TWI506075B - Encapsulated flame retardants for polymers - Google Patents

Description

Encapsulated flame retardant for polymers

The present invention relates to a method of producing particles comprising at least one halogen-free flame retardant and comprising at least one metal oxide or semi-metal oxide, wherein the particles may be a flame retardant in the core and the metal oxide or half The core-shell particles of the metal oxide in the shell, or the particles of the flame retardant and the distribution of the metal oxide or semimetal oxide are substantially uniform. The invention further relates to a particle molding composition comprising at least one halogen-free flame retardant and comprising at least one metal oxide or semi-metal oxide, a polymer molding composition comprising the particles and comprising at least one thermoplastic or thermosetting polymer, and It is also useful for the use of such particles in a polymeric molding composition or for providing flame retardancy to a polymeric molding composition.

Composite materials including flame retardants and including other materials are known in the prior art.

PMSE Preprints (2008), 98, 533 to 535 discloses microcapsules having a core-shell structure. Indole (2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-oxo-4-methanol) phosphate (trimer) is present as a flame retardant. Within the core of the microcapsules. The melamine resin forms the shell of the microcapsules.

JP 2000263733 discloses a method of impregnating a fibrous substrate with a phenolic resin varnish comprising microcapsules containing a phosphate ester.

Donghua Daxue Xuebao, Ziran Kexue Ban (2007), 33(6), 701 to 705 disclose the inclusion of water-soluble methylphosphonate dimethyl ester (DMMP) as a nuclear material and an acetal product of PVA and GA (glutaraldehyde). As the core-shell particles of the shell material, it can be obtained via an emulsification process.

The prior art does not disclose any of the particles comprising a halogen-free, preferably water-insoluble, flame retardant in combination with at least one metal oxide or semi-metal oxide (e.g., SiO ₂ /TiO ₂ and/or ZnO). Additionally, processes for forming cerium oxide via a sol-gel process have not been disclosed, for example.

In view of the prior art, the present invention therefore aims to convert such materials into free flowing powders by using a metal oxide or semi-metal oxide in combination with a liquid halogen-free flame retardant. The liquid, halogen-free flame retardant in a combined form can then advantageously be used in the polymer molding composition.

These objectives are achieved by a method of the invention that produces particles comprising at least one halogen-free flame retardant and at least one metal oxide or semi-metal oxide, the method comprising at least the following steps:

(A) producing an aqueous emulsion comprising at least one flame retardant and at least one precursor compound of at least one metal oxide or semimetal oxide,

(B) forming core-shell particles, wherein at least one flame retardant is present in the core and at least one metal oxide or semi-metal oxide is present in the shell of the particles, and

(C) drying the core-shell particles from step (B) as needed, or

(D) producing a mixture comprising water, at least one polar solvent, at least one halogen-free flame retardant, and at least one precursor compound of at least one metal oxide or semi-metal oxide,

(E) converting at least one precursor compound of at least one metal oxide or semi-metal oxide into at least one metal oxide or semi-metal oxide, thereby obtaining at least one metal oxide or semi-metal oxide and comprising at least one Halogen-free flame retardant particles, and

(F) Dry the granules from step (E) as needed.

The various steps of the two alternative methods of the invention are explained in detail below:

The method 1 of the present invention for producing particles comprising at least one halogen-free flame retardant and comprising at least one metal oxide or semi-metal oxide comprises at least the following steps:

(A) producing an aqueous emulsion comprising at least one flame retardant and at least one precursor compound of at least one metal oxide or semimetal oxide,

(B) forming core-shell particles, wherein at least one flame retardant is present in the core and at least one metal oxide or semi-metal oxide is present in the shell of the particles, and

(C) Drying the core-shell particles from step (B) as needed.

Step (A):

Step (A) of Process 1 of the present invention comprises producing an aqueous emulsion comprising at least one flame retardant and comprising at least one metal oxide or a semi-metal oxide of at least one precursor compound.

The present invention uses a halogen-free flame retardant which is preferably water-insoluble. Another preferred embodiment of the invention uses a halogen-free flame retardant that is liquid under standard conditions (i.e., at a temperature of 25 ° C and a pressure of about 1 bar (a)).

In another embodiment, the flame retardant useful in the present invention is solid under standard conditions, but melts below 100 °C. The flame retardant which can be used in the present invention is generally insoluble in water.

For the purposes of the present invention, "halogen-free" means that the flame retardant useful in the present invention does not include atoms selected from the group consisting of halogens (i.e., fluorine, chlorine, bromine, and iodine). For the purposes of the present invention, "atomic free" means that the amount of such atoms is below the detection limit of the analysis.

The preferred flame retardant of the present invention is a liquid halogen-free P-containing flame retardant. Such flame retardants are well known to those skilled in the art.

The present invention particularly preferably uses a flame retardant corresponding to the following formulas (I)-(VI):

Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ and X are independently of each other as follows: R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² And R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ^{18 are} each independently hydrogen, a hydroxyl group or an aryl group, an alkyl group, and/or a cycloalkyl moiety having a functional group, respectively.

X is oxygen or sulfur independently of each other.

The aryl moiety in the present invention is a moiety having a parent skeleton of 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms, and consisting of an aromatic ring or a plurality of condensed aromatic rings. Examples of suitable parent skeletons are phenyl, naphthyl, anthracenyl, and phenanthryl. The parent skeleton may be unsubstituted, wherein all of the substitutable carbon atoms have thus a hydrogen atom, or they may be substituted at one, plural, or all substitutable positions on the parent skeleton. Examples of suitable substituents are alkyl moieties, preferably alkyl moieties having from 1 to 8 carbon atoms, more preferably methyl, ethyl or isopropyl; aryl moieties, preferably C ₆ -C _{a 22} -aryl moiety, particularly preferably a C ₆ -C ₁₈ -aryl moiety, preferably a C _6- C ₁₄ -aryl moiety, ie having a phenyl, naphthyl, phenanthryl, or fluorenyl parent skeleton An aryl moiety, wherein the moiety may in turn be a substituted or unsubstituted moiety; and a heteroaryl moiety, preferably a heteroaryl moiety comprising at least one nitrogen atom, preferably a pyridyl moiety; and an alkenyl moiety Preferably, it is an alkenyl moiety having a double bond, and particularly preferably an alkenyl moiety having a double bond and having 1 to 8 carbon atoms.

