KR19990049934A - Manufacturing method of thermoplastic composite material - Google Patents

Abstract

The present invention is a monomer mixture consisting of 50 to 90 parts by weight of aromatic vinyl compounds, 10 to 50 parts by weight of vinyl cyanide compounds and 0.01 to 50 parts by weight of clay minerals or organically treated clay minerals as inorganic additives. In the polymerization by adding together with the control agent, the content of acrylonitrile in the initial monomer introduced into the polymerization system before the start of polymerization is lower than the content of acrylonitrile in the total monomers to initiate the polymerization and proceed with the initial polymerization. The remaining monomer mixture having a higher acrylonitrile content than the mixture is introduced into the polymerization system in a batch or continuously or intermittently, and the styrene-acrylonitrile copolymer present as a matrix and the styrene-acrylonitrile copolymer polymerized between the layers of clay. Acrylonitrile content in the same level The present invention relates to a method for producing a thermoplastic composite having excellent mechanical properties, heat resistance and thermal stability by polymerizing as much as possible.

Description

[Name of invention]

Manufacturing method of thermoplastic composite material

Detailed description of the invention

(Field of invention)

The present invention relates to a method for producing a thermoplastic composite material. More specifically, the present invention relates to the polymerization of styrene-acrylonitrile copolymers in the presence of clay minerals, to the styrene-acrylonitrile copolymers present in a matrix and styrene-acrylonitrile copolymers polymerized between layers of clays. It relates to a method for producing a thermoplastic composite material having excellent mechanical properties, heat resistance and thermal stability by allowing acrylonitrile content to polymerize to the same level.

(Background of invention)

The present invention relates to a method for producing a thermoplastic composite material in which plate-shaped clay minerals are uniformly distributed in a thermoplastic resin of an aromatic vinyl compound and a vinyl cyanide compound, and in particular, a styrene-acrylonitrile copolymer polymerized between layers of clay minerals. A styrene-acrylonitrile copolymer present as a matrix has a uniform acrylonitrile content, and relates to a method for producing a thermoplastic composite having good mechanical properties, heat resistance and thermal stability.

In general, inorganic additives such as glass fiber, talc, mica and the like are used to improve mechanical strength and heat resistance of thermoplastic resins.

However, resins reinforced by the general technique of simply blending inorganic additives in resins still have many problems. That is, since the bond strength between the inorganic additive and the resin is not sufficient to show the reinforcing effect required in the actual application part, a large amount of inorganic additive must be used to have the desired mechanical strength, heat resistance, and other physical properties. This happens too.

Therefore, in order to have proper mechanical strength, heat resistance and other physical properties with only a small amount of inorganic additives added to the thermoplastic resin, by using plate-like clay minerals surface-treated with an appropriate organic compound during polymerization, the bonding strength between the clay mineral and the resin is improved and thermoplastic A method has been proposed that allows the clay minerals in the resin to be uniformly dispersed in nano-size layers.

However, in the case of styrene-acrylonitrile copolymers using styrene and acrylonitrile as monomers, polar monomers are easily impregnated between layers of clay minerals among the monomers used for polymerization. Impregnation between these clay layers is easier than styrene. Therefore, the acrylonitrile content of the styrene-acrylonitrile copolymer polymerized between the layers of clay and the styrene-acrylonitrile copolymer present in the matrix in the final polymer is different. In particular, the high acrylonitrile content of the styrene-acrylonitrile copolymer polymerized between the layers of clay not only causes yellowing at the time of molding, but also lowers the physical properties of the resin and also causes the appearance quality of the final product.

The present invention is to solve the above problems, in the polymerization of styrene-acrylonitrile copolymer in the presence of clay minerals, styrene-acrylonitrile copolymer polymerized between the layers of clay and styrene- present in the matrix It is to provide a method for producing a thermoplastic composite material excellent in mechanical properties, heat resistance and thermal stability by allowing the acrylonitrile content of the acrylonitrile copolymer to polymerize to the same level.

(Purpose of invention)

An object of the present invention is to provide a method for producing a thermoplastic composite having excellent mechanical properties.

