GB2073047A - Peroxide Emulsions and Sizing Composition Containing Same - Google Patents

Abstract

An oil-in-water emulsion of an insoluble organic peroxide that is solid at 20 DEG C, having an average particle size of 1.5 microns or less and comprising a hydrocarbon solvent, having a high kauri-butanol number if the organic peroxide has a substantial amount of aromaticity and a low kauributanol number if the organic peroxide has little or no aromaticity, one or more nonionic emulsifers and at least 35 weight percent of water. There is also disclosed a method of preparing such an emulsion, a size for glass fibers containing such an emulsion, sized glass fibers and a polymer matrix reinforced with such glass fibers.

Description

SPECIFICATION Peroxide Emulsions and Sizing Composition Containing Same The present invention is directed to an aqueous emulsion prepared from a solid peroxide, to an aqueous size containing the emulsion, and to sized glass fibers. More particularly, the present invention is directed to an aqueous peroxide emulsion made from a solid organic peroxide, to an aqueous treating solution containing same, and to sized glass fibers prepared for bonding to polymers in the reinforcement of polymeric materials.

Organic peroxides that decompose by initial cleavage of the oxygen-oxygen bond to produce free radicals act as initiators for vinyl monomers and other vinyl containing materials. There are over fifty different organic peroxides classified into nine major types that are used commercially in the polymer and resin industries. The half-life (T1Ar2) which is given as a function of temperature can range for the various peroxides from a short half-life of 0.01 hours at elevated temperature to as long a half-life as 1,000 hours at lower temperatures around 1 6O0Cfor the more stable peroxides. The half-life is a measure of the thermal stability of organic peroxides by measuring the time for decomposition of 50 percent of the original amount of peroxide which is a half-life for a first-order reaction.These organic peroxides have been used in the polymerization of vinyl monomers to produce bulk polymers, polymer films and other polymer compositions.

Depending on the thermal stability and other physical characteristics of the particular peroxides, various organic peroxides can be used in different forms when acting as an initiator or curing agent for vinyl polymerization. Some of the organic peroxides such as the highly reactive percarbonates are so unstable that they must be shipped as a frozen solid or an undiluted liquid under refrigeration. Some less reactive organic peroxides, such as lauroyl peroxide and dibenzoyl peroxide, are more stable at room temperature and can be activated with greater facility and with less stringent precautions. For example, the relatively more stable benzoyl peroxide, which is a solid at room temperature having a melting point of 106 to 1 070C., can be used as granules or crystals or in a thick paste compounded with a phlegmatiser such as tricresyl phosphate.Also, benzoyl peroxide can be used in an aqueous solution as is shown in U.S. Patent 2,343,084 (Smith) wherein the small amount of benzoyl peroxide is dissolved in one or more polymerizable conjugated compounds and may also contain a resin in solution. This solution can be combined with a water solution of a partially saponified polyvinyl acetate.

Also, it has been suggested in U.S. 3,795,630 (Jaspers et al) to have a chemically stable nonseparating organic peroxide composition of an organic peroxide which is a solid at room temperature.

The composition is obtained by mixing the solid peroxide, like benzoyl peroxide, with a liquid phlegmatiser like phthalate plasticizers, epoxidized soya bean oil and glycols, and a hydrophobic alkyl group-containing silica. in addition, it is shown in U.S. Patent 4,039,475 (Jannes) to have a stable, pumpable aqueous suspension of organic peroxides containing one nonionic emulsifier having a maximum HLB value of 12.5 and a second nonionic emulsifier having a minimum HLB value of 12.5 or a second emulsifier that is anionic.

Organic peroxides such as aryl alkyl peroxides like dicumyl peroxide; ester peroxides and aromatic and aliphatic acyl peroxides have been used in compositions for sizing fibrous materials for use in polymer application as shown in U.S. Patent 3,013,915 (Morgan). These peroxides which have low volatilities and low decomposition temperatures, usually below that about 180oF. (820C.), are deposited from an organic solution. In the composition along with the organic peroxide, there is present a suitable coupling agent.

It is also known as is shown in U.S. Patent 3,837,898 (McCombs et al) to form a polybutadiene emulsion that contains heat activated curing agents to operate as a catalyst in the size coating on the fibers. The curing agents are the well-known free radical catalysts such as organic peroxides, e.g., benzoyl peroxide, lauroyl peroxide, tert-butyldiethyl peracetate, diacetyl peroxide, as well as inorganic peroxides, such as potassium persulfate. The polybutadiene emulsion is prepared by mixing the polybutadiene with an emulsifying agent and with benzoyl peroxide. To this mixture there is added sufficient water to form an emulsion of the liquid polymer in aqueous medium.The emulsion is then mixed with a mixture of water, glass fiber anchoring agents and a gel agent and the resulting composition is homogenized to form a sizing composition having a solids content of about 2.80 and a pH of about 10.0 to 10.5. The emulsifying agents that can be used are any conventional emulsifying agents. but preferably are the nonionic emulsifying agents such as the polyoxyethylene derivatives of fatty acid, partial esters of sorbitol anhydrides, or the polyoxyethylene derivatives of fatty alcohols, or of the alkyl substituted phenols.

It was recently suggested in U.S. Patent 3,849,148 (Temple) to prepare an aqueous size for glass fibers to be used in reinforcing polyolefin materials wherein the size contained a coupling agent, a heat stable organic peroxide, a non-ionic surfactant and usually a lubricant or softener, and optionally a filmformer. The heat stable organic peroxide includes organic peroxides having peak decomposition temperatures above about 2000F. (930C.), for example, alpha alpha' bis(t-butyl peroxy)-diisopropyl benzene, tris(t-butyl peroxy)-diisopropyl benzene,2,5(t-butyl peroxy)hexane, and 2,5(t-butyl peroxy) hexyne. These heat stable peroxides are used in emulsions with non ionic surfactants such as polyethoxy phenols being prepared and dispersed in water containing a coupling agent.Emulsions prepared at temperatures in the range of 1200F. (49 OC.) to 2100F. (99 OC.) including isooctyl phenyl polyethoxy ethanol are particularly useful. Other useful nonionic surfactants belonging to the class of polyethoxy phenols are nonyl polyethoxy ethanol and alkyl etherpolyethoxyethanol. Other nonionic surfactants which are useful are polyalkylene glycol ethers, alkyl polyether alcohol and alkyl aryl polyether alcohol. The emulsion is prepared by thoroughly mixing the peroxide initiator with the nonionic surfactant maintaining the temperature of the mixture above the melting point of the free radical initiator. Suitable temperature control is possible by immersing the mixing vessel in a bath of boiling water.After thoroughly mixing the free radical peroxide initiator with nonionic surfactant, water is slowly added to the mixture at a temperature above the melting point of the free radical initiator, preferably in the range of about 1 400F. (600C.) to 1500 F. (660C.) until the emulsion inverts. The emulsion is slowly cooled to ambient conditions by continued water addition. This emulsion is then slowly added to the aqueous mixture containing the coupling agent and the remaining water is added to the mixture to form an aqueous sizing composition for treating glass fibers.

