JPS5925806A - Preparation of novel polymer composition - Google Patents

Abstract

PURPOSE:To prepare a novel polymer composed of carbon fibers and an organic polymer integrated firmly with the fibers, and having excellent elastic modulus, heat deformation temperature and electrical properties, by polymerizing a vinyl monomer in a polymerization system dispersed with carbon fibers in the presence of an unsaturated carboxylic acid monomer. CONSTITUTION:The objective polymer composition can be prepared by polymerizing one or more radically polymerizable vinyl monomers (e.g. methyl methacrylate) in a polymerization system dispersed with carbon fibers in the presence of a carboxylic acid monomer of formula I (R1 is H, 1-15C alckyl, carboxyl, halogen or phenyl; R2 is H, 1-15C alkyl, carboxyl, halogen, phenyl, etc.; R3 is H, 1-15C alkyl, halogen or phenyl; X is H, NH4 or alkali metal) or formula II (R4 and R5 are H, 1-5C alkyl, halogen or phenyl).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel polymer composition in which carbon fibers (hereinafter abbreviated as CF) and an organic polymer are strongly integrated.

Various polymerization methods are known for the polymerization of hinyl monomers, such as radical polymerization, ionic polymerization, and coordination polymerization.

There are not necessarily many industrially convenient polymerization methods that require the addition of some kind of polymerization initiator or a moisture control tube in ionic polymerization. Moreover, although non-catalytic polymerization methods that do not use a polymerization initiator have been reported for a few unique systems, they have hardly been of practical use from an industrial standpoint.

In view of the above-mentioned current situation, the inventors of the present invention have made extensive studies and found that a vinyl monomer capable of radical polymerization in the presence of a specific carboxylic acid monomer is brought into contact with CF as a third component.

It was discovered that the polymerization activity of the monomer can be significantly increased, CF and organic polymer are strongly integrated, and a novel polymer composition with excellent granulation properties, which cannot be obtained by conventional methods, can be obtained, and the present invention has been achieved. It was completed.

Conventionally, the development of composite materials that mutually complement the properties of the constituent materials and create new effective functions by combining two or more types of materials has been actively conducted, and as a filling material for V model combination. Regarding compounding with useful inorganic compounds, see 1.
A wide range of performance improvements have been reported, including, for example, elastic modulus, heat distortion temperature, and mechanical properties. However, when an organic polymer and an inorganic compound are combined, the properties of the composite materials differ significantly, so they are not compatible.

In addition, it has poor interfacial affinity such as adhesion and is unable to exhibit sufficient composite effects, and in particular, powdered inorganic fillers inevitably deteriorate some of the physical properties of the resin, such as toughness. It has its drawbacks.

To improve this point, a mechanochemical method involves grinding an inorganic compound in the presence of a reactive monomer to graft an organic polymer, and a radiation method involves irradiating an inorganic compound with high-energy radiation to graft an organic polymer. Attempts have been made to improve the interfacial affinity between organic polymeric substances and inorganic compounds using methods such as methods, but these require pulverization processes, radiation generation equipment, etc., resulting in complicated processes and a significant increase in manufacturing costs. There are major problems in terms of practicality.

As a result of intensive studies to improve this point, the present inventors have devised a practical method for producing composites in which various powdered inorganic compounds are firmly integrated with vinyl polymers in the presence of specific carboxylic acid monomers. Heading, first patent application No. 56-35549
I applied for the issue. Subsequently, as a result of further investigation, it was found that CF is particularly rich in polymerization activity as an inorganic compound and has a high interfacial bonding ability.
The present invention has been completed by discovering that the present invention has excellent granulation properties, and exhibits remarkable granulation properties not only for powdered fine fibers but also for relatively long fibers.

That is, the present invention is based on the following general formula (5) (In the formula, R5 is an alkyl group having 1 to 15 H2 carbon atoms.

cooy, halogen atom or phenyl group and its derivatives, R2 is H2 alkyl group having 1 to 15 carbon atoms, c
ooz, halogen atom or phenyl group and its derivatives, R8 is H, Jj [number 1 to 15 alkyl group, halogen atom or phenyl group and its derivatives, x, y
, z each represent H, NH, or an alkali metal atom. ) or a small number of carboxylic acid monomers represented by the general formula (wherein R, , R, respectively represent H9 an alkyl group having 1 to 15 carbon atoms, a halogen atom box, or a phenyl group and its derivatives) (6) CF and organic polymer, characterized by polymerizing at least one kind of radically polymerizable vinyl monomer in the presence of one kind and in a polymerization system in which OF is dispersed. The present invention provides a method for producing a novel polymer composition in which the coalescence is strongly integrated.