Another object of the present invention is to provide a method for producing a thermoplastic composite having excellent heat resistance.

Still another object of the present invention is to provide a method for producing a thermoplastic composite having excellent thermal stability which reduces thermal discoloration of the resin.

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

(Summary of invention)

The present invention is a monomer mixture consisting of 50 to 90 parts by weight of aromatic vinyl compounds, 10 to 50 parts by weight of vinyl cyanide compounds and 0.01 to 50 parts by weight of clay minerals or organically treated clay minerals as inorganic additives. In the polymerization by adding together, the content of acrylonitrile in the initial monomer added to the polymerization system before the start of polymerization is lower than the content of acrylonitrile in the total monomers to initiate polymerization to proceed with the initial polymerization, and the initial monomer mixture Residual monomer mixtures having a higher acrylonitrile content are added to the polymerization system in batches or continuously or intermittently to obtain styrene-acrylonitrile copolymers present in the matrix and styrene-acrylonitrile copolymers polymerized between the layers of clay. Acrylonitrile content at the same level By superposing | polymerizing as much as possible, it is related with the manufacturing method of the thermoplastic composite material excellent in mechanical property, heat resistance property, and heat stability.

The aromatic vinyl compound used in the present invention is selected from the group consisting of styrene, alphamethylstyrene, vinyltoluene, styrene having an alkyl substituent on the benzene ring, and styrene having a halogen substituent on the benzene ring; The vinyl cyanide compound is selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile; The initiator may be selected from the group consisting of benzoyl peroxide, t-butyl perbenzoate, t-butyl peracetate, azobisisobutylonitrile, percarbonate, and azobis-2-methylbutylonitrile alone or in combination of two or more. Mixtures; The molecular weight modifier is selected from the group consisting of t-dodecyl multicaptan, and n-dodecyl multicaptan.

(Detailed Description of Specific Embodiments of the Invention)

The present invention is a monomer mixture consisting of 50 to 90 parts by weight of aromatic vinyl compounds, 10 to 50 parts by weight of vinyl cyanide compounds and 0.01 to 50 parts by weight of clay minerals or organically treated clay minerals as inorganic additives. In the polymerization by adding together with the control agent, the content of acrylonitrile in the initial monomer introduced into the polymerization system before the start of polymerization is lower than the content of acrylonitrile in the total monomers to initiate the polymerization and proceed with the initial polymerization. The remaining monomer mixture having a higher acrylonitrile content than the mixture is introduced into the polymerization system in a batch or continuously or intermittently, and the styrene-acrylonitrile copolymer present as a matrix and the styrene-acrylonitrile copolymer polymerized between the layers of clay. Acrylonitrile content in the same level It is characterized by producing a thermoplastic composite having excellent mechanical properties, heat resistance and thermal stability by polymerizing as much as possible.

Aromatic vinyl compounds used as monomers in the present invention include styrene, alphamethylstyrene, vinyltoluene, styrene having an alkyl substituent on the benzene ring (for example, o-, m- or p-methylstyrene and o-, m- or pt-butylstyrene) and styrene having halogen substituents on the benzene ring (eg o-, m- or p-chlorostyrene and o-, m- or p-bromostyrene). , Acrylonitrile, methacrylonitrile, ethacrylonitrile and the like.

In addition, the clay mineral as an inorganic additive used in the present invention is a plate-like mineral having a length and a width of about 500-1000 mm 3 and a width of 9-12 mm 3, and the distance between each layer is about 10 mm 3 and usually such a plate layer is stacked. It is in the form of agglomeration as a state.

