JP2000327833A - Preparation of thermoplastic nano-compositie material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of preparing thermoplastic nano-composite materials in which silicate salt layers are debonded and uniformly dispersed in a polymer matrix to be able to impart stronger mechanical reinforcing properties. SOLUTION: A method of preparing thermoplastic nano-composite materials comprises (a) a step of bringing a swelling phyllosilicate into contact with a polymerizable aminoaryl lactam monomer to insert the lactam monomer in between any adjacent layers of the phyllosilicate and (b) a step of accelerating the polymerization reaction of the lactam monomer by mixing the lactam monomer-inserted phyllosilicate with a thermoplastic polymer and heating the resulting mixture to effect the debonding of the phyllosilicate, thereby forming a thermoplastic nano-composite material in which the debonded silicate layers have been dispersed in the polymer matrix.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a thermoplastic nanocomposite in which a silicate layer exfoliated from a layered silicate is dispersed in a polymer matrix. Further, a polymerizable lactam monomer is inserted into the layered silicate, and the layer of the layered silicate is exfoliated and dispersed in the polymer matrix by a polymerization reaction of the lactam monomer, and the composite material has mechanical reinforcement. It concerns a series of processes that can be applied.

[0002]

2. Description of the Related Art Nanocomposites are a new class of materials having an ultrafine layer dimension, and their characteristics are particularly remarkable in the range of 1 to 100 nm. From many experimental results,
Virtually all types and classes of nanocomposites have better properties than micro and macro composites, with higher stiffness, strength and heat resistance, and less hygroscopic, flammable and breathable properties I know.

In the process of producing a thermoplastic nanocomposite, for example, a swelling agent such as a long-chain organic cation and a water-soluble oligomer or polymer are inserted or inserted between each layer of a layered silicate of smectite clay. By absorbing and isolating each layer, each layer of the layered silicate can be made to contain polymer chains when mixed with the molten polymer. Such known techniques include, for example, US Pat.
52,469, WO93 / 04117, JP-A-8-1
Nos. 51,449, 7-207,134, 7-228,762, 7-331,092, 8-259,806, and 8-25.
9,846, and the like. However, the layered silicates obtained by these known methods mostly do not exfoliate one by one and do not provide mechanical reinforcement to the polymer matrix, but can only expand. In addition, the swelling agent obtained by swelling sometimes precipitates and causes deterioration of the mechanical properties of the composite material.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method for producing a thermoplastic nanocomposite in which the silicate layer exfoliates and is uniformly dispersed in the polymer matrix to provide greater mechanical reinforcement. The purpose is to provide.

[0005]

According to the present invention, a polymerizable lactam monomer is inserted into a layered silicate, and the layered silicate layer is formed by a polymerization reaction of the lactam monomer. A novel method is provided for producing thermoplastic nanocomposites that can exfoliate and disperse in a polymer matrix to provide mechanical reinforcement when mixed with a thermoplastic molten polymer.

That is, the present invention provides (a) a step of contacting a swellable phyllosilicate with a polymerizable aminoaryllactam monomer and inserting the lactam monomer between adjacent layers of the phyllosilicate. And (b) mixing the layered silicate into which the lactam monomer is inserted with a thermoplastic polymer and heating the mixture to promote the polymerization reaction of the lactam monomer, exfoliating the layered silicate, and exfoliating. Forming a thermoplastic nanocomposite in which the silicate layer is dispersed in a polymer matrix.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The process of the present invention comprises the steps of: (a) contacting a swellable layered silicate with a polymerizable aminoaryl lactam monomer, the lactam monomer being placed adjacent to the layered silicate; (B) mixing the layered silicate with the lactam monomer inserted therein with a thermoplastic molten polymer and heating the mixture to promote the polymerization reaction of the lactam monomer, Exfoliating the silicate to form a thermoplastic nanocomposite in which the exfoliated silicate layer is dispersed in a polymer matrix.

When a layered silicate having a lactam monomer inserted therein and a molten polymer (at a temperature of 200 ° C. or higher) are mixed, the layered silicate undergoes polypolymerization to form a polyamide having a hard molecular chain. Thus, the layered silicate can be easily exfoliated by separating the adjacent layers. More specifically, the lactam monomer, as a result of the polymerization reaction, forms a high melting point aromatic polyamide having terminal groups that are reactive, ie, compatible, with the polymer matrix of the composite material. In addition, the polyamide obtained from the lactam monomer can promote exfoliation of the silicate layer on the one hand and provide mechanical reinforcement to the polymer matrix on the other hand.

The polymerizable lactam polymer used in the present invention is an aminoaryllactam, which is produced by a one-step method of coupling an aromatic amino acid with a lactam having a cyclic structure having 1 to 12 carbon atoms. . As a specific example, N- (p-aminobenzoyl)
Examples include caprolactam, N- (p-aminobenzoyl) butyrolactam, N- (p-aminobenzoyl) valerolactam, and N- (p-aminobenzoyl) dodecanelactam.

