JPS6250314A - Production of polymer composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition comprising an inorganic compound and an organic polymer which are tightly united with each other and being excellent in strength, etc., by radical-polymerizing a vinyl monomer in the presence of a specified sulfonic acid having a double bond in an aqueous medium containing a dispersed inorganic compound. CONSTITUTION:A sulfonic acid (salt) of formula I (wherein R is H, a 1-20C alkyl, phenyl or a halogen, X is -CONH-, a group of formula II or the like, R2 and R3 are each H or a 1-15C alkyl, R4 is 1-15C alkylene, Y is H, NH4 or an alkali metal), e.g., 2-acrylamido-2-methylpropanesulfonic acid, is prepared. A radical-polymerizable vinyl monomer (e.g., methyl methacrylate) is polymerized in the presence of this sulfonic acid (salt) in an aqueous polymerization system containing a dispersed inorganic compound (e.g., aluminum oxide or silicon carbide) by using a radical initiator (e.g., benzoyl peroxide) to obtain the purpose polymer composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a novel polymer composition in which an inorganic compound and an organic polymer are strongly integrated.

[Conventional technology]

Conventionally, the development of composite materials that create new effective functions by combining two or more types of materials has been actively carried out by mutually complementing the properties of the constituent materials. Composite materials of powders and organic polymers, in which inorganic compounds themselves are given advanced functions, are attracting attention, not only for their use in composite materials, but also for ceramic materials, magnetic materials, dental materials, etc. However, in this case, the properties of the composite materials differ significantly, resulting in poor interfacial compatibility such as compatibility and adhesion, making it impossible to sufficiently increase the composite efficiency, and the function of the inorganic compound powder itself. It has the essential drawback of being difficult to fully express.

Various powder surface modification methods have been proposed to improve this point, improve the interfacial affinity between organic polymer substances and inorganic compounds, and achieve high filling, uniform dispersion, and high strength. For example, a mechanochemical method of grinding an inorganic compound in the presence of a reactive monomer and grafting an organic polymer onto it. - Radiation methods, in which organic polymers are grafted by irradiation with radiation, are examples, but they require a crushing process, a radiation generator, etc., which complicates the process and greatly increases production costs, making them impractical. There are big problems in terms of

Furthermore, as an example of a powder surface modification method using in 51tu polymerization in the microencapsulation method, the present inventors previously conducted radical polymerization in the presence of a specific sulfonic acid monomer or sulfo/acid monomer. proposed a method for strongly integrating an inorganic compound and an organic polymer by bringing the vinyl monomer into contact with an inorganic compound as a third component (Japanese Unexamined Patent Publication No. 57-1
15412)・1～ However, since it is a non-catalytic polymerization of vinyl monomer by contacting a specific sulfonic acid monomer or sulfonate monomer with an inorganic compound, the polymerization rate of the monomer is strongly unified. There is a problem that the ratio of the organic polymer to the resulting polymer, that is, the grafting efficiency, is not necessarily sufficient, and the target vinyl monomer is limited to those whose main component is methyl acrylate or methyl methacrylate. Another problem was that the monomers lacked versatility.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a polymer composition in which the surface of an inorganic compound is uniformly and firmly fixed with an organic polymer at an extremely high polymerization rate and grafting efficiency.

[Means for solving problems]

According to the present invention, the following general formula, HC=C-X-8o, Y (1) R in the C formula
1 represents H, C, ~C2o alkyl group, phenyl group and derivatives thereof, or halodane atom, X-C0NH-C-
R4- represents H or C-C alkyl group, R4 is C1-Ci
5), -COO(CH2+rm(
In the formula, m is an integer of 1 to 20) or +CI (2+n (in the formula, m is 0 or an integer of 1 to 20), and Y is II.

In the presence of a sulfonic acid or a sulfonic acid salt represented by NH4 or an alkali gold i atom, at least one radically polymerizable vinyl monomer is radical-polymerized in an aqueous polymerization system in which an inorganic compound is dispersed. Provided is a method for producing a polymer composition in which an inorganic compound and an organic polymer are strongly integrated, characterized in that the polymerization is carried out using an initiator.

Furthermore, the present invention is characterized in that the interaction between the surface of the inorganic compound and the polymer applied by the method of the present invention goes beyond adhesion in a physical sense due to simple adsorption or van der Waals forces. The reason is that it originates from strongly integrated chemical bonds.

An example of an embodiment when carrying out the present invention is as follows:
After suspending and dispersing the inorganic compound in an aqueous medium under the temperature conditions within the range in which the radical initiator separates, the organic vinyl monomer, sulfonic acid motumer or sulfonate monomer and the radical initiator are added and stirred. By causing an aqueous heterogeneous polymerization reaction, the surface of the inorganic substance is uniformly coated with the copolymer of the vinyl monomer and the sulfonic acid monomer or the sulfonate monomer with an extremely high polymerization rate and grafting efficiency within a predetermined polymerization time. It can be firmly fixed.