Clay minerals used in the present invention are smectite type clays such as montmorillonite, saponite, and hectorite, and these may be used alone or in mixture of two or more thereof. The clay used is a plate-like clay mineral with a cationic substitution capacity of 50 to 200 milligrams per 100 grams, and the clay is easily organicized by ion exchange with onium ions such as ammonium ions to improve dispersibility in the matrix. do. Compounds used for the organic treatment of clays include vinylbenzyltrimethylammonium chloride, vinylbenzyltrimethylammonium bromide, vinylbenzyltrimethylammonium iodide, vinylbenzyltriethylammonium chloride, vinylbenzyltriethylammonium bromide, vinylbenzyltriethyl Ammonium iodide, 2-methacryloyloxy ethyl trimethylammonium chloride, 2-methacryloyloxy ethyl trimethylammonium bromide, 2-methacryloyloxy ethyltrimethylammonium iodide, 2-methacryloyloxy Ethyl triethylammonium chloride, 2-methacryloyloxy ethyl triethylammonium bromide, 2-methacryloyloxy ethyl triethylammonium iodide, 2-acryloyloxy ethyl trimethylammonium chloride, 2-acryloyl jade Ethyl trimethylammonium bromide, 2-acryloyloxy ethyl trimethyl Monium iodide, 2-acryloyloxy ethyl triethylammonium chloride, 2-acryloyloxy ethyl triethylammonium bromide, 2-acryloyloxy ethyl triethylammonium iodide, 3-methacryloylamino Propyl trimethylammonium chloride, 3-methacryloylamino propyl trimethylammonium bromide, 3-methacryloylamino propyl trimethylammonium iodide, 3-acryloylamino propyl trimethylammonium chloride, 3-acryloylaminopropyl trimethyl Onium ions, such as ammonium bromide, 3-acryloylamino propyl trimethylammonium amide, diallyldimethyl ammonium chloride, diallyldimethyl ammonium bromide, and diallyldimethylammonium iodide, which can undergo ion exchange reaction with clay The other side has a vinyl group capable of radical polymerization Compounds are used and these may be used alone or in a mixture of two or more. Through organic treatment of clays, organic compounds exist in the spaces between clay layers, and the distance between clay layers increases according to the molecular size of organic compounds, which makes monomer easier to space between clay layers during polymerization. Resin is formed through the polymerization, and the possibility of directly inserting oligomers or polymer chains having a small molecular weight is increased.

The content of the clay mineral used in the present invention is in the range of 0.01 to 50 parts by weight with respect to 100 parts by weight of the monomer mixture, and if the content of clay is less than 0.01 parts by weight, it is insufficient to show the expected reinforcing effect, and 50 parts by weight or more. If the amount of resin is too small, molding becomes impossible. In addition, clay and organically treated clay may be used alone or as a mixture of two kinds.

Useful initiators used in the present invention include organic peroxides or azo compounds and the like, and examples thereof include benzoyl peroxide, t-butyl perbenzoate, t-butyl peracetate, azobisisobutylonitrile, percarbonate, azobis- 2-methylbutylonitrile, and the like, and these polymerization initiators may be used alone or as a mixture of two or more thereof. It is also possible to use t-dodecyl multicaptan and n-dodecyl multicaptan as molecular weight regulators if necessary to control the molecular weight of the resulting polymer.

The polymerization method can be prepared by block polymerization, block-suspension polymerization, block-emulsification polymerization, or the like.

The thermoplastic composite material obtained by the above production method is excellent in mechanical properties, heat resistance properties and thermal stability, so its industrial use value is large.

The present invention will be further illustrated by the following examples, which are only described for the purpose of illustrating the present invention and are not intended to limit the protection scope of the present invention.

(Example)

(Example 1)

As the initial monomer mixture, 35 parts by weight of styrene, 12 parts by weight of acrylonitrile, 5 parts by weight of clay, and 0.1 parts by weight of t-dodecyl multicaptan were added to the reactor, mixed well, and polymerized at 150 ° C. for 10 minutes, followed by 35 parts by weight of styrene. And 18 parts by weight of acrylonitrile was continuously added and reacted for 4 hours to proceed the polymerization up to a polymerization conversion rate of about 75%, and then a resin was prepared through a devolatilization process. The prepared resin was prepared by using a 5.3 oz. Injection molding machine, and the mechanical properties thereof were measured and the results are shown in Table 2.