Particularly preferred aryl moieties are selected from the group consisting of phenyl, alkyl substituted phenyl, naphthyl, and alkyl substituted naphthyl.

The alkyl moiety in the present invention is preferably a moiety having 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, and preferably 1 to 8 carbon atoms. The alkyl moiety may be a branched or unbranched moiety and may optionally have one or more heteroatoms, preferably N, O, Si or S. This alkyl moiety may additionally be substituted with one or more substituents as described for the aryl group. Likewise, the alkyl moiety can have one or more aryl groups. Any of the aryl groups listed above are suitable for use herein. Further, the alkyl moiety may have one or more functional groups, preferably a hydroxyalkyl moiety or a cyanoalkyl moiety.

Particularly preferred alkyl moieties are selected from the group consisting of methyl, ethyl, propyl (eg, n-propyl and isopropyl), butyl (eg, n-butyl, isobutyl, and Tributyl), and octyl and its isomers.

The cycloalkyl moiety in the present invention is preferably a ring having 3 to 20 carbon atoms, particularly preferably 3 to 10 carbon atoms, and preferably 3 to 8 carbon atoms (e.g., 3, 4, 5, or 6). Shaped part. The cycloalkyl moiety can be substituted or unsubstituted and optionally heteroatomized with one or more heteroatoms, preferably N, O, Si, or S. The cycloalkyl moiety can be substituted with one or more substituents as described for the aryl group. Likewise, the cycloalkyl moiety can carry one or more aryl groups. Any of the aryl groups listed above are suitable for use herein. Additionally, the cycloalkyl moiety can carry one or more functional groups.

Particularly preferred cycloalkyl moieties are selected from the group consisting of cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl, and alkyl substituted derivatives of such groups.

All of the moieties as described in R ¹ to R ^{18 in} the present invention may have a functional group.

Functional groups suitable for use in the present invention are, for example, selected from the group consisting of carbonyl groups, and preferably carboxylic acid groups, ketone groups, aldehyde groups, ester groups, amine groups, guanamine groups, hydroxyl groups, cyanogens. Base, sulfur group, and SCN group.

The preferred compounds of the formulae (I) to (VI) in the present invention are selected from the group consisting of triphenylphosphine (formula (I) wherein R ¹ , R ² , and R ³ are phenyl groups). , diphenyl (o-tolyl) phosphine (formula (I), R ¹ , R ² -phenyl), R ³ -o-tolyl), tributylphosphine oxide (formula (III), wherein R ⁷ , R ⁸ and R ⁹ -butyl, and X-based oxygen), trioctylphosphine oxide (formula (III), wherein R ⁷ , R ⁸ , and R ⁹ are octyl, and X-based oxygen), diphenyl phosphite a base (formula (V) wherein R ¹³ and R ¹⁵ are phenyl, R ¹⁴ is hydrogen, and X is oxygen), triphenyl phosphite (formula (II), wherein R ⁷ , R ⁸ , and R ⁹ series phenyl), decyl (decylphenyl) phosphite (formula (II), wherein R ⁷ , R ⁸ , and R ⁹ are nonylphenyl), dimethyl methylphosphonate (formula V), wherein R ¹³ , R ¹⁴ , and R ¹⁵ are methyl, and X is oxygen, and dioctyl phenylphosphonate (formula (V), wherein R ¹³ and R ¹⁵ are octyl, and R ¹⁴ a phenyl group, and X-type oxygen), triphenyl phosphate (formula (VI), wherein R ¹⁶ , R ¹⁷ and R ¹⁸ are phenyl groups, and X-based oxygen), and tricresyl phosphate (formula (VI) , wherein R ¹⁶ , R ¹⁷ , and R ¹⁸ are o-tolyl, and X is oxygen, and mixture.

Further, the present invention can use (preferably) a flame retardant corresponding to the following formula (VII) and/or (VIII):

Wherein R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , X, Q, L, n and m are independently of each other as follows:

R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ and R ^{26 are} each independently hydrogen or, if necessary, an aryl group, an alkyl group and/or a cycloalkyl moiety having a functional group.

X is oxygen or sulfur independently of each other.

Q and L are, independently of each other, an organic group having at least two hydroxyl functional groups, wherein the groups provide a bond of a P atom or a bond to another group Q or a separate L, respectively.

In a preferred embodiment of the process of the present invention, Q and/or L in the compounds of the formula (VII) and the respective (VIII) are independently selected from the group consisting of resorcinol and p-phenylene Phenol, bisphenol A, bisphenol F, polycarbonate segments having terminal hydroxyl groups (e.g., phenolic groups), and mixtures thereof. The hydrogen atoms in these compounds are cleaved on the bond to P. This is known to those skilled in the art.

For the aryl, alkyl, and/or cycloalkyl moieties present in the compounds of formula (VII) or (VIII), the information provided above for compounds (I) to (VI) applies.

R ¹⁹ , R ²⁰ , R ²¹ and R ^{22 are} preferably a phenyl group or a phenyl group substituted by an alkyl group. R ²³ , R ²⁴ , R ²⁵ , and R ^{26 are} preferably a methyl group, a phenol, a phenyl group or an alkyl group-substituted phenyl group.

n is usually independently an integer of from 1 to 100, preferably from 1 to 10.

m is usually independently an integer of from 1 to 1000, preferably from 1 to 25.

The flame retardant additives of the formulae (VII) and (VIII) may be present as individual compounds or preferably as a mixture of compounds having different values of n and m.

