KR20020044426A - Thermoplastic Composition and Method of Preparing the same - Google Patents

Abstract

PURPOSE: Provided are a thermoplastic composite material containing uniformly dispersed clay mineral particles of nano size into a resin, and which has excellent mechanical property without lowering impact resistance, and a method for producing the composite material. CONSTITUTION: The thermoplastic consists of (a) 100 parts by weight of polymer or mixture thereof produced with vinyl-based monomer or vinyl-based monomer capable of radical polymerization, and (b) 0.01-50 parts by weight of surface-modified clay minerals containing azoic or peroxide group. The alkylammonium-based initiator is selected from the group consisting of 2,2-azobis(isobutyramidine hydrochloride), 1-trimethyl ammonium-6-t-butyldioxyhexane bromide, 4-methoxycarbonyl benzyltriethyl ammonium chloride, 4-carboxybenzyl triethylammonium chloride, 4-t-butyldioxy carbonyl benzyltriethylammonium chloride, 5-ethoxycarbonyl pentyltriethylammonium bromide, 5-t-butyldioxy carbonyl pentyltriethylammonium chloride, and a mixture of 1 or 2 or more thereof.

Description

Thermoplastic Composition and Method of Preparing the same

Field of invention

The present invention relates to a thermoplastic composite having excellent mechanical strength and heat resistance. More specifically, the present invention provides a clay mineral particle in the resin through a polymerization reaction proceeding from the clay mineral surface or inside by using a plate-like clay mineral surface-treated with alkylammonium ions containing azo or peroxide groups for the polymerization of the thermoplastic resin. The present invention relates to a thermoplastic composite having excellent mechanical properties and thermal stability by uniformly dispersing it uniformly in nano size and a method of manufacturing the same.

Background of the Invention

In general, inorganic additives such as glass fiber, talc, mica and the like are used as methods for improving mechanical strength and heat resistance of thermoplastic resins. However, the resins reinforced by the technique of simply blending the inorganic additives in the resin still have many disadvantages. That is, since the bond strength between the inorganic additive and the resin is not enough to show the reinforcing effect required in the actual application part, a large amount of inorganic additive should be used to have the necessary mechanical strength, heat resistance and other physical properties. There is a problem that the strength is sharply lowered.

Accordingly, in order to have proper mechanical strength, heat resistance and other physical properties by only adding a small amount of inorganic additives to thermoplastic resins, plate-like clay minerals surface-treated with appropriate organic compounds during polymerization are used to improve the bonding strength between clay minerals and resins. A method has been proposed that allows clay minerals in thermoplastics to be uniformly dispersed in nano-sized layers. However, when surface-treated clay particles are surface-treated with an organic compound, there is a part where the clay particles are not uniformly dispersed in nano size because there is dependence on the compatibility of the surface of the clay particles with the thermoplastic resin or monomer used. Since the distance between layers is not sufficiently increased by the insertion of resin into the clay particles of, there is a limit to dispersing the clay particles into nano size, so it is difficult to expect the effect of improving mechanical strength, heat resistance and impact resistance at the same time. .

Therefore, the compatibility of the surface of the monomer and the clay particles and the uniform dispersion of the clay mineral particles in the resin in the resin has emerged as an important problem in the production of the thermoplastic composite material.

MEANS TO SOLVE THE PROBLEM In order to solve the conventional problem mentioned above, this inventor uses the plate-shaped clay mineral surface-treated with the alkylammonium ion type water-soluble radical initiator containing an appropriate azo- or peroxide group, and superposition | polymerization which advances from the clay mineral surface or inside. By uniformly dispersing the clay mineral particles in the nano-sized resin through the reaction to develop a thermoplastic composite material having excellent mechanical properties and thermal stability without deterioration of impact resistance.

An object of the present invention is to provide a thermoplastic composite material in which clay mineral particles are uniformly dispersed in a nano size in a resin.

Another object of the present invention is to provide a thermoplastic composite having excellent mechanical properties without deteriorating impact resistance in polymerizing thermoplastic resins in the presence of clay minerals.