In forming an emulsion for use in a sizing composition for glass fibers, it is necessary to obtain an emulsion with a small particle size and that is shear, shelf and process stable, that is, the particles of the internal phase do not coalesce when the emulsion is stirred or is stored for a period of time or is applied to the glass fibers. It is necessary to have an emulsion rather than a dispersion because of the particle size limitation. An emulsion is a two-phase system consisting of two incompletely miscible liquids, the one being dispersed as fine droplets in the other, whereas a suspension is a two-phase system where the dispersed phase is a solid. The particle size and particle size distribution of an emulsion are controlled by such factors as the quantity or the efficiency of the emulsifier, the order of mixing and the type of agitation employed.The stability of an emulsion depends upon such factors as (1) particle size, (2) difference between the densities of the material in the internal phase, which is the liquid broken-up into droplets and of the material of the external phase, which is the surrounding liquid, (3) the viscosity of the emulsion concentrate, (4) the charges on the particles, (5) choice of emulsifier type and amount of emulsifier used, and (6) the conditions of storage and use, including the temperatures of storage and use, agitation, dilution, and evaporation.

The average particle size and particle size distribution of the emulsion are controlled by such factors as the quantity or the efficiency of the emulsifier, the order of mixing and the agitation employed. The average particle size and particle size distribution of the emulsion are important factors, since large liquid particles or droplets in the emulsion or, for that matter, particles of solid material as in a suspension would not provide an adequate uniform coating to the glass fibers. Also solid particles would abrade the glass fibers, and large liquid particles would cover the surface of the glass fiber in a spotty fashion leaving hiatuses in the coating along the fibers that as a result would not adequately contact the matrix resin to be reinforced.

The emulsion in a sizing composition for glass fibers must be dilute to the extent of approaching a water thin liquid in order to facilitate application to the glass fibers during formation of the fibers.

Dilution of an emulsion, especially dilution to the extent of a water thin liquid, can lead to an unstable emulsion. Also, the emulsion in a sizing composition must be shear stable to withstand the mixing of the sizing composition before being applied to the glass fibers. In addition, the emulsion must be shelf stable for periods of for example three days to more than a week so that the material may be stored before application to the glass fibers. Also, the emulsion must be process stable so it can be applied to the glass fibers.

A problem that has recently surfaced with the use of heat stable, solid organic peroxides is that when they are used in an emulsion which is formed at temperatures above the melting point of the peroxide the resultant emulsion that is used at temperatures below the melting point of the peroxide tends to have particle sedimentation or particle creaming.

An additional problem with the use of solid organic peroxides in aqueous treating solutions in general in the chance of a violent decomposition reaction during the emulsification process. Since the solid peroxides must be heated to be melted, the use of the elevated temperatures would bring the peroxide closet to its decomposition temperature and a possible violent reaction could occur if the decomposition temperature is reached.

By practice of the present invention there may be provided one or more of the following (i) a safer method of preparing an emulsion of a solid organic peroxide that has a melting point and decomposition temperature at elevated temperatures; (ii) an emulsion of a solid peroxide that can be diluted to have a viscosity approaching the viscosity of water and that has improved shear stability, shelf stability, and process stability by comparison with the emulsions of U.S. 3,849,148; (iii) an emulsion of a heat-stable organic peroxide that can be used in a sizing composition for glass fibers, where the emulsion is shear stable and shelf stable and process stable within the sizing composition; ; (iv) processes for preparing an emulsion of a heat-stable organic peroxide and a sizing composition containing same where the peroxide emulsion has improved dilutability, shear stability, shelf stability, and process stability by comparison with the emulsions of U.S. 3,849,148 and fine particle size with a minimum particle size distribution; and (v) sized glass fiber strands having fibers in the strand with a coating of an aqueous sizing composition containing a coupling agent, an emulsion of heat stable organic peroxide that has improved dilutability, shear stability, shelf stability and process stability by comparison with the emulsions of U.S. 3,849,148, and a minimum particle size distribution and fine average particle size; and usually a lubricant or softener; and optionally a film-former.

The average particle size and particle size distribution of the emulsion is an important factor, since large liquid particles in the emulsion, or for that matter particles of solid material as in a suspension, would not efficiently coat the surface of the glass fibers and would be prone to separate from the sizing composition. In addition, solid hard particles in the sizing composition could abrade the glass fibers.

In accordance with the present invention there is provided an oil-in-water emulsion of an organic peroxide that is a solid at 20 C. and that forms active free radicals at elevated temperatures and that is water insoluble or that has limited water solubility, one or more hydrocarbon solvents, one or more non-ionic emulsifiers giving the emulsion an HLB value in the range of about 9 to about 20, and water.

The solid peroxides that are water-insoluble or that are of limited water solubility include hydroperoxides, a-oxy and n-peroxy hydroperoxides, dialkyl peroxides, aldehyde or ketone peroxides, diacyl peroxides peroxyesters, peroxyacids, peroxydicarbonates, peroxymonocarbonates and perketals.

Where reference is made to the peroxide having limited water solubility, the amount of solubility tolerated in the present invention is obviously up to that at which it is no longer practical to use the emulsion of the invention, but rather to simply dissolve the peroxide in water. Any known method of using solubility parameters to predict solubility of one component in another component can be used to predict solubility of the peroxide.

The hydrocarbon solvent for use in the inventive emulsion can be any of the low polar, strongly hydrophobic solvents for example pine oils, white spirits, special boiling point spirits and aromatic solvents. Special boiling point spirits are petroleum fractions of lower boiling ranges than the white spirits, frequently closer-cut and with aromatic contents for the most part in the 2 to 1 5% range. These fractions are referred to in many parts of the world as SVP solvents with a suffise to indicate type or boiling range. In the U.S. the solvents in this range are known as VM and P naphthas or just naphthas.

There are a few exceptions to this generalization, a limited number of cuts with higher aromatic contents between 35% and 60% being available. The one or more hydrocarbon solvents have a kauributanol number from about 40 to about 100 when the solid peroxide is of aromatic character or have a kauri-butanol number of around 10 to about 60 when the solid peroxide is of an aliphatic character.

Character in this sense means respectively that the main portion of the peroxide molecule is aromatic with aromatic or aliphatic side groups, or the main portion is aliphatic with aliphatic or aromatic side groups. In addition, it is most beneficial if the hydrocarbon solvent is a fugitive solvent that can be removed from the aqueous emulsion when the emulsion is dried on a substrate.

The emulsion also has one or more nonionic emulsifiers giving the emulsion an HLB (hydrophiliclipophilic balance) value in the range of about 9 to about 20. Non-exclusive examples include emulsifier types such as polyethoxy phenols, polyalkylene glycol ethers, alkyl polyether alcohol, alkylaryl polyether alcohol, ethylene, oxide, ethoxylated alcohols; ethoxylated alkyl phenols, ethoxylated fatty acids, fatty esters and oils, fatty acids, glycerol esters, glycol esters, monoglycerides and derivatives, sorbitan derivatives, and sucrose esters and derivatives, alkylated phenol condensation products and condensation products of ethylene oxide and propylene glycol in sufficient amounts to emulsify the organic peroxide.The emulsifiers are most useful in a three emulsifier blend with emulsifiers from the aforementioned emulsifier types selected in proper weight ratios to give an overall HLB in the range of about 9 to about 20.

