DE10334889A1 - Flame-retardant polymethyl methacrylate molding made by bulk polymerization in casting cell, used in building, furniture, space-, air- or water-craft or land vehicle, contains fine ammonium sulfate powder as flame retardant - Google Patents

Abstract

Flame-retardant polymethyl methacrylate resin molding, made by the bulk polymerization in casting cell, is produced from a monomer mixture (I) containing ammonium sulfate (II) of particle size less than 50 mu m, in an amount of 1-200 wt.% with respect to (I). An independent claim is also included for composition containing 1-200 wt.% (II) with respect to (I).

Description

Territory of invention

The The invention relates to the use of halogen-free flame retardants for the production of flame-retardant Plastic moldings. The plastic moldings have good mechanical properties and about a good flame retardant.

State of technology

ammonium sulfate is a long known and widely used flame retardant. The first applications concerned paper and curtains, which were impregnated with water aqueous Ammonium sulphate solution flame-retardant equipped were.

In addition to the use in plastics, the use of AMSU as a flame retardant in paper (eg JP 11228968 . CN 1123351 ), Textiles (WO 9632459), solid wood ( JP 11105011 ) and in pressboard and fiber composite panels ( DE 19621606 ). In the construction sector, building materials were generally ( EP 426179 ) and insulation materials ( DE 19748751 ) protected against fire. In all of these examples, AMSU was incorporated into the material, in solid wood, for example, by soaking. In addition, ammonium sulfate is also used in the production of flame-retardant coatings ( CN 1124272 ) and for the preparation of extinguishing agents for forest fires (WO 9807472). Also in the field of plastics there are many possible uses of ammonium sulfate as a flame retardant. Kishore et al studied AMSU as a flame retardant for PS (Kishore, K. Mohandas, K. Fire Mater (1989) 14 (2), 39-41). However, the formulations described therein contained only very small amounts of AMSU, in which no significant flame retardant effect could be detected.

WHERE 00/294 80 describes a process for the production of flame-retardant plastic moldings Methacrylic monomers, the 10-80 Wt .-% of a mineral filler containing either aluminum trihydroxide, magnesium hydroxide, Talc or Baliumsulfat can be. Furthermore, this plastic molding jewelry particles added. The mixture is melt extruded at temperatures greater than 150 °.

JP 48083136 contains in addition to AMSU as a flame retardant still organic or inorganic halogenated flame retardants. The use of halogen-containing flame retardants inevitably leads to a strong flue gas toxicity in case of fire.

In JP 08325574 the production of hydrophobically coated AMSU particles is claimed. These particles can be used to provide molding compounds flame retardant. The process describes the precipitation of AMSU in a special apparatus by the slow addition of a water-miscible organic solvent. It is regarded as advantageous that the process yields very finely divided particles which can still be provided with a coating in the solution. A disadvantage of this method is the very special structure, and that after precipitation, a mixture of an organic solvent and water is present, which must be recycled and disposed of.

task The present invention is to plastic molding with a halogen-free flame retardant equip so that the remaining mechanical and optical properties of the plastic molding are affected as little as possible. The plastic molding the corresponding fire tests must pass without any problems.

solution

Is solved the task by using 1-200 mass% of a particular finely divided ammonium sulfate, based on the polymerized Monomer formulation. After the polymerization, a flame-retardant translucent is obtained Plastic moldings.