Another object of the present invention is to provide a thermoplastic composite having excellent thermal stability.

Still another object of the present invention is to provide a method for producing a thermoplastic composite having excellent mechanical properties and thermal stability without deteriorating impact resistance in polymerizing thermoplastic resins in the presence of clay minerals.

Both the above and other objects of the present invention can be achieved by the present invention described below.

The thermoplastic composite material of the present invention (a) 100 parts by weight of a polymer or copolymer made of a vinyl monomer capable of radical polymerization or a mixture of vinyl monomers; And (b) 0.01 to 50 parts by weight of clay mineral whose surface is modified with an alkylammonium-based initiator containing an azo or peroxide group.

The method for producing a thermoplastic composite material of the present invention comprises the steps of surface treating a clay mineral with an alkylammonium initiator containing an azo or peroxide group before polymerization, and a vinyl monomer capable of radical polymerization of the surface treated clay mineral or And polymerizing with a mixture of vinyl monomers.

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

(a) Vinyl monomer

As the vinyl monomer used in the present invention, styrene, α-methylstyrene, vinyltoluene, styrene having an alkyl substituent on the benzene ring (for example, o-, m- or p-methylstyrene and o- can be radically polymerized). , m- or pt-butylstyrene), styrene having a halogen substituent on the benzene ring (for example o-, m- or p-chlorostyrene and o-, m- or p-bromostyrene), divinylbenzene, Acrylonitrile, methacrylonitrile, ethacrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, acrylic acid, butadiene, isoprene, chloroprene, butene, vinyl chloride, vinyl Lithenate, acrylamide, methyl acrylamide, ethyl acrylamide, vinyl alcohol, vinylpyridine, vinylpyrrolidone, vinyl acetate, maleic anhydride, maleimide, N-phenyl maleimide And the like, and these may be used alone or as a mixture of two or more thereof.

(b) clay minerals

The clay mineral used as the inorganic additive in the present invention is a plate-like mineral having a length and width of about 500-1000 mm 3 and a thickness of 9-12 mm 3, and the distance between each layer is about 10 mm 3. Clay minerals are usually in the form of stacks of plate-like layers, which are in the form of agglomerations and have a cationic substitution capacity of 50 to 200 milligrams per 100 grams.

Clay minerals of the present invention are smectite type clays such as montmorillonite, saponite, hectorite and these may be used alone or in mixtures of more.

The thermoplastic composite material of the present invention is (1) an alkylammonium-based initiator containing an azo or peroxide group to modify the surface of the clay mineral, and (2) a radically polymerizable vinyl monomer or a mixture of vinyl monomers 100 It is characterized in that it is prepared by polymerization with 0.01 to 50 parts by weight of the modified clay mineral.

Alkyl ammonium-based initiators containing azo and peroxide groups used for the modification of the clay are onium ions capable of ion-exchange reaction with clay, and azo or peroxides capable of radical polymerization with vinyl monomers on the other. It is a compound which has a group.

Therefore, the clay is modified through an ion exchange reaction with onium ions such as ammonium ions containing azo or peroxide groups. Thus, by using the clay modified through the ion exchange reaction to the onium ions before the start of the polymerization, the clay mineral particles are uniformly dispersed in the nano-sized resin through the polymerization reaction proceeding from the surface or the inside of the clay mineral.

Alkyl ammonium-based initiators containing azo and peroxide groups used for the modification of the clay include 2,2'-azobis isobutylamidine hydrochloride, 1-trimethylammonium-6-t-butyldioxyhexanebromide , 4-methoxycarbonyl benzyl triethyl ammonium chloride, 4-carboxybenzyl triethyl ammonium chloride, 4-t-butyldioxy carbonyl benzyl triethyl ammonium chloride, 5-ethoxycarbonyl pentyl triethyl Ammonium bromide, 5-t-butyldioxy carbonyl pentyltriethylammonium chloride, 10-methoxycarbonyl decyltriethylammonium bromide, 10-t-butyldioxy carbonyl decyltriethylammonium chloride, 3-t-butyldioxy propyltrimethylammonium bromide, 10-t-butyldioxy decyltrimethylammonium bromide, 4-t-butyldioxy butyltrimethylammonium bromide, 5-t-butyldi Oxy pentyltrimethylammonium bromide and the like, which can be used alone or in mixture of more.