The expression "derivative" as used throughout the specification is intended to mean a derivative which does not interfere with the essentially required properties of the compound.

The emulsion also contains water in sufficient amounts to make the emulsion an oil-in-water emulsion. If the emulsion is to be shipped any considerable distance, the amount of water added is just that amount needed to invert most of the water-insoluble or limited solubility material to an oil-inwater emulsion thereby making the emulsion a concentrated oil-in-water emulsion. The concentrated oil-in-water emulsion can be further diluted at the location of use.

The aforedescribed emulsion of the organic peroxide has many uses including uses in vinyl and diene polymerization. The emulsion is particularly useful in a sizing composition for glass fibers to be used in polymer applications, e.g. the reinforcement of polymers such as polyolefins and polyamines and polyesters. The sizing composition is an aqueous composition containing a coupling agent, the organic peroxide-containing emulsion, and usually a lubricant or softener, and optionally a film-former.

The process for preparing the emulsion containing the organic peroxide involves first solubilizing the solid organic peroxide in the hydrocarbon solvent and then adding one or more surfactants and adding water and emulsifying using equipment and techniques known to those skilled in the art.

The aqueous size containing the organic peroxide emulsion is used to treat glass fibers during the formation of the glass fibers. The glass fibers so treated are then heated to drive off a predominant amount of the water in the aqueous sizing composition and the dried treated glass fibers are used for bonding or reinforcing polymers such as homo- or copolymers of polyolefins, polyamides and polyesters.

The most useful solid, water-insoluble, or limited water-soluble, organic peroxides in the aqueous sizing composition are those having the formula: (R-O-O-)x-R' where R is a tertiary alkyl or aralkyl or aryloyl or alkyloyl radical and x is a number 1 2, or 3, and R' is the same as R or of the structure:

where Rlv is a phenyl, alkylphenyl, alkyne or alkyl group having the structure: (CH2-CH2)n where n is 1,2 or 3; and where R" and R"' are either hydrogens, or individual hydrocarbon radicals or are alkylene radicals connected to form a cycloalkylene radical.Either hydrocarbon radical R" and R"' may be alkyl, cycloalkyl, aralkyl, or aryl hydrocarbon radicals, when Rlv is a phenyl group, and either R" or R"' hydrocarbon radicals are phenyl, aryl or larger than C7H15 radical when Rlv is the (CH2-CH2)n radical. The (R-O-O) can be attached at any position on the R' group, for example in bis or tris arrangement when R' is di or tri-alkyl benzene where the alkyl groups are located on any position such as ortho, meta and/or para or in 8,11 arrangement when R' is (CH2-CH2).

Non-exclusive examples of the solid, water-insoluble, organic peroxides are: 2,5 dihydroperoxy-2,5-dimethylhexane; 1,4 dihydroperoxy-1 4-dimethylbutane; 1,4 dihydroperoxy- 1 ,4-dimethyl-2-butyne; 1,3- and 1 ,4-bis(a-hydrnpernxyisoprnpyl)-benzene; bis( 1 - hydroxycyclohexyl)peroxide, 1-hydroperoxy-1'-hydrodicyclohexyl peroxide, dicumyl peroxide, 2,5-di (hydroperoxy)-2,5-dimethylhexyne, 2,5-di(hydroxperoxy)-2,5-dimethyl hexane and hydroperoxides having the structural formulas as follows: tert butyl-CMeEt-O-OH; HO-O-CMe2(CH2)4CME2 O--OH:HO-O-CMeEt-C=C-C=C-CMeEt-O-OH; HO-0-C[ < (CH2)5]-C-C-[ < (CH2)8]-- O--OH; HO-O-C[ < (CH2)5j-C-C-C-C-C[ < (CH2)5j-O-OH; 1,3- and 1 ,4(di-tert butylperoxyisopropyl)benzene, 8,11 bis-(tertiary butylperoxy)-8,1 1 dimethyl octadecane, and mixtures thereof, tribenzyl; tertiary butyl bis peroxide; di-tetradecone peroxide; di-hexadecane-peroxide; di tribenzyl methyl peroxide; dilauroyl peroxide; didecanoyl peroxide; dipelargonyl peroxide; dicaprylyl peroxide; diisononanoyl peroxide; dibenzoyl peroxides and nuclear substituted derivatives thereof; 2,5 dimethyl-2,5-di(benzoylperoxy)hexane; dimyristyl peroxydicarbonate; dicetyl peroxidicarbonate bis(4 tert butyl cyclohexyl peroxydicarbonate; 2,2 bis 4,4 ditert butyl peroxycyclohexyl propane 1 ,1 -ditert butylperoxy-4-tert butylclohexane; 2,5-bis-(tertiary amylperoxy)-2,5 dimethylhexane; 1,1 'ethylene bis[ 1 -(tertiary-amylperoxy)cyclohexane]' 2,5-bis (tertiary-butyl peroxy)-2,5-diphenylhexane; 2,6 bis(tertiary-butyl peroxy)-3,6-dimethyloctane; a,a,o",ct'-tetrnmethyl isophthalyl di-t-butyl bis peroxide; Q,n.a',a' tetramethyl isophthalyl dicumyl bis peroxide; and tris-(t-butyl peroxy)diisopropyl benzene.

An aqueous emulsion can be made with any of the aforedescribed solid, water-insoluble, or limited water-soluble, organic peroxides that are more dilutable, stable and safer and that has a fine particle size and minimum particle size distribution by using the hydrocarbon solvent and one or more emulsifiers and then emulsifying with water.

The particular hydrocarbon solvents, emulsifiers, and method of making the emulsion would be the same for any of the aforementioned solid, water-insoluble or limited water-soluble organic peroxides. The solid, water-insoluble or limited water-soluble organic peroxides for which the aqueous emulsion and method of making same is most useful are the peroxides having a melting point closer to the decomposition temperature of the peroxide than to ambient temperature. For these peroxides the temperature required for melting would cause a safety risk in two closely approaching the decomposition temperature. As a result, especially in production facilities with less than perfectly controlled and monitored equipment, violent decomposition reactions may occur.

The emulsion and method of making the emulsion is most useful for even the more heat stable organic peroxides, since even these peroxides may have melting points that approach the decomposition temperatures of the peroxide and could be used in a safer operation.

