CA2059626A1

CA2059626A1 - Moldings based on fibers

Info

Publication number: CA2059626A1
Application number: CA002059626A
Authority: CA
Inventors: Bernhard Dotzauer; Manfred Schwartz; Wilhelm F. Beckerle; Ulrich Filges
Original assignee: Individual
Current assignee: BASF SE
Priority date: 1991-01-26
Filing date: 1992-01-20
Publication date: 1992-07-27
Also published as: EP0497101A3; JPH04333695A; FI920326A0; EP0497101A2; DE4102345A1; ATE127494T1; DK0497101T3; EP0497101B1; DE59203505D1; FI920326A; ES2076562T3

Abstract

O.Z. 0050/42165 Abstract of the Disclosure: Moldings based on fibers (component A), containing B) from 5 to 25% by weight, based on A, of a polymer of b1) from 75 to 99.9% by weight, based on B, of vinylaromatic monomers, methyl methacrylate, methyl acrylate, acrylonitrile, methacrylo-nitrile, vinyl halides, acrylates and meth-acrylates of alcohols of 2 to 12 carbon atoms and/or vinyl esters of not more than 20 carbon atoms, where the sum of the acrylates and methacrylates of alcohols of 2 to 12 carbon atoms and of the vinyl esters may be not more than 20% by weight, based on B, b2) from 0.1 to 25% by weight, based on B, of one or more monomers of the formula I

I

where R1 and R2 are each -H or C1-C4-alkyl, R3 is a bridge member of 1 to 20 carbon atoms, R4 is -C(O)R6, -C(O)OR5 or -CN, R5 is -H, -C(O)R9, -C(O)OR9 or -CN, X is -O- or -NR7-, Z is a single bond, -CH2-, -O-, -NR8- or -O-C(O)- and R5, R7, R8 and R9 are each -H, alkyl, aryl, alkaryl or aralkyl of not more than 12 carbon atoms, and b3) from 0 to 10% by weight, based on B, of further copolymerizable monomers, and the production thereof are described.

Description

2 ~ ' 2 ~
O.Z. 0~50/42165 Moldings based on f ibers The present invention rela~es to moldings based on fibers (component A), containing B) from 5 to 25~ by weight, based on A, of a polymer of b1) from 75 to 99.9% by weight, based on B, of vinylaromatic monomers, methyl methacrylate, methyl acrylate, acrylonitrile, methacrylo-nitrile, vinyl halides, acrylates and meth-acrylateæ of alcohols of 2 to 12 carbon atom~
and/or vinyl esters of not more than 20 carbon atoms, where the sum of the acrylates and methacrylates of alcohols of 2 to 12 carbon a~oms and of the vinyl esters may be not more than 20~ by weight, based on B, b2) from 0.1 to 25% by weight, based on ~, of one or more monomers of the general formula I

l1 l2 8 l4 CH=C ~ -X-R3-Z IH

where Rl and R2 are each -H or Cl-C4-alkyl, R3 is a bridge member of 1 to 20 carbon atoms, R4 is -C(o)R5, -C(O)ORB or -CN, Rs is -H, -C(O)R9, -C(O)OR9 or -CN, X is -O- or -NR7-, Z is a single bond, -CE2-, -O-, -NR3- or -O-C(O)- and R6, R7, R8 and R9 are each -H, alkyl, aryl, alkaryl or aralkyl of not more than 12 carbon atoms, and b3) from 0 to 10% by weight, based on B) of further copolymerizable monomers.
Moldings based on mineral fibers are known per se. For example, DE-A 29 24 085, US-A 4 187 142 and US-A 4 189 345 describe a process for the production of fiber boards, in which the additive~ together with the binder, which may be a precipi~ated binder, are filtered 2 ~ 6 - 2 - o.z. 0050/42165 on a Fourdrinier wire ~ie. sheet formation) and the fiber boards are then dried at elevated temperatures.
Ceiling panels are produced in this manner, for example from kaolin, mineral fibers and starches. The serious disadvantage of such panels, which are in prin-ciple very rigid, is that they lose their shape, ie. sag under their own weight, in humid warm rooms~ ie. the visual appearance of such sagging ceilings is unattrac-tive and therefore undesirable. Another disadvantage is the sensitivity of such sheet-like structures to the degradation of the binder starch by microorganisms, which is manifested by dark spots and the loss of mechanical strength. Such panels can of course be treated with microcides, for example with formaldehyde depot sub-stances. By gradually reducing formaldehyde, theseensure protection against attack. However, to ensure protection over many years, it i8 necessary to choose relatively high doses of preservatives, which may lead to odor annoyances or, in certain circumstances, to allergic reactions of the inhabitants.
EP-A 367 023 discloses fiber boards which contain acrylate copolymers. These can be used as aqueous solution. When these binder sy~tems are employed in practice, it has been found, however, that certain aspects are still unsatisfactory. For example, in the production of mineral fiber boards on the Fourdrinier wire, it ha~ been found that the viscosity of the polymer solutions is too high for conventional operational measures, such a~ conveying and meteringO The viscosity of such polymer solutions which are about 10% s~rength is about 25 Pa.s. Only solutions having solid contents substantially below 10% by weight can be readily used on virtually all units, but this is uneconomical owing to the large amount of the diluent water. Furthermore, such polymers tend to migrate during drying of the crude boards, ie. tend to result in a loss of bindsr in the interior of the mineral fiber boards, which may have an 2~62~