Particularly preferred compounds of the formula (VI) or (VII) in the present invention are selected from the group consisting of resorcinol bis(diphenyl phosphate) (formula (VII) wherein R ¹⁹ , R ²⁰ , R ²¹ , and R ²² are phenyl, X-based oxygen, Q-based resorcinol, and n is 1 to 7), bisphenol A bis (diphenyl phosphate) (formula (VII), wherein R ¹⁹ , R ²⁰ , R ²¹ , and R ²² are phenyl, X-based oxygen, Q-based bisphenol A, and n is 1 to 5), poly(methylphosphonic acid-phenylene) (formula (VIII) Wherein R ²³ and R ²⁶ are phenol, R ²⁴ and R ²⁵ are methyl, L is resorcinol, X is oxygen, and mixtures thereof.

In the present invention, at least one metal oxide or semimetal oxide is present in the particles produced. The present invention can be used with any of the metal oxides or semi-metal oxides known to those skilled in the art and suitable for producing particles comprising at least one flame retardant.

In a preferred embodiment, the at least one metal oxide or semi-metal oxide is selected from the group consisting of metal oxides or semi-metal oxides which are respectively produced by a sol-gel process known to those skilled in the art. In a particularly preferred embodiment, the at least one metal oxide or semimetal oxide is selected from the group consisting of SiO ₂ , TiO ₂ , ZnO, ZrO ₂ , Al ₂ O ₃ , and mixtures thereof.

The above metal oxide and semimetal oxide precursor compounds are preferably individual monomer units, or the precursor compounds may be composed of a plurality of monomer units.

In a particularly preferred embodiment, SiO ₂ is used in the process of the invention.

At least one precursor compound of at least one metal oxide or semi-metal oxide is a compound that can be converted to the corresponding metal oxide or semi-metal oxide during a sol-gel process known to those skilled in the art. Suitable compounds are typically converted to any of the desired metal oxide or semi-metal oxide precursor compounds via the sol-gel process described above.

In a preferred embodiment, the precursor compound for SiO ₂ comprises a compound of formula (IX):

Wherein R ²⁷ , R ²⁸ , R ²⁹ and R ^{30 are} each independently hydrogen, an alkyl moiety, an aryl moiety, an alkoxy moiety, and/or an aryloxy moiety.

The above information applies to the alkyl moiety and/or aryl moiety involved in the compound of formula (IX). In the present invention, the alkoxy moiety and/or the aryloxy moiety present in the compound of the formula (IX) as required is different from the above alkyl moiety and/or aryl moiety in that it is bonded to the oxygen atom to Si atom.

In the compound of the formula (IX), it is preferred that R ²⁷ , R ²⁸ , R ²⁹ and R ^{30 are} independently of each other selected from the group consisting of hydrogen, methyl, ethyl, propyl (for example n-propyl or isopropyl) ), butyl (eg n-butyl, isobutyl, tert-butyl), phenyl, methoxy, ethoxy, propoxy (eg n-propoxy, isopropoxy), butoxy A group (for example, n-butoxy, isobutoxy or tri-butoxy) or a phenoxy group.

The preferred precursor compounds of SiO _{2 are} selected from the group consisting of tetraalkoxy decanes (e.g., tetramethoxy decane (TMOS), tetraethoxy decane (TEOS)), methyl trialkoxide. Alkane (for example, methyltrimethoxydecane (MTMS), methyltriethoxydecane (MTES)) and phenyltrialkoxydecane (such as phenyltrimethoxydecane (PTMS) and phenyltriethoxylate) Base decane (PTES)), and mixtures thereof. Particularly preferred in the present invention are mixtures of two or more of the above compounds, for example, a mixture of tetraethoxydecane (TEOS) and phenyltriethoxydecane (PTES). The quantitative ratio of TEOS to PTES in this preferred mixture is, for example, from 1:1 to 10:1, preferably from 6:1 to 3:1.

Step (A) of Process 1 of the present invention comprises producing an aqueous emulsion comprising at least one flame retardant present in at least one of the at least one metal oxide or semimetal oxide.

The emulsion can generally be produced in step (A) by any method known to those skilled in the art for producing an emulsion, for example, via a combination of appropriate amounts of the various components.

The emulsion produced in step (A) of the process of the invention is an aqueous emulsion, and the water is thus the main solvent or the presence of a dispersion medium.

In a preferred embodiment, the aqueous emulsion of step (A) may comprise at least one surfactant, particularly preferably a nonionic surfactant, for example selected from the group consisting of alcohol ethoxylates (eg, Equivalent to C ₁₂ -alcohols, such as C ₁₂ H ₂₅ (OCH ₂ CH ₂ O) ₆ OH), alkylphenol ethoxylates (eg, octylphenol ethoxylate), fatty acid ethoxylates (eg RCOO-(CH ₂ CH ₂ O) _n H, wherein R = 12 to 18), and mixtures thereof.

Typical nonionic surfactants suitable for use as emulsifiers in the emulsions of the invention are, for example, sorbitan esters and ethoxylated derivatives thereof, fatty acid esters of sorbitan (known as Span products) and Its ethoxylated derivatives (known as Tween products), such as monolauryl ester of polyoxyethylene sorbitan, monooleate of polyoxyethylene sorbitan, and monostearyl of polyoxyethylene sorbitan Acid ester.

Based on a water-immiscible phase in each case (this is a phase formed by at least one water-insoluble flame retardant in the present invention), if the present invention uses a nonionic surfactant or a non-ionic surface The mixture of active agents has a concentration of, for example, from 0.05% by weight to 5% by weight, preferably from 0.5% by weight to 2% by weight.

The aqueous emulsion of step (A) may further preferably comprise at least one non-polar solvent. However, if a majority of the flame retardant soluble in at least one of the metal oxide or semimetal oxide precursor compounds is used, then the presence of a non-polar solvent is not required.

Those skilled in the art will generally use the term non-polar solvent to mean solvents having a dielectric constant of less than 15.

In a preferred embodiment of the process of the invention, the non-polar solvent used in step (A), if desired, is a solvent having a low dielectric constant (e.g., less than 15) and which is immiscible with water. "Not miscible with water" means combining with water to form two durable phases.

Examples of non-polar solvents which are preferably used in the present invention are selected from the group consisting of benzene (C ₆ H ₆ ), carbon tetrachloride (CCl ₄ ), diethyl ether (CH ₃ CH ₂ OCH _{2 ).} CH ₃ ), pentane, cyclopentane, hexane, cyclohexane, toluene, 1,4-dioxane, chloroform, tetrahydrofuran, dichloromethane, and mixtures thereof.