The more heat stable organic peroxides can be used as free radical initiators in the polymerization of vinyl and diene containing monomers or polymers. By "more heat stable organic peroxide" it is intended that those peroxides having a half-life exceeding 60 hours at 212 OF. (1 000C.) and 20 minutes at 300 F. (1490C.) be encompassed. The term half-life is a measure of reactivity of the organic peroxide and is defined as the time it takes for one half of a given quantity of peroxide to decompose at a particular temperature.Particularly useful more heat stable organic peroxides are like those with the formula as shown above, i.e., (R--OO-OO---),-R' and where R' is

Non-exclusive examples of these organic peroxides are solid dialkyl peroxides and diaralkyl peroxides such as the bis(tertiaryalkyl peroxy) alkanes in which R is a tertiary alkyl radical having 4 to 8 carbon atoms and either R" or R"' is a primary alkyl radical having 1 to 8 carbon atoms, while the other is a primary alkyl radical having greater than 3 carbon atoms. Additional non-exclusive examples are: 2,5-bis-(tertiary amylperoxy)-2,5-dimethyl-hexane, 1,1' ethylene bis 1 (tertiaryamyl peroxy)cyclohexane; 2,5-bis(tertiary-butyl peroxy)-2,5-diphenylhexane; 3,6-bis(tertiarybutylperoxy)-3,6 dimethyloctane.Non-exclusive examples of the diaralkyl peroxide that can be used are 1 ,3 and/or 1,4(ditertiary butyl peroxy) diisopropylbenzene; alpha, alpha, alpha', alpha'-tetramethylisophthalyl-di-t-butyl bis peroxide; alpha, alpha, alpha', alpha' tetramethyl-isophthalyl-di-cumyl-bisperoxide; and tris(t-butyl peroxy)diisopropyl benzene. Other dialkyl peroxides that can be used are, for example, 2,5(t-butyl peroxy) hexane and 2,5(t-butyl peroxy)hexyne and 8,1 1-bis(tertiary butylperoxy) 8,1 1-dimethyl octadecane. In addition to the tert-alkyl peroxy esters, also known as peresters, other peroxy esters that are more stable (i.e. have similar stabilities to the tert-alkyl peroxy esters) can also be used.Examples of these peroxy esters are tert-butyl peroxy acetate; tert-butyl peroxy benzoate; di-tertbutyl diperoxyphthalate; mono-tert-butyl permaleate; di-tert-butyl peroxy hexahydro terephthalate; ditert-butyl peroxy adipate; di-tert-butyl peroxy terephthalate; di-tert-butyl peroxy phthalate; and monotert-butyl peroxy phthalate. The amount of the solid peroxide used in the emulsion is that amount needed to incorporate into the sizing composition an amount of active peroxide in the range of about 0.1 to about 6.0 percent by weight. Generally the amount can range from about 1 to about 70 weight percent of the emulsion, and preferably has a lower limit of at least 10 weight percent for use in a sizing composition.

Acceptable fugitive hydrocarbon solvents for use in liquifying or solubilizing the solid organic peroxide, will, if predominantly aliphatic, have a low kauri-butanol value, for example from about 10 to about 60 and having boiling ranges which lie within the range of ambient temperature to about 2000C.

If the organic peroxide compound has more than about 60 percent aromaticity the acceptable hydrocarbon solvent will have a kauri-butanol value of from about 40 to about 100 with a boiling range which lies within the range of about 100 to about 250 C. The kauri-butanol number is a measure of solvent power of petroleum thinners where the value is the number of milliliters of solvent required to cause cloudiness when added to 20 grams of a solution of kauri gum in butyl alcohol. The solution is prepared in the proportion of 100 grams of kauri gum and 500 grams of butyl alcohol. Solvents of low aromatic content are strong precipitants for the resin and, therefore, give low values. Conversely, the solvents having a high aromaticity give high values.The kauri-butanol numbers are preferably determined against one of two standards where the one standard is a one degree toluene with a value of 105 used when the hydrocarbon solvent gives a kauri-butanol value of over 60 and the other standard is a mixture of 75 percent of n-heptane and 25 percent toluene when the hydrocarbon solvent has a kauri-butanol number of 40. This is discussed in ASTM Standard D .1133-54 T.

Examples of hydrocarbon solvents with low kauri-butanol numbers useful when the organic peroxide has a substantial amount of aliphatic components, or only a minor amount, if any, of aromatic components, are the isoparaffinic hydrocarbon solvents. Suitable examples are those of the series of commercially available isoparaffinic hydrocarbon solvents sold by Exxon Company, U.S.A. under the trademark "isobar", or Phillips Petroleum under the trademark "Soltrol", which have boiling ranges within the above ranges.

Examples of hydrocarbon solvents with high kauri-butanol values include the solvents commercially available under the tradenames Hl-SOL-1 0 or HI-SOL 1 5 available from Ashland Chemical Co., Ohio, where the Hl-SOL-1 0 has a boiling point of 3080F (1 53 OC) and a flash point of 1 050F (40.60C) and an evaporation rate of 25.0 using ether base of 1. Also, the hydrocarbon solvent sold by Exxon Co. USA division of Exxon Corp. Company under the name "Solvesso 150" or "Solvesso 100" can be used.

The ratio of organic peroxide to hydrocarbon solvent is at least a ratio of 1 to 0.75 when the hydrocarbon solvent has a kauri-butanol number of 70. If the solvent is a better solvent for the peroxide, like Hi-Sol-1 0 solvent that has a kauri-butanol number like 92-93 when the organic peroxide is alpha, alpha' bis(t-butyl peroxy)-diisopropyl benzene, the minimum amount of solvent that could be used would be less than that in the ratio above, such as 1 peroxide to around 0.4 and even as low as 0.19 solvent. If the solvent is a poorer solvent than the one having the kauri-butanol value of 70 when the organic peroxide is alpha, alpha' bis(t-butyl peroxy)diisopropyl benzene, then the minimum amount of solvent would be higher than the above ratio.The amount of the hydrocarbon solvent used in making up the emulsion of the solid organic peroxide will generally vary within the range of about 1 to about 70 and preferably about 10 to about 55 percent by weight of the emulsion. More solvent can always be added, but there is no benefit to such a practice, since the solvent is usually removed at some later time.

The non-ionic emulsifiers that are preferably selected from polyethoxy phenols, polyalkylene glycol ethers, alkyl polyether alcohols alkylaryl polyether alcohols, ethylene oxide alkylated phenol condensation products, and condensation products of ethylene oxide and propylene glycol having an HLB value in the range of about 9 to about 20 can be used singly or in a combination in the emulsion to give the desired HLB value. An example of an emulsifier used singly is the octyphenoxy polyethoxy ethanol available from Rohm 8 Haas Company, under the brandname or trade designation "Triton X100", which is nonionic and has a HLB of 13.5. The HLB as used herein refers to the hydrophilic/lipophilic balance.The types of emulsifiers such as the "Triton X-1 00" can be prepared from alkyl substituted phenols, where the alkyl group has 6 to 12 carbon atoms. The number of moles of ethylene oxide per mole of hydrophobe (alkyl phenol) can vary between 1.5 and about 30. The weight percent of combined ethylene oxide is usually from about 40 to about 95 percent to achieve good water solubility, more typically, about 60 to 95 percent. Another example of such an emulsifier is nonylphenoxy poly(ethyleneoxy) ethanol. It is not necessary that a single emulsifier be used to give the proper HLB. Any two or more surfactants having known HLBs can be combined using the proper proportions, and if the HLB is not known for a particular emulsifier it can be calculated from one of several known formulas. See the article by W. C.Griffin, entitled: "Calculation of HLB Nonionic Surfactant" in the December 1954 issue of the Journal of the Society of Cosmetic Chemistry. The emulsifier represents from about 1 to about 1 5 weight percent, more usually from about 3 to about 1 2 weight percent, of the emulsion. The exact amount of the emulsifier required can be ascertained easily by simple trial and error technique using the aforementioned ranges as a guideline. Once a stable emulsion is obtained, use of more emulsifiers is not necessary and would not give any further benefits and could prove detrimental in leading to increased migration of an aqueous treating solution containing the emulsion from a treated substrate like a package of fibrous material.