1. The monomer preparation to be polymerized has the following composition: 100 GewT monomer mix 1-300 GewT finely divided ammonium sulfate 0-60 GewT dispersing agent 0.05-1 GewT stabilizers 0-1.0 GewT controller 0.0001-1.0 GewT initiators 0-0.1 GewT release agent

The monomer mixture has the following composition: 100 GewT methylmethacrylate 0-6 GewT of an unsaturated carboxylic acid 0-6 GewT of a crosslinker 0-100 GewT further vinylically unsaturated monomers

When Dispersing aids can For example, detergents are used whose hydrophobic part on branched or unbranched alkyl, alkenyl or phenylalkyl radicals builds. The hydrophilic part of these detergents is based, for example on carboxylic acid salts (-COO-Me +), sulfonic acid salts (-SO3-Me +), Esters of sulfuric acid salts (-OSO3-Na +), esters of phosphoric acid salts (-O-PO3Na2), phosphonates (-PO3Na2), oligoethylene glycols, sugars, amines, ammonium salts, Phosphonium salts, sulfonium salts or on amino acids.

Another group of possible dispersing aids are, for example, polymers and copolymers which contain ionic groups, and salts thereof. A concrete example is a copolymer of methyl methacrylate, methyl acrylate, hydroxyethyl methacrylate and dimethylaminoethyl methacrylate ( DE 33239517 ) called.

Prefers be 0-30 % By weight, more preferably 1-0 Gew% dispersing agent based on ammonium sulfate used.

As stabilizers, for example, benzotriazoles, HALS products, thioethers or sterically hindered phenols or mixtures of the abovementioned components can be used. HALS compounds are understood as meaning sterically hindered amines, as described, for example, in US Pat JP 0347856 are described. These hindered amine light stabilizers capture the radicals that form when exposed to radiation from the polymer.

When Regulators are used, for example, gamma-terpinene and terpinolene.

When Initiators can all commercial Radical initiators are used, such as 2.2'azobis (isobutyronitrile).

Examples for release agents are glycerol monostearate or other suitable fatty acid derivatives, silicic acid derivatives or talc. Furthermore, can Esters of fatty acids or fatty acid amides or long-chain carboxylic acids be used.

When unsaturated carboxylic acid may be, for example, methacrylic acid or acrylic acid be used.

When Crosslinkers can For example, glycol dimethacrylate and triallyl cyanurate are used become.

When further vinylic unsaturated Monomers can for example, esters of methacrylic acid and acrylic acid and aromatic vinyl compounds are used.

Becomes Styrene as further unsaturated used vinylic compound, then the transparency can be clearly be improved, since the total refractive index of the polymer matrix is adjustable to that of the ammonium sulfate.

According to the invention, a finely divided ammonium sulfate is incorporated as flame retardant. The determination of the particle sizes of the ammonium sulfate can be carried out, for example, microscopically or by light scattering methods. The particle size is quantified by the d50 value. d50 is the that size, which have or fall below 50% by weight of the examined particles.

Under finely divided in the context of the invention, an ammonium sulfate with d50 <50 microns, preferably d50 <15 μm and especially preferably understood d50 <5 microns.

The finely divided AMSU according to the invention can advantageously be incorporated in the form of a thickened syrup into the monomer mixture to be polymerized. The syrup phases are used to stabilize non-soluble additives, such as the AMSU, in the monomer mixture to be polymerized. A syrup phase is characterized by the fact that the solution prepared before the polymerization is significantly increased in viscosity by a specific process. It is known in this case the use of a syrup phase in PMMA, which is grafted on and continuously monomer is added. Therefore, such a phase consists of a monomer portion and a polymer portion and will be referred to hereinafter as the PMMA syrup phase. The final polymerization of the mixture is usually carried out between two parallel glass plates. Due to the increase in viscosity, it is possible to enter, for example, insoluble dyes or mineral additives, but also other non-soluble additives in this way in the reaction mixture that their distribution over the reaction mixture in the glass chamber is homogeneous and that no sedimentation during the casting process Polymerization takes place. The syrup phase used generally has the following physical characteristics:
Viscosity: 100 and 1000 mPas
Average molecular weight of the dissolved polymer: 300,000 g / mol
Content of inorganic solid: 0 to 70% by weight

The present invention relates to a polymerizable composition. "A polymerizable composition" in the meaning of the present invention refers to a composition which comprises one or more monomers which can be converted into high molecular weight compounds, ie polymers, by the polymerization processes known in the art, for example free-radical polymerization The present invention provides a number average molecular weight P _n index n of at least 10. For further details, reference is made to the disclosures of HG Elisa's Macromolecules, Volumes 1 and 2, Basel, Heidelberg, New York, Huttig & Wopf 1990, and Ullmanns Enzyklopädie of Industrial Chemistry 5. Edition, keyword: Polymerization Process referenced.