The individual components of the emulsion in step (A) of Process 1 of the present invention can generally be combined with one another in any conceivable order.

In a preferred embodiment of step (A) of method 1, at least one halogen-free flame retardant is first dissolved in a solution of at least one metal oxide or a semi-metal oxide of at least one precursor compound. The at least one optional nonionic surfactant is then preferably dissolved in water and then the aqueous solution is combined with an organic solution.

The above components for producing the emulsion of step (A) can usually be mixed by using a simple mixer or agitator known to those skilled in the art. In a preferred embodiment, step (A) is carried out by exposing the emulsion to high shear forces to achieve effective mixing of the components. In a preferred embodiment, the emulsion of step (A) is produced by exposure to high shear or high shear rates. The shear rate is preferably from 5,000 rpm to 10,000 rpm.

In another preferred embodiment, a high pressure homogenization process can be performed. The energy consumed by the high pressure on the emulsion can bring about many different rheological effects, such as cavitation, turbulence, shear, and impact, which promote the formation of a uniform distribution of nanodroplets.

For example, step (A) of the method of the invention can be carried out by using a homogenization valve or a comminution chamber, optionally exposed to a high pressure (e.g., 500 to 2000 bar, preferably 800 to 1500 bar). An example of a high pressure homogenizer is a microfluidizer.

Step (B):

After forming the emulsion having the desired oil droplet size in the emulsification step (A), it is preferred to induce sol-condensation at the oil-water phase boundary in step B) of the process, preferably by establishing a suitable pH (for example via the addition of an acid or a base). Hydrolysis and polycondensation of the gel precursor.

Step (B) of Process 1 of the present invention comprises forming core-shell particles wherein at least one flame retardant is present in the core and at least one metal oxide or semi-metal oxide is present in the shell of the particles.

Step (B) can generally be carried out by any of the methods known to those skilled in the art, wherein the methods will be used in step (A) and in relation to at least one metal oxide or semi-metal oxide At least one precursor compound is converted to the corresponding metal oxide or semimetal oxide.

In a preferred embodiment of the process of the invention, the core-shell particles are formed in step (B) by varying the pH in the emulsion.

The pH in the present invention can be varied via the addition of an acid or a base, and this depends on the pH of the initial emulsion. In a preferred embodiment, an acid is added in step (B) to provide an emulsion having a pH of 2 to 6. In another embodiment, a base is added to step (B) of the process of the invention to obtain an emulsion having a pH of from 8 to 12.

Examples of acids which can be used in step (B) of Process 1 of the present invention to establish pH are hydrohalic acids such as hydrochloric acid (HCl), hydrobromic acid (HBr), hydroiodic acid (HI), and solutions thereof. Other suitable acid halogen oxyacids such as hypochlorous acid, chlorous acid, perchloric acid (HClO ₄ ), and periodic acid (HIO ₄ ). Sulfuric acid (H ₂ SO ₄ ), fluorosulfuric acid, nitric acid (HNO ₃ ), phosphoric acid (H ₃ PO ₄ ), fluoroantimonic acid, fluoroboric acid, hexafluorophosphoric acid, and chromic acid (H ₂ CrO ₄ ) are also suitable for use in the present invention. in. These acids are preferably used in aqueous solutions.

Examples of preferred bases are alkali metal hydroxides (such as sodium hydroxide or potassium hydroxide), alkaline earth metal hydroxides (such as calcium hydroxide), or ammonia. It is especially preferable to use sodium hydroxide, potassium hydroxide or ammonia. These bases are preferably used in aqueous solutions.

In a preferred embodiment, step (B) of Process 1 of the present invention adjusts the emulsion from step (A) to a particular pH by using (preferably) at least one aqueous solution of the above acid or base. This pH is, for example, 2 to 12, preferably 2 to 6, or 8 to 12. A pH of 8 to 10 is excellently established.

Step (B) can usually be carried out at a temperature of from 10 ° C to 80 ° C. In a preferred embodiment, step (B) is carried out for at least two hours, for example from 2 hours to 16 hours.

In a preferred embodiment, no other components are present in the core of the particles produced in the present invention together with a liquid, halogen-free flame retardant. In a particularly preferred embodiment, the concentration of the at least one liquid halogen-free flame retardant is at least 50% by weight, particularly preferably at least 60% by weight, based on the total weight of the core.

In a preferred embodiment, the core of the particles produced in the present invention is a liquid core, and the core is excellently a liquid oily core.

In each case, based on the entire particle, the preferred amount of at least one liquid flame retardant present in the core of the present invention to produce core-shell particles is from 50% to 99% by weight, especially 60% by weight of the particle. % to 90% by weight. In each case, based on the entire particle, the preferred amount of at least one metal oxide or semi-metal oxide present in the core of the core-shell particle to be produced in the present invention is from 1% by weight to 50% by weight of the particle. In particular, it is from 10% by weight to 40% by weight. In a preferred embodiment, the total amount of the at least one flame retardant and the at least one metal oxide or semimetal oxide is 100% by weight.

After step B), process steps known to those skilled in the art can be performed, such as centrifugation, filtration, evaporation, resuspension in an aqueous medium, or dialysis. These optional steps of the process are used to separate the resulting core-shell particles from the liquid component of the emulsion of the present invention.

Step (C):

An optional step (C) of Process 1 of the invention comprises drying the core-shell particles from step (B).

Preferably, the optional embodiment of the invention is practiced when the ratio of water or other organic solvent in the core-shell particles obtained from step (B) is too high to be further processed (for example, to produce a polymer molding composition) Step (C).

In the present invention, step (C) can be carried out by using any of the methods known to those skilled in the art, such as spray drying.

The diameter of the particles produced by the method 1 of the present invention is, for example, 0.1 μm to 100 μm, preferably 0.2 μm to 20 μm, particularly preferably 0.5 μm to 5 μm. In the present invention, the diameter means the maximum distance within the particles produced in the present invention.