It is particularly useful to use a three emulsifier blend in the emulsion of the present invention.

The three emulsifiers are selected with proper weight ratios to give an overall HLB value in the range of about 9 to about 20 and preferably 9 to 15. One emulsifier is selected that has a high HLB value in the range of about 12 to about 20. A second emulsifier has a lower HLB value in the range of about 6 to about 12, and a third emulsifier has a HLB value in a middle range of about 9 to about 15. The three emulsifiers are used in amounts that give a total HLB in the range of about 9 to about 20. It is particularly useful to use the emulsifiers in equal proportions, although any proportion of the various emulsifiers can be used to give the desired HLB range.

In preparing the emulsion of the present invention, one or more of the desired peroxides is dissolved in the fugitive hydrocarbon solvent suitable for the particular organic peroxides involved. This mixture may be subjected to moderately elevated temperatures to facilitate solubilization of the organic peroxide. The mixture of peroxide dissolved in the hydrocarbon solvent has added to it the one or more emulsifiers, and this mixture is emulsified using standard techniques, conditions and apparatus.

When the emulsifier is the three components emulsifier blend the individual emulsifiers can be added separateiy to the mixture of peroxide and hydrocarbon solvent, or they can be added in a combination of all three, or any two can be added as a combination and then the third emulsifier added individually. After the emulsifiers are added, the resulting mixture is subjected to standard techniques, conditions and equipment of emulsification known to those skilled in the art. Such techniques include subjecting the mixture to high shear and diluting slowly with water, where the water can be at ambient temperature or at some elevated temperature. The water is added until the emulsion inverts to an oilin-water emulsion and then the emulsion is slowly cooled to ambient conditions by continued water addition.The amount of water added to the emulsion is at least about 35 percent, e.g. at least about 45 percent, of the emulsion composition. If the emulsion is to be shipped any considerable distance, the least amount of water is used so that there is inversion of most of the water-insoluble or limited water-soluble materials to an oil-in-water emulsion.

The emulsion composition is then formed into an aqueous sizing composition having a coupling agent, and usually a lubricant or softener, and optionally a film-former. This formation can involve slowly adding the emulsion to an aqueous mixture containing the coupling agent and any lubricant or softening agent and film-former and the remaining water to make the aqueous sizing composition.

Also, any lubricant or softening agent or film-former to be used in the sizing composition can be added after the emulsion is added to the aqueous mixture containing the coupling agent. The amount of the emulsion composition incorporated into the sizing composition depends on the amount of peroxide in the emulsion composition. Depending on this amount of peroxide, the amount of emulsion used in the sizing composition is that amount to give an amount of active organic peroxide in the sizing composition in the range of about 0.1 to about 6 percent by weight of the sizing composition. Once the emulsion of the present invention is prepared the aqueous sizing composition can be made in a manner similar to that as described in U.S. Patent 3,849,148 (Temple) which is hereby incorporated by reference.Generally, the amount of coupling agent, (e.g. organic-silane coupling agent, preferably a vinyl-containing silane) in the sizing composition is in the range of about 0.5 to about 10 percent by weight of the aqueous sizing composition. The amount of lubricant in the sizing composition, which may, for example, be a cationic active acid solubilizable fatty acid amide, is generally in the range of about 0.001 to about 1 percent by weight of the aqueous sizing composition. If a film-former is used, it is usually a polyvinyl acetate polymer or copolymer in an amount in the range of about 0.05 to about 1 2 weight percent of the size.

The aqueous sizing composition may be applied to individual glass fibers during their formation by any conventional method of applying sizing to glass fibers. Such methods are shown in U.S. Patent 3,849,148 (Temple) which has been incorporated by reference.

The sized glass fibers are dried to remove moisture and the fugitive hydrocarbon solvent, although some residual moisture and solvent may remain on the glass fibers. The dried sized glass fibers can be used in any form such as fibers, strands, wet or dry chopped strands, mats and the like for reinforcing polymers, like polyamides, polyesters, and particularly polyolefins. Glass fiber mats for reinforcing polyolefins are shown in U.S. Patent 3,849,148 which shows the production of glass fiber reinforced polyolefin laminates which has been incorporated by reference.

The emulsion of the present invention is preferably an emulsion of alpha, alpha' bis(t-butyl peroxy)-diisopropyi benzene including meta and para isomers which is commercially available from Hercules, Inc., under the trade designation "Vul-Cup R" vulcanizing agent and polymerization catalyst.

The solid peroxide is used in a ratio of peroxide to hydrocarbon solvent in amounts to facilitate solubilization of the peroxide, but preferably in a ratio of peroxide to solvent in the range of about 50/50 to about 70/30, and most preferably a ratio of around 60/40 peroxide solvent. The hydrocarbon solvent is preferably the solvent commercially available under the trade designation "HI-SOL 10", available from Ashland Chemical Company. The organic peroxide is dissolved in the Hl-SOL-1 0 where the amount of Hl-SOL-1 0 is in the range of about 10 to about 30 weight percent of the aqueous emulsion composition.

It is preferred to use the three emulsifier blend, in the preparation of the emulsion of the present invention. The first emulsifier is preferably a trimethyl nonyl polyethylene glycol ether, such as that commercially available from Union Carbide Corporation by the trade designation "Tergitol TMN-6" having an HLB of 11.7. This ether is preferably used in an amount of about 0.1 to about 5 weight percent of the emulsion. The ether emulsifier is combined with the second emulsifier which is preferably nonyl phenoxy polyethyleneoxy ethanol, commercially available from GAF Corporation Chemical Products, under the trade designation "Igepal CO-630" having an HLB of 1 3 and preferably used in an amount of about 0.1 to about 5 weight percent of the aqueous emulsion. These two emulsifying agents are combined and stirred until clear.The third emulsifying agent is preferably a condensate of propylene oxide with hydrophilic bases formed by condensing ethylene oxide with ethylene glycol and is commercially available from BASF Wyandotte Industrial Chemical Group, under the trade designation "Pluronic-P-65" which has a HLB of 17 and is preferably used in an amount in the range of about 0.1 to about 5 weight percent of the aqueous emulsion composition. The total amount of the three emulsifier blend in the aqueous emulsion composition is preferably in the range of about 1 to about 1 5 weight percent (preferably about 3 to about 1 2 weight percent) of the sizing composition. An amount in excess of 1 5 weight percent could be used but it would lead to migration of the size from the sized glass fibers.

