NO158680B - ORGANIC ALFA, OMEGA ALKYLENTITANATE FOR USE IN TREATMENT OF FINE CORN INORGANIC MATERIAL. - Google Patents

Description

The present invention relates to a new and improved class of organic titanate compounds. More particularly, the invention relates to organic titanate chelates which are particularly useful for the treatment of fine-grained inorganic substances.

Inorganic substances have for a long time been used as fillers, pigments, reinforcements and chemical reactants in polymers. They are essentially hydrophilic, that is, easily wetted by water and able to absorb water. However, their compatibility with polymers is limited. Therefore, they have been poorly utilized as potential enhancers, dyes or opacifiers, or with a view to the chemical reactivity of the organic material.

It has been proposed to use surfactants to facilitate the incorporation of these inorganic substances into polymers. However, the known materials have had many shortcomings such as poor stability in the presence of free water and limited ability to completely disperse large amounts of filler materials in the polymeric material.

The present invention provides opportunities for obtaining a reinforced polymer which has a lower melt viscosity, improved physical properties and better pigmentation properties than what is described in the known technique.

In order to overcome the above-mentioned shortcomings, the present invention relates to an organic a, a> alkylene titanate for use in the treatment of fine-grained inorganic material used as fillers, pigments, reinforcements or chemical reactants in polymers, and these titanates are characterized by the formula:

wherein A means a non-hydrolyzable aroxy-, thioaroxy-, -OCOR'-, -OS02R"-, -OSOR"-, (R"0)2P(0)OP(OH) (0 ) - or (R"0 )2P(0)0 group, B is an R2C group or a carbonyl group; provided that when B is CH2, A does not include OCOR"; R is hydrogen or an alkyl group having from 1-6 carbon atoms; R' and R" are hydrogen or an alkyl, alkenyl, aryl, aralkyl or alkaryl group, or a alkyl, alkenyl, aryl, aralkyl, alkaryl, halogen, amino, epoxy, ether, thioether, ester, cyano, carbonyl or aromatic nitro-substituted derivative thereof; and n is 1 or 2.

The aroxy group can be a substituted or unsubstituted phenoxy or naphthyloxy group containing up to 60 carbon atoms. It may be substituted with alkyl, alkenyl, aryl, aralkyl, alkaryl, halogen, amino, epoxy, ether, thioether, ester, cyano, carbonyl or aromatic nitrogen groups.

Preferably, no more than 3 substituents are present per aromatic ring.

The thioaroxy groups are essentially the same as the above-mentioned aroxy groups except that the phenolic oxygen is replaced by sulphur. Of aroxy and thioaroxy groups, phenoxy and naphthoxy are preferred.

By non-hydrolysable is meant a group that does not split in neutral aqueous solution at a temperature below 100°C. Hydrolysis can be determined by analysis of liberated acid or alcohol.

In this connection, reference should be made to the divided application 820 741 which concerns a material mixture containing an organic a, w-alkylene titanate as described here.

Examples of specific R' ligands are: methyl, propyl, cyclopropyl, cyclohexyl, tetraethyloctadecyl, 2,4-dichlorobenzyl, 1-(3-bromo-4-nitro-7-acetylnaphthyl)-ethyl, 2-cyanofuryl, 3 -thiomethyl-2-ethoxy-1-propyl and methallyl.

Examples of A-ligands that can be used are 11-thiopropyl-12-phenyloctadecylsulfonyl, 2-nitrophenylsulfinyl, di(2-co-chlorooctyl)-phenylphosphate, diisonicotinyl pyrophosphate, 2-nitro-3-iodo-4-fluorothiophenoxy, 2- metallylphenoxy, phenylsulfinyl, 4-amino-2-bromo-7-naphthylsulfonyl, diphenylpyrophosphate, diethylhexylpyrophosphate, di-sec-hexylphenylphosphate, dilaurylphosphate, methylsulfonyl, laurylsulfonyl and 3-methoxynaphthalenesulfinyl. Examples of aryloxy groups are 2,4-dinitro-6-oxyl-7-(2-bromo-3-ethoxyphenyl)-1-naphthoyl and 3-cyano-4-methoxy-6-benzoylphenoxy.

