invention can be prepared in various ways. Thus, if the polyisocyanate is used as a binder resin without diluents, such as water, then the phosphate delivery agent can be incorporated into the polyisocyanate by simple mixing. When the polyisocyanate is used as a binder resin in the form of an aqueous emulsion, the phosphate-providing composition can be added as a separate component during or after emulsion preparation, or in a particularly preferred embodiment, the phosphate is premixed with the organic piolyisocyanate and then emulsified. The organic polyisocyanate and the phosphate-providing composition may be premixed and the compositions of the invention may be stored for any period of time prior to emulsion preparation. When emulsifying agents are used to prepare the emulsion, the emulsion may also be incorporated into a mixture of organic polyisocyanate and phosphate-providing medium to form a mixture stable at the base, which may be^alreadye in Kbovotaé times^Econvert to an aqueous emulsion by a simple process^willn^andm vo^dy. This emutoe is m^alreadye to use ja as a binder resin.

Pioužívá-H-I ^to the polyisocyanates popvo as an aqueous emulsion, the proportion of organic polyisocyanate present in the aqueous emulsion, ^with preference 0.1 to 99% by weight -About and ^h cdné above about 25 and ^about 75% by weight.

When the phosphate-providing composition is introduced in combination with the polyisocyanate, the phosphate-providing composition is used in the range of about 0.1 to about 0.5%. ²⁰ days by weight per ¹⁰⁰ dB of polyisocyanate, and preferably in the range of about 2 to ¹⁰ dRa by weight per WO of the polyisocyanate. The proportion of emulsifying agent required prio prepare the aqueous emulsion is not critical and varies according to the particular e $ emulgačmho Pro® RedK ^{t ob} ^ public but is in the range of about 0Д ^{s and} about ^{20% of} the tnostmc ^ ^ based on the polyisocyanate.

It was found that when the panels of bonded particles produced in a batch or continuous process using a mixture of a polyisocyanate and a composition giving a phosphate of the invention, so obtained boards ^{characterized} pojenýc ^{h No} particle release readily from the metal plates Usu used in their manufacture, and do not attempt to glue or stick to the boards. ^T o is the antithesis к ^{d EXAMPLE} vejs ^experience with the use of polyisocyanates alone as pojiivlové r'ys ^{alkyl p-resins.}

Although they may use the means providing the phosphate as defined above, either alone ^or in com ^ clo ^ is ρ · η způsio ^b in accordance with the invention preferred to use pyrophosphates · formula III and IV or mixed pyrophosphates derived from a mixture of acidic phosphates of the general formulas I and II . Free hydroxy groups present in pyrlofosfátech or a hydroxy group present in the form of unconverted acid phosphate výchoztoo material are obv ^yk le sufficiently hindered to be unreactive at temperatures _ neighborhood using the polyisocyanate and pyrophosphates may be stored in admixture with polyisiokyanátem longer without her was obvious any deterioration. However, when the mixture of pyrophosphate and polyisocyanate is emulsified and used in production, the process temperature and steam generated in the bonded particle board production is likely to result in phosphate hydrolysis upon regeneration of the corresponding acid phosphates, which then serves to facilitate subsequent release of bonded particle board from the press plates. . It is to be understood that the theory set forth above is for the purpose of explanation only and is not intended to limit the scope of the invention in any way.

As pop) -S'ánK> above, mono-hydrogen phosphates of the general formula II and dihydrogenphosphate of the formula I and their salts are obtained by conventional procedures such as by rea ^kc ^ vWajfctoo alkohofu formula

ROH where

R is as defined above, with phosphorus pentoxide as described by Koso-lapoif (cited). As will be understood by those skilled in the art, it is possible to use mixtures of two or more different alcohols in the above reaction to obtain a corresponding mixture of acidic phosphates of formula I or formula II in which the different components of the mixture have different R group meanings. The mixture of the mono- and di-phosphorophosphates softened ^{in the} reaction mentioned above can be separated into the individual components by conventional methods such as fractional crystallization and the like and the individual compounds thus obtained can be used according to the invention. Otherwise, preferably, mixtures of mono- and dihydrogen phosphate, obtaining ^and rea ^the c listed sho ^ e m ^already used as such. ^d without Elena ^will at ^world Pumo ^components recited in the method of the invention or can be converted to the corresponding mixture of pyrophosphate to be used in procedures discussed above, and this mixture is then used in · the process.