These monomers are well known. These include (meth) acrylates derived from saturated alcohols, such as
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate and 2-ethylhexyl (meth) acrylate;
(Meth) acrylates derived from unsaturated alcohols, such as. B.
Oleyl (meth) acrylate, 2-propynyl (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate;
Aryl (meth) acrylates, such as benzyl (meth) acrylate or phenyl (meth) acrylate, wherein the aryl radicals may each be unsubstituted or substituted up to four times;
Cycloalkyl (meth) acrylates such as 3-vinylcyclohexyl (meth) acrylate, bornyl (meth) acrylate; Hydroxylalkyl (meth) acrylates, such as
3-hydroxypropyl (meth) acrylate,
3,4-dihydroxybutyl (meth) acrylate,
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate;
Glycol di (meth) acrylates, such as 1,4-butanediol (meth) acrylate,
(Meth) acrylates of ether alcohols, such as
Tetrahydrofurfuryl (meth) acrylate, vinyloxyethoxyethyl (meth) acrylate;
Amides and nitriles of (meth) acrylic acid, such as
N- (3-dimethylaminopropyl) (meth) acrylamide,
N- (diethylphosphono) (meth) acrylamide,
1-Methacryloylamido-2-methyl-2-propanol;
Sulfur-containing methacrylates, such as
Ethylsulfinylethyl (meth) acrylate,
4-Thiocyanatobutyl (meth) acrylate,
Ethylsulfonylethyl (meth) acrylate,
Thiocyanatomethyl (meth) acrylate,
Methylsulfinylmethyl (meth) acrylate,
Bis ((meth) acryloyloxyethyl) sulfide;
polyvalent (meth) acrylates, such as
Trimethyloylpropantri (meth) acrylate.
Phosphorus-containing (meth) acrylates, such as
Methacrylamidomethanphosphonsäure,
Methacrylamidomethanphosphonsäuredimethylester,
Methacrylamidomethanphosphonsäurediethylester,
Methacrylamidomethanphosphonsäurediisopropylester,
Dimethylphosphorsäuremethacryloylethylester,
cyclic phosphonic acid derivatives such as
9,10-dihydro-9-oxa-10-phosphaphenantren-10-oxide-10-methyl methacrylate.

In addition to the (meth) acrylates set out above, the compositions to be polymerized may also contain other unsaturated monomers which are copolymerizable with methyl methacrylate and the abovementioned (meth) acrylates. These include, inter alia, 1-alkenes, such as hexene-1, heptene-1; branched alkenes such as vinylcyclohexane, 3,3-dimethyl-1-propene, 3-methyl-1-diisobutylene, 4-methylpentene-1;
acrylonitrile; Vinyl esters, such as vinyl acetate;
Heterocyclic vinyl compounds, such as 2-vinylpyridine, 3-vinylpyridine, 2-methyl-5-vinylpyridine, 3-ethyl-4-vinylpyridine, 2,3-dimethyl-5-vinylpyridine, vinylpyrimidine, vinylpiperidine, 9-vinylcarbazole, 3-vinylcarbazole, 4-vinylcarbazole, 1-vinylimidazole, 2-methyl-1-vinylimidazole, N-vinylpyrrolidone, 2-vinylpyrrolidone, N-vinylpyrrolidine, 3-vinylpyrrolidine, N-vinylcaprolactam, N-vinylbutyrolactam, vinyloxolane, vinylfuran, vinylthiophene, vinylthiolane, vinylthiazoles and hydrogenated vinylthiazoles, vinyloxazoles and hydrogenated vinyloxazoles;
Vinyl and isoprenyl ethers;
Maleic acid derivatives such as maleic anhydride, methylmaleic anhydride, maleimide, methylmaleimide; and
Dienes, such as divinylbenzene.