It is preferred to add the emulsifier blend in the following manner. The glycol-oxide product emulsifier has the total amount to be added split into two portions. The first portion, preferably around one-half of the total amount, is added to the peroxide in the solvent along with the mixture of the ether emulsifying agent and the ethanol emulsifying agent that is added to the hydrocarbon peroxide solution. The remaining portion of the glycol-oxide product emulsifier is dissolved in water with agitation in around a 50 to 50 blend and is added to the other materials during the emulsification operation. This emulsification operation includes agitating the materials and adding an amount of warm water of about 25 to about 30"C. in the range of about 1 5 to 30 weight percent of the aqueous emulsion composition.An amount of cold water is added to give an amount of active peroxide in the range of about 35 to 65 weight percent and preferably around 50 weight percent of the aqueous emulsion.

The aqueous emulsion is preferably added to an aqueous composition containing a coupling agent, that is preferably vinyl tris(beta methoxy ethoxy) silane, present in an amount of about 0.5 to about 10 weight percent of the aqueous sizing composition. In an alternative embodiment a lubricant such as "Emerylube" 617 commercially available from Emery Industries is present in the sizing composition in an amount in the range of about .001 to about 3 weight percent of the aqueous sizing composition. In another alternative embodiment a film-former like a polyvinyl acetate copolymer is used in an amount of around 0.5 to about 12 weight percent of the aqueous sizing composition. The amount of water in the aqueous sizing composition ranges from about 70 to about 99 weight percent of the sizing composition.

The aqueous sizing composition may be applied to individual glass fibers during their formation according to the manner illustrated for example in U.S. Patent 3,849,148 (Temple) hereby incorporated by reference. The aqueous emulsion of the organic peroxide can be used for example in any of the sizing compositions described in U.S. Patent 3,849,148.

The aqueous emulsion of the present invention will be further elucidated by making reference to the following Examples.

Table I presents Examples showing components of the aqueouos emulsion in their gram weight amounts and weight percent amount.

Table I Samples-gram wt./(wt.%) Component 1 2 3 4 5 6 7 alpha, alpha' bis(t-butyl peroxy)-diisopropyl 315(22./7) 2363 2363 2363 1260(53.6) 630(26.1) 437(25) benzene "Vul Cup R" peroxide (42.7% solids) 242(17.4) 1814 1814 1814 242(10.3) 484(20) 198(10) hydrocarbon solvent - - - - - - Hi-Sol-10 solvent Solvesso 150 Solvent Ratio of Peroxide/solvent 1/.77 1/.77 1/.77 1/.77 1/0.19 1/.77 1/0.4 Nonionic Emulsifiers;; Trimethyl nonyl polyethylene glycol ether 25(1.8) 187.6 140.7 93.8 50(2.1) 50(2.1) 38(2.0) (Tergitol TMN-6) Nonyl phenoxy polyethyleneoxy ethanol (Igepal 25(1.8) 187.6 140.7 93.8 50(2.1) 50(2.1) 38(2.0) CO-630) propylene oxide-ethylene oxide condensate 25(.8) 187.6 140.7 93.8 50(2.1) 50(2.1) 38(2.0) (Pluronic-P-65) Octylphenoxypolyethoxyethanol (Triton-X-100) Water (Warm) 313(22.5) sufficient to - 700 626(26) 22.5(11.9) (Cold) 443(21.9) give a solids 2352 - 88.9(47) content of 50%#0.15% Table I (Continued) Samples-gram wt./(wt.%) Component 8 9 10 11 12 13 alpha, alpha' bis(t-butyl peroxy)-diisopropyl 945(27) 1890(31.3) 2363(37.9) 6300(37.7) 394(35) 4726(38.3) benzene "Vul Cup R" peroxide (42.7% solids) 726(20.8) 1050(17.4) 1818(29) 4848(29) 303(27) hydrocarbon solvent - - - - - 3635(29.5) Hi-Sol-10 solvent 1/0.8 1/0.55 1/.76 1/0.77 1/0.77 1/0.77 Solvesso 150 Solvent Ratio of peroxyde/solvent Nonionic Emulsifiers; 75(2.1) 150(2.5) - - 23.5(2.1) 282(2.3) Trimethyl nonyl polyethylene glycol ether (Tergitol TMN-6) 75(2.1) 150(2.5) - - 23.5(2.1) 282(2.3) Nonyl phenoxy polyethyleneoxy ethanol (Igepal CO-630) 75(2.1) 150(2.5) - - 23.5(2.1) 282(2.3) propylene oxide-ethylene oxide condensate (Pluronic-P-65) 370(5.9) 1008(6.0) 120(10.7) 1400(11.4) Octylphenoxypolyethoxyethanol (Triton-X-100) 470(13.4) 940(15.6) 1689(27) 4542(27.2) 243.5(21) 1718(13.9) Water (Warm) 1128(32.2) 1706(28.3) (Cold) In Table I, the emulsion preparation, number 5, was made by initially melting the organic peroxide using a hot water bath at a temperature of 140 to 1 500 F. (60 to 660C.). Afterwards, the hydrocarbon solvent was added with mixing. The ether and ethanol type emulsifiers were added next with continued mixing.This blend was subjected to a high speed Eppenbach mixer without heat in order to uniformly distribute the emulsifiers. One half of the total amount of the propylene oxide ethylene oxide condensate emulsifier was added and the blend was agitated for around 10 minutes. The other half of the propylene oxide ethylene oxide condensate emulsifier was combined with water and added to the blend with continuous agitation. This split addition avoids any possibility of any salting out of the emulsifier. Cold water was added to the Eppenbach to bring down the temperature to 11 00F. (43 OC.) or less. The blend was emulsified by adding cold water with high speed mixing. After around 10 to 30 minutes the speed of the high speed mixer was reduced and the emulsion was diluted to the desired concentration.

In the other emulsions and sizing compositions the organic peroxide was dissolved in the hydrocarbon solvent with a slight heating usually not above 1000F. (3780C.). Standard mixer was used for approximately 45 minutes and the final solution was usually clear. The ether type and ethanol type emulsifiers were added to this mixture and then the condensate type emulsifier was dissolved in hot water, and stirred about 30 minutes until cool. The hydrocarbon mixture of emulsifiers and organic peroxide was subjected to an Eppenbach mixer then the aqueous solution of the propylene oxideethylene oxide condensate type emulsifier was added to the mixture slowly until the inversion phase occurred. The inverted mixture was then diluted with cold water to the desired peroxide concentration.

Table II shows sizing compositions made with several of the emulsions of Table I.

The sizing compositions were prepared by placing approximately 2-1/2 gallons (9.5 liters) of cold water in a mix tank, and adding acetic acid with stirring. Slowly the silane was added to the main mix tank and stirred for around 30 minutes until near complete hydrolysis of the silane occurred. The lubricant, partially amidated, polyalkylene amine was dissolved in hot water and diluted with cold water until reaching a temperature 9f 1000F. (37.80C.) and then added to the main mix tank. The emulsion which was previoulsy prepared was then added to the main mix tank. The polyvinyl acetate film-former was added to cold water with agitation and added to the main mix tank. The volume of the sizing composition was then brought to 10 gallons (38 liters).