The invention also provides a method 2 comprising at least steps (D), (E), and (F). These steps are explained in detail below:

Step (D):

Step (D) includes producing a mixture comprising water, at least one polar solvent, at least one halogen-free flame retardant, and at least one precursor compound of at least one metal oxide or semi-metal oxide.

Step (D) of the present invention uses at least one polar solvent. Any of the polar solvents known to those skilled in the art can be used in the present invention. The polar solvent in the present invention is a solvent having a dielectric constant of more than 15.

In a further preferred embodiment of the process of the invention, the at least one polar solvent in step (D) is at least one alcohol.

Suitable alcohols are selected from the group consisting of methanol, ethanol, propanol (eg n-propanol, isopropanol), butanol (eg n-butanol, isobutanol, tert-butanol), pentane Alcohol (eg n-pentanol, isoamyl alcohol, tri-pentanol, methylpentanol), n-hexanol, dimethylbutanol, ethylbutanol, n-heptanol, n-octyl alcohol, n-decyl alcohol , n-decyl alcohol and the like.

In each case, the amount of at least one polar solvent present in the mixture is generally from 10% by weight to 60% by weight, preferably from 20% by weight to 50% by weight, particularly preferably from 30% by weight to 40% by weight, based on the entire mixture. .

Water is also present in the mixture provided in step (D) of Process 2 of the present invention. The water is usually present in an amount of from 5% by weight to 35% by weight, preferably from 10% by weight to 30% by weight, particularly preferably from 15% by weight to 25% by weight, based on the entire mixture.

For the at least one halogen-free flame retardant involved, and for at least one precursor compound involving at least one metal oxide or semi-metal oxide, the above information relating to step (A) of method 1 is the same Be applicable.

In each case, the amount of at least one halogen-free flame retardant present in the mixture is generally from 5% by weight to 40% by weight, preferably from 10% by weight to 30% by weight, particularly preferably from 15% by weight, based on the entire mixture. 25 wt%.

The amount of at least one precursor compound of at least one metal oxide or semimetal oxide present in the mixture is usually from 10% by weight to 60% by weight, preferably from 20% by weight to 50% by weight, based on the entire mixture in each case. %, particularly preferably from 30% by weight to 40% by weight.

The amount of the component present in the mixture of step (D) of Process 2 of the present invention amounts to 100% by weight.

In a preferred embodiment, the mixture produced in step (D) of Process 2 of the present invention may comprise a buffer solution.

For the purposes of the present invention, a buffer solution is a mixture of a weak acid and its conjugate base, or a weak base with its conjugate acid. When using a buffer solution, the pH change (when a small amount of strong acid or base is added) can be only small. A buffer solution is used to maintain the pH of the solution at a substantially constant value. Examples of buffer solutions are the following aqueous solutions: hydrochloric acid and sodium citrate, citric acid and sodium citrate, acetic acid and sodium acetate, K ₂ HPO ₄ and KH ₂ PO ₄ , Na ₂ HPO ₄ and NaH ₂ PO ₄ , and borax and hydrogen Sodium oxide, preferably borax and sodium hydroxide.

All of the components present in the mixture of step (D) of Process 2 of the present invention can be mixed with one another in a manner known to those skilled in the art (e.g., by using a magnetic stirrer).

The agitator speed is typically from 100 rpm to 600 rpm, preferably from 200 rpm to 500 rpm, and particularly preferably about 300 rpm. The stirring time should be long enough, for example 2 minutes to 10 minutes.

Step (E):

The step (E) of the method 2 of the invention comprises converting at least one precursor compound of at least one metal oxide or semimetal oxide into at least one metal oxide or semimetal oxide, thereby obtaining at least one metal oxide or half. A metal oxide and comprising particles of at least one halogen-free flame retardant.

In step (E) of the process of the invention, at least one precursor compound of at least one metal oxide or semi-metal oxide can be converted to at least one metal by any of the methods known to those skilled in the art. Or a semi-metal oxide.

In a preferred embodiment, step (E) is carried out by heating the mixture from step (D). In this embodiment, the mixture is usually heated to a temperature of from 30 ° C to 100 ° C, preferably from 40 ° C to 80 ° C. The heating process can be carried out in any of the reactors known to those skilled in the art, for example, in stirred hot plates known to those skilled in the art. The heating method in step (E) preferably allows the escape of the solvent, i.e., water and/or polar solvent.

The heating in step (E) preferably forms a gel from the liquid mixture.

After the gel is formed, drying can also be carried out in the step (E) of the method 2 of the invention. The drying is preferably carried out to remove the solvent present, i.e., water and/or polar solvent, from the particles. During the optional drying process, the gel also ages to form granules. The drying process is usually carried out at a temperature of from 100 ° C to 200 ° C in, for example, a spray dryer.

Since step (D) of the process of the invention produces a substantially homogeneous mixture, step (E) forms particles which comprise at least one halogen-free flame retardant and at least one metal oxide or semi-metal oxide and are substantially uniformly distributed.

Step (F):

An optional step (F) of the process of the invention comprises drying the particles from step (E).

In a preferred embodiment of the method of the invention, step (F) is carried out.

Preferably, in step (F), the respective samples from step (E) are first spray dried to remove water, respectively, by using a B-290 mini spray dryer (B). Chi, Switzerland) to remove water. The conditions for the spray drying process are preferably as follows: the inlet temperature is, for example, about 80 ° C to 150 ° C, preferably 110 ° C to 130 ° C, for example 120 ° C; and the outlet temperature is, for example, about 40 ° C to 65 °C, preferably 45 ° C to 60 ° C, such as 55 ° C. It is preferred to use a two-fluid nozzle. Further, it is preferred to use nitrogen as a spray gas.

The fine powder obtained in the step (F) has a particle diameter of, for example, 0.1 μm to 50 μm, preferably 0.5 μm to 20 μm, particularly preferably 1 μm to 5 μm.

The invention also provides particles comprising at least one halogen-free flame retardant and a metal oxide or semi-metal oxide selected from the group consisting of SiO ₂ , TiO ₂ , ZnO, ZrO ₂ , Al ₂ O ₃ , and mixtures thereof.