Generally, when vinyl monomers are quickly polymerized in the presence of an acid under temperature conditions that do not cause thermal polymerization reactions, the polymerization rate is extremely low even after several days of polymerization time. However, according to the present invention, by adding CF as a third component, a very specific polymerization activity can be increased by 1, and a polymer with a high polymerization rate that is of practical value can be obtained in a few hours. In addition, this method provides an extremely clean Ih polymerization form that does not generate current due to gas phase polymerization.

A further feature of the present invention is that the interaction between the CF surface and the polymer applied by the method of the present invention goes beyond adhesion in the sense of simple adsorption and is strongly integrated. At the point.

In addition, it can be applied not only to fine powder CF but also to relatively long CF such as chopped strand fiber, which is normally difficult to process in a medium due to decreased cohesiveness, entanglement and agglomeration between fibers. This can be said to be a great practical value of the present invention.

An example of an embodiment when carrying out the present invention is as follows:
After suspending and dispersing the organic vinyl fiber yarn and CF in an aqueous medium under temperature conditions that do not cause a thermal polymerization reaction, a calginic acid monomer is added and stirred to cause an aqueous heterogeneous polymerization reaction. The polymer of the vinyl monomer can be uniformly and firmly fixed to the surface of the CF coating at a high polymerization rate over a predetermined polymerization time. At this time, it is an essential condition that the three components mentioned above are brought into contact with each other in coexistence, but it is not necessarily necessary to bring them into contact at the same time. That is, 1. Even if CF is pretreated with, for example, a carboxylic acid monomer, 2. a similar polymer composition can be obtained by the method of the present invention without adding a new carboxylic acid monomer during monomer polymerization. I can do it.

Conventionally, a method for obtaining a similar polymer composition in the presence of Mizuki sulfite ions is known, but since a large amount of current from gas phase polymerization adheres and the product is extremely fine particles, it requires washing and recovery. One drawback regarding industrial practicality is that post-processing is not easy. Regarding these problems, the method of the present invention uses a constant 1% carbo/acidic monomer, resulting in a clean polymerization form with almost no current formation, and, more surprisingly, the resulting polymer composition can be granulated. Because of its excellent properties, it provides a method for obtaining a product with extremely easy post-processes such as washing and recovery.

The specific carboxylic acid monomer used in the present invention has a carboxylic acid group as an active side that brings about monopolymerization activity, and a double bond as an active side that causes strong bonding between the produced polymer and CF. The presence of these two types of functional groups is essential, and a compound having a structural formula as shown in the above-mentioned general formula CI) or [■] formula can be applied. Specific examples include (9) acrylic acid, methacrylic acid, crotonic acid, tiglic acid, cinnamic acid, maleic anhydride, citraconic anhydride, etc., with acrylic acid, methacrylic acid, and crotonic acid being particularly prominent. It exhibits graininess and has high polymerization activity (preferably). These compounds can be used alone or in a mixture of two or more.

The CF used in the present invention includes polyacryloni)
High-strength or high-elasticity CF, petroleum high-temperature decomposition pitch made of IJ or its copolymer.

Examples include CF made from coal tar pitch and coal depolymerized materials, and CF produced by vapor phase growth, and both carbonaceous and graphitic CFs are applicable. Further, various types of CF may be subjected to a commonly performed surface oxidation treatment. A wide range of fiber lengths can be used, from a powdery one with a diameter of about 0.1 mm to a chopped strand with a large aspect ratio of about 3 to 2 Orams, and the fiber diameter is not particularly limited. . All of the composites obtained by the present invention have good interfacial adhesion (10) and are obtained in the form of granules with excellent handling and workability. Among them, chopped strand CF is treated by stirring in water or an organic solvent.

Generally, single fibers coagulate and are difficult to blend with resin, but according to the present invention, by taking advantage of their excellent granulation properties, by adjusting conditions, pellets of about 1 to 5 yen can be easily handled. You can get something like this. Particularly in the case of pitch-based CF, 1. When the fiber length exceeds mXE, the CF' itself is already flocculent and agglomerated, so 1. It cannot be blended with a normal resin, but 1. When the formulation of the present invention is applied,
Since a pellet-shaped composite with good extrusion or injection molding processability can be obtained, the present invention is extremely unique and has high practical value as a method for controlling the shape of the composite in addition to the interfacial effect. The present invention can also be applied to roving-like long fibers if they are left to stand or are subjected to gentle agitation, and excellent interfacial effects can be obtained.

