JP3259005B2 - Dispersant, surface-treated fine particles and method of using dispersant - Google Patents

Description

The present invention relates to a dispersant, and more particularly, to an organic medium,
In a medium such as a polymer, a fine particle substance, for example, a filler, a reinforcing agent, a magnetic powder, an inorganic fine particle such as a pigment, or an organic fine particle or an organic fine particle such as a single fiber chop to uniformly disperse and prevent reaggregation. Of a dispersant.

 The invention also relates to the use of the dispersant.

[Conventional technology]

In various coating compositions such as paints and printing inks, particulate inorganic substances such as titanium oxide and zinc oxide are blended as pigments, and particulate organic substances are used as pigments and coating modifiers. Used. Inorganic substances such as calcium carbonate and silica are used as reinforcing agents and fillers in polymers such as rubber and plastics, and organic fine particles such as single fiber chops and granular polymers are compounded as reinforcing agents and surface treatment agents. ing.

As described above, the compounding of a particulate inorganic substance and organic fine particles into an organic medium and a polymer has been performed in a wide range of fields.

In any case, in order to obtain high performance, it is necessary to uniformly disperse the particulate inorganic substance or the organic fine particles in the organic medium or the polymer. Therefore, various dispersants and coupling agents have been proposed for the purpose of improving the dispersibility or the adhesion at the interface between the two.

Among them are, for example, silane coupling agents, titanium coupling agents, metal salts of fatty acids, and the like.
The use of these compounds improves the adhesiveness at the interface between the particulate matter and the polymer, but does not sufficiently improve the dispersibility, and also limits the types of applicable particulate matter. There is a problem that.

[Problems to be solved by the invention]

An object of the present invention is to provide a novel dispersant which can be applied to various kinds of fine inorganic substances and / or fine organic substances, and improves the dispersibility of the fine substances in a medium such as an organic medium or a polymer. It is in.

Another object of the present invention is to provide a particulate substance which has been treated with the above dispersant and has improved dispersibility in a medium such as an organic medium or a polymer.

Another object of the present invention is to provide a method for using the above dispersant.

The present inventors have conducted intensive studies to achieve the above object. As a result, a compound having a structure in which a specific heterocyclic structure is introduced into a molecule (in a molecular chain or at a terminal of a molecular chain) can be converted into an organic medium or various inorganic compounds into a polymer. They have been found to exhibit excellent action as dispersants for substances and organic fine particles.

In addition, it has been found that the compound suppresses an increase in the viscosity of a system to which inorganic and / or organic fine particles are added, so that processability, transportability, filling property, and the like are improved.

The present invention has been completed based on these findings.

[Means for solving the problem]

Thus, according to the present invention, a dispersant for dispersing a particulate material in a medium containing a polymer of a polymerizable monomer having a functional group selected from oxazolone groups, oxazinium ions and oxazolonium ions Is provided.

Further, according to the present invention, there is provided a particulate substance surface-treated with the dispersant.

Further, according to the present invention, there is provided a method for using a dispersant, which comprises mixing the particulate matter with the dispersant in a medium.

 Hereinafter, the configuration of the present invention will be described in detail.

(Dispersant) Polymer of oxazolone group-containing polymerizable monomer The dispersant of the present invention is a polymer having an oxazolone group [general formula (2)] in the molecule, and these groups are contained in the polymer.
It is preferably contained in an amount of about 0.01 to 10% by weight.

(Wherein, R _{1 to} R ₄ represent hydrogen or a substituent.) Polymer of Oxazinium Ion or Oxazolonium Ion-Containing Polymerizable Monomer The dispersant of the present invention has an oxazinium ion structure [general formula] (3)] or a polymer having an oxazolonium ionic structure [general formula (4)], and the ionic structure is preferably contained in the polymer in an amount of about 0.01 to 10% by weight.