For the halogen-free flame retardants involved and the above metal oxides or semi-metal oxides, the information given above in relation to the methods 1 and 2 of the invention applies. In a particularly preferred embodiment, at least one metal oxide or semi-metal oxide is SiO ₂ . At least one halogen-free flame retardant is preferably selected from the group consisting of triphenylphosphine, diphenyl (o-tolyl) phosphine, tributyl phosphine oxide, trioctyl phosphine oxide, diphenyl phosphite. Ester, triphenyl phosphite, decyl phenyl phosphite, dimethyl methylphosphonate, dioctyl phenyl phosphonate, triphenyl phosphate, tricresyl phosphate, Resorcinol bis(diphenyl phosphate), bisphenol A bis (diphenyl phosphate), poly(methylphosphonate phenyl ester) (formula (VIII)), and mixtures thereof.

In a preferred embodiment, the present application also provides particles of the invention, the particles being core-shell particles, wherein at least one halogen-free flame retardant is present in the core and at least one metal oxide or semi-metal oxide is present in In the shell. In this embodiment, the amount of at least one halogen-free flame retardant in the granules is preferably greater than 50% by weight, and particularly preferably greater than 70% by weight, based in each case on the entire particle.

The ratio of the average thickness of the shell to the average diameter of the capsule is preferably from 1:20 to 1:200, particularly preferably from 1:50 to 1:100.

In another preferred embodiment, the invention also provides particles of the invention wherein at least one of the halogen-free flame retardants and at least one metal oxide or semi-metal oxide are substantially uniformly dispersed. In this embodiment, preferably, the amount of at least one halogen-free flame retardant in the particles is greater than 70% by weight, based in each case on the entire particle.

The advantage of the granules produced in the present invention is that it is easier for process technology to incorporate into the polymeric molding composition than with liquid flame retardants. For example, the use of the particles of the present invention avoids the sticking effect on the tool used to create the molded composition. Another advantage is that when the particles of the invention are used in a polymeric molding composition, undesirable plasticizing effects of the flame retardant can be avoided because the flame retardants are oxidized with metal oxides or semimetals. The form of the combination of substances, not the liquid form. In addition, the flame retardant effect of the flame retardant used is more effective in the form of the present invention than in the free form. The invention is additionally protected from the type of leaching of the flame retardant from the polymer molding composition which can occur when a liquid flame retardant is used.

The invention also provides a polymeric molding composition comprising the particles of the invention and comprising at least one thermoplastic or thermoset polymer.

Any of the polymers known to those skilled in the art may be present in the polymer molding compositions of the present invention, for example, selected from the group consisting of polyesters (e.g., poly(terephthalic acid). Ethylene diester), poly(butylene terephthalate), poly(propylene terephthalate), poly(cyclohexanedimethylene terephthalate), or derived from an alkyl diacid (eg Polyester of adipic acid), polyamine (such as nylon-6, nylon-6,6, or other types of polyamine), polyolefin (such as polyethylene, polypropylene, poly(vinyl chloride), Poly(vinyl acetate), poly(vinyl alcohol), poly(methyl methacrylate), polyacrylate, polystyrene, poly(acrylonitrile-butadiene-styrene), polyurethane , polycarbonate, epoxy resin, unsaturated polyester as desired crosslinked, and mixtures of such polymers and individual blends.

The amount of the particles of the invention normally present in the polymer molding compositions of the invention is from 1% to 50% by weight, preferably from 1% to 30% by weight, based in each case on the entire polymer molding composition. .

Nitrogen-containing synergists may be present in the polymer molding compositions of the present invention as desired, such as melamine, melam, melem, melamine cyanurate, melamine polyphosphate, ammonium phosphate, ammonium pyrophosphate, ammonium polyphosphate, And mixtures thereof. In each case, based on the entire polymer molding composition, the nitrogen-containing synergists are preferably present in an amount of from 0 to 50% by weight, preferably from 1% to 50% by weight, particularly preferably 1% by weight. Up to 30% by weight.

The anti-drip agent may be present in the polymer molding composition of the present invention as needed, and other synergists may be present, such as poly(tetrafluoroethylene), zinc oxide, zinc borate, cerium oxide, ceric acid salt, and a ring. Oxides, and mixtures thereof. In each case, based on the entire polymer molding composition, the additives are preferably present in an amount of from 0 to 10% by weight, preferably from 0.2% to 10% by weight, particularly preferably from 0.2% to 4% by weight. .

Other halogen-free flame retardants may be present in the polymer molding compositions of the present invention as desired. These other halogen-free flame retardants are optionally present in an amount of, for example, from 0 to 30% by weight, preferably from 0 to 20% by weight. For example, the flame retardants are metal phosphinates or metal hydroxides.

Other polymeric additives may optionally be present in the polymeric molding compositions of the present invention to, for example, improve flame retardant, mechanical, electrical, or chemical and hydrolysis properties, and the like. Such polymers include, for example, epoxy polymers, polyacrylates, rubbers, polyfluorene oxides, maleic anhydride modified polymers, and the like. In each case, based on the entire polymer molding composition, the additives are preferably present in an amount of from 0 to 50% by weight, preferably from 1% to 50% by weight, particularly preferably from 5% to 20% by weight. .

Glass fibers can also be present in the polymer molding compositions of the present invention as desired. The glass fibers are preferably present in an amount of from 0 to 80% by weight, preferably from 15% to 30% by weight, based in each case on the entire polymer molding composition.

Other additives which are optionally present are selected from the group consisting of lubricants, nucleating agents, stabilizers, crosslinking agents and the like.

The present invention also provides a method of producing a polymer molding composition of the present invention by mixing particles and at least one thermoplastic or thermosetting polymer.