The vinyl monomer used in the present invention includes:

Any ordinary vinyl monomer that can be radically polymerized can be used, but methyl methacrylate is particularly preferred because it has a specific high polymerization activity (and good compatibility between the produced polymer and CF). When a mixture of two or more monomers is used, it is preferable to use methyl methacrylate as one component, especially from the viewpoint of polymerization activity.

According to the invention, the concentration of carbo/acid monomers is CF
and about 0.05 to 100% by weight based on the total weight of monomers.
, preferably 0.1 to 50% by weight.

Particular preference is given to using amounts of 0.5 to 30% by weight.

In most cases, it is preferable to increase the amount of carboxylic acid monomer as the monomer component increases. The weight ratio of monomer or monomer mixture to CF used can vary within a wide range and range from about 500:1 to 1:5. Preferably the ratio is from about 50=1 to about 1:l. The amount of water is about 1 to several hundred times, preferably about 10% to 10 times, based on the total weight of CF and monomer. The reaction is preferably carried out under an atmosphere of an inert gas, such as nitrogen, at a temperature of about 10 to 1
The temperature is preferably 20 to 80°C. The specific reaction temperature here is selected as appropriate depending on the vinyl monomer used, but it is important to carry out the reaction at a temperature at which thermal polymerization is suppressed to a negligible level, and at a high temperature that would cause extremely thermal polymerization to occur. When this is done, the integrity and homogeneity of the resulting conjugate is inhibited. Reaction time is 30 minutes to about 15 hours. The resulting complex is heated between about 10 and 300°C2, preferably at about 50°C.
It can be dried at a temperature range of ~200°C. In addition.

The interaction between the surface of CF 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, and this fact is true for vinyl polymers. This is clear from the fact that even after extraction with a good solvent, a large amount of unextracted polymer was observed.

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

Example 1. Comparative Examples 1 to 6 Cooling tube, nitrogen introduction tube, stirring rod, and internal temperature detection (13) Pitch-based graphite CF (Kenbetsu Kagaku Kogyo Co., Ltd.) was placed in a 500TLl fourth flask equipped with a thermocouple. Chop M-201) 38,7/ was suspended and dispersed in 280 d of deionized water, and the mixture was purged with nitrogen for 30 minutes. Next, methyl methacrylate 30. OJ' was added with vigorous stirring under nitrogen flow. Next, the temperature of the reaction solution was raised to 50°C in a hot water bath, and after confirming the uniform dispersion of the additives, commercially available special grade acrylic acid 2. Ol was gradually added, and the polymerization reaction was carried out at the same temperature for 8 hours. After the polymerization was completed, about 21 samples were taken from the two reaction solutions, and the amount of remaining unreacted monomer was determined by gas chromatography using dioxane as an internal standard reagent to determine the polymerization rate. For comparison, the polymerization behavior in the case of not adding CF, the case of not adding the carboxylic acid monomer, the case of adding propanecarboxylic acid, which is a saturated organic carboxylic acid, and the case of adding sulfite water, was also conducted using the same polymerization operation and Evaluation after polymerization was conducted and discussed (14). The results are shown in Table 1.

Note that all parts in Table 2 represent parts by weight.

As is clear from Table 1, the system shown in Comparative Example 4 in which no carboxylic acid monomer was added showed no polymerization activity, and the simple two-component system of carboxylic acid monomer and vinyl monomer showed no polymerization activity. In contrast, the method of the present invention in which CF is added as a third component significantly increases the monomer polymerization rate, whereas the conventional polymerization system using sulfite water shown in Comparative Example 6 has a high monomer polymerization rate. However, the polymerization conditions such as cullet adhesion and secondary agglomeration performance (granulation properties) were significantly inferior to the method of the present invention, indicating that the method of the present invention dramatically improves the practicality.

Examples 2-6. Comparative Examples 7 to 9 All examples were the same as in Example 1 except that methacrylic/I/acid, crotonic acid, tiglic acid, cinnamic acid, and maleic anhydride were used instead of acrylic acid as the carboxylic acid monomer in Example 1. Polymerization was carried out in the same manner, and the monomer polymerization rate was measured and evaluated.

The results are shown in Table 2 in comparison with Example 1.

Table 2 As is clear from Table 2, the single polymerization activity is extremely high for acrylic acid, methacrylic acid, and chloro/acid.

Tiglic acid, cinnamic acid, and maleic anhydride showed slightly lower levels.