(Wherein R _{1 to} R ₄ are hydrogen or a substituent, R ₅ is a substituent, and Z is an electrophilic group.) Method for producing dispersant The dispersant of the present invention having the above structure is (1) oxazolone A method of polymerizing a polymerizable monomer having a group, an oxazinium ion-containing group and an oxazolonium ion-containing group together with another polymerizable monomer as necessary, (2) an oxazine group represented by the general formula (1) or A method comprising treating a polymer having an oxazolone group represented by the general formula (2) with an alkylating agent or the like, and converting a nitrogen atom in the group into a quaternary ammonium to generate an oxazinium ion or an oxazolonium ion. is there.

Examples of the polymerizable monomer having an oxazine group include 2-vinyl-2-oxazine, 2-vinyl-4-methyl-2-
Oxazine, 2-vinyl-4-ethyl-2-oxazine, 2-isopropenyl-2-oxazine, 2-isopropenyl-4-methyl-2-oxazine, 2-isopropenyl-4-ethyl-2-oxazine, 2 -Isopropenyl-4,5-dimethyl-2-oxazine and the like.

Examples of the polymerizable monomer having an oxazolone group include 2-
Vinyl-5-oxazolone, 2-vinyl-4-methyl-
5-oxazolone, 2-vinyl-4-ethyl-5-oxazolone, 2-isopropenyl-5-oxazolone,
-Isopropenyl-4-methyl-5-oxazolone, 2
-Isopropenyl-4-ethyl-5-oxazolone, 2
-Isopropenyl-4,4-dimethyl-5-oxazolone and the like.

Examples of the polymerizable monomer having an oxazinium ion structure include N-methyl-2-vinyl-2-oxazinium salt,
N-methyl-2-isopropenyl-2-oxazinium salt, N-methyl-2-vinyl-4-methyl-2-oxazinium salt, N-methyl-2-isopropenyl-4-methyl-2-oxazinium salt and the like No.

Examples of the polymerizable monomer having an oxazolonium ion structure include the oxazolonium ion salts of the above-described polymerizable monomer having an oxazolone group.

The monomer used as required together with these monomers is not particularly limited as long as it can be copolymerized,
For example, styrene monomers such as styrene, p-methylstyrene and p-methoxystyrene; acrylic acid, methyl acrylate, butyl acrylate, stearyl acrylate,
Acrylic acid or methacrylic acid-based monomers such as methacrylic acid and methyl methacrylate; ethylene, propylene, vinyl chloride, vinyl acetate, acrylamide, acrylonitrile, N-vinylpyrrolidone, etc., and one or more of these are used. Used.

As the polymerization initiator used for the polymerization, oil-soluble peroxide-based or azo-based initiators that are generally used can be used. For example, peroxide initiators such as benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl hydroperoxide, 2,2'-azobisisobutyronitrile, 2,2 '-Azobis- (2,4-dimethylvaleronitrile), 2,2'-azobis-2,3,3-trimethylbutyronitrile, 1,1'-azobis- (cyclohexane-1-carbonitrile), 4, There are peroxide initiators such as 4'-3 azobis-4-cyanovalerate and dimethyl-2,2'-azobisisobutyrate. Further, a usual anion polymerization catalyst (for example, an organic lithium compound or the like) can also be used.

When a peroxide initiator is used as the polymerization solvent, acetonitrile, nitromethane, toluene, benzene, xylene, or the like is used.When an anion polymerization catalyst is used, a solvent which is generally inert to the catalyst is used. Is done. The polymerization is usually carried out at a temperature between -20C and 150C.

An N-alkylating agent such as an alkyl halide, methyl p-toluenesulfonate, or dimethyl sulfate is used to convert the oxazine group into an oxazinium ion and the oxazolone group into an oxazolonium ion. Although this ion is introduced into the polymer chain by this method, a functional group to which the ion has not been introduced may be partially contained.

(Particulate matter) The particulate matter targeted by the present invention is an inorganic or organic substance having a granular form, a flake form or a fibrous form. The particle size is not particularly limited, but is usually 0.1 mm or less,
Preferably it is 0.01 to 50 μm.