- 3 - O.Z. 0050/42165 adverse effect on the further processing of the crude hoards. The skilled worker knows that thiR binder migration can be counteracted by the use of substances having inverse solubility, for example polyvinyl methyl ethers. However, they give rise to additional costs and ` may increase the moisture absorption of the end products.
EP-A 386 579 discloses moldings which are bound with acrylate dispersions. Overall, the shaped articles produced with these binders and with those of EP-A 367 023 have satisfactory properties, but their mechanical strength and their water absorption can still be im-proved. An increase in the water resistance can be achieved with a higher dose of agents which impart water repellency, but it is then necessary to accept a decline lS in the mechanical strength as well as wetting and ad-hesion problems in the shaped articles.
DE-A 23 46 310 discloses glass fiber-reinforced polyamides. About 1% by weight of a copolymer which predominantly contains butyl acrylate with small amounts of butanediol monoacrylate acetoacetate is used as a size. A thermoplas~ic molding material having high impact strength is obtained in this manner. There is no reference to fiber boards. However, if such polymers are nevertheless used for the production of fiber boards, undesirably high densities are obtained in conjunction with acceptable stability and an impressibility unaccept-able for acoustic panels.
According to EP-A 241 127, textile materials can be bound with aqueous polymer dispersions. These are copolymers which contain ethyl acrylate and butyl acrylate as main components, with small amounts of, for example, acetoacetoxyethyl acrylate. An important aim is to obtain textiles having high flexibility. The skilled worker was therefore prevented from considering polymers of the disclosed type for the production of rigid fiber boards or fiber moldings.
It is an ob~ect of the present invention to 2~5~
_ 4 _ o.z. 0050/42165 provide moldings based on fibers, which avoid the dis-advantages described above and combine low water absorp-tion with high rigidity.
We have found that this object is achieved by the moldings defined at the outset and a process for their production. The preferred embodiments ara described in the subclaims.
Suitable fibers are mineral fibers, for example rockwool, basalt wool, slag wool and glass fibers having fiber lengths of, in general, from 0.2 to 5 cm, in particular from 0.5 to 2.5 cm, and thicknesses of from about 1.7 to 3.3 dtex. Organic fibers are also suitable.
These include primarily wood fibers, such as comminuted and/or digested wood, such as pinewood. Such wood fibers are usually produced from wood chips, chopped wood or sawdust (for example Ullmann's Encyklopadie der tech-nischen Chemie, 4th Edition, Vol. 12, page 720 et saq.).
Other organic fibers, such as cellulose fibers or fibers of synthetic polymers, such as polypropylene fibers and/or polyacrylonitrile fibers, may also be added to the wood fibers, in general in amounts of 5 to 6Q, preferably from 15 to 40, in particular from 15 to 25, % by weight, based on wood fibers. These fibers usually have a length of from 0.3 to 1.5 cm and a thickness of from 10 to 30 dtex.
The polymer B i~ used in amounts of from 5 to 25, preferably ~rom 5 to 15, ~ by wei~ht, based on fibers A.
It is preferably composed of from 75 to 96% by weight of b1, from 2 to 20% by weight of b2 and from 0 to 20% by weight o~ b3.
Suitable vinylaromatic monomers are those of not more than 20 carbon atoms, preferably vinyltoluene, ~-and para-methylstyrene, ~-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and particularly preferably styrene.
The vinyl halides are e~hylenically unsaturated compounds substituted by chlorine, fluorine or bromine, preferably vinyl chloride or vinylidene chloride.

2 ~ 2 ~

5 - O.Z. 0050/42165 Other suitable monomers b, are esters of acrylic or methacrylic acid with alcohols of 2 to 12 carbon atoms, preferably alkanols. Examples of alcohols are methanol, ethanol, n- and isopropanol, n-, sec- and tert-butanol, n-pentanol, isoamyl alcohol, n-hexanol, cyclo-; hexanol, octanol, 2-ethylhexanol, lauryl alcohol, benzyl alcohol and vinylethanol.
Examples of esters of acrylic and methacrylic acid are hexyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl acrylate, phenylethyl methacrylate, methyl acrylate, ethyl acrylate, n-, sec- and tert-butyl (meth)-acrylate, benzyl methacrylate, cyclohexyl methacrylate, methyl methacrylate, ethyl methacrylate and especially 2-ethylhexyl acrylate and n-butyl acrylate.
15Vinyl esters of not more than 20 carbon atoms are, for example, vinyl acetate, vinyl propionate, vinyl laurate and vinyl stearate.
In the general formula I of b2, the following sub~tituents are preferred: Rl is H, R2 is H or methyl, R3 is an aliphatic or aromatic bridge member, such as -CH2-, -C2H4-, -C4H8- and furthermore -C3H6- or -C8H16-, R4 is -C(O)R6, such as acetyl, benzoyl or -CN, R5 is -H or -C(O)R9, such as benzoyl or acetyl, X is -O- or -NH-, Z is -oc(o)- or a ~ingle bond, and R6 and R9 are each methyl, ethyl or phenyl.
Acetoacetoxyethyl acrylate and methacrylate IR R R
CH 2=C--C~ ( CH 2 ) 2~C--CH 2--C--CH 3 acetoacetoxybutyl acrylate and methacrylate CH 2=C--C~ ( CH 2 ) 4{)--C--CH 2--C--CH 3, and cyanoacetoxyethyl methacrylate and cyanoacetoxyethyl acrylate CH~C-C-O-C2H4-O-C-CH2-CN , 2 ~