(Example 2)

35 parts by weight of styrene as an initial monomer mixture, 18 parts by weight of acrylonitrile, 8 parts by weight of clay organicized with 2-methacryloyloxy ethyl trimethylammonium chloride, 0.3 part by weight of benzoyl peroxide, 0.08 weight by t-dodecyl multicaptan Part was added to the reactor and sufficiently mixed and polymerized at 100 ° C. for 10 minutes, and then 25 parts by weight of styrene and 22 parts by weight of acrylonitrile were added in a batch to react for 10 hours to complete polymerization to prepare a resin. The prepared resin was prepared by using a 5.3 oz. Injection molding machine, and the mechanical properties thereof were measured and the results are shown in Table 2.

(Example 3)

45 parts by weight of styrene as an initial monomer mixture, 13 parts by weight of acrylonitrile, 5 parts by weight of clay organicated with 2-methacryloyloxy ethyl trimethylammonium chloride, 0.2 part by weight of t-butylperbenzoate, t-dodecyl 0.1 parts by weight of captan was added to the reactor and sufficiently mixed and polymerized at 120 ° C. for 1 hour, and then 30 parts by weight of styrene and 12 parts by weight of acrylonitrile were added and mixed thoroughly, and the materials shown in Table 1 were added and sufficiently stirred, The produced mass polymer is prepared in a suspended state.

TABLE 1

When the bulk polymer was completely dispersed in the suspension, the temperature was started and suspension polymerization was carried out at 120 ° C. for 5 hours and at 135 ° C. for 6 hours.

The resulting bead-shaped polymer was treated with 1.0 part by weight of hydrochloric acid, washed with beads using a fine mesh to remove the dispersant, and then dehydrated and dried to make pellets using an extruder at 220 ° C. to produce a rubber-modified thermoplastic composite. To obtain. Test specimens of the polymerization product were prepared using a 5.3 oz. Injection molding machine and the mechanical properties thereof were measured. The results are shown in Table 2.

Comparative Example 1

The monomer mixture was prepared in the same manner as in Example 1 except that 69 parts by weight of styrene, 31 parts by weight of acrylonitrile, 8 parts by weight of clay, and 0.1 parts by weight of t-dodecyl multicaptan were added to the reactor and sufficiently mixed and polymerized. . The prepared resin was prepared by using a 5.3 oz. Injection molding machine, and the mechanical properties thereof were measured and the results are shown in Table 2.

Comparative Example 2

60 parts by weight of styrene as an initial monomer mixture, 40 parts by weight of acrylonitrile, 10 parts by weight of clay organicized with 2-methacryloyloxy ethyl trimethylammonium chloride, 0.3 part by weight of benzoyl peroxide, 0.08 weight by t-dodecyl multicaptan Part was added to the reactor and mixed sufficiently to react for 10 hours at 100 ℃ to complete the polymerization to prepare a resin. The prepared resin was prepared by using a 5.3 oz. Injection molding machine, and the mechanical properties thereof were measured and the results are shown in Table 2.

TABLE 2

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (2)

In the polymerization by adding a monomer mixture consisting of 50 to 90 parts by weight of an aromatic vinyl compound and 10 to 50 parts by weight of a vinyl cyanide compound and 0.01 to 50 parts by weight of a clay mineral as an inorganic additive together with a small amount of an initiator and a molecular weight regulator as necessary, the polymerization is carried out. The content of acrylonitrile in the initial monomer introduced into the polymerization system before the start is lower than the content of acrylonitrile in the total monomers to initiate polymerization to proceed with initial polymerization, and the residual amount of the monomer having a higher acrylonitrile content than the initial monomer mixture. The mixture was introduced into the polymerization system batchwise or continuously or intermittently to polymerize so that the acrylonitrile content of the styrene-acrylonitrile copolymer polymerized between the layers of clay and the styrene-acrylonitrile copolymer present in the matrix was the same level. Heat side characterized in that The method of the small thermoplastic composite material. The clay according to claim 1, wherein the clay is smectite-type clay such as montmorillonite, saponite, hectorite, and has a cation substitution capacity of 50 to 200 milliliters per 100 grams and a length and width of 500 to 1000 mm 3. A method of producing a thermoplastic composite, characterized in that it is used to organically treat the plate-like clay mineral having a thickness of 9 ~ 12Å by organic ionium ion through an ion exchange reaction, and these are used alone or as a mixture thereof.