The sulfonic acid monomer or sulfonate monomer represented by the general formula [1] has a double bond as an active side that brings about polymerization activity by the zocal initiator, and has OH present on the surface of the produced polymer and the inorganic substance. The presence of a sulfonic acid group as an active side that exhibits strong integration through interaction with groups is essential, and any compound having a structural formula containing these functional groups can be applied; for example, 2-acrylamide-2 -Methylgulononine sulfone v11 (hereinafter abbreviated as AMPS), sodium 2-methacrylethanesulfonate (hereinafter SEM)
(abbreviated as Na), sodium 3-methacrylethanesulfonate (hereinafter abbreviated as SPS), sodium 2-7'robensulfo/acid (hereinafter abbreviated as NaAS), sodium 2-methyl-2-propenesulfonate (hereinafter abbreviated as NaAS), NaM
! 9), but in particular AMPS containing an amide bond, SEM-Na and sps containing an ester bond.
etc. have extremely high polymerization activity and grafting efficiency (formation, j?
A strong coalescence rate of remer) is high and preferred.

As the inorganic compound used in the present invention, all compounds that are sparingly soluble in water can be applied, but among them, compounds from the periodic table r and n
, m, ■, V group, transition group metals and their oxides,
Hydroxides, chlorides, sulfites, carbonates, phosphates, silicates, and mixtures and complex salts thereof are effective, especially aluminum oxide, silicon carbide, silicon nitride, zirconium oxide, and nitride. Zirconium, zirconium boride, zirconium carbide, magnesium oxide, aluminum hydroxide, calcium sulfite, calcium sulfate,
Silicon dioxide, antimony dioxide, Merck, clay, calcium carbonate, carbon black, 2, Kel powder, iron powder,
Zinc powder, copper powder, iron oxide, zinc oxide, barium sulfate, barium oxide, and a-tite are especially preferred because they have a particularly remarkable effect of activating the vinyl monomer and strongly integrating it with the polymer.

As the vinyl monomer used in the present invention, any ordinary vinyl monomer that can be radically polymerized can be used.

As the radical initiator used in the present invention, all common peroxides and azo compounds can be used, but preferably radical initiators that can be decomposed in a temperature range of 40'C to 100'C are particularly effective. .

Among them, peroxides such as benzoyl peroxide, azobisisobutyronitrile, and potassium persulfate, and azo compounds are particularly effective and preferred from the viewpoint of grafting rate.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1, Comparative Examples 1 to 4 In a 10QQag four-loop flask equipped with a cooling tube, nitrogen introduction tube, stirring rod, and thermocouple for internal temperature detection, 270.0.9% of aluminum oxide was added as an inorganic compound to 700% of deionized water.
Suspend in m and count 1. Me 3o daytime string replacement was performed. Next, methyl methacrylate was used as the vinyl monomer28.
O, @ were added with vigorous stirring under nitrogen flow.

Next, the temperature of the reaction solution was raised to 70°C in a hot water bath, and after confirming that the added monomer was uniformly dispersed, the sulfonate monomer was added using SEM-Na10. Ofly
20114 in deionized water and benzoyl peroxide 1. as a radical initiator. Ogr as methyl methacrylate2. A solution dissolved in Ogr was gradually added, and a polymerization reaction was carried out at the same temperature for 8 hours. After the polymerization was completed, about 5 gr was sampled from the reaction solution, and the amount of remaining unreacted monomer was determined by gas chromatography using dioxane as an internal standard reagent to determine the polymerization rate.

The polymer composition after the reaction was thoroughly dried at 105° C. for a day and night, and then completely calcined at 650° C. for 3 hours, and the amount of the inorganic compound was calculated from the weight loss.

For comparison, similar polymerization operations and post-polymerization evaluations were conducted to examine the polymerization behavior in the case of a non-catalytic polymerization system of Jubei without the addition of a radical initiator and in the case of no sulfonic acid monomer or sulfonate monomer. did. The results are shown in Table 1.

As is clear from Table 1, although the system shown in Comparative Example 2 without the addition of sulfonic acid monomer or sulfonate monomer shows a high polymerization rate, the composite rate is extremely low, and the inorganic compound and homopolymer tend to separate. Can be seen. Furthermore, compared to Comparative Example 1, the method of the present invention (
It can be seen that in Example 1), both the monomer polymerization rate and the composite rate are significantly improved.

The polymer compositions of Example 1 and Comparative Examples 1 and 2 shown in Table 1 were treated with benzene, which is a good solvent for methyl methacrylate-8EM-Nh copolymer, for 50 hours, and with acetone for 50 hours. Table 2 shows the results of examining the decrease in polymer content by performing continuous Soxhlet extraction with formamide for 200 hours. Here, the polymer content after sufficient extraction with trimethylformamide for 200 hours is defined as the true grafting rate in the sense that the polymer is firmly integrated onto the surface of the inorganic compound through chemical bonds. It was determined that

For comparison, we also prepared polymer coated compositions prepared by solvent blending polymethyl methacrylate and methyl methacrylate-3EM/N-breath copolymer with inorganic powder (aluminum oxide). Similar extraction operations were performed for Examples 3 and 4), and the decrease in polymer content was compared and studied.