Table II Size from Emulsions in Table I Emulsions 1 5 6 7 10 11 12 13 Components gm/wt% gm/wt% gm/wt% gm/wt% gm/wt% gm/wt% gm/wt% gm/wt% Emulsion 278(7.3) 5560(7.4) 483(12.8) 378(10) 201.2(5.3) 416(5.5) 16,698(7.7) 224.4(5.9) Acetic Acid 4.2(.1) - 8.4(.2) 6.3(.2) 4.2(.1) 10.5(.1) 442(.2) 5.3(.1) Vinyl tris (2-methoxy ethoxy) silane [A-172 available from Union Carbide Corp.] 106.4(2.8) 2128(2.8) 212.8(5.6) 159.6(4.2) 106.4(2.8) 266(3.5) 10,632(3.5) Partially amidated polyalkyleneimine fiber lubricant [Emery 6717] 0.7(.02) 14(.02) 1.4(.04) 1.1(.03) 0.7(.02) 1.8(.02) 70.3(.03) 0.9(.02) Polyvinyl acetate Natrional Starch "Resyn 25-1031" 56(1.5) 1120(1.5) 112(3.0) 84(2.2) - 98(1.3) 3,920(1.8) 49(1.3) Water 3340(88.2) 66800(88.3) 2967(78.4) 3156(83.4) 3472.5(91.7) 6778(89.5) 184,708(85.3) 3372(89.1) pH 3.95 3.9 4.1 4.0#0.5 Solids 7.77% 3.1%% 4.39% 6.97 4.44% Table III shows physical characteristics for several emulsions of Table I and of the sizing compositions of Table II. These physical characteristics include the particle size of the emulsion and sizing composition along with the stability of the emulsion in sizing composition at various periods of time.

Table III Results for Emulsions and Size of Tables I et II 1 6 7 9 10 11 12 13 14 Particle Size (microns) Emulsion 1.59 1.25 0.97 0.99 - - Size 1.73 5.36 3.61 - - Stability Initial Emulsion good very good good excellent good - ok(L-LY) good(ovly) Size good good good - good - " " 24 hrs. shelf Stability Emulsion very good(vl) - - good ok(oly) M-M-Y good(o,l,y) Size - very good - - good " " " 48 hrs. shelf stability Emulsion - - - - good ok(oly) M-M-Y good(o,l,y) Size - - - - good " " " 72 hrs. shelf stabillity Emulsion good good(vl) ok(l) - - ok(oly) M-M-Y good(ovly) Size good light separation ok(l) - - ok " " redispersible 4 day Emulsion ok(oly) M-M-Y good(o,l,y) Size ok(oly) " " 7 day Emulsion ok oily appearance HHY good(o,l,y) Size - - - - ok few particles " where Y=Dispersible sedimentation or separation O=Zero, no separation H=Heavy sedimentation M=Moderate sedimentation L=Light sedimentation The foregoing has described an emulsion of a solid, water-insoluble or limited water-soluble organic peroxide in a hydrocarbon solvent along with one or more emulsifiers to produce an emulsion which can have a shelf stability of as long as three months and that is dilutable and safe that requires fewer precautions when prepared.The organic peroxide can be selected from various organic peroxides as discussed above and the hydrocarbon solvent varies somewhat with the type of organic peroxide.

For example, when the organic peroxide has a low amount of aromaticity, the hydrocarbon solvent will have a kauri-butanol number in the range of about 10 to about 60. If the organic peroxide has a substantial amount of aromaticity, the hydrocarbon solvent 'Nil I have a kauri-butanol number in the range of about 40 to about 1 00. One or more emulsifiers can be used for emulsification, but it is preferred to use the three component emulsifier blend wherein one emulsifier has a HLB in the range of about 12 to about 20 while the second emulsifier has a HLB in the range of about 6 to about 12, and the third emulsifier has a HLB in the middle range, a range of about 9 to about 1 5.

The sizing composition contains the above-described emulsion along with any of the conventional sizing composition components, such as coupling agents, fiSm-formers, lubricants, and the like.

The process of producing the emulsion involves solubilizing the organic peroxide in the hydrocarbon solvent and then producing the emulsion.

Sized glass fibers in any form such as chopped fibers, strands, chopped strands, roving, and woven glass fiber strands made from any type of glass but usually made from "E-glass" or "621-glass" or low boron and/or low fluorine modifications thereof can be used for polymer reinforcement. Such a polymer reinforced product is a polyolefin type product, namely polypropyiene, reinforced with glass fiber strands sized with a sizing composition containing the aforedescribed emulsion. Other polymeric reinforced products include other polyolefins, polyamides, e.g., nylon, thermosetting polyesters and the like.

Claims (31)

Claims

1. An oil-in-water emulsion with good stability and dilutability and with an average particle size of around 1.5 microns or less and good particle size distribution of at least one organic peroxide that is a solid at about 20"C and that has limited solubility or is insoluble in water, comprising a) about 1 to about 70 percent by weight of the solid organic peroxide with limited water solubility or water insoluble selected from the group consisting of hydroperoxides, a--oxy, and a-peroxy hydroperoxides, dialkyl peroxides, aldehyde and ketone peroxides, diacyl peroxides, peroxyesters, peroxy acids, peroxy dicarbonates, monopernxycarbonates and perketals;; b) about 1 to about 70 weight percent of at least one hydrocarbon solvent having a kauri butanol number from about 10 to about 60 when the organic peroxide is substantially aliphatic, or having a kauri butanol number of about 40 to about 100 when the organic peroxide has substantial aromaticity; c) about 1 to about 1 5 weight percent of an emulsifier system comprising:: i) one nonionic emulsifier having an HLE from about 12 to about 20, ii) one nonionic emulsifier having an HLB from about 6 to about 12, and iii) one nonionic emulsifier having an HLB from about 9 to about 1.5 wherein the nonionic emulsifiers are selected from the group consisting of polyalkylene glycol ethers, alkylaryl poiyether alochols, polyoxypropylene-polyoxyethylene condensates, and phenozypolyethoxyethanols ethoxylated alcohols, ethoxylated fatty acids, fatty esters and oils; fatty acids, glycol esters, monoglycerides and derivatives, sorbitan derivatives and sucrose esters and derivatives and wherein the emulsifiers selected from each HLB group are used in an amount to give an HLB for the system in the range of about 9 to about 20, and d) at least about 35 weight percent of water.

2. An oil-in-water emulsion as claimed in claim 1 wherein the solid organic peroxide is present in an amount of at least 10 weight per cent of the emulsion.

3. An oil-in-water emulsion as claimed in claim 1 or claim 2, wherein the hydrocarbon solvent is present in an amount of about 10 to about 55.