Examples 1 to 60 Polymer compositions obtained by the method 1
The polymer extraction rate of the composition was measured by weighing 01 together with a cylindrical cap and performing a 24-hour Soxhlet extraction experiment using benzene, which is a good solvent for methyl methacrylate polymer, as an extraction solvent. For comparison, a composition coated with polymethyl methacrylate (Comparative Example 7) prepared by dispersing pitch-based CF in a methylene chloride solution of polymethyl methacrylate and then evaporating the solvent was prepared. The composition produced using a radical polymerization catalyst (
Comparative Examples 8 and 9) were also evaluated and examined in the same way. The results are shown in Table 3. The polymer components in the compositions shown in the comparative examples were completely extracted in a 24-hour extraction test, whereas the polymer components in the composites obtained by the method of the present invention were completely extracted. The extraction rate is small, and most of it is not extracted [it is strongly integrated into CF].

(19) Table 3 *l Akrivet (VH) f manufactured by Mitsubishi Rayon Co., Ltd.
AIBN for fl: Azobisisobutyronitrile KP
8: Potassium persulfate (2o) Example 7 The reaction was carried out in the same manner as in Example 1 except that the type of CF was changed, and! ! Table 4 shows the results of evaluating the prepared compositions.

As is clear from Table 4, in the case of untreated CF, especially pitch-based CF, when the fiber length reaches approximately 1 mN or more, the CF itself is already flocculent and agglomerated, so it is blended with resin and extruded. However, when the method of the present invention is applied, a pellet-like composite with good extrusion or injection molding processability can be obtained, making blend extrusion extremely easy.

In addition, in the method of the present invention, no CF selectivity regarding monopolymerization activity was observed, and the monopolymerization rate was generally good, and the extraction rate of the polymer component in the produced complex was small, with most of it not being extracted. First, it can be seen that it is strongly integrated with CF.

Example 8 In place of methyl methacrylate as the vinyl monomer,
The reaction was carried out in the same manner as in Example 1 except that one type of vinyl monomer or a mixture of two types shown in the table was used, and the results of evaluation of the obtained compositions are shown in Table 5.

Table 5 *l The weight ratio of the mixed system is 50150ST: styrene,/BuA n-acrylic acid n-methyl ester.

/MMA: Methyl methacrylate Example 9 In a Henschel mixer for powder kneading, pitch-based CF (M
-201) 38.77' and acrylic @2,0! Add 1
After stirring thoroughly for 0 minutes, the entire amount of the treated filler was mixed with deionized water using a reactor set in the same manner as in Example 1.
The mixture was suspended and dispersed in 0 d of water and replaced with nitrogen for 30 minutes. Next, methyl methacrylate 30.
OL was added with vigorous stirring under a stream of nitrogen.

Next, the temperature of the reaction solution was raised to 50° C. in a hot water bath, and a polymerization reaction was carried out at the same temperature for 8 hours. After completion of polymerization, Example 1
As a result of evaluation in the same manner as above, the monomer polymerization rate was 85.6%, and the obtained composite was a composition in which the CF surface was uniformly and firmly fixed with the polymer of the vinyl monomer. Met.

Example 10 The polymer composition obtained according to the present invention was blended with general purpose polymer pellets, the CF content was adjusted to 30%,
Composite molded products were created using an extruder, and the mechanical and thermal properties of the molded products were evaluated.

For comparison, untreated CF (shown as a simple blend in the table) was similarly blended and evaluated. 6th result
Shown in the table.

(25) Table 6 * Manufactured by Ube Industries, Ltd. As is clear from Table 6, the polymer composition produced by the method of the present invention is a composition with excellent practical properties such as 9 mechanical properties and heat resistance. It shows.

Patent applicant: Mitsubishi Rayon Co., Ltd. (26)

Claims (1)

[Claims] 1. The following general formula (wherein R1 is an alkyl group having 1 to 15 H2 carbon atoms, C0
0Y, halogen atom or phenyl group and its derivatives, R2 is H1 carbon number 1 to 1577) 7? group,
COO2, halokenite or phenyl group and derivatives thereof. R8 is H1 an alkyl group having 1 to 15 carbon atoms, a halogen atom or a phenyl group and its derivatives, X, Y,
Z represents H, NH, or an alkali metal atom, respectively. ) or the presence of at least one carboxylic acid monomer represented by the general formula (wherein R,, R, each represents an alkyl group having 1 to 15 H1 carbon atoms, a halogen atom, or a phenyl group, and a derivative thereof) 1. A method for producing a novel polymer composition, which comprises polymerizing at least one radically polymerizable vinyl monomer in a polymerization system in which carbon fibers are dispersed. 2. The method for producing a novel polymer composition according to claim 1, wherein the carboxylic acid monomer is acrylic acid, methacrylic acid, or crotonic acid. 3. The method for producing a novel polymer composition according to claim 1, wherein the vinyl monomer is methyl methacrylate or a monomer mixture containing methyl methacrylate as a main component.