JP2000191925A - Organic and inorganic composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organic and inorganic composite material excellent in dispersibility to a vinyl monomer or organic polymer or the like, and interfacial adhesiveness with these organic phase by inserting a specific polymer to the intercalation of a lamellar silicate. SOLUTION: The polymer of formula [R1-R3 are each H, an alkyl of <=18C; X is a 2-4C alkylene; Y is (meth)acrylate, vinyl aromatic monomer, (meth) acrylonitrile or the like] is inserted to the intercalation of the lamellar silicate. Smectite based clay minerals such as beidellite, nontronite, hectorite or the like are cited as the lamellar silicate, lamellar phylo silicate comprising magnesium silicate or aluminum silicate having 7-12A thickness is preferred. A polymerizable composition is obtained by dispersing this composite material in a vinyl monomer[preferably, vinyl monomer including >=50 wt.%. of (meth) acrylate].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite obtained by reacting a layered silicate and an ammonium salt of a vinyl polymer, and further relates to a polymerizable compound obtained by dispersing the composite in a vinyl monomer. It relates to a composition.

[0002]

2. Description of the Related Art For the purpose of improving the strength and heat resistance of a polymer material, calcium carbonate, glass fiber,
Although an inorganic filler such as talc is used, a generally used inorganic filler has low interfacial adhesion to the organic polymer side, and thus the mechanical strength of the obtained material is one step away. There are several proposals for increasing the interfacial adhesion between an organic polymer and an inorganic filler, and one of them is to use a sol-gel method in which fine silica is precipitated in a resin using alkoxysilane as a starting material. Hybrid materials are known. In addition, there is also a method of synthesizing a polyamide or polystyrene between layers of a clay mineral to obtain a composite [“Polymer” Vol. 19, p. 759, issued by The Society of Polymer Science (1979)].

Further, Japanese Patent Application Laid-Open No. 9-227118 reports a composite in which a polymer ammonium ion having both oxypropylene units and oxyethylene units is inserted between layers of a clay mineral. However, the composite disclosed in the publication has poor compatibility with hydrophobic polymers such as polymethyl methacrylate, polystyrene, and polyamide, and is insufficiently effective in improving the strength of those polymers.

[0004]

SUMMARY OF THE INVENTION In the present invention, an organic-inorganic composite having excellent dispersibility in a vinyl monomer or an organic polymer, and excellent interfacial adhesion with an organic phase made of such a material is provided. The purpose was to provide.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the first invention in the present invention is an organic-inorganic composite in which a polymer represented by the following formula 2 is inserted between layers of a layered silicate.

Embedded image (Wherein, R ^{1 to} R ³ are hydrogen or an alkyl group having 18 or less carbon atoms, X is an alkylene group having 2 to 4 carbon atoms, Y is a (meth) acrylate, an aromatic vinyl monomer, (meth) A vinyl monomer unit selected from acrylonitrile, vinyl ester or vinyl ether, and the average degree of polymerization n is 4 to 60.) Further, the second invention provides the above-mentioned composite and the (meth) acrylate monomer content Is a polymerizable composition comprising a vinyl monomer having a content of 50% by weight or more. Hereinafter, the present invention will be described in more detail.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The layered silicates in the present invention include smectite clay minerals such as beidellite, nontronite, hectorite, saponite, stevensite, montmorillonite and bentonite, vermiculite, halloysite and the like. Alternatively, any of synthetic ones can be used. A preferred layered silicate is a layered phyllosilicate mineral formed of a magnesium silicate or aluminum silicate layer having a thickness of 7 to 12A. In the present invention, a layered silicate having an exchange capacity of 50 to 200 meq / 100 g is preferable. If the capacity is less than 50 meq / 100 g, the amount of ion exchange is insufficient and complexing with the ammonium ion-containing polymer tends to be insufficient, while if the capacity exceeds 200 meq / 100 g, the interlayer bonding force is too strong and ammonium ion is too strong. Insertion of the contained polymer becomes difficult. Further, for the same reason as this, it is preferable occupied area of the layer surface per negative charge monovalent is 25~200A ^2. The layered silicate may contain 50% by weight or less of non-clay impurities.