4. An oil-in-water emulsion as claimed in any of claims 1 to 3, wherein the emulsifier system is present in an amount of from about 3 to about 12 weight percent cf the emulsion.

5. An oil-in-water emulsion as claimed in any of claims 1 to 4 wherein the water is present in an amount of at least about 45 weight percent of the emulsion.

6. An oil-in-water emulsion as claimed in any of claims 1 to 5, wherein the three emulsifiers are present in equal amounts.

7. An oil-in-water emulsion as claimed in any of claims 1 to 6 wherein the organic peroxide has a half-life exceeding 60 hours at 21 20F (1 000C) and 20 minutes at 3000F (1 490C).

8. An oil-in-water emulsion as claimed in any of claims 1 to 7, wherein the organic peroxide is alpha, alpha' bis(t-butyl-peroxy)-diisopropyl benzene.

9. An oil-in-water emulsion as claimed in claim 8 wherein the hydrocarbon solvent has a kauributanol number of around 92 to 93.

1 0. An oil-in-water emulsion as claimed in claim 9, wherein the peroxide to solvent ratio is at least 11.4.

11. An aqueous emulsion with an average particle size of around 1.5 microns or less and with good stability of at least one organic peroxide that is a solid at about 200 C. and that has limited solubility or is insoluble in water and that has a half-life exceeding 60 hours at 212 OF (1 000C) and 20 minutes at 3000F (149 OC) comprising: a) about 1 to about 70 percent by weight of at least one organic peroxide having the formula: (R--OO--O-),R' where R is a tertiary alkyl, aryloyl or alkyloyl radical with or without a phenyl group attached to the tertiary carbon atom, where x is a number 1,2 or 3, where R' is the same as R or is an organic moiety having the formula::

where RIV is selected from phenyl, alkylphenyl, alkyne, or alkyl radicals having the formula (CH2CH2)n where n is 1,2 or 3; where R" and R"' are selected from hydrogens, (R--OO--O-), alkyl, cycloalkyl, aralkyl, or aryl hydrocarbon radicals, where RIV is a phenyl group either R" or R"' hydrocarbon radicals are radicals selected from phenyl, aryl or alkyl with more than seven carbon atoms;; b) about 10 to about 55 weight percent of at least one hydrocarbon solvent having a kauributanol number from about 10 to about 60 when the organic peroxide has R, R', R", R"' and RIV radicals having aliphatic radicals or a minor amount of aromaticity, or having a kauri-butanol number of about 40 to about 100 when the R, R', R", R"' and RlV have a substantial amount of aromaticity;; c) about 1 to about 1 5 weight percent of one or more emulsifiers selected from i) one or more polyalkylene glycol ethers, or ii) one or more alkylaryl polyether alcohols, or iii) one or more polyoxypropylene-polyoxyethylene condensates, or iv) one or more phenoxypolyethoxyethanols giving an HLB for the one or more emulsifiers in the range of about 9 to about 20, and d) at least about 35 weight percent of water.

12. An oil-in-water emulsion as claimed in claim 11 wherein the water is present in an amount of at least about 45 weight percent of the emulsion.

13. An oil-in-water emulsion substantially as hereinbefore described and with reference to the foregoing Examples.

1 4. A sizing composition for treating glass fibers, comprising an oil-in-water emulsion as claimed in any of the preceding claims, said oil-in-water emulsion being present in an amount sufficient to provide an amount of active peroxide in the range of about 0.1 to about 6 weight percent, about 0.5 to about 10 weight percent of d coupling agent, and about 70 to about 99 weight percent water.

1 5. A sizing composition as claimed in claim 14, which also comprises 0.001 to 1 weight percent of a lubricant.

1 6. A sizing composition as claimed in claim 15, wherein the lubricant is a cationic, acid solubilized fatty acid amide.

1 7. A sizing composition as claimed in any of claims 13 to 1 6 wherein the coupling agent is vinyl tris (beta methoxy ethoxy) silane.

1 8. A sizing composition as claimed in any of claims 12 to 17, which also comprises 0.5 to about 12 weight percent of a film-former.

19. A sizing composition as claimed in claim 1 8, wherein the film-former is a vinyl acetate copolymer.

20. A sizing composition substantially as hereinbefore described and with reference to the foregoing Examples.

21. Sized glass fibers having thereon the dried residue of a sizing composition as claimed in any of claims 14 to 20.

22. A polymer matrix reinforced with glass fibers as claimed in claim 21.

23. A polymer matrix as claimed in claim 22 wherein the polymer is polypropylene.

24. A method of preparing an oil-in-water emulsion as claimed in any of claims 1 to 13, which comprises solubilizing the solid organic peroxide in the hydrocarbon solvent, adding the emulsifier, and adding the water to emulsify the peroxide, solvent and emulsifier into an oil-in-water emulsion.

25. A method of preparing an oil-in-water emulsion of alpha, alpha' bis(t-butylperoxy)-diisopropyl benzene comprising: a) solubilizing the alpha, alpha' bis(t-butyl peroxy)-diisopropyl benzene in a hydrocarbon solvent having a kauri-butanol number in the range of about 70 to about 100 in a ratio of peroxide to solvent of at least about 1 to about 0.4; b) adding about 1 to about 15 weight percent of the emulsion of one or more emulsifiers selected from 1) one or more polyalkylene glycol ethers, or 2) one or more alkylaryl polyether alcohols, or 3) one or more polyoxypropylene-polyoxyethylene condensates, or 4) one or more phenoxypolyethoxyethanols or in any mixture thereof in ratios to given an HLB for the one or more emulsifiers in the range of about 9 to about 20; and c) adding water in an amount of at least about 35 weight percent of the emulsion to emulsify the peroxide, solvent and one or more emulsifiers into an oil-in-water emulsion.

26. A method as claimed in claim 25, wherein the one or more emulsifiers is a three emulsifier blend comprising: 0.1 to about 5 weight percent of the emulsion of trimethyl nonyl polyethylene glycol ether with an HLB of 11.7, 0.1 to about 5 weight percent of the emulsion of nonylphenoxypoly(ethyleneoxy)ethanol with an HLB of 13, and 0.1 to about 5 weight percent of the emulsion of condensates of ethylene oxide with hydrophobic bases formed by condensing propylene oxide with propylene glycol having an HLB of 17.0.

27. A method as claimed in claim 26 wherein the trimethyl nonylpolyethylene glycol ether and nonylphenoxypoly(ethyleneoxy)ethanol and first portion of the total amount of ethylene oxide condensate emulsifiers are added separately or together to the peroxide-solvent mixture and the remaining portion of the ethylene oxide condensate emulsifier is mixed in around a 50/50 mixture with water and added to the mixture.

28. A method as claimed in claim 26 wherein the hydrocarbon solvent has a kauri-butanol number of around 92 to 93.

29. A method of preparing an oil-in-water emulsion substantially as hereinbefore described with reference to the foregoing Examples.

30. An oil-in-water emulsion prepared by a method as claimed in claim 24.

31. An oil-in-water emulsion prepared by a method as claimed in any of claims 25 to 28.