- 6 - O.Z. 0050/42165 where R in each case is H or CH3, are preferred.
Such compounds are known per se from DE-A 17 93 660, US-A 4 088 499 or EP-A 241 127 and can be prepared in a conventional manner by reacting a hydroxyalkyl ester, for example the hydroxyethyl ester of acrylic or methacrylic acid, with diketene or cyanoacetyl chloride.
Good results are also obtained with 1,1-dibenzoyl-2-mathacrylamidoethane, 1,1-dibenzoyl-2-acryl-amidoethane o R O
CH2-c-c-NH-cH2--CH O
\11~

l-benzoyl-l-acetyl-2-methacrylamidoethane and l-benzoyl-l-acetyl-2-acrylamidoethane I R
CH2=C--C--NH-CH2--CH O

where R is H or CH3.
Such compounds are known per se from DE-A 38 19 455 and can be prepared in a conventional manner by amidomethylation of 1,3-diketone3 in the presence of strong acids.
b3 are, for example, acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic acid, fumaric acid, itaconic acid, maleic anhydride, butanediol mono-acrylate, glycidyl methacrylate or diunsaturated mono-mers, such as di~inylbenzene, butan~diol diacrylate, diallyl phthalate, butadiene or chloroprene. Acrylic acid and methacrylic acid are preferred and are generally 2 ~

- 7 - O.Z. 0050/42165 used in amounts of from 1 to 8% by weight, based on B.
Good results are obtained with polymers of ; b1) a mixture of from 55 to 90% by weight, based on B, of a vinylaromatic monomer, from 2 to 25% by weight, s based on B, of one or more monomers selected from the group consisting of methyl acrylate, acrylo-nitrile and methacrylonitrile and from 0 to 20, preferably from 5 to 20, % by weight, based on B, of ` acrylates and/or methacrylates of alcohols of 2 to 12 carbon atoms, b2) from 2 to 15% by weight, based on B, of a monomer of the general formula I, and b3) ~rom 0 to 10% by weight of further copolymerizable monomers, and with polymers of bl) a mixture of from 55 to 96, preferably not more than 95, ~ by weight, based on B, of methyl methacrylate, from 0 to 35% by weigh~ of one or more monomers selected from the group consisting of methyl acrylate, acryloni~rile and methacrylonitrile and from 0 to 20, preferably from 1 to 20, % by weight, based on B, of acrylates and/or methacrylates of alcohols of 2 to 12 carbon atoms, b2) from 4 to 20~ by weight of a monomer of the general formula I
and b3) from 0 to 10, preferably 0, ~ by weight, based on B, of further copolymerizable monomers.
The polymer B is preferably prepared by free radical emulsion polymerization in the aqueous phase.
Batch processes or feed processe~ in which the initiator and/or the monomers, which may be emulsified in water, are fed in a little at a time or continuously during the polymerization, may be used (cf. for example Encyclopaedia of Polymer Science and Engineering, Vol. 6 (1986), 1 to 52). The agueous copolymer dispersions 2~6 :;