When a thermoplastic polymer is used, the mixing process can generally be carried out using any of the processes known to those skilled in the art, such as in the form of a melt. Mixers, kneaders, extruders, and blenders known to those skilled in the art can be used, preferably extruders. Single or twin screw extruders with different diameters and capacities can be used. It is preferred that the various components are mixed with each other in the form of a melt. The resulting thermoplastic molding composition can then be converted into pellets, for example, by chopping. In the present invention, a molded article can be produced from the pellets, for example, via injection molding. These methods are well known to those skilled in the art.

When a thermosetting polymer is used, examples are epoxy resins or unsaturated polyesters which are crosslinked as desired, and the components can be reacted with each other in standard processes including mixing and curing, or other known processes. The above methods are well known to those skilled in the art.

The invention also provides the use of the particles of the invention in a polymeric molding composition.

The invention also provides for the use of the particles of the invention in providing flame retardancy to a polymeric molding composition.

The information given above with respect to the particles of the invention and for the molding compositions of the invention is equally applicable to the use of the invention in question.

Example:

The following abbreviations are used in these examples:

TEOS tetraethoxy decane,

PTES phenyl triethoxy decane,

RDP bis(diphenyl phosphate),

PMP poly(methylphosphonic acid phenyl ester),

PC polycarbonate,

SAN polystyrene-acrylonitrile, including 76% by weight of styrene and 24% by weight of acrylonitrile.

ABS poly(acrylonitrile-butadiene-styrene) comprising 38% by weight of styrene, 12% by weight of acrylonitrile, and 50% by weight of butadiene,

PTFE poly(tetrafluoroethylene),

Ultradur B4300 G6 poly(butylene terephthalate) resin, including 30% by weight of glass fiber. The resin has an intrinsic viscosity of 130 mL/g, which is measured for a 0.5% by weight solution in phenol/o-dichlorobenzene (1:1 mixture).

MC cyanuric acid melamine,

Aerosol 8200 was used as the cerium oxide.

Example 1: Encapsulation of RDP in a core-shell structure

12 g of RDP was dissolved in 12 g of TEOS solution at room temperature. 0.6 g of Tween 80 was dissolved in 144 g of water. The oil phase was homogenized using a high pressure homogenizer (M-110 F microfluidizer, Mikrofluidix) at a pressure of 500 bar for one minute using an aqueous phase. The final emulsion was transferred to a 1 L glass beaker equipped with a magnetic stirrer (300 rpm). 8 g of citric acid-sodium hydroxide solution-sodium chloride buffer solution (pH 4) was added as a catalyst, and the emulsion was stirred for 10 hours. The suspension was dried by means of a spray dryer and a fine powder was obtained.

The particle size distribution was measured using a Bluewave (Microtrack S3500 Bluewave, Microtrack) with experimental values of D50 = 0.5 μm and D90 = 1.0 μm.

The product was calcined in vacuum at 280 ° C for 20 minutes to remove residual moisture and surfactant. The final product was used as Compound A in the following examples. After calcination, Compound A comprised 7.9% by weight of phosphorus, indicating an RDP loading of 73% by weight.

Example 2: Encapsulation of RDP in a core-shell structure

12 g of RDP was dissolved in 9 g of TEOS solution and 3 g of PTES solution at room temperature. 0.6 g of Tween 80 was dissolved in 144 g of water. The oil phase was homogenized using a high pressure homogenizer (M-110 F microfluidizer, Mikrofluidix) at a pressure of 500 bar for one minute using an aqueous phase. The final emulsion was transferred to a 1 L glass beaker equipped with a magnetic stirrer (300 rpm). 8 g of citric acid-sodium hydroxide solution-sodium chloride buffer solution (pH 4) was added as a catalyst, and the emulsion was stirred for 16 hours. The suspension was dried by means of a spray dryer and a fine powder was obtained.

The particle size distribution was measured using a Bluewave (Microtrack S3500 Bluewave, Microtrack), and the experimental values were: D50 = 0.6 μm, and D90 = 1.2 μm.

Example 3: Encapsulation of RDP in matrix structure

20 g of RDP was dissolved in 30 g of TEOS solution and 10 g of PTES solution at room temperature. The mixture was dissolved in 20 g of ethanol. The oil phase was added to 20 g of citric acid-sodium hydroxide-sodium chloride buffer solution (pH 4). The solution was stirred for 2 minutes using a magnetic stirrer (300 rpm). The solution was transferred to a stirred hot plate at a temperature of 40 ° C and held for 10 hours. The suspension was dried by means of a spray dryer and a fine powder was obtained. The particle size distribution was measured using a Bluewave (Microtrack S2500 Bluewave, Microtrack), and the experimental values were: D50 = 1.0 μm, and D90 = 1.6 μm.

Example 4: Encapsulation of PMP in matrix structure

13 g of PMP was dissolved in 10 g of TEOS solution and 3 g of PTES solution at 60 °C. The mixture was immediately added to ethanol. 60 g of citric acid-sodium hydroxide-sodium chloride buffer solution (pH 4) was heated to 60 °C. The oil phase was mixed with the water at 60 ° C and the mixture was stirred for two minutes. The solution was transferred to a stirred hot plate at a temperature of 80 ° C and held for 10 hours. The suspension was dried by means of a spray dryer and a fine powder was obtained. The particle size distribution was measured using a Bluewave (Microtrack S3500 Bluewave, Microtrack), and the experimental values were: D50 = 1.5 μm, and D90 = 2.5 μm.

The product was calcined in vacuum at 280 ° C for 20 minutes to remove residual moisture and surfactant. The final product was used as the compound B in the following examples. After calcination, Compound B comprised 12.9% by weight of phosphorus, indicating a PMP loading of 72% by weight.

Example 5: RDP in FR Application in PC/ABS (comparative)

Table 1 shows the FR PC/ABS composition. The material was mixed in a 17 mL mini-extruder at 280 ° C for three minutes using a screw rotation rate of 80 rpm and then cast into an injection mold at a pressure of 15 bar during injection molding to produce a UL 94 sample ( The measured value is 1.6 mm). The resulting sample was tested according to UL 94 conditions (two flames were applied in sequence for 10 seconds) and the V-0 requirement was met by self-extinguishing and no droplets. During the mixing process, the RDP adheres to the feeder and is difficult to meter. The heat distortion temperature of the test sample was low (85 ° C), and this indicates the plasticizer effect of RDP.