[0010] Layered silicates suitable for the present invention are 50 to 2
It preferably has a cation exchange capacity of 00 meq / 100 g. If it is less than 50 meq / 100 g, covalent bonds between layers are too strong to cause intercalation. If it exceeds 200 meq / 100 g, ionic bonds between layers are too strong and intercalation tends not to occur.

Representative examples of such layered silicates include smectite clay, vermiculite (vermiculite),
Swellable clay materials such as halloysite and sericite (sericite), and mica-based swellable minerals such as fluoro-mica. here,
The smectite clay is specifically montmorillonite, saponite, beidellite, nontronite, hectorite or stevensite.

The fluoromica used in the present invention is obtained by heating a mixture of 65 to 90% by weight of talc and 10 to 35% by weight of at least one of silicon fluoride, sodium fluoride and lithium fluoride. Can be prepared. The layered silicate is Nanoco
It is preferably montmorillonite having an amino acid with a trade name of “Aminoclar” inserted by the company r.

The nanocomposite according to the present invention preferably contains 0.05 to 80% by weight of a layered silicate as an inorganic component, more preferably 1 to 30% by weight. When the content is less than 0.05% by weight, no mechanical reinforcing effect is exerted on the nanocomposite material, and when the content is more than 80% by weight, the interlayer distance does not increase sufficiently and the workability tends to be poor.

The production method according to the present invention is suitable for all types of thermoplastic polymers, including crystalline polar polymers such as nylon 6, crystalline nonpolar polymers such as polypropylene (PP), and non-crystalline polymers such as polystyrene (PS). And non-crystalline polar polymers such as polycarbonate (PC).

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS To further clarify the above and other objects, features and advantages of the present invention, preferred embodiments will be described below with reference to the drawings.

Production Example 1 (Synthesis of polymerizable lactam monomer) In a 1000 mL round bottom flask equipped with a condenser and a trap with a saturated NaOH solution, p-aminobenzoic acid (100 g, 0.703 mol) and thionyl chloride ( 385 mL, 5.370 mol) and refluxed for 4 hours to obtain a clear solution. Then, unreacted thionyl chloride is removed by concentration, and distilled under reduced pressure to remove p-sulfinylaminobenzoyl chloride.
chloride).

Next, in a 3000 mL three-necked reactor,
Caprolactam (150 g, 0.703 mol), toluene (1300 mL) and pyridine (680 mL) were added and sealed with nitrogen gas. The reactor was then ice-bathed and the resulting mixture was stirred and p-sulfinylaminobenzoyl chloride (147.1 g, 0.730 mol
After 1) was added, the ice bath was stopped, and the mixture was stirred at room temperature for 14 hours. Further, pyridine chloride was removed by filtration, and the obtained filtrate was washed twice with 5% sodium bicarbonate and then condensed to remove the solvent. As a result of recrystallization of the residue from ethyl acetate, a polymerizable lactam monomer N-
(P-Aminobenzoyl) caprolactam was obtained.

Examples 1-4 (Preparation of thermoplastic nanocomposites) Step (a) N- (p-aminobenzoyl) caprolactam and "Aminoclay" were placed in a flask containing pyridine.
(Montmorillonite into which 12-aminolauric acid was inserted, manufactured by Nanocor) was added at a weight ratio of 1: 1, and dimethylaminopyridine (DMAP, 0.58 phr) was added as a catalyst for ion exchange, followed by sufficient stirring. . The pyridine was evaporated under vacuum to give the aminolaclay complex with the lactam inserted.

Step (b) The lactam-aminoclay complex was then mixed with nylon 6, polypropylene, polystyrene and polycarbonate in a kneader (brabender). For each of the four mixtures obtained, the lactam-aminoclay complex accounts for (a) 1%, (b) 2%, (c) 5% and (d) 10% by weight of the composite. Four such thermoplastic composites were prepared. Finally,
The obtained composite material was processed into a film by hot pressing and subjected to X-ray diffraction. As a result, the diffraction diagrams shown in FIGS. 1 to 4 were obtained.

From (a) and (b) of FIGS. 1 to 4 and (c) of FIG. 4, all kinds of composite materials containing 1% by weight or 2% by weight of a lactam-aminoclay complex, and the same complex, In the case of the diffraction spectrum of the polycarbonate composite material containing 5% by weight, it can be seen that the diffraction peak at 2 ° to 10 ° (2θ) is missing. Therefore, it is clear that exfoliation occurred in the layered silicate.

From the above, it can be seen that mixing a lactam monomer-layered silicate complex with a thermoplastic molten polymer results in a thermoplastic nanocomposite in which the exfoliated silicate layer is dispersed. .