Examples of the R' groups are numerous. These groups include straight chain, branched chain and cyclic alkyl groups such as hexyl, heptyl, octyl, decyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl, nonadecyl, eicosyl, docosyl, tetracosyl, cyclohexyl, cycloheptyl and cyclooctyl. Alkenyl groups include hexenyl, octenyl and dodecenyl.

Halogen-substituted groups include bromohexyl, chlorooctadecyl, iodotetradecyl and chlorooctahexenyl. One or more halogen atoms may be present such as e.g. in difluorohexyl or tetrabromooctyl. Ester substituted aryl and alkyl groups include 4-carboxyethyl capryl and 3-carboxymethyltoluyl. Amino substituted groups include aminocaproyl, aminostearyl, aminohexyl, aminolauryl and diaminooctyl.

In addition to the preceding aliphatic groups, groups containing heteroatoms such as oxygen, sulfur or nitrogen in the chain can also be used. Examples of such residues are ethers of the alkoxyaryl type, including methoxyhexyl and ethoxydecyl. Alkylthioalkyl groups include methylthiodecyl groups. Primary, secondary and tertiary amines can also serve as the end part of the hydrophobic group. These include diisopropylamino, methylaminohexyl and aminodecyl.

Aryl groups include phenyl and naphthyl groups and substituted derivatives. Substituted alkyl derivatives include tolyl, xylyl, pseudocumyl, mesityl, isodurenyl, durenyl, pentamethyl-phenyl, ethylphenyl, n-propylphenyl, cumyl, 1,3,5-triethylphenyl, styryl, allylphenyl, diphenylmethyl, triphenylmethyl, tetraphenylmethyl, 1,3 ,5-triphenylphenyl. Nitro- and halogen-substituted groups can be exemplified by chloronitrophenyl, chlorodinitrophenyl, dinitrotoluene and trinitroxylyl.

Amine substituted components include methylaminotoluene, trimethylaminophenyl, diethylaminophenyl, aminomethylphenyl, diaminophenyl, ethoxyaminophenyl, chloroaminophenyl, bromoaminophenyl and phenylaminophenyl. Halogen-substituted aryl groups include fluoro, chloro, bromo, iodophenyl, chlorotoluyl, bromotoluene, methoxybromophenyl, dimethylaminobromophenyl, trichlorophenyl, bromochlorophenyl and bromoiodophenyl.

Groups derived from aromatic carboxylic acids are also useful. These include methylcarboxylphenyl, dimethylaminocarboxyltouyl, laurylcarboxyltoluyl, nitrocarboxyltoluyl and aminocarboxylphenyl. Groups derived from substituted alkyl esters and amides of benzoic acid can also be used. These include aminocarboxyphenyl and methoxycarboxyphenyl.

Titanates where R' is an epoxy group include tall oil epoxies (a mixture of alkyl groups with 6-22 carbon atoms) containing on average one epoxy group per molecule and glycidoethers of lauryl and stearyl alcohol.

Substituted naphthyl groups include nitronaphthyl, chloronaphthyl, aminonaphthyl and carboxynaphthyl groups. The organotitanium chelates according to the invention can be prepared by reacting esters with the formula (OR)2Ti(A)2 with an equimolar amount of 2-hydroxypropionic acid or hydroxyacetic acid or their carbon-substituted derivatives. When oxoderivatives (B - R2C) are used, the titanium ester is reacted with a 1,2- or 1,3-glycol such as ethylene glycol or 1,3-butanediol.

(OR ^Ti (A ^ compounds can be readily prepared as disclosed in US-PS 3,660,134, 3,697,494 and 3,697,495.

The inorganic materials can be particulate or fibrous and of varying shape and size as long as the surfaces are reactive with the hydrolyzable groups in the organo-titanium compound. Examples of inorganic reinforcing substances are metals, clay, carbon black, calcium carbonate, barium sulphate, silicon dioxide, mica, glass and asbestos. Reactive inorganic substances include metal oxides of zinc, magnesium and lead as well as calcium and aluminium, iron filings etc., as well as sulphur. Examples of inorganic pigments include titanium dioxide, iron oxides, zinc chromate and ultramarine blue. For practical reasons, the particle size of the inorganic substances should not be more than 1 mm, preferably from 0.1 pm to 500 pm.