Example 6: Application of encapsulated RDP (Compound A) FR PC/ABS with core-shell structure

Compound A was produced as described in Example 1. Table 1 shows the FR PC/ABS composition. The method of processing and testing the materials was the same as in Example 5. Compound A in powder form was used and was easy to meter. The sample self-extinguishes and has no droplets and can be classified as V-0. The heat distortion temperature of the test sample was 92 ° C, and this indicates that encapsulation can reduce the plasticizer effect of the liquid RDP.

Example 7: Application of PMP in FR PBT (comparative)

Table 2 shows the FR PBT compositions. The material was mixed in a 17 mL mini-extruder at 260 ° C for three minutes using a screw rotation rate of 80 rpm, and then cast into an injection mold at a pressure of 15 bar during injection molding to produce a UL 94 sample ( The measured value is 1.6 mm). During mixing, PMP tends to stick to the feeder and is difficult to meter. The mold filling rate in the melt during the injection process was 60%. The resulting sample was tested according to UL 94 and subjected to complete combustion with a corresponding UL 94 rating of V--. Due to the plasticizer effect of PMP, the glass transition temperature of the composite was 27 ° C, which was significantly lower than the standard PBT (40 ° C).

Example 8: Application of PMP in FR PBT (comparative)

Table 2 shows the FR PBT compositions as described in Example 9 for cerium oxide and PMP loading. The extent of processing and testing of the materials was the same as in Example 7. During mixing, PMP tends to stick to the feeder and is difficult to meter. During the injection process, the mold fill rate in the melt was 50%, which is less than in Example 7, and this indicates that the presence of cerium oxide increases the melt viscosity of the polymer. The resulting sample was tested according to UL 94 and self-extinguishing was achieved without any droplets, thereby achieving a V-0 rating. The glass transition temperature of the composite was 30 °C.

Example 9: Application of encapsulated PMP (Compound B) with matrix structure in FR PBT

Compound B was produced as described in Example 5. Table 2 shows the FR PBT compositions. The method of processing and testing the materials was the same as in Example 7. Compound B is powdery and easy to meter. The mold filling rate was 60%, which was the same as in Example 7, but higher than in Example 8, and this indicates that the melt viscosity of the encapsulated PMP did not change. The resulting sample was tested according to UL 94 and self-extinguishing was achieved without any droplets, thereby achieving a V-0 rating which was much better than in Example 7. The encapsulated PMP system is superior to the liquid PMP flame retardant. The glass transition temperature of the composite was 36 ° C, which was higher than in Examples 7 and 8, because the encapsulated PMP reduced its plasticizing effect.

Claims (14)

A method of producing particles comprising at least one halogen-free flame retardant which is liquid under standard conditions and comprising at least one metal oxide or semi-metal oxide, the method comprising at least the following steps: (A) producing an aqueous emulsion The aqueous emulsion comprises the at least one flame retardant and at least one precursor compound of the at least one metal oxide or semimetal oxide, (B) forming core-shell particles, wherein the at least one flame retardant is present in the The core of the particle and the at least one metal oxide or semi-metal oxide are present in the shell, and (C) drying the core-shell particles from step (B) as needed, or (D) producing a mixture, It comprises water, at least one polar solvent, at least one halogen-free flame retardant, and at least one precursor compound of the at least one metal oxide or semi-metal oxide, (E) oxidizing the at least one metal oxide or semimetal Converting the at least one precursor compound into the at least one metal oxide or semi-metal oxide, thereby obtaining and including at least one metal oxide or semi-metal oxide At least one of halogen-free flame retardant particles, and (F) optionally drying such particles from step (E) of. The method of claim 1, wherein the at least one halogen-free flame retardant is selected from the group consisting of triphenylphosphine, diphenyl(o-tolyl)phosphine, tributylphosphine oxide, trioctylphosphine oxide , diphenyl phosphite, phosphorous Triphenyl acrylate, decyl phenyl phosphite, dimethyl methylphosphonate, dioctyl phenyl phosphonate, triphenyl phosphate, tricresyl phosphate, and mixtures thereof Or a group selected from the group consisting of resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), poly(methylphosphonate phenyl ester), and mixture. The method of claim 1 or 2, wherein the at least one metal oxide or semimetal oxide is selected from the group consisting of SiO ₂ , TiO ₂ , ZnO, ZrO ₂ , Al ₂ O ₃ , and mixtures thereof. The method of claim 3, wherein the precursor compounds for the SiO ₂ compound comprise a compound of the formula (IX) Wherein R ²⁷ , R ²⁸ , R ²⁹ and R ^{30 are} each independently hydrogen, an alkyl moiety, an aryl moiety, an alkoxy moiety, and/or an aryloxy moiety. The method of claim 1 or 2, wherein in step (B), the core-shell particles are formed by changing the pH of the emulsion. The method of claim 1 or 2, wherein the at least one polar solvent in step (D) is at least one alcohol. A granule comprising at least one halogen-free flame retardant which is liquid under standard conditions and a metal oxide or semi-metal oxide selected from the group consisting of SiO ₂ , TiO ₂ , ZnO, ZrO ₂ , Al ₂ O ₃ , and mixtures thereof. The granule of claim 7, which is a core-shell particle, wherein the at least one halogen-free flame retardant is present in the core and the at least one metal oxide or semi-metal oxide is present in the shell. The particle of claim 7, wherein the distribution of the at least one halogen-free flame retardant and the at least one metal oxide or semi-metal oxide included is substantially uniform. The granule of claim 7 or 8, wherein the concentration of the core material is greater than 50% by weight based on the total weight of the granule. A polymer molding composition comprising the particles of claim 7 or 8 and at least one thermoplastic or thermosetting polymer. A method of producing a polymer molding composition according to claim 11 which is produced by mixing the particles and the at least one thermoplastic or thermosetting polymer. A method of using the particles of claim 7 or 8 in a polymeric molding composition. A method of using the particles of claim 7 or 8 to provide flame retardancy to a polymeric molding composition.