- 8 - O.Z. 0050/42165 ,:
formed generally have a copolymer concentration, ie. a solids content, of from 40 to 60, in many cases from 45 to 5S, % by weight. From 0.2 to 3~ by weight, based on the monomers used, of anionic and/or nonionic S emulsifiers, for example sodium dialkylsulfosuccinates, sodium salts of sulfated oils, sodium salts of alkylsulfonic acids, sodium, potassium and ammonium alkylsulfates, alkali metal salts of sulfonic acids, fatty acids, fatty alcohols, fatty amides and alkylphenols, ethoxylated and/or sulfated derivatives thereof, as well as sodium salts of fatty acids, such as sodium stearate and sodium oleate, and sulfonated alkyl diphenyl ethers, are generally used as emulsifiers.
The pH of the polymer dispersions is from 3 to 9, preferably from 4 to 8.5. The polymer dispersions generally have a low viscosity, ie. from about 10 to 20 mPa.s at 23C, and a shear gradient of ~80 s-1. The median particle size is from lO0 to 300 ~m, preferably from 100 up to 200 ~m (d5~ value, ultracentrifuge, W.
Maechtle, Nakromolekulare Chemie 185 (1984), 1025).
Good results are obtained if the polymer B has a glass transition temperature of from 60 to 150C, prefer-ably from 70 to 100C, in particular from 70 to 95C.
The low residual monomer content of the polymers used according to the invention, which is generally less than 500 ppm, based on the dispersion, i3 advantageous for processing. This means that the concentration of working substance in ~he air at the workplace is extreme-ly low and that th~ finished articles are virtually odorless.
The polymer dispersions are stable to shear forces and can be transported without problems and conveyed by means of suitable pumps. Nevertheles~, they have very advantageous precipitation behavior. They coagulate with the circulation or process water en-countered in mineral fiber works wi~hout further addi-tives, so that the addition of precipitating agents, 2~9B26 ; - 9 - O.Z. 0050/42165 eg. aluminum sulfate, can advantageously be dispensed with. However, in the production of shaped wood articles, it may sometimes be advantageous to promote the coagulation of the polymer dispersions by small doses of, for example, dilute aqueous aluminum sulfate solutions.
The novel moldings may contain nonfibrous fillers C in addition to the components A and B. These may be fire-dried sands, finely divided clays, such as kaolin or montmorrilonite, feldspar, chalk, kieselguhr and mica, which are preferably used with the mineral fibers. Their amounts may be from 20 to 80, preferably from 30 to 60, % by weight, based on the fibers used.
The moldings may additionally contain not more than 10, preferably from 1 to 3, % by weight, based on fibers, of conventional fireproofing agents, such as aluminum silicate and aluminum hydroxide, borates, such as sodium tetraborate, and/or phosphates, such as primary sodium phosphate.
Not more than 5, preferably from l to 2, % by weight, based on the fibers, of conventional water repellant agents, such as silicones and/or wa~es, are sometimes added during the production of the moldings.
It is also possible to add starch, such as corn starch or potato starch, generally in amounts of from 1 to 5% by weight, based on the fibers.
Rnown flocculants, such as polyacrylamides, may also be present in small amounts.
The moldings can be produced by various methods.
An aqueous suspension can be prepared, for example, from fibers A, if required the fillers C and further additives with thorough mixing. The polymer B, as an aqueous dispersion, is advantageously added at the same time or afterward. The process is carried out in general at room temperature, ie. at from 15 to 35C. The suspension is then generally flocculated by adding a flocculant. The resulting mixture is introduced into a mold and dewatered, which may be effected, for example, 2 ~
:
- 10 - O.Z. 0050/42165 .
by suction and/or pressing. The still wet molding is usually dried in the course of from 0.1 to 5 hours at from 100 to 250C. Dryiny ovens, circulating-air dryers, ` IR lamps or microwave emitters and/or heatable presses may be used.
Other production methods are also possible. For example, in the production of sheet-like structures, sheet formation can be carried out on a Fourdrinier wire and drying can be effected at elevated temperatures (from about 70 to 150C). It is also possible to carry out a molding process after sheet formation before effecting drying at elevated temperatures. Furthermore, all additives can be mixed in the dry or moist state, and mixing may be effected in a fluidized bed. Thereafter, the mixture is molded and the molding is dried, prefer ably at elevated temperatures.
Other production proce~ses which have proved suitable in practice in many cases comprise moistening of the fibers and any further additives by spraying or immersion, followed by squeezing off and subsequent drying at elevated temperatures, and it is possible to adjust the densities of such sheet-like structures during the drying process by pressing to a greater or lesser extent.
Furthermore, it is pos~ible first to convert fibers and, if required, precipitating agents and addi-tives into a molding, which is then impregnated with an aqueous dispersion of the polymer B. ~his process is described in EP-~ 386 579.
The base moldings are advantageously first impregnated with the aqueous dispersion, all-round impregnation being preferred, and are dried and then coated with the pigmented dispersion for decoration.
In order to obtain coatings having an attractive appearance, it is advantageous to carry out the total coating procedure in a plurality of operations and to dry the particulax layer applied between the individual 2 ~
~ o.Z~ 0050/42165 -opera~ions, genexally at from lO0 to 180C. The process can be particularly advantageously used for the production of sound~insulating panels having improved dimensional stability in the presence of atmospheric humidity, and the sheet-like base moldings can, if required, be provided with sound-absorbing structures.
The novel materials may be applied by spraying, roller-coating or pouring, the surface of the base molding generally being ground beforehand. The amounts applied are in general from 2 to 100 g~m2 (calculated in amounts M of the anhydrous copolymer present in the coating material or impregnating material).
The novel, generally concrete-free moldings are in particular boards, ie. square elements, usually having a width/length ratio of from 1 : l to 1 : 5 and a height/
length ratio of from 1 : 10 to 1 : 100.
Examples are mineral fiber boards or wood fiber boards, which may be used as ceiling panel~ or sound-insulating panels. The visible surface of the panels may be provided with known sound-absorbing structures and, in a conventional manner, with decorative coatings. The sound-insulating (ceiling) panels obtained in this manner have very good insulating behavior, are very rigid, even in the moist s~ate, and readily release the absorbed moisture again.
Surprisingly, the disadvantages described above are avoided in the novel moldings. Although the polymers B are thermoplastics, as components of the moldings they perform all binding functions of the thermosetting plastics, such as rigidity. Also surprising is the fact that these hydrophilic polymers ensure that the moldings are rigid also in a humid and warm atmosphere and even if a limited amount of starch is present in the shaped articles. Another positive factor is that the polymers can be readily prepared by emulsion polymerization.
Treatment of the moldings with biocide~ or fungicides can be dispensed with since the polymers are not degxaded 2 ~