When Styrenes can Styrene, substituted styrenes having an alkyl substituent in the Side chain, e.g. α-methylstyrene and α-ethylstyrene, substituted styrenes having an alkyl substituent on the ring, such as vinyltoluene and p-methylstyrene, halogenated Styrenes such as monochlorostyrenes, dichlorostyrenes, tribromostyrenes and tetrabromostyrenes.

in the Generally, these comonomers are in an amount of 0 to 60 Wt .-%, preferably 0 to 40 wt .-% and particularly preferably 0 to 20 wt .-%, based on the weight of the monomers used, wherein the compounds can be used singly or as a mixture.

The Polymerization is generally done with known radical initiators started. Among the preferred initiators include those in the Well-known azo initiators such as AIBN and 1,1-azobiscyclohexanecarbonitrile, and peroxy compounds, such as methyl ethyl ketone peroxide, acetylacetone peroxide, Dilauryl peroxide, tert-butyl per-2-ethylhexanoate, ketone peroxide, methyl isobutyl ketone peroxide, Cyclohexanone peroxide, dibenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, 2,5-bis (2-ethylhexanoylperoxy) -2,5-dimethylhexane, tert -butylperoxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, Dicumyl peroxide, 1,1-bis (tert-butylperoxy) cyclohexane, 1,1-bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane, Cumyl hydroperoxide, tert-butyl hydroperoxide, Bis (4-tert-butylcyclohexyl) peroxydicarbonate, mixtures of two or more of the aforementioned compounds with each other and mixtures the aforementioned compounds with compounds not mentioned, which can also form radicals.

These Connections become common in an amount of 0.01 to 10% by weight, preferably 0.5 to 3 Wt .-%, based on the weight of the monomers used.

in this connection can various poly (meth) acrylates are used, for example in molecular weight or in the monomer composition.

Example 1:

To 1000 g of methyl methacrylate (Akzo Nobel example PERKAOS ^® 16S) are mixed with 0.07 g bis (4-tert-butylcyclohexyl) peroxydicarbonate added and the mixture heated with stirring until the viscosity of the mixture 60s, as measured in a 6 mm Ford cup at 20 ° C, was.

Subsequently, 3965 g of methyl methacrylate, 20 g of a poly [(methyl methacrylate) -co- (2-dimethyl aminoethyl methacrylate) -co- (2-hydroxyethyl methacrylate)] ( DE 33239517 ), 2.5g soy lecithin and 10g 2,2'-azobis (2,4-dimethylvaleronitrile).

As flame retardant, 5000 g of ammonium sulfate (d ₅₀ = 5 μm) were added to the mixture.

The Mixture was stirred until homogenization and then 15.0 h at 45 ° C in one of two glass plates of size 50 × 50cm and a 0.5cm thick Edge seal formed chamber polymerized. Subsequently was the polymer for final polymerization for 3 h at 115 ° C annealed.

The thus obtained plate was white translucent.

The heat release according to FAR 25.853 (c) was HR = 60 kWmin / m ² or HRR _max = 124 kW / m ² , the smoke gas density test according to FAR 25.853 (c), AITM 2.0007 with a value of 5 passed. The sample was classified as UL094 as V0.0s.

Example 2:

To 1000 g of methyl methacrylate (Akzo Nobel example PERKAOS ^® 16S) are mixed with 0.07 g bis (4-tert-butylcyclohexyl) peroxydicarbonate added and the mixture heated with stirring until the viscosity of the mixture 60s, as measured in a 6 mm Ford cup at 20 ° C, was.