Specific examples of the inorganic fine particles include, for example, metals as inorganic reinforcing materials, clay, carbon black, calcium carbonate, barium sulfate, silica, mica, glass and asbestos; zinc, magnesium as reactive inorganic materials,
Metal compounds such as lead and aluminum. Titanium dioxide, iron oxide (including redwood), pigment carbon, zinc chromate, etc. as inorganic pigments; zinc oxide, magnesium oxide, antimony oxide, barium ferrite, strontium ferrite, strontium ferrite, beryllium oxide, pumice, hydroxide as inorganic filler Aluminum, magnesium hydroxide, basic magnesium carbonate, dolomite, dawsonite, calcium sulfate, talc, mica, glass balloon, shirasu balloon, glass powder, glass fiber, calcium silicate, montmoronite, bentonite, carbon fiber, barium titanate , Tin oxide, zinc borate, silicon carbide fiber,
And zirconium titanate.

Specific examples of the organic fine particles include low molecular weight organic compounds such as anthracene, pyrene, and ferrocene; oils such as pitch and petroleum and naphtha at normal or reduced pressure; asphaltenes; azo pigments, mordant dye lakes, and phthalocyanine pigments And organic pigments such as organic fluorescent pigments; fine particles such as benzoguanamine resin, methacrylic acid resin, silicone resin, polyamide resin, polyester resin, polyphenylene oxide and phenolic thermosetting resin; single fibers such as aramid fiber, polyester fiber and polyamide fiber And the like.

(Medium) The medium in the present invention is not particularly limited as long as the above-mentioned particulate matter does not dissolve or is hardly compatible, and includes a liquid or solid medium. Specific examples include water,
Various solvents such as tetrahydrofuran, acetonitrile, benzene, toluene, xylene, hexane, methyl ethyl ketone, acetone, ethyl acetate, and alcohol; known carnauba wax, montan wax, paraffin wax, microcrystalline wax, oxide wax, low molecular weight polyethylene wax, and low molecular weight Natural or synthetic waxes such as polypropylene wax; mineral base oils for various lubricating oils, α-olefin synthetic bases, etc .; aromatic, naphthenic, paraffinic process oils, light oils, hydraulic oils;
Plasticizers such as dioctyl phthalate and dibutyl phthalate; oligomers or high molecular weight polymers such as vinyl chloride resins, vinyl chloride resins such as vinyl chloride / vinylidene chloride copolymer; vinyl acetate polymers, ethylene / vinyl acetate Polymers, vinyl ester resins such as vinyl acetate / methyl methacrylate copolymer; (meth) acrylate (co) polymer, (meth) acrylate / acrylonitrile copolymer, (meth) acrylate・ (Meth) acrylic ester based resin such as styrene copolymer; styrene based resin such as polystyrene, ABS resin, AS resin, polyethylene, chlorinated polyethylene, polypropylene, polyisobutylene, polybutadiene, polyisoprene, and partially hydrogenated polybutadiene , Partial hydride of polyisoprene, etc. Olefin resins, polyethylene terephthalate, polycarbonate, polyamide, generic engineering plastics such as polyester, cellulose acetate,
Cellulose derivatives such as nitrocellulose; silicone resin; acrylic resin; alkyd resin, phenol resin,
Epoxy resin, unsaturated polyester resin, polyurethane resin; natural rubber, styrene-butadiene copolymer rubber,
Ethylene-propylene-diene copolymer rubber, styrene-butadiene di- and triblock copolymers, elastomers such as acrylonitrile-butadiene copolymers and their partially hydrides, but are not limited to these examples. Absent.

(Method of Using Dispersant) The amount of the dispersant containing the oxazolone group, oxazinium ion-containing group or polymer having an oxazolonium ion-containing group of the present invention is determined by the amount of inorganic and / or organic fine particles (hereinafter referred to as “ Dispersion ") varies depending on the type of medium in which the dispersant is dispersed, the content of the oxazolone group in the dispersant, the content of the oxazinium ion-containing group or the oxazolonium ion-containing group, and is usually at least per 100 parts by weight of the dispersion. It is 0.05 parts by weight, preferably 0.5 to 100 parts by weight, and more preferably 3 to 50 parts by weight.

As a method of using the dispersant, for example, the following methods are available.

A method in which a dispersant is added to a medium in advance, and then a substance to be dispersed is added.

 A method in which a dispersant is added to a medium together with a substance to be dispersed.