:- 12 - O. Z . OOS0/42165 ;under the conditions of production and use of the boards.
Nevertheless, the disposal of binder residues and also of the moldings produced therewi~h presents no problems.
The polymers foxm water-insoluble compounds with poly-valent ions, eg. calcium ions, magnesium ions or Fe(III) ions, or are precipi~ated by these and thus cannot enter the groundwater. The calcium compounds are very highly adsorbed onto the solid particles in waste water treatment plants. Polymers which are composed only of carbon, hydrogen and oxygen have particular ad~antages in this respect.
In the examples which follow, parts and per-centages are by weight, unless stated otherwise.
The investigations of the boards produced by way of example were carried out by the following methods:
Density of the mineral fiber boards Test specimens having the dimensions 250 mm x 50 mm are cu~ out. The thickness is determined with a calliper gage and is used for calculating the volume.
The density is calculated in g/cm3, as a mean value of 2 test specimens.
Density of the wood fiber boards Circular test specimens with D = 9 mm are punched out by means of a punch. The thickne~s is measured with a calliper gage and is used to calculate the volume, and the density is calculated in g/cm3 as the mean value of 3 test specimens.
Water absorption Test specimens having the dimensions 250 mm x 50 mm are stored under water at room temperature under a load for 1 hour or 2 hours. After removing excess liquid by dabbing off, the weight increase is determined by weighing as the mean value of 2 test specimens in each case, as a percentage of the weight increase.
Dimensional stability ~measure of the rigidity) Test specimens measuring 250 mm x S0 mm are ground by means of a belt grinder until ~hey are 15 mm ~ 2~ ;2~
- 13 - O.Z. 0050/42165 thick. The side facing away from the wire during sheet formation is ground.
The test specimens thus obtained are placed flat in an atmosphere of 38C and 95% relative humidity, horizontally close to the end edges and loaded with a 1 kg weight in the middle, so that the load acts on the total length of the test specimen. The sag of the test specimen is measured after the load has been removed and an indication of the long-term behavior of mineral fiber boards is thus obtained.
Strength The dried test specimens (dimensions 17 cm x 2 cm x 2 cm) are placed close to the end edges and are subjected in the middle to a continuously increasing force, so that the load acts on the total length of the test specimen. The force applied at fracture is stated as the mean value of five test specimens, in kg/cm2.
Breaking force The breaking force i5 determined according to DIN
53,455.
The following abbreviations are used:
AAEM Acetoacetoxyethyl methacrylate AN Acrylonitrile AA Acrylic acid EHA 2-Ethylhexyl acrylate MMA Methyl methacrylate MA Methyl acryla~e MAA Methacrylic acid n-BA n-Butyl acrylate S Styrene The polymer dispersions B used as binders in the examples were prepared according to the following gen~ral method:
The dispersions were prepared by aqueous free radical emulsion polymarization from the monomers, which had been emulsified with the aid o the emulsi~iers in half the water employed for preparationl usin~ 0.5% by 2 ~ 2 ~
- 14 - o.z. 0050/42165 weight, based on the monomers, of sodium peroxodisulfate as an initiator in the form of a 2.5% strength by weight aqueous solution at 80C. For thiq purpose, half t~e water employed for preparation was initially taken and 10% by weight of the initiator solution were added while stirring at the polymerization temperature. Thereafter, the monomer emulsion was fed continuously into the polymerization vessel in the course of~2 hours and the initiator solution in the course of 2.5 hours, while stirring. For post-polymerization, stirring was con-tinued for a further 2 hours at the polymerization temperature and working up was then carried out in a known manner. The amount of wa~er employed for the preparation was such that the stated solids contents were obtained.
The fatty acid salts stated in Examples 3, 4, 5, 7 to 13 and Vl as emulsifiers were prepared in situ by neutralizing the corresponding carboxylic acids with sodium hydroxide solution. The monomer emulsions were prepared by adding the monomers and, if required, water or the other emulsifiers. In these examples, further-more, one third of the water employed for preparation was initially taken and two thirds were used for the monomer emulsion. Otherwise, the procedure was as described above.
The glass transition temperatures T8 were deter-mined by differential thermal analy~i~ (DTA) according to ASTM D 3418-82 tmidpoint temperature).