Then be 4965 g of methyl methacrylate and 10 g of 2,2'-azobis (2,4-dimethylvaleronitrile) were added.

As flame retardant, 4000 g of ammonium sulfate (d ₅₀ = 5 μm) were added to the mixture.

The Mixture was stirred until homogenization and then 15.0 h at 45 ° C in one of two glass plates of size 50 × 50cm and a 0.5cm thick Edge seal formed chamber polymerized. Subsequently was the polymer for final polymerization for 3 h at 115 ° C annealed.

The thus obtained plate was white translucent.

The Smoke density test according to FAR 25.853 (c) AITM 2,0007 was passed with a value of 4. The sample was self-extinguishing. It was further classified as UL94 V0, 10s.

Example 3:

To 4000 g methyl methacrylate (Akzo Nobel example PERKAOS ^® 16S) are mixed with 0.28 g bis (4-tert-butylcyclohexyl) peroxydicarbonate was added and the mixture with stirring heated until the viscosity of the mixture 60s, as measured in a 6 mm Ford cup at 20 ° C, was.

Then be 2965 g of methyl methacrylate and 10 g of 2,2'-azobis (2,4-dimethylvaleronitrile) were added.

As flame retardants, 3000 g of ammonium sulfate (d ₅₀ = 5 μm) were added to the mixture.

The Mixture was stirred until homogenization and then 15.0 h at 50 ° C in one of two glass plates of size 50 × 50cm and a 0.5cm thick Edge seal formed chamber polymerized. Subsequently was the polymer for final polymerization for 3 h at 115 ° C annealed.

The thus obtained plate was white translucent.

The Smoke density test according to FAR 25.853 (c) AITM 2,0007 was passed with a value of 10.

Example 4:

To 6000 g of methyl methacrylate are added with 0.42 g of bis (4-tert-butylcyclohexyl) peroxydicarbonate (eg PERKAOS ^® 16S Akzo Nobel) and the mixture is heated with stirring until the viscosity of the mixture 60s, measured in a Ford Ford 6mm cup at 20 ° C, was.

Then be 1965 g of methyl methacrylate and 10 g of 2,2'-azobis (2,4-dimethylvaleronitrile) added.

As a flame retardant, 2000 g of ammonium sulfate (d ₅₀ = 5 microns) were added to the mixture.

The Mixture was stirred until homogenization and then 15.0 h at 50 ° C in one of two glass plates of size 50 × 50cm and a 0.5cm thick Edge seal formed chamber polymerized. Subsequently was the polymer for final polymerization for 3 h at 115 ° C annealed.

The thus obtained plate was white translucent.

The Smoke density test according to FAR 25.853 (c) AITM 2,0007 was passed with a value of 35. The sample was self-extinguishing

Example 5:

To 1000 g of methyl methacrylate (Akzo Nobel example PERKAOS ^® 16S) are mixed with 0.07 g bis (4-tert-butylcyclohexyl) peroxydicarbonate added and the mixture heated with stirring until the viscosity of the mixture 60s, as measured in a 6 mm Ford cup at 20 ° C, was.

Subsequently, 2235 g of methyl methacrylate, 1725 g of styrene, 20 g of a poly [(methyl methacrylate) -co- (2-dimethylaminoethyl methacrylate) -co- (2-hydroxyethyl methacrylate)] ( DE 33239517 ), 2.5g of soy lecithin, 10g of 2,2'-azobis (2,4-dimethylvaleronitrile) and 5g of azo (isobutyronitrile).

As flame retardant, 5000 g of ammonium sulfate (d ₅₀ = 5 μm) were added to the mixture.

The Mixture was stirred until homogenization and then 20.0 h at 50 ° C in one of two glass plates of size 50 × 50cm and a 0.5cm thick Edge seal formed chamber polymerized. Subsequently was the polymer for final polymerization for 3 h at 115 ° C annealed.

The thus obtained plate was white transparent. The transmission measured at an observation angle of 10 ° in daylight D65 was 62%.