In order to increase the polymerization rate, a conventional initiator may be mixed with the water-soluble initiator used in the clay modification. The initiators used in the present invention include benzoyl peroxide, t-butylperbenzoate, t-butylperacetate, azobisisobutylonitrile, percarbonate, azobis-2-methylbutylonitrile, and the like. It may be used alone or in combination. In addition, t-dodecyl multicaptan and n-dodecyl multicaptan may be used as a molecular weight regulator if necessary to control the molecular weight of the resulting polymer.

The content of the clay mineral is used in the range of 0.01 to 50 parts by weight based on 100 parts by weight of the monomer mixture. If the content of clay is less than 0.01 parts by weight, it is insufficient to exhibit the necessary reinforcing effect, and if it is 50 parts by weight or more, the amount of the resin becomes too small, so that molding is impossible.

The polymerization method can be produced by conventional methods such as bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization, etc., and can be produced by mixing the above polymerization method if necessary.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Parts and percentages in the present specification are based on weight unless otherwise specified.

Example

Example 1

2 parts of modified clay surface treated with 4-t-butyl dioxy carbonyl benzyltriethyl ammonium chloride, 75 parts of styrene, a monomer mixture of 25 parts of acrylonitrile, and 0.3 parts of benzoyl peroxide were introduced into the reactor and thoroughly mixed. The polymerization was carried out at 3 hours. The usual suspension aqueous solution was added thereto, and the mixture was sufficiently stirred to prepare the produced bulk polymer in a suspended state. Once the bulk polymer was completely dispersed in suspension, the temperature was started and suspension polymerization was carried out at 130 ° C. for 5 hours.

The resultant bead-shaped polymer was dehydrated and dried and pelletized using an extruder at 220 ° C. to obtain a rubber-modified thermoplastic composite. Using a 5.3 oz injection molding machine, a test piece of the polymerization product was made and its mechanical properties were measured. The measured results are shown in Table 1.

Example 2

4 parts of modified clay surface-treated with 1-trimethyl ammonium-6-t-butyl dioxyhexane bromide, 75 parts of styrene, 25 parts of acrylonitrile and 0.4 part of azobis isobutylonitrile were introduced into the reactor and thoroughly mixed. 3 hours at 80 ° C. A conventional suspension solution was added thereto, followed by sufficiently stirring to prepare the formed mass polymer in a suspended state, after which the polymerization was completed by the method of Example 1. The polymer obtained at this time was also shown in Table 1 by measuring the mechanical properties by the method of Example 1.

Comparative Example 1

75 parts of styrene, 25 parts of acrylonitrile, and 0.3 parts of benzoyl peroxide were added to the reactor as an initial monomer mixture without addition of clay, and the polymerization was carried out in the same manner as in Example 1.

Comparative Example 2

A monomer mixture of 5 parts of modified clay surface-treated with dimethyl distearyl ammonium chloride, 75 parts of styrene, 25 parts of acrylonitrile, and 0.4 part of azobis isobutylonitrile were introduced into the reactor, sufficiently mixed and polymerized at 80 ° C. for 3 hours. . To this, a common aqueous solution of suspending agent was added thereto, and the mixture was sufficiently stirred to prepare the produced mass polymer in a suspended state, after which the polymerization was completed by the method of Example 1. The polymer obtained at this time was also shown in Table 1 by measuring the mechanical properties by the method of Example 1.

Examples 1 and 2 The polymers of Comparative Examples 1 and 2 were dehydrated and dried and pelletized using an extruder at 220 ° C. to obtain a rubber-modified thermoplastic composite. Using a 5.3 oz injection molding machine, a test piece of the polymerization product was made and its mechanical properties were measured.