In the present invention, the organic polymer inserted between the layers of the layered silicate is an ammonium ion-containing polymer represented by Chemical Formula 2. In the present invention, the ammonium ion in the polymer ion-exchanges with the cation in the layered silicate, so that the polymer is inserted between the layers of the silicate to form a complex. As R ^{1 to} R ³ in the general formula 2, hydrogen or an alkyl group having 10 or less carbon atoms is preferable. When R ^{1 to} R ³ are an alkyl group having more than 10 carbon atoms, the dispersing ability of the resulting composite in a hydrophobic polymer tends to decrease. As the structural unit X, an ethylene structure having 2 carbon atoms is preferable from the viewpoint of availability of raw materials. As the monomer unit Y of the polymer, a (meth) acrylate monomer unit or an aromatic vinyl monomer unit is preferable. As Y, single or plural kinds of monomer units can be used. Average degree of polymerization n
Is preferably 5 to 30. If the average degree of polymerization n is less than 5, the dispersibility in the vinyl monomer and the polymer is poor, and if it exceeds 30, the ionic bonding property on the surface of the silicate layer is reduced. The average degree of polymerization in the present invention is a number average degree of polymerization.

The above ammonium ion-containing polymer can be synthesized, for example, by the following method. That is, 2-aminoethanethiol or a hydrochloride thereof is used as a chain transfer agent to radically polymerize a radical polymerizable monomer such as (meth) acrylate or styrene. When using 2-aminoethanethiol as a chain transfer agent,
After polymerization, the amino group is neutralized with an acid such as hydrochloric acid or sulfuric acid to convert it into ammonium. It is preferable to use 2-aminoethanethiol hydrochloride from the viewpoint of high efficiency of chain transfer in radical polymerization. As the polymerization solvent, a chain transfer agent,
Preferably, both the monomer and the resulting vinyl polymer are dissolved, and specific examples include dimethylformamide, dimethylacetamide, dimethylsulfoxide, and a mixed solvent thereof with water.

[0009] The organic-inorganic composite of the present invention is obtained by ion-exchanging cations in the layered silicate with ammonium ions in an ammonium ion-containing polymer. Is an inserted compound. The ion exchange,
It can be carried out by mixing an aqueous dispersion of a layered silicate and a solution of an ammonium ion-containing polymer in an organic solvent in a liquid state. The solid content concentration of the aqueous dispersion of the layered silicate is preferably 0.1 to 30% by weight, while the solid content concentration of the organic solvent solution of the polymer is preferably 1 to 70% by weight. A mixture of both solutions is usually prepared at room temperature to 90 ° C. for 5 minutes.
Stirring for minutes to 5 hours completes the ion exchange. As a result of the ion exchange, the organic-inorganic composite produced is precipitated as a precipitate. The target substance can be isolated by washing and purifying the obtained precipitate, followed by drying.

The proportion of the layered silicate and the polymer used in the above ion exchange is preferably such that at least 30% of the cation exchange capacity of the layered silicate is ion-exchanged with ammonium ions in the polymer, more preferably. This is the rate at which 50% or more of the cation exchange capacity of the layered silicate is converted to ammonium ions. further,
In view of the dispersibility of the obtained organic-inorganic composite in a polymer or the like described below, the inorganic component forming the composite (layered silicate)
The weight ratio of the organic component (ammonium ion-containing polymer) and the inorganic component / organic component is preferably from 1 / 0.5 to 1/5.

By dispersing the organic-inorganic composite in a vinyl monomer, a polymerizable composition can be obtained. As the vinyl monomer, one or two or more monomers selected from (meth) acrylate, (meth) acrylic acid, aromatic vinyl monomer, (meth) acrylonitrile, vinyl ester and vinyl ether Is mentioned.
As the (meth) acrylate, aromatic vinyl monomer, vinyl ester or vinyl ether, a monomer having two or more vinyl groups in one molecule can also be used. Preferred vinyl monomers are curable vinyl monomers having a (meth) acrylate content of at least 50% by weight. In the polymerizable composition comprising the organic-inorganic composite and the vinyl monomer, based on the total amount of all components,
The content of the organic-inorganic composite is preferably 0.5 to 40% by weight, more preferably 1 to 25% by weight. The organic-inorganic composite of the present invention has an excellent affinity for a vinyl monomer, and is usually easily dispersed or dissolved. However, when uniformly dispersing the organic-inorganic composite in the vinyl monomer, a kneading device or an ultrasonic mixing device can be used as necessary.

The polymerizable composition of the present invention is polymerized by heat or irradiation of ultraviolet rays or electron beams to form a resin composition (nanocomposite) in which layered inorganic components are finely dispersed. Known radical initiators and photoinitiators can be added according to the polymerization means. Also, for the purpose of adjusting the liquid viscosity and controlling the physical properties of the cured product, various organic solvents, plasticizers, chain transfer agents,
Additives such as pigments, dyes, reinforcing elastomers, and fillers may be used.