The heat release according to FAR 25.853 (c) was HR = 55 kWmin / m ² or HRR _max = 103 kW / m ² , the flue gas density test according to FAR 25.853 (c), AITM 2.0007 with a value of 10 passed. The sample was classified as UL094 as V0.0s. The vertical flame test according to 25.853 (c) is the sample with 0s afterburn time.

Relatively were added to 1000 g of methyl methacrylate 0.078 bis (4-tert-butylcyclohexyl) peroxydicarbonate (eg PERKAOS ^® 16S from Akzo Nobel) was added and the mixture was heated with stirring until the viscosity of the mixture 60s, as measured in a 6 mm Ford cup at 20 ° C , amounted to.

Then be 3990 g of methyl methacrylate and 10 g of 2,2'-azobis (2,4-dimethylvaleronitrile) were added.

As flame retardant, 5000 g of ammonium sulfate (d ₅₀ = 5 μm) were added to the mixture.

The Mixture was stirred until homogenization and then 20.0 h at 50 ° C in one of two glass plates of size 50 × 50cm and a 0.5cm thick Edge seal formed chamber polymerized. Subsequently was the polymer for final polymerization for 3 h at 115 ° C annealed.

The the plate thus obtained was milky white again. The transmission measured at an observation angle of 10 ° in daylight D65 was 40%.

Comparative Example:

To 6000g methyl methacrylate 0.42 g of bis (4-tert-butylcyclohexyl) peroxydicarbonate (eg PERKAOS ^® 16S from Akzo Nobel) are added and the mixture with stirring heated until the viscosity of the mixture 60s, as measured in a 6 mm Ford cup at 20 ° C, was. Subsequently, 1965 g of methyl methacrylate and 10 g of 2,2'-azobis- (2,4-dimethylvaleronitrile) are added.

The Mixture was stirred until homogenization and then 15.0 h at 50 ° C in one of two glass plates of size 50 × 50cm and a 0.5cm thick Edge seal formed chamber polymerized. Subsequently was the polymer for final polymerization for 3 h at 115 ° C annealed.

The thus obtained plate was highly transparent.

in the Flammversuch the sample was not self-extinguishing, but there was the Sample the flue gas density test according to FAR 25.853 (c), AITM 20007.

Claims (6)

Flame-retardant plastic molded article of polymethyl methacrylate, prepared in Gusspolymerisationsverfahren, characterized in that the monomer mixture between 1 and 200% by weight, based on the monomer mixture, of ammonium sulfate having a particle size below 50 microns. Composition, characterized in that 1 to 200 wt .-% of ammonium sulfate having a particle size of d50 <50 microns, preferably d50 <15 microns and more preferably d50 <5 microns based on the wt .-% of the monomers, is used, wherein the Composition is given by: 100 GewT monomer mix 1-300 GewT finely divided ammonium sulfate 0-60 GewT dispersing agent 0.05-1 GewT stabilizers 0-1.0 GewT controller 0.0001-1.0 GewT initiators 0-0.1 GewT release agent, wherein the monomer mixture is again given by: 100 GewT methylmethacrylate 0-6 GewT of an unsaturated carboxylic acid 0-6 GewT of a crosslinker 0-100 GewT further vinylically unsaturated monomers Composition according to Claim 1, characterized that 30-80 % By weight of ammonium sulfate with a particle size of d50 <50 μm, preferably d50 <15 μm and especially preferably d50 <5 μm, based on the weight of the monomers is used. Composition according to one of the preceding claims 1-3, characterized characterized in that the composition with Dekokörnern, containing colored PMMA is offset. Use of a PMMA sheet of a plastic molding according to the above claims in trade fair construction, in shopfitting, in private construction and in furniture construction. Space, air, water or land vehicle, or building characterized in that it is wholly or partly made of a polymer body with a composition as described in the preceding claims, consists.