Binder: 42% strength aqueous dispersion of a polymer of 92% by weight of MMA
7% by weight of AAEM
1~ by weight of MAA
T8: 97C
Emulsifier: 0.9~, based on monomers, of sodium laurylsulfate pH: 4.8 2 ~ 2 ~
- 15 - O.Z. OOS0/42165 A suspension of 240 g of basalt wool 90 g of kaolin 15 g of aluminium hydroxide 57 g of the abovementioned polymer dispersion 3 g of a commercial, abou~ 35% strength, polysiloxane dispersion as a water repellant agent in ~ 1 of process water i~ prepared with gentle stirring.
About 3 minutes are required for this purpose. This suspension is flocculated by adding 4.5 g of a 10~
strength aqueous solution of a polymer of 70% by weight of acrylamide and 30% by weight of diethylaminoethyl acrylate. The fiber slurry thus obtained is poured into a wire frame having a wire area of 25 cm x 25 cm and is lS distributed uniformly using a wooden spatula. The fiber slurry layer is drained under slightly reduc~d pressure and with careful pressing with a punch t25 cm x 25 cm, pressure not more than 0.1 bar~, no more than 0.5 minute being required for this purpose.
A crude board about 18 mm thick and having an average residual moisture content of 60% is obtained.
The crude board is dried on siliconized paper in a circulating-air dryer at 180C, drying taking about 2.5 hours.
Properties of the mineral fiber board Density : 0.33 g/cm3 Water absorption after 1 h: 5.5 after 2 h: 8.2~
Dimensional stability : less than 1 mm after 290 h Binder: 46% strength aqueous dispersion of a polymer of 88% by weight of NMA
12% by weight of AAEM
T8 : 85C 5 Emulsifier: 1.3%, based on monomers, of sodium Cl2-Cl5- alkylsulfonate pH : 5.5 2~6~
- 16 - o.z. 0050/42165 Procedure according to Example 1 The following are used:
250 g of basalt wool lO0 g of kaolin 38 g of the abovementioned polymer dispersion 8 g of corn starch Flocculant and water repellant agent according to Example 1.
Properties Density : 0.31 g/cm3 Water absorption after 1 h: 6.0%
after 2 h: 7.9%
Dimensional stability : 1 mm after 288 h Binder: 48% strength aqueous dispersion of a polymer of 60% by weight of NMA
25~ by weight of AN
10% by weight of AAEM
5~ by weight of MA
T8 : 79C
Emulsifier: 1.7%, based on monomers, of sodium oleate pH : 8.1 The following are used:
235 g of slag wool 80 g of kaolin lO g of aluminum hydroxide 37 g of the abovementioned polymer dispersion Procedure, flocculant and water repellant agent according to Example 1.
Properties Density : 0.30 g/cm3 Water absorption after l h: 4.9%
after 2 h: 7.9%
Dimensional stability : 1 mm after 280 h Binder: 43~ strength aqueous dispersion of a polymer of 73~ by weight of S

2 ~ 2 ~
- 17 - o.z. O0S0/42165 15% by weight of n-BA
12% by weight of AAEM
T8 : 79C
Emulsifier: 3.2%, based on monomers, of sodium oleate S pH : 7.8 The following are used:
240 g of slag wood 95 g of kaolin lS g of aluminum hydroxide 6.3 g of potato starch 36 g of the abovementioned polymer dispersion Procedure, flocculant and water repellant agent according to Example 1.
Properties Density : 0.29 g/cm3 Water absorption after 1 h: 4.3%
after 2 h: 5~8~
Dimensional stability : less than 1 mm after 291 h Binder: 45.8% strength aqueous dispersion of a polymer of 60% by weight of S
20% by weight of AN
12% by weight of n-BA
8% by weight of AAEM
~8 : 89C
Emulsifier: 3.5%, based on monomers, of sodium oleate pH : 8.5 ~he following are used:
220 g of slag wood 120 g of kaolin 10 g of aluminum hydroxide 7.5 g of corn starch 27 g of the abovementioned polymer dispersion Procedure, flocculant and water repellant agent according to Example 1 Properties 2~5~
- 18 - o.Z. 0050/42165 Density : 0.33 g/cm3 Water absorption after 1 h: 5.8%
after 2 h: 7.1%
Dimensional stability : less than 1 mm after 266 h Binder: 39% strength aqueous dispersion of a polymer of 78~ by weight of MMA
16% by weight of NA
6~ by weight of cyanoacetoxyethyl methacrylate T8 : 75C
Emulsifier: 0.9% based on monomers, of sodium C12-Cls-alkylsulfonate pH : 5.1 The following are used:
235 g of slag wood 80 g of kaolin 12 g of aluminum hydroxide 2.5 g of corn starch 50 g of the abovementioned polymer dispersion Procedure, flocculant and water repellant agent according to Example 1.
Properties Density : 0.28 g/cm3 Water absorption after 1 h: 6.0%
after 2 h: 8.4~
Dimensional stability : 2 mm after 266 h Binder: 50.8% strength aqueous dispersion of a polymer of 65% by weight of MMA
30% by weight of AN
5% by weight of MA
T8 : 81C
Emulsifier: 1.85~, based on monomers, of sodium laurate pH : 6.7 The following are used:
235 g of slag wood 2~S~2~
- 19 - o.z. 0050/42165 80 g of kaolin 10 g of aluminum hydroxide 35 g of the abovementioned polymer disp~rsion Procedure, flocculant and water repellant agent according to Example 1.
Properties Density : 0.32 g/cm3 Water absorption after 1 h: 13.7%
after 2 h: 25.1% 0 Dimensional stability : 3 mm after 268 h A suspension of fibers in 6 1 of wa~er is prepar-ed with thorough stirring. About 3 minutes are required for this purpose. If necessary, a water repellant agent is then added. The next step is the addition of the aqueous binder dispersion, if necessary followed by aluminum sulfate. 4.5 g of a 10% strength aqueous solution of a polymer of 70~ by weight of acrylamide and 30% by weight of diethylaminoethyl acrylate are added as flocculant, likewise with stirring.
For sheet formation, the fiber slurry is poured into a wire screen having a wire area of 25 cm x 25 cm and the material is distributed uniformly by means of a wooden spatula. The material is then drained under slightly reduced pressure. Moist crude boards, which are generally from 8 to g mm thick and contain about 60% of water are obtained with gentle pressing (less than 0.1 bar) with a punch (25 cm x 25 cm) and suction filtration.
The crude boards are dried in a microwave oven to residual moisture contents of from 10 to 15~ and then in a heated press at 220C and 50 kp/cm2 for 90 s.
Binder: 45% strength aqueous dispersion of a polymer of 62% by weight of MMA
20~ by weight of AN
10% by weight of MA
8% by weight of AAEM
T8 : 82C