The organic-inorganic composite according to the present invention comprises:
It is mixed with a hydrophobic vinyl polymer such as polymethyl methacrylate, polystyrene and polyvinyl chloride to give a resin composition. The weight ratio of the complex in the total composition is 0.5
-40%, preferably 1-25%. If the content of the organic-inorganic composite does not reach the lower limit, the resin performance is poor, and if it exceeds the upper limit, the toughness of the resin decreases. The organic-inorganic composite of the present invention has excellent affinity with the above-mentioned vinyl polymer and is easily dispersed or dissolved. However, various mechanical stirring devices, kneading devices, ultrasonic irradiation devices, and the like can be used as needed for the purpose of more evenly dispersing. Further, the resin composition obtained by the above method, a pigment,
Various additives such as dyes, fillers, lubricants, plasticizers, reinforcing elastomers, glass fibers, carbon fibers, and ultraviolet absorbers may be added.

[0014]

Examples and Comparative Examples Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. In addition, all the parts of the component blend in each example are parts by weight. <Reference Example 1> Synthesis of ammonium terminal MMA-St copolymer (a) 80 parts of methyl methacrylate (MMA) and styrene (S
t) 20 parts were mixed to prepare a monomer mixture, and 90 parts of isopropyl alcohol (IPA) and 10 parts of distilled water were separately mixed to prepare a mixed solvent. In a glass flask equipped with a reflux condenser, a nitrogen inlet tube, a thermometer, two dropping funnels and a stirrer, 30 parts of the monomer mixture,
40 parts of a mixed solvent and 2-aminoethanethiol hydrochloride 3
The mixture was stirred, heated and refluxed. 70 parts of the monomer mixture in one dropping funnel, 7 parts of cysteamine hydrochloride, 0.2 part of 2,2′-azobis- (2-methylbutyronitrile) (hereinafter referred to as ABN-E) and the mixture in the other dropping funnel. 17.5 parts of the solvent was added, and both were added dropwise under reflux over 2 hours. Subsequently, a solution composed of 0.1 parts of ABN-E and 2.5 parts of the mixed solvent was added dropwise over 1 hour, and a solution composed of 0.8 parts of ABN-E and 40 parts of the mixed solvent was added dropwise over 2 hours. Thereafter, the mixture was refluxed for 2 hours to complete the polymerization, thereby obtaining a transparent solution of an ammonium-terminated MMA-St copolymer. The molecular weight in terms of polystyrene determined by gel permeation chromatography of the above MMA-St copolymer was a number average molecular weight of 1500 and a weight average molecular weight of 2400. Acid value obtained from alkali titration is 0.41
It was 8 meq / g, which was almost the same as the theoretical value (0.417 meq / g).

REFERENCE EXAMPLE 2 Ammonium-terminal MMA
Synthesis of -St copolymer (b) A polymerization reaction was carried out in the same manner as in Reference Example 1, except that the total amount of cysteamine hydrochloride charged was increased from 10 parts in Reference Example 1 to 16 parts. The obtained MMA-St copolymer had a number-average molecular weight of 1,100 and a weight-average molecular weight of 1,500, as determined by gel permeation chromatography, in terms of polystyrene. The acid value obtained from the alkali titration was 0.638 meq / g, which was the theoretical value (0.649 meq.
/ g).

[0016]

Example 1 While 120 parts of distilled water was heated and stirred at 80 ° C., 2 parts of high-purity Na-type montmorillonite (Kunimine F, manufactured by Kunimine Kogyo Co., Ltd.) was added little by little, and mixed and dispersed for 1 hour to produce montmorillonite. A dispersion was prepared. In a separate container, terminal ammonium type MMA-St synthesized in Reference Example 1
5.61 parts (2.34 meq) of the copolymer (a) solution, 10 parts of IPA and 2 parts of distilled water were added and mixed. Into this, the previously prepared montmorillonite dispersion 10
0 parts (1.95 meq) were added in portions and mixed for an additional 15 minutes. After standing for 1 hour, the precipitate was filtered by suction and washed several times with warm water. The residue was vacuum-dried at 50 to 100 ° C. to obtain a powder of the organic-inorganic composite (a). FIG. 1 shows a powder X-ray diffraction pattern of the obtained composite, and FIG. 2 shows a powder X-ray diffraction pattern of high-purity Na-type montmorillonite used as a raw material. According to thermal analysis (TG), the weight loss of this composite at 500 ° C. was 61%. Since the theoretical value of the inorganic / organic weight ratio of the composite is about 40/60, it is considered that almost all of the polymer component was thermally decomposed at 500 ° C.