Illustrative of the dihydrogenphosphates of formula I above, which may be used singly or in combination with other acidic phosphates in the composition of the invention, are miono-O-octyl-, mono-O-nonyl-, monO'-O-decyl-, mono- O-undecyl-, miano-4-O-dodecyl-, mono-O-tridecyl-, monio-O-tetradecyl-, mono-O-pentadecyl-, mono-O-hexadecyl-, mono-O-heptadecyl-, mono-O -oktad-ecyl-, mloιno-0-nonadecylt, monιo O ^y tikos LT-MonoTi heneikiosy1-, mιo-lo-d-0-K0 ^ o ^ s · yl, mιO'nlo O tгikosyl- , monэtOtpentak □ sιylt, mono-O-hexakosyl-, □ ^tO mon -htpta ^{the y} axis ^LT míonot -ιofctatóos ^O · ^{y l,} mono-O-nonakosyl- m □ 0-no-ttiakonty1- mono- O-pentatriacontyl, monio-O-dodecenyl-, mono-tridecenyl-, mon (o-O-tetradecyl-, mono-pentadecenyl-, mon) -O-hexadecenyl-, mono- - heptadecene l - o moinO'tO ^to tadectnyl-, mιono O nlonadecenyl-, _MON) Oto-l- ^yl eikostn mono -he not ekosenyl - mιono-0tdloιk (osienylt, mono-TT ^ ikosenyl- , OO- шon ^{í p} tntakDsenylt, morio-04 ^^ 71 ^ 111 - and ^mono-O-Y pentatlrak.αsen ldíhydriogθnfosfáty diydnogenfiosfáty and in which the esterifying radical is derived from lauryl alcohol · netfo similar jednlos taého and ^y ^ Abou kte221525 rice was prepared using about 1 to 5 moles ethylenloixidu.

Illustrations of the monohydrogen phosphates of formula II above which may be used singly or in combination with other acidic phosphates in the composition of the invention are Ο, Ο-di (octyl) -, 0,0-di (nonyl) -, Ο, Ο- di (decyl) -, Ο, Ο-di (unidecyl) -, Ο, Ο-di (dodecyl) -, Ο, Ο-di (tridecyl) -, O, O-di (tetradecyl) -, O, O- di (pentadecyl) -, Ο, Ο-di (hexadecyl) -, 0,0-di (hepitadecyl) -, O, O-di (octadecyl) -, O, O-di (nonadecyl) -, Ο, Ο-di (eiclosyl) -, 0,0-di (heneicosyl) -, Ο, Ο-di (docosyl) -, Ο, Ο-di (triktayl) -, 0,0-di (pentacosyl) -, Ο, Ο-di (hexacosyl) -, Ο, Ο-di (heptacosyl) -, Ο, Ο-di (octacosyl) -, Ο, Ο-di (nlonacosyl) -, Ο, Ο-di (triacontyl) -, Ο, Ο-di (pentatriacontyl) -, Ο, Ο-di (dodecenyl) -, Ο, Ο-di (tridecenyl) -, Ο, Ο-di (tetradecenyl) -, Ο, Ο-di (pentadecenyl) -, Ο, Ο-di (hexadecenyl) -, Ο, Ο-di (heptadecenyl) Ο, Ο-di (octadecenyl 1) -, O, O -di (nonadelate 1) -, Ο, Ο-di (eicosenyl) - , Ο, Ο-di (heneicosenes 1) -, Ο, Ο-di (docosenyl) -, Ο, Ο-di (triacoisenyl) -, Ο, Ο-di (pentakiosenyl) -, Ο, Ο-di (triacontenyl) - and

Ο, Ο-di (pentatraclosenes 1) monohydrophosphonates and diesiterified solvated mionohydrogen phosphates in which the esterifying radical is derived from lauryl alcohol or a similar monohydric alcohol which has been treated with 1 to 6 moles of ethylene oxide. Illustrations of the latter type of phosphate which is suitable in admixture with the corresponding dihydrogen phosphates are those sold under the trade name Tryfac by Ernery Industries Inc.

Illustrative of the pyriophosphates of formula (III) above which may be used singly or in combination with other pyrophosphates in the composition of the invention are tetraoctyl, tetranonyl, tetradecyl, tetraundecyl, tetradiodecyl, tetra (tridecyl) -, tetra (tetradecyl) -, tetra (pentadecyl) -, tetra (hexadecyl) -, tetra (heptadecyl) -, tetra (octadecyl) -, tetra (nonadecyl) -, tetra (eiciosyl) -, tetra (heneicosyl) -, tetra (dlokoses 1) - , tricose 1 -, tetra (pentacosyl) -, tetra (hexacosyl) -, tetra (heptacosyl) -, tetra (octacosyl) -, tetra (nionakioisyl) -, tetra (triacontyl) -, tetra (pentatriaconty 1) - , tetra (dodecenyl) -, tetra (tridecenyl) -, tetra (tetradecenyl) -, tetra (pentadecenyl) -, tetra (hexadecenyl) -, tetra (heptadecenyl) -, tetra (octadecenyl) -, tetra (nonadecenyl) -, tetra (eicosenyl) -, tetra (heneikiosenyl) -, tetra (docosenyl) -, tetra (tricosenyl) -, tetra (pentacosenyl) -, tetra (triacontenyl) - and tetra (pentatriacosenyl) pyrlophosphates.