After adding the material to be dispersed to the medium, the dispersant is added,
Method of mixing and stirring.

A method of stirring and mixing under a temperature condition of 50 to 300 ° C., and adding a substance to be dispersed which has been surface-treated with a dispersant in advance to a medium.

In the case of using an object to be dispersed which has been previously surface-treated with the dispersant of the present invention, in order to achieve the object of the present invention, the amount of the surface treatment (adhesion amount) of the dispersant to the object to be dispersed, the amount of the dispersant Is at least 1% by weight, preferably 3% by weight or more, although there is a difference depending on the molecular weight of the compound and the content of the functional group.

The surface treatment method of the dispersant with the dispersant is not particularly limited, but a method of dissolving the dispersant in an inert organic solvent and immersing the dispersant in this solution, a dispersant solution or an inert solution such as water. A method of applying a suspension using a medium to an object to be dispersed, a method of dry blending, and the like can be given.

In order to produce a dispersion in which the dispersant is uniformly dispersed in the polymer using the dispersant of the present invention and the surface-treated dispersion, it is necessary to sufficiently mix the polymer and the dispersion. It is. Preferred mixing conditions depend on the type of polymer, whether it is thermoplastic or thermoset, its chemical structure, and the like.

Further, the dispersant and the material to be dispersed, using a conventional type of kneading machine, for example, Henschel mixer, Hobart mixer, Banbury mixer, double concentric screw, etc., after the surface treatment of the material to be dispersed, and the polymer You may mix.

Processing of the polymer, for example, high shear mixing, is generally performed at a temperature well above the second order transition temperature of the polymer, preferably at a temperature at which the polymer has a low melt viscosity. For example, low-density polyethylene has a temperature range of 170-230 ° C, high-density polystyrene has a temperature of 200-250 ° C, polystyrene has a temperature of 230-260 ° C, polypropylene has a temperature of 230-270 ° C, and epoxy resin has a temperature of 120-1 ° C.
At 50 ° C, nylon 6 is 244-292 ° C, ABS resin (impact-medium) is 244-292 ° C, polycarbonate is 267-292 ° C.
~ 361 ° C, and polybutylene terephthalate at 260 ° C
Is best processed. As for the temperature conditions for mixing the other polymer and the material to be dispersed, a mixing device of a type well known to those skilled in the art is used, for example, a two-roll mill,
You may mix with a Waring blender.

(Effect of the Invention) The dispersant of the present invention has a function of facilitating uniform dispersion of various inorganic and / or organic fine particles (substance to be dispersed) in a medium and a function of stabilizing dispersion to prevent reaggregation.

Further, since the increase in the viscosity of the system to which the substance to be dispersed is added is suppressed, the processability and transportability of the mixture or the filling property of the substance to be dispersed are improved.

The dispersant of the present invention includes, for example, bonded magnets, magnetic recording media (toner for electrostatic image development, disks, tapes), magnetic materials such as magnetic fluids; paints and molded articles for EMI; thermal transfer inks and conductive inks Ink; conductive and electrostatic composite materials;
Flame-retardant materials such as electric wires and building materials; anti-reflective materials (backlight materials), anti-reflective materials for laminated heat sinks, FRP and FRTP materials; dispersion and stabilizing agents for pigments, dyes and catalysts; dispersion with lubricating oil and heavy oil It is suitable for use as an agent (sludge dispersant or detergent dispersant).

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples, Synthesis Examples, and Comparative Examples, but the present invention is not limited to these Examples.

In Examples, Comparative Examples and Reference Examples, parts and% are
Unless otherwise stated, it is based on weight.

Synthesis Example 1 3 parts of vinyloxazine and styrene were placed in a flask equipped with a stirrer, a nitrogen gas inlet tube, a reflux condenser, and a thermometer.
250 parts of toluene in which 97 parts were dissolved were charged. Further, 10 parts of benzoyl peroxide was added. The mixture was heated to 80 to 100 ° C. while blowing nitrogen gas, and was polymerized for 5 hours with stirring in this state. After returning to room temperature and removing the solvent by evaporation, the mixture was poured into 500 parts of methanol, coagulated, and dried to obtain a polymer having an oxazine group as a functional group. This polymer was used as dispersant A.