The impact strength of the resin composition prepared by the above method was measured by ASTM D-256, the flexural modulus was measured by ASTM D-790, and the tensile strength was measured by ASTM D-638. The thermal stability was measured by using a thermogravimetric analyzer to measure the decomposition start temperature.

The interlayer distance of clay was measured by X-ray diffraction (XRD).

The physical properties measured in Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1. Examples 1 and 2 used clay modified with the initiator according to the present invention, Comparative Example 1 was polymerized without the addition of clay, and Comparative Example 2 used clay modified with the initiator not according to the present invention. to be.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Clay content (wt%) 2 4 0 5 Clay Interlayer Distance No specific peak (uniform dispersion) No specific peak (uniform dispersion) - 50Å Impact strength (kgcm / cm) 2.8 2.7 2.7 1.8 Flexural modulus (kg / cm ² ) 39,000 46,200 31,000 34,000 Tensile Strength (kg / cm ² ) 790 810 710 740 Decomposition start temperature (℃) 431 447 418 425

From the results of Table 1 above, in the case of using a plate-shaped clay mineral surface-treated with an alkylammonium-based initiator containing an azo or peroxide group according to the present invention, the clay mineral particles are uniformly dispersed in a nano-sized resin and impacted. It was found that the mechanical properties such as strength, flexural modulus, and tensile strength were superior to those of the comparative example, and the thermal stability was also high.

The thermoplastic composite material of the present invention has the effect of the invention to provide a thermoplastic composite material having excellent mechanical properties and thermal stability without a decrease in impact resistance by uniformly dispersing the clay mineral particles in a nano-sized resin.

Simple modifications and variations of the present invention can be readily made by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (4)

(a) 100 parts by weight of a polymer or copolymer prepared from a vinyl monomer or a mixture of vinyl monomers capable of radical polymerization; And (b) 0.01 to 50 parts by weight of clay minerals surface-treated with alkylammonium-based initiators containing azo or peroxide groups; Thermoplastic composite material, characterized in that consisting of. The method of claim 1, wherein the alkylammonium-based initiator containing an azo or peroxide group is 2,2'-azobis (isobutyramidine hydrochloride), 1-trimethylammonium-6-t-butyldioxyhexane Bromide, 4-methoxycarbonyl benzyltriethylammonium chloride, 4-carboxybenzyl triethylammonium chloride, 4-t-butyldioxy carbonyl benzyltriethylammonium chloride, 5-ethoxycarbonyl pentyltri Ethylammonium bromide, 5-t-butyldioxy carbonyl pentyltriethylammonium chloride, 10-methoxycarbonyl decyltriethylammonium bromide, 10-t-butyldioxy carbonyl decyltriethylammonium chloride , 3-t-butyldioxy propyltrimethylammonium bromide, 10-t-butyldioxy decyltrimethylammonium bromide, 4-t-butyldioxy butyltrimethylammonium bromide, 5-t-butyldioxy pen A thermoplastic composite material selected from the group consisting of tiltrimethyl ammonium bromide and one or two or more thereof. According to claim 1, wherein the vinyl monomer is styrene, alpha methyl styrene, vinyl toluene, styrene having an alkyl substituent on the benzene ring (for example o-, m- or p-methyl styrene and o-, m- or pt -Butyl styrene), styrene having halogen substituents on the benzene ring (e.g. o-, m- or p-chlorostyrene and o-, m- or p-bromostyrene), divinylbenzene, acrylonitrile, meta Chloronitrile, ethacrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, acrylic acid, butadiene, isoprene, chloroprene, butene, vinyl chloride, vinylitrate chloride, Acrylamide, methylacrylamide, ethylacrylamide, vinylalcohol, vinylpyridine, vinylpyrrolidone, vinylacetate, maleic anhydride, maleimide, N-phenylmaleimide, and one or more mixtures thereof Thermoplastic composite material, characterized in that selected from the group consisting of. Surface treatment of clay minerals through ion exchange reactions with alkylammonium initiators containing azo or peroxide groups and polymerization of the surface treated clay minerals with a vinyl monomer or a mixture of vinyl monomers capable of radical polymerization Method for producing a thermoplastic composite material comprising the step of.