2~5~2~
- 20 - O.Z. 0050/42165 Emulsifier: 2.1%, based on monomers, of sodium laurate pH : 8.5 The following are used:
105 g of wood fibers 10 g of cellulose fibers 10 g of polypropylene fibers 15 g of an 8% strength aqueous emulsion of stearyl-diketene (water repellant agent) 18 g of the abovementioned polymer dispersion 11 g of an aqueous 10% strength aluminum sulfate solu~ion 4.5 g of a flocculant Properties Density : 0.85 g/cm3 Water absorption after 1 h: 6.5~
after 2 h: 8.0%
Breaking force : 12 N/mm2 Binder: 41% strength aqueous dispersion of a polymer of 75% by weight of S
15~ by weight of n-BA
10% by weight of AAEM
T8 : 80C
Emulsifier: 4.0%, based on monomers, of sodium oleate pH : 8.0 The following are used:
6 l of process water 100 g of wood fibers 10 g of cellulsoe fibers 10 g o~ polypropylene fibers 24 g of the abovementioned polymer dispersion 4.5 g of the flocculant as described in Example 7 Properties Density : 0.87 g/cm3 Water absorption after 1 h: 5.0%
after 2 h: 7.5%
Breaking force : 14 N/~m2 2 ~
- 21 - O.z. 0050/42165 sinder: 46.s~ strength aqueous dispersion of a polymer of 91% by weight of MMA

9% by weight of AAEM
T8 : 91C
Emulsifier: 2.8%, based on monomers, of sodium laurate pH : 7.5 The following are used:
6 l of process water 90 g of wood fibers 10 g of cellulose fibers 20 g of polypropylene fibers l9 of the abovementioned polymer dispersion 3 g of a 10% strength aqueous aluminum sulfate solution 4.5 g of the flocculant as described in Example 7 Properties Density : 0.76 g/cm~
Water absorption after 1 h: 4.5%
after 2 hs 6.0%
Breaking force : 12 N~mm2 Binder: 38% strsngth aqueous dispersion of a polymer of 82~ by weight of S
10% by weight of MA
7% by weight of acetoacetoxy-n-butyl acrylate 1% by weight of AA
T~ : 95C
Emul~ifier: 2.7~, based on monomers, of sodium laurate pH : 8.3 The following are used:
6 l of process water 100 g of wood fibers 5 g of cellulose fibers 15 g of polyacrylonitrile fiber~
24 g of the abovementioned polymer dispersion 4.5 g of the flocculant a~ described in Example 7 2~5~
- 22 - O.Z. 0050/42165 Properties Density : 0.91 g/cm3 Water absorption after 1 h: 6.0%
after 2 h: 7.2~
Breaking force : 14.5 N/mm2 Binder: 42.5% strength aqueous dispersion of a polymer of 80~ by weight of S
10~ by weight of EHA
5% by weight of 1,1-dibenzoyl-2-acrylamidoethane 5~ by weight of AA
T8 : 88C
Emulsifier: 0.25% sodium lauryl sulfate and 2.7~ of sodium oleate, based in each case on monomers pH : 8.1 The following are used:
6 1 of process water 20100 g of wood fibers 10 g of polyacrylonitrils fibers 10 g of polypropylene fibers 25 g of the abovementioned polymer dispersion 4.5 g of the flocculant as de~cribed in Example 7 25Properties Density : 0.95 g/cm3 Water absorption after 1 h: 4.0~
after 2 h: 5.8%
Breaking force : 13 N/mm2 Binder: 44% strength aqueous dispersion of a polymer of 79~ by weight of S
5~ by weight of AN
10% by weight of EHA
355% by weight of 1-benzoyl-1-acetyl-2-acrylamidoethane 1% by weight of AA
T8 : 80C

2 ~ 2 ~

- 23 - O.Z. 0050/42165 Emulsifier: 1~ of sodium oleate and 0.5% of sodium laurate, based in each case on monomers pH : 7.9 The following are used:
6 1 of process water g5 g of wood fibers 5 g of cellulose fibers 10 g of polyacrylonitrile fibers 10 g of polypropylene fibsrs 26 g of the abovementioned polymer dispersion 4.5 g of the flocculant as described in Example 7 Properties Density : 0.83 g/cm3 Water absorption after 1 h: 5.6%
after 2 h: 7.0%
Breaking force : 12 N/mmZ