Synthesis Example 2 The polymerizable monomer used in Synthesis Example 1 was styrene 98
And a polymer having an oxazolone group as a functional group was obtained by repeating the same method as in Synthesis Example 1 except that the parts were changed to 2 parts of isopropenyloxazolone. This polymer was used as dispersant B.

Synthesis Example 3 In Synthesis Example 1, the polymerizable monomer used was styrene 70
, A polymer having an oxazinium ion structure as a functional group was obtained by repeating the same method as in Synthesis 1 except that the amount was 25 parts, stearyl methacrylate 25 parts, and N-methylisopropenyl oxazinium tosylate 5 parts. This polymer was used as Dispersant C.

Synthesis Example 4 Styrene-vinyl oxazine copolymer obtained in Synthesis Example 1
Dissolve 100 parts of 300 parts of benzene, 5 parts of methyl chloride,
One part of sodium iodide was added and reacted under reflux for 12 hours. The obtained reaction solution was poured into 1000 parts of methanol, reprecipitated, and then dried. A part of the obtained polymer is dissolved in chloroform, and an ultraviolet / visible multi-wavelength spectral detector (manufactured by JASCO Corporation)
The UV-visible spectrum of the polymer component was measured by GPC to which MULTI-330) was connected, and an absorption attributable to oxazinium having a UVmax of 310 nm was obtained. It was confirmed that the obtained polymer contained an oxazinium ion structure. This polymer was used as Dispersant D.

Example 1 This example shows the effect of the dispersant of the present invention to suppress the aggregation of various inorganic and organic fine particles dispersed in toluene.

The experiment uses the ratio of the average particle size (median diameter D50: particle size to 50% of the cumulative distribution of particle size) when dispersed under ultrasonic operation and the average particle size 10 minutes after ultrasonic cessation. The dispersing effect of the compound was measured. The average particle size was measured using a laser diffraction particle sizer (SK LASER MIC manufactured by Seishin Enterprise Co., Ltd.).
RON SIZER PRO-7000S).

 The conditions for measuring the particle size are as follows.

Amount of inorganic and organic fine particles 50 to 100 mg Toluene amount 300 ml Ratio of particle size 0 minute and 10 minutes after stopping the ultrasonic wave [D50 (10) / D5
0 (0)] was defined as the degree of aggregation. Table 1 shows the measurement results for various particles. The amount of the dispersant added was indicated by the weight fraction of the fine particles.

The results in Table 1 clearly show that the dispersant of the present invention prevents aggregation of inorganic and organic fine particles and has a dispersion stabilizing effect.

Example 2 The viscosity when calcium carbonate (NS # 100 manufactured by Nitto Powder Chemical Co., Ltd.) was dispersed in a liquid epoxy resin (Epimart 828 manufactured by Ciel Chemical Co., Ltd.) was measured with a B-type viscometer. The results are shown in Table 2.

Addition of the dispersant reduced the viscosity of the calcium carbonate dispersion in the liquid epoxy resin from about 50% to 60%.

Example 3 100 mg of various inorganic fine particles and 20 ml of benzene were put into a test tube with a stopper, and a predetermined amount of a benzene solution of the dispersant was added. After the test tube was vigorously shaken for 1 minute, the sedimentation state of the fine particles in a state where the test tube was allowed to stand was observed.

◎ Does not settle for 1000 minutes ○ Does not settle for 300 minutes × Settles in 3 minutes This experiment shows that the dispersant has an effect of preventing aggregation and sedimentation of the inorganic fine particles.

Claims (3)

(57) [Claims] 1. A polymer obtained by polymerizing a polymerizable monomer having a functional group selected from the group consisting of an oxazolone group, an oxazinium ion-containing group and an oxazolonium ion-containing group. A dispersant for dispersing the particulate matter in a liquid or solid medium. 2. The dispersant according to claim 1, wherein said polymer is a copolymer of said monomer and a monomer copolymerizable therewith. 3. A method for using a dispersant, comprising mixing a particulate substance in a liquid or solid medium in the presence of the dispersant according to claim 1 or 2.