While the preferred embodiments have been disclosed above, they do not limit the scope of the invention in any way, and anyone skilled in the art will be able to provide the same without departing from the spirit and scope of the invention. Various variations and additions should be made, and accordingly, the protection scope of the present invention is based on the contents specified in the claims.

[0023]

According to the production method of the present invention, it is possible to obtain a thermoplastic nanocomposite material in which the silicate layer exfoliates and is uniformly dispersed in the polymer matrix, so that a stronger mechanical reinforcing property can be imparted. .

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE FIGURES FIG. 1. Amino clay / nylon 6 composite material containing (a) 1% by weight, (b) 2% by weight, (c) 5% by weight, and (d) 10% by weight of a lactam-aminoclay complex, respectively. (E) It is a diffraction diagram as a result of having performed X-ray diffraction with respect to the lactam-amino clay complex.

FIG. 2: Amino clay / polypropylene (PP) composite containing (a) 1% by weight, (b) 2% by weight, (c) 5% by weight and (d) 10% by weight of a lactam-aminoclay complex, respectively. It is a diffraction diagram as a result of having performed X-ray diffraction with respect to the material and (e) lactam-amino clay complex.

FIG. 3 Amino clay / polystyrene (PS) composite containing (a) 1% by weight, (b) 2% by weight, (c) 5% by weight, and (d) 10% by weight of a lactam-aminoclay complex, respectively. It is a diffraction diagram as a result of having performed X-ray diffraction with respect to the material and (e) lactam-amino clay complex.

FIG. 4. Amino clay / polycarbonate (PC) composite containing (a) 1% by weight, (b) 2% by weight, (c) 5% by weight, and (d) 10% by weight of a lactam-aminoclay complex, respectively. It is a diffraction diagram as a result of having performed X-ray diffraction with respect to the material and (e) lactam-amino clay complex.

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[Procedure amendment]

[Submission date] March 27, 2000 (2003.
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 5

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] Layered silicates suitable for the present invention are 50 to 2
00meq / 100g (50-200 meq / 100
It preferably has a cation exchange capacity of g) . 50
When the amount is less than meq / 100 g (50 meq / 100 g) , the covalent bond between the layers is too strong, no intercalation occurs, and 200 meq / 100 g (200 meq)
/ 100 g) , the ionic bond between the layers is too strong, and there is a tendency that intercalation does not occur.

Continued on the front page F term (reference) 4F070 AA15 AA18 AA50 AA54 AC22 AD01 AD07 AE01 FA14 FA17 FB02 4J002 BB121 BC031 CG011 CL011 CL012 DJ006 DJ056

Claims (12)

[Claims] (A) contacting a swellable layered silicate with a polymerizable aminoaryllactam monomer and inserting the lactam monomer between adjacent layers of the layered silicate; and (b) ) The layered silicate in which the lactam monomer is inserted is mixed with a thermoplastic polymer and heated to accelerate the polymerization reaction of the lactam monomer, exfoliate the layered silicate, and exfoliate the silicate. A method for producing a thermoplastic nanocomposite comprising forming a thermoplastic nanocomposite having layers dispersed in a polymer matrix. 2. The method according to claim 1, wherein the aminoaryl lactam is prepared by coupling an aromatic amino acid with a lactam. 3. The production method according to claim 2, wherein the lactam moiety of the aminoaryllactam has a cyclic structure having 1 to 12 carbon atoms. 4. The method according to claim 1, wherein the aminoaryllactam is N- (p
The production method according to claim 3, wherein the compound is (aminobenzoyl) caprolactam. 5. The method according to claim 1, wherein said layered silicate is 50 to 200 meq.
2. The method according to claim 1, wherein the cation exchange capacity is 100 g / 100 g. 6. The method according to claim 1, wherein the nanocomposite contains 0.05 to 80% by weight of the layered silicate. 7. The layered silicate according to claim 1, wherein said layered silicate is selected from the group consisting of smectite clay, vermiculite, halloysite and sericite.
The manufacturing method as described. 8. The smectite clay is montmorillonite, saponite, beidellite, nontronite,
The method according to claim 7, wherein the clay is selected from the group consisting of hectorite and stephensite. 9. The method according to claim 1, wherein the layered silicate is montmorillonite into which an amino acid has been inserted. 10. The method according to claim 1, wherein the layered silicate is fluoromica. 11. The fluoromica comprises talc of 65%.
And at least one of silicon fluoride, sodium fluoride and lithium fluoride by 10 to 35% by weight.
11. The method according to claim 10, wherein the mixture is prepared by heating a mixture of the components by weight. 12. The method according to claim 1, wherein the thermoplastic polymer is a polymer selected from the group consisting of a crystalline polar polymer, a crystalline nonpolar polymer, a noncrystalline nonpolar polymer, and a noncrystalline polar polymer. Method.