Illustrative of the pynophosphates of formula (VI) above, which may be used singly or in combination with other pyrophosphates in the composition of the invention, are di (octyl) -, di (nionyl) -, di (decyl) -, di (undecyl) -, di ( dodecyl) -, di (tridecyl) -, di (tetradecyl) -, di (pentadecyl) -, di (hexadecyl) -, di (heptadecyl) -, di (octadecyl) -, di (nonadecyl) -, di (eicosyl) -, di (heneicosyl) di (docpsyl) -, di (tricteyl) -, di (pentacosyl) -, di (hexacosyl) -, di (heptacosyl) -, di (octacosyl) -, di (noinacosyl) -, di ( triacontyl) -, di (pentatriacontyl) -, di (dodecenyl) di (tridecenyl) di (tetradecenyl) -, di (pentadecenyl) -, di (hexadecenyl) -, di (heptadecenyl) -, di (octadecenyl) -, di ( nonadecenyl) di (eicosenyl) -, di (heneikiosenyl) -, di (docosenyl) -, di (triciosenyl) -, di (pentacosenyl) -, di (triacontenyl) - and di (pentratriacosenyl) pyrophosphates.

Of particular importance is the finding that the mixture of polyisioicyanate and the phosphate binder composition of the present invention can be used in conjunction with thermosetting resin binders hitherto used in the art, such as phenolformaldehyde, resorcinformaldehyde, melamine disiormaldehyde, urea of or maldehyde, urea furfural and urea. condensed furfuryl alcohols. The use of such a combination makes it possible to avoid the problems of adhesion of the final bonded particle boards to the press plates, which have previously been encountered with mixtures of isocyanate and the aforementioned types of thermosetting resin bonding, but the physical properties of bonded particle boards thus produced are clearly better when using the composition of the invention.

The following preparation examples, as well as examples as such, describe the method of making and using the invention. They disclose the best method expected in the practice of this invention, but the data is not intended to limit the invention.

Example 1

A solution of 30.4 parts by weight of acidic lauryl phosphate (a mixture of 0,0-dilauryl monohydrogenphosphate and O-lauryl dihydriogen phosphate,

215 (25) by Hoioker Chemical Company) in 21 parts by weight of toluene was charged to a dry nitrogen pre-purged reactor. The solution is heated to 40 degrees Celsius with stirring, at which point a solution of 7.6 parts by weight of polymethylene polyphenyl polyisocyanate [equivalent weight 133, functionality 2.8, methylenebis] phenyl isocyanate content of about 50% in 5 parts by weight toluene is added. Phosgene is introduced into the resulting mixture with stirring at a rate of about 0.1 parts by weight per minute, and the temperature is allowed to slowly rise to room temperature. 80 ° C. The temperature of the network is maintained at this level with the continuous introduction of phosgene until a total of 20 parts by weight is introduced. The total time for phosgene introduction was 5 hours 50 minutes. The reaction mixture was heated to the same temperature for a further 40 minutes after the phosgene addition was complete and then heated to 90-95 ° C and purged with nitrogen for 2 hours to remove excess phosgene. The pressure in the reactor was then reduced until the reflux of toluene began and nitrogen purification was continued for a further 2 hours. The toluene is then distilled off under reduced pressure and its last traces are removed under vacuum. The residue was cooled to room temperature, treated with desiccant soil (Cslite 545), stirred for 30 minutes and further filtered. 23.7 parts by weight of a mixture of lauryl pyrophosphate and polymethylene polyphenyl polyisocyanate are obtained. The mixture was determined to contain 6.08% phosphorus by weight.

This mixture. it is stable and its properties do not change by storage.

The stable storage compositions can be conveniently used in the manufacture of bonded particle boards irrespective of time. elapsed since preparation of the mixture. The method of production of boards, as well as the properties of boards of bonded particles, is described in detail in Czechoslovakia. No. 221-524.

Claims (4)

1. on storage stable organic polyisocyanates for the production of bonded particle boards, characterized in that it comprises: (a) polymethylenipolyphenyl polyisocyanate ‘containing 25 to 90% by weight of methylene bis (phenyl isocyanate), the remainder being oligomeric polymethylene polyphenyl polyisocyanates having a functionality greater than 2; and b) 0.1 to 20 parts by weight, per 100 parts by weight of polyisocyanate, of pyrophosphate derived by removing condensation water from at least one phosphate selected from the group consisting of acidic phosphates of formula I O t RO-P-OH OH (I) and formula (II) O t / o> - - OH OF THE INVENTION where R is independently selected from the group consisting of C 8 -C 35 alkyl, C 8 alkenyl. to 35 inclusive carbon atoms and a radical of the formula ^{R- (O-CH} -CH clays AB, where R‘ is alkyl of 8 to 35 carbon atoms inclusive, one of A and B is hydrogen and the other is selected from the group consisting of hydrogen and methyl and n is an average of 1-5, and mixtures of at least two of these acid phosphates. 2. A composition according to claim 1, wherein the pyriol phosphate is derived from a mixture of lauryl dihydrofluorophosphate and dilauyl monohydrogen phosphate. 3. The composition of claim 1, wherein the pyriophosphate is derived from a mixture of oleyl dihydrogen phosphate and ditblylmionohydrogen phosphate. 4. A composition according to claim 1, optionally containing an emulsifying agent.