[0017]

Example 2 Ammonium-terminal M synthesized in Reference Example 2
3.62 parts (2.31 parts) of the MA-St copolymer (b) solution
The same operation as in Example 1 was carried out, except that milliequivalent) was used, to obtain a powder of the organic-inorganic composite (b). The weight loss of the obtained composite at 500 ° C. was 49%.

[0018]

Examples 3 to 5 Complexes (a) prepared in Examples 1 and 2
Alternatively, (b), MMA, St and lauroyl peroxide (LPO) were mixed at the ratio shown in Table 1 below. After removing dissolved oxygen by bubbling nitrogen for 5 minutes, a thickness of 1 m
m Teflon mold, heat and cure in a sealed state with the top and bottom sandwiched by PET film,
A sheet was formed (heating condition: 70 ° C. for 2 hours, 90 ° C. 2
Time, 120 ° C. for 1 hour). Each sheet was transparent in appearance. A 5 mm x 50 mm test piece was cut out from the obtained sheet, and a viscoelastic spectrum was measured (measurement conditions:
(Tensile mode, frequency 10 Hz, heating rate 4 ° C./min).
Table 1 shows the data of the storage elastic modulus E ′, the transition temperature E ″ max, and the tan δmax (the temperature at which the loss elastic modulus and tan δ have the maximum values) at 40 ° C. and 130 ° C. Thermal analysis (DS
C, TG), the glass transition point (Tg) and the thermal decomposition temperature (5% decomposition temperature) were measured. The results are shown in Table 1. The heating rate was 10 ° C./min for DSC and 20 ° C. for TG.
/ Min, and all were measured under a nitrogen stream.

[0019]

Comparative Example In the same manner as in Examples 3 to 5, the components shown in Table 1 were mixed, and the resulting polymerizable composition was polymerized to form a sheet.

[0020]

[Table 1]

As can be seen from the table, the elastic modulus and heat resistance are improved by adding a small amount of the composite of the present invention.
Although the amount of the inorganic component in the resin composition is as small as 5% or less, the elastic modulus in the temperature range above the glass transition point is remarkably improved, and the thermal decomposition temperature is increased by 30 ° C or more. I have. The slightly lower glass transition point of the cured product of the example than that of the comparative example is considered to be due to the plasticizing effect of the ammonium-containing polymer used for producing the composite. In order to prevent a decrease in the glass transition point, the Tg of the polymer may be set higher.

[0022]

The composite of a conventionally known silicate and an organic substance is as follows:
Since a long-chain alkyl group or a polyalkylene oxide component is used as an organic component, when the complex is dispersed in a general molding polymer, the compatibility with the polymer is often poor, and Was restricted. On the other hand,
In the organic-inorganic composite of the present invention, since a vinyl polymer used in combination with a silicate can be molecularly designed according to the purpose, a resin composition excellent in dispersibility in a matrix resin and interfacial adhesion can be obtained.

[Brief description of the drawings]

FIG. 1 is a powder X-ray diffraction diagram of a composite (a) obtained in Example 1.

FIG. 2 is a powder X of Na-type montmorillonite [Kunipia F manufactured by Kunimine Kogyo Co., Ltd.] used as a raw material of the composite (a).
FIG.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08F 16/12 C08F 16/12 18/04 18/04 20/10 20/10 20/44 20/44 C09C 3/10 C09C 3/10 // C09C 1/28 1/28 F term (reference) 4G073 BB02 BB28 BB36 BB71 BD16 CA06 CM10 CM14 CM15 CM16 CM19 CM20 CM21 CN03 GA01 GA21 UA08 4J002 AA001 BC001 BC002 BE041 BE042 BF011 BF012 BG011 BG041 BG041 BG041 BG041 BG041 BG041 BG041 BG092 DJ006 FB072 FB086 4J011 AA05 PA13 PB02 PB22 PB40 PC08 4J037 AA17 CC13 CC15 CC16 CC29 EE17 EE28 EE43 FF13 FF15 FF17 4J100 AB01P AB01Q AB02P AB02Q AE02P AE02Q04 AG02P02AL03

Claims (2)

[Claims] 1. An organic-inorganic composite in which a polymer represented by the following formula 1 is inserted between layers of a layered silicate. Embedded image (Wherein, R ^{1 to} R ³ are hydrogen or an alkyl group having 18 or less carbon atoms, X is an alkylene group having 2 to 4 carbon atoms, Y is a (meth) acrylate, an aromatic vinyl monomer, (meth) A vinyl monomer unit selected from acrylonitrile, vinyl ester or vinyl ether, and the average degree of polymerization n is 4 to 60.) 2. A polymerizable composition comprising the composite according to claim 1 and a vinyl monomer having a content ratio of the (meth) acrylate monomer of 50% by weight or more.