It is important that the titanate is thoroughly mixed with the inorganic material to allow the surface of the latter to react sufficiently. The optimum amount of alkoxy titanate used depends on the desired effect, the available surface area and the amount of bound water in the inorganic material.

The reaction is facilitated by mixing under suitable conditions. Optimum results depend on the properties of the alkoxy titanate, namely whether it is a liquid or solid, as well as the decomposition point and flash point. The particle size, the geometry of the particles, the specific weight, the chemical composition and other things must also be taken into account. In addition, the treated inorganic material must be thoroughly mixed with the polymer medium. The suitable mixing conditions depend on the type of polymer, whether it is thermoplastic or thermosetting, the chemical structure, etc., as will be obvious to those skilled in the art.

Once the inorganic material is permeated with organic titanate, it can be mixed in any suitable type of intensive mixer such as Henschel or Hobart type mixers, or in a Waring mixer. Hand mixing can also be used. Optimum time and temperature are determined to achieve significant reaction between the inorganic material and the organic titanate. The mixture is carried out under conditions in which the organic titanate is present in liquid phase at temperatures below the decomposition temperature. While it is desirable that the main mass of the hydrolyzable groups is reacted in this step, this is not essential when the materials are later to be mixed with a polymer because the substantial completion of the reaction can occur in this later mixing step.

Polymer processing, i.e. mixing under high shear, is generally carried out at a temperature well above the polymer's second-order transformation cycle, preferably at a temperature where the polymer has a low melt viscosity. For example, low density polyethylene is preferably processed at a temperature range of 170-230"C; high density polyethylene from 200-245"C; polystyrene from 230-260°C; and polypropylene from 230-290°C.

Temperatures for mixing other polymers are known to those skilled in the art and can be determined by reference to the existing literature. A wide range of mixing equipment can be used, e.g. twin roll mills, Banbury mixers, double concentric screws, counter or co-rotating twin screws and ZSK types of Werner, Pfaulder and Busse mixers. When the organic titanate and the inorganic substances are dry-mixed, a thorough mixing and/or reaction is not easily achieved, and the reaction is brought to completion when the treated filler is mixed with the polymer. In this latter step, the organic titanate can also react with the polymer material if one or more of the R' groups are reactive with the polymer.

The treated fillers can be incorporated into any of the conventional polymaterials, regardless of whether this is thermoplastic or thermosetting, rubber or plastic. They are described in detail in the three US patents cited above. The amount of filler depends on the particular polymer material, filler and the property requirements for the finished product. In general, from 10-500 parts of filler can be used per 100 parts of polymer, preferably from 20-250 parts. The optimum amount can be easily determined by the person skilled in the art.

While the compounds according to the invention can be used with any of the above-mentioned fillers, it is particularly surprising that they remain extremely active even in the presence of large amounts of free water. For this reason, they can be used together with wet-process silicon dioxide, soft or hard clays, talc, aluminum silicate, hydrated aluminum oxide and fiberglass. While it is not fully understood how the chelate compounds retain their activity, they are clearly superior to other titanates, such as e.g. described in the above cited US patents, in the presence of moisture.

The following examples are typical for the preparation of compounds according to the invention.

Example A

Preparation of di(dioctyl phosphate lettyl titanate.

1.0 ml of tetraisopropyl titanate is added to a 1 liter reactor of the type described above. The unit is set to reflux at atmospheric pressure. 1.0 ml of ethylene glycol is then added, followed by 2.0 mol of dioctyl hydrogen phosphate, both parts within half an hour. Limited heat development is noted upon addition of each reagent. After the addition is complete, the reaction mixture is refluxed for 1 hour at atmospheric pressure. The reaction mixture is then cooled to below 50°C and the by-product isopropanol is removed by distillation under reduced pressure to a sump temperature of about 150°C at 10 mm Hg. The volatilized isopropanol is recovered via capture in a receiver, cooled with liquid nitrogen. Recovery of isopropanol is approximately 3.7 ml, i.e. 9056 of the theoretical. A paste-like white product is obtained as a residue in an amount of more than 90% of the theoretical. Purification is carried out by recrystallization from ligroin and white crystals with a melting point are obtained 41-43°C.

Example B.