Binder: 49.3~ strength aqueous dispersion of a polymer of 90% by weight of MMA
5% by weight of AAEM
5% by weight of AA
T~ : 102C
Emulsifier: 2.1%, based on monomers, of sodium olea~e pH : 7.5 The following are used:
6 1 of process water 100 g of wood fibers 10 g of polyacrylonitrile fibers 10 g of polypropylene fibers 21 g of the abovementioned polymer dispersion 4.5 g of the flocculant as described in Example 7 Properties Density , 0.85 g/cm3 Water absorption after 1 h: 4.0~
after 2 h: 6.9%

2 ~
- 24 - O.Z. 0050/42165 Breaking force : 15 N/mm2 Binder: 40~ strength aqueous dispersion of a pol~mer of 60% by weight of ~MA
S 30~ by weight of n-BA
10% by weight of MAA
T8 : 78C
Emulsifier: 1.35%, based on monomers, of sodium laurylsulfate pH : 7.3 The following are used:
86 g of wood fibers lO g of cellulose fibers : 24 g of polypropylene fiber~
24 g of an 8% strength aqueous stearyldiketene emulsion 24 g of the abovementioned polymer dispersion 25 g of a 10% strength aqueous aluminum sulfate solution 4.5 g of the flocculant as described in Example 7 Properties Density : 0.80 g/cm3 Water absorption after 1 h: 11.0%
after 2 h: 15.0~
Breaking force : 8 N/mm2 Binder: 30.2~ strength aqueous dispersion of apolymer of 70~ by weight of ~MA
30~ by weight of MAA
~8 : 128C
Bmulsifier: 1.2~, based on monomers, of sodium laurylsulfate pH : 4.0 The following are used:
86 g of wood fibers 10 g of cellulose fibers 24 g of polypropylene fibers 24 g of an 8~ strength aqueous stearyldiketene emulsion 24 g of the abovementioned polymer dispersion 2 ~
- 25 - O.Z. 0050/~2165 25 g of a 10% strength aqueous aluminum sulfate solution 4.5 g of the flocculant as described in Example 7 Properties Density : 0.81 g/cm3 Water absorption after l h: 10.0%
after 2 h: 16.0%
Breaking force : 7 N/mm2 Binder: 29.2% strength aqueous dispersion of a polymer of 6Q~ by weight of MMA
35% by weight of n-BA
5% by weight of AAEM
T6 : 61C
Emulsifier: 1.4~ of the Na salt of a half-ester of an ethoxylated fatty alcohol with sulfuric acid (degree of ethoxylation: 2) pH : 2.9 Procedure according to Example 1 The following are used:
250 g of basalt wool 100 g of kaolin 60 g of the abovementioned polymer dispersion Properties Density : 0.28 g/cm3 Water absorption after l h: 49.0%
after 2 h: 58.9%
Dimensional stability : Fracture after 190 h COMPARATIVE EXAMP~E 5 Binder: As in Comparative Example 4 Procedure according to Example 7 The following are used:
105 g of wood fibers 10 g of cellulose fibers 10 g of polypropylene fibers 15 g of an 8% strength aqueous emulsion of stearyl-diketene (water repellant agent) 2~59~
- 26 - O.Z. 0050/42165 29 g of the abovementioned polymer dispersion ll g of 10% strength aqueous aluminum sulfate solution 4.5 g of a flocculant Properties Density : 0.69 g/cm3 Water absorption after 1 h: 41.8%
after 2 h: 56.6%
Breaking force : O.2 N/mmZ

Claims

1. A molding based on fibers (component A), containing B) from 5 to 25% by weight, based on A, of a polymer of b1) from 75 to 99.9% by weight, based on B, of vinylaromatic monomers, methyl methacrylate, methyl acrylate, acrylonitrile, methacrylo-nitrile, vinyl halides, acrylates and meth-acrylates of alcohols of 2 to 12 carbon atoms and/or vinyl esters of not more than 20 carbon atoms, where the sum of the acrylates and methacrylates of alcohols of 2 to 12 carbon atoms and of the vinyl esters may be not more than 20% by weight, based on B, b2) from 0.1 to 25% by weight, based on B, of one or more monomers of the formula I

I

where R1 and R2 are each -H or C1-C4-alkyl, R3 is a bridge member of 1 to 20 carbon atoms, R4 is -C(O)R6, -C(O)OR6 or -CN, R5 is -H, -C(O)R9, -C(O)OR9 or -CN, X is -O- or -NR7-, Z is a single bond, -CH2-, -O-, -NRa- or -O-C(O)- and R6, R7, R8 and R9 are each H, alkyl, aryl, alkaryl or aralkyl of not more than 12 carbon atoms, and b3) from 0 to 10% by weight, based on B, of further copolymerizable monomers.

2. A molding as claimed in claim 1 in the form of a board.

3. A molding as claimed in claim 1, wherein mineral fibers are used as component A.

4. A molding as claimed in claim 1, wherein organic - 28 - O.Z. 0050/42165 fibers are used as component A.

5. A process for the production of moldings as claimed in claim 1, wherein an agueous suspension con-taining the fibers A is prepared using an aqusous disper-sion of B, this suspension is then flocculated, the resulting fiber slurry is molded and the molding is dried.