2nd table wood 1 The inorganic compound used is aluminum oxide *2 Comparative examples 2 and 3 using Acrypet (vH) manufactured by Mitsubishi Rayon Co., Ltd.
．． The polymer component in the composition shown in No. 4 is completely extracted by the continuous extraction operation described above, regardless of the polymer solution blend system. This indicates that even in the polymerization system, in the absence of the sulfonic acid monomer or sulfonate monomer, the produced polymer is merely chemically or physically adsorbed onto the surface of the inorganic compound. Furthermore, in Comparative Example 1, although some of the produced polymers were strongly integrated, the level of the grafting ratio was extremely low. On the other hand, in Example 1 according to the method of the present invention in which a radical initiator was added in the presence of a sulfonic acid monomer or a sulfonate monomer, the extraction rate was very small even after a series of severe extraction operations, and a high grafting rate was achieved. and further polymer composition with NaOH
Even after washing with an aqueous solution, the grafting rate is almost the same as after the extraction operation, so the integration of this strong polymer with the surface of the inorganic compound requires hydrogen bonding at the interface, which is stronger than ionic bonding. It was confirmed that a chemical bond tank, that is, a covalent graft bond, exists.

Examples 2 to 5 In Example 1, SEM-Na was used as a sulfonic acid monomer or a hasulfonate monomer,
Polymerization was carried out in the same manner as in Example 1, except that , AMPS, NaAS, and NaMS were used, and the grafting efficiency was measured and evaluated. The results are shown in Section 3.

As is clear from Table 3, the grafting efficiency is SEM-Nm
, SPS and AMPS showed extremely high levels. Examples 6 to 9 The reaction was carried out in the same manner as in Example 1, except that the type of radical initiator was changed, and the results of evaluating the obtained compositions are as follows. It is shown in Table 4.

As is clear from Table 4, the lipophilic radical initiators BPO, LPO, AIBN, etc. have a relatively higher 1-g-2-ft efficiency than water-soluble AIBA, KPS, etc.

Example 10 - Process 1 The reaction was carried out in the same manner as in Example 1, except that the vinyl monomer shown in Table 5 was used in place of methyl methacrylate, and the resulting composition was evaluated. The results are shown in Table 5.

As is clear from Table 5, according to the method of the present invention, high grafting efficiency can be achieved with any vinyl monomer (Example 10.11).

Example 12 The reaction was carried out in the same manner as in Example 1 except that the type of inorganic compound was changed, and the results of evaluating the obtained composition were shown in the sixth example.
Shown in the table.

As is clear from Table 6, the method of the present invention is applicable to almost all inorganic compounds, is significantly higher than conventional non-catalytic polymerization systems in terms of both polymerization rate and grafting efficiency, and is capable of producing more advanced polymers. It is shown that the composition is provided.

Example 13, Comparative Examples 5 to 7 As one way to evaluate the applicability of the polymer composition obtained by the method of the present invention to composite materials, the combination of the polymer composition and polymethyl methacrylate as a matrix or a wax was evaluated. Composite (inorganic compound content 80wt%) at 200℃ p 20
Table 7 shows the results of examining the appearance and bending strength of molded products press-formed under the conditions of kl/cR2.

(-h----11--------,----1 Table 7 As is clear from Table 7, the method of the present invention (Example 13) significantly improves the composite effect on the appearance and strength of molded products. is recognized.

Claims (4)

[Claims] (1) The following general formula, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1) [In the formula, R_1 is H, an alkyl group of C_1 to C_2_0,
Indicates a phenyl group and its derivatives or a halogen atom,
-CONH-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼(
In the formula, R_2 and R_3 are each H or C_1 to C_1_
5, and R_4 represents an alkylene group of C_1 to C_1_5), -COO(CH_2)-_m(
m is an integer from 1 to 20) or -(CH_2)-_n(
In the formula, n is 0 or an integer of 1 to 20), Y is H,
In the presence of a sulfonic acid represented by NH_4 or an alkali metal atom] or its sulfonate, at least one radically polymerizable vinyl monomer is reacted with a radical initiator in an aqueous polymerization system in which an inorganic compound is dispersed. 1. A method for producing a polymer composition in which an inorganic compound and an organic polymer are strongly integrated, the method comprising polymerizing the composition using the following method. (2) The above sulfonic acid or its salt is 2-acrylamido-2-methylpropanesulfonic acid, sodium 2-methacrylethanesulfonate, sodium 3-methacrylatepropanesulfonate, sodium 2-propenesulfonate, 2-methyl-2- The manufacturing method according to claim 1, which is sodium propenesulfonate. (3) The above inorganic compound belongs to Periodic Table I, II, III, IV,
Claims selected from group V or transition group metals and their oxides, hydroxides, chlorides, sulfates, sulfites, carbonates, phosphates, silicates and mixtures and complex salts thereof. Manufacturing method of scope 1. (4) The manufacturing method according to claims 1, 2, and 3, wherein the radical initiator is decomposed in a temperature range of 40°C to 100°C.