By following the general procedure indicated above, further compounds were prepared which are within the scope of the invention. The following table describes the particular compound with reference to the chelating ligand and the monovalent ligands A and A' and indicates the physical description, melting point and viscosity of the product. To show the usability of the compounds according to the invention, the following examples are given.

Example I

This example demonstrates the importance of the chelate structure for viscosity control for wet silica in organic dispersions. A dlspersion was made by mixing 20 parts of a 0.8 µm wet process silica in a solution of 0.2 parts titanate in 80 parts heavy mineral oil (flash point about 105°C) in a Waring mixer.

The first three known titanates listed in the table,

while causing a significant viscosity reduction compared to the control, were nevertheless significantly inferior to the three acetyl compounds at the end of the table. It is believed that this is because the compounds according to the invention retain their activity in the presence of the moisture in the silicon dioxide present.

Example II

The effect of selected titanates on the tensile strength of polypropylene filled with 3 pm water-washed clay and talc in a system using 50 wt-* filler and 0.5 wt-* titanate is shown in the following table:

This example shows the increase of the tensile strength in both talc- and clay-filled polypropylene with two of the compounds according to the invention.

Example III

The effect of selected titanates on the "Dart Impact" strength of nylon 6 filled with 50 wt-* water-washed 3 pm clay. The filler was pre-treated with 2 wt* titanate before incorporation into the polymer matrix.

In each case, the treated material had an improved flexural strength and a marked improvement in impact strength.

Example IV

The effect of selected titanates according to the invention on the properties of polyurethane filled with 0.8 pm wet process silicon dioxide. The formulation contained 20 wt-* filler pre-treated with 2.0 wt-* titanate before incorporation.

All the treated compounds showed improved tensile strength compared to the control. The phosphate derivative also showed improved elongation. The structure of the non-hydrolyzable A group has been shown to be important in determining property improvements.

The chemical structure of the foregoing compounds was primarily determined by a consideration of the reactants and the by-products formed. In selected cases, elemental analysis, IR analysis and analysis with a view to free hydroxyl groups were carried out. These verified the postulated chemical structures.

Example V

This example shows the effect of titanium chelates on unfilled epoxy. Two epoxy curing compounds were prepared containing 80 parts "Epon 828" and 20 parts of an aliphatic amine curing agent, "Celanese 874". Two parts of 2-acetyldi(dodecylbenzenesulfonyl)titanate were added to one of these newly prepared samples. Both mixtures were stirred for 2 min. and the viscosity measured on a Brookfield viscometer. The results obtained are shown in the table.

These given data show that the last composition has a significantly higher viscosity than the second sample.

Example VI

This example shows the use of an ethylene di(dioctyl phosphate) titanate to increase the coloring effect of pigments in a water-based acrylic paint. The paint used was a commercial "SRW30X White" and the pigment paste dispersion

("Tint-Ayd No. WD-2228, Aqueous Tinting Color, Phtalo Blue")

contained 32* pigments and 39* total solids. Ethylene di-(dioctyl phosphate) titanate was first mixed with the pigment to form mixtures containing 0.3, 0.6, 0.9, 1.2 and 1.5* titanate, based on the weight of the paste dispersion. To 100 parts of paint was added 0.2 parts of each of the treated paste dispersions. Observation showed that compared to the control, even at the 0.3* level, increased dispersion and flow were achieved. While increased staining results were obtained in all cases, the increase in blue color was optimal with the 0.9* sample.

Claims (1)

Organic a, u alkylene titanate for use in the treatment of fine-grained inorganic material used as fillers, pigments, reinforcements or chemical reactants in polymers, characterized by the formula: wherein A means a non-hydrolyzable aroxy-, thioaroxy-, -OCOR'-, -OS02R"-, -OSOR<»->, (R"0)2P(0)0P(0H)(0) - or (R "0)2P(0)0 group, B is an R2C group or a carbonyl group; provided that when B is CH2, A does not include 0C0R"; R is hydrogen or an alkyl group with from 1 to 6 carbon atoms; R<* >and R" are hydrogen or an alkyl, alkenyl, aryl, aralkyl or alkaryl group, or an alkyl, alkenyl, aryl, aralkyl, alkaryl, halogen, amino, epoxy , ether, thioether, ester, cyano, carbonyl or aromatic nitro substituted derivative thereof; and n is 1 or 2.