JPS63312337A - Fluorine-containing polymer composition - Google Patents

Abstract

PURPOSE:To obtain a fluorine-containing polymer composition having excellent heat resistance and solvent resistance, neither coloring nor foaming during molding, consisting of a terpolymer of tetrafluoroethylene, chlorotrifluoroethylene and ethylene and a specific polymer. CONSTITUTION:A fluorine-containing polymer composition which consists of (A) a terpolymer comprising tetrafluoroethylene (hereinafter referred to as TFE), chlorotrifluoroethylene (hereinafter referred to as CTFE) and ethylene (hereinafter referred to as ET), preferably 10-60mol.% TFE, 20-60mol.% CTFE ad 20-40mol.% ET, having >=325 deg.C thermal decomposition starting temperature, <=250 deg.C melting point, >=120 deg.C difference between melting point and thermal decomposition point and >=60 oxygen index and (B) one or more polymers (e.g. tetrafluoroethylene-ethylene copolymer) having a higher thermal decomposition temperature than the melting point of the component A and has preferably 10-90wt.% component A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluoropolymer composition.

[Conventional technology] In the past, in order to impart the heat resistance, solvent resistance, low surface energy, and other effects that are characteristic of fluoropolymers to hydrocarbon polymers, methods of laminating fluororesin films and surface modification were developed. A method of fluoridation is known. However, when laminating fluororesin films, it is difficult to laminate articles with complicated shapes, and since the adhesiveness of the films is not sufficient, there are problems such as peeling at the adhesive surface. On the other hand, the method of fluorinating the surface can give the properties of fluororesin to objects with complex shapes, but the fluorine gas and hydrogen fluoride used as fluorinating agents are highly dangerous and difficult to handle. There's a problem. In addition, since both methods impart the characteristics of fluororesin only to the surface, they cannot be said to be essential improvements, and there is also the problem that the improvement effect will be lost if the surface wears out with use. there were.

On the other hand, one possible method to improve wood quality is to blend fluorine-based polymers, but since fluorine-based polymers have a high molding temperature, if they are blended with hydrocarbon-based polymers, discoloration and foaming may occur during molding. There was a problem. Among fluoropolymers, polyvinylidene fluoride has a relatively low melting point, so it can be blended with hydrocarbon polymers, but polyvinylidene fluoride itself is a polymer with low solvent resistance, so even if blended with it, it will not be resistant to solvents. There was also the problem that there was almost no improvement in sex.

[Problems to be Solved by the Invention] An object of the present invention is to overcome the drawbacks of the prior art.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and uses a tertiary copolymer of tetrafluoroethylene, chlorotrifluoroethylene, and ethylene. The present invention provides a fluoropolymer silicate characterized by containing one polymer and at least one second polymer having a thermal decomposition point higher than the melting point of the first polymer.

In the present invention, the first polymers include tetrafluoroethylene (hereinafter referred to as TFE), chlorotrifluoroethylene (hereinafter referred to as CTFE), and ethylene (hereinafter referred to as E
This is a tertiary copolymerization in which T is copolymerized. By using a terpolymer of 'T'FE, CTFE and ET as the first polymer, the excellent effects of the fluororesin are not impaired, and even when blended with a hydrocarbon polymer, there is no problem during molding. This eliminates problems such as coloring and foaming. Moreover, it is preferable that the first polymer has a thermal decomposition initiation temperature of 325° C. or higher. A polymer with a thermal decomposition point that is too low is not preferable because it may not be possible to obtain a molded product with a good appearance when a polymer with a high melting point, such as a fluorine-based polymer, is used as the second polymer described later. Furthermore, the difference between the melting point and the thermal decomposition point of the first polymer is 120
It is preferable that the temperature is less than 2°C. If the difference between the melting point and the thermal decomposition point is too small, the molding conditions and the type of the second polymer will be finely limited, which is not preferable.

Moreover, it is preferable that the first polymer has an oxygen index of 60 or more. By using a polymer with an oxygen index of 60 or more, flame retardancy can be imparted to the composition, making it possible to apply it to uses such as electric wire coatings and fireproofing materials. Moreover, it is preferable that the first polymer has a melting point of 250° C. or lower. If the melting point of the first polymer is too high, the molding temperature will be high and a large amount of energy will be required, and the second polymer that can be blended will be limited, which is not preferable. Further, since the first polymer has good mechanical strength and good moldability, the volume flow rate defined below is preferably about 5 to 200 mm37 seconds, particularly 10 to 150 mm3/second.

The term "volume flow rate" used herein is defined as follows and serves as a measure of molecular weight. That is, using a Koka type flow tester, 1 g of sample is extruded through a nozzle with a nozzle diameter of 1 mm and a land of 2 mm under a specified temperature and a specified load of 30 kg/cm2, and the melt extruded per unit time. The value expressed in volume of the sample is defined as the "volume flow rate", and its units are mm'/sec. Here, the predetermined temperature is selected from within the moldable temperature range (temperature range between melting point and thermal decomposition point) of a specific polymer.

Therefore, 300°C is selected as the predetermined temperature for the first polymer in the present invention.

In addition, in the first polymer, the copolymerization ratio of the three components is
It is not particularly limited, and can be selected as appropriate to achieve the required physical properties. In particular, terpolymers in which TFE, CTFE, and ET are copolymerized in proportions of 10 to 60 mol%, 20 to 60 mol%, and 20 to 40 mol%, respectively, have relatively low melting points and are extremely flame retardant. It is preferable because it is excellent. Particularly preferably, TFE, CTFE, and ET each have a content of 15 to 55%.
It is a terpolymer copolymerized at a ratio of 20 to 55 mol% and 25 to 35 mol%.

In order to produce the terpolymer which is the first polymer of the present invention, conventionally known or well-known polymerization methods for copolymers such as TFE and CTFE can be employed without particular limitation. For example, any method such as solution polymerization, suspension polymerization, or emulsion polymerization can be used.

Polymerization initiators that can be used in solution polymerization include, for example, cy(chlorofluoroacyl)-peroxide,
C (perfluoroacyl) - peroxide, C (
ω-hydroperfluoroacyl)-peroxide,
Examples include t-butyl peroxyisobutyrate and diisopropyl peroxydicarbonate. In addition, a chlorofluoroalkane is used as a solvent, and examples of the chlorofluoroalkane include trichlorofluoromethane, dichlorodifluoromethane, dichlorofluoromethane, chlorodifluoromethane, trifluoromethane,
Examples include trichlorotrifluoroethane, dichlorotetrafluoroethane, chloropentafluoroethane, difluoroethane, and the like. Further, a chain transfer agent may be added for controlling the molecular weight if necessary, such as carbon tetrachloride, n-pentane, n-hexane, and isopentane.

Preferably, chain transfer agents such as trichlorofluoromethane and methanol are used.

In suspension polymerization, the same radical polymerization initiators as mentioned above for solution polymerization can be used, and the solvent used is a mixture of water and a chlorofluoroalkane as mentioned for solution polymerization above, and the mixing ratio is usually Water:chlorofluoroalkane-1,9-9:1 in weight ratio. Preferably 1:
5 to 5: ] level. Furthermore, as the chain transfer agent, it is desirable to use the solution-polymerized one described above. Furthermore, as suspension stabilizers, fluorocarbon emulsifiers, such as C
, F, 6COONH4, C3FI7COONH4, etc. may be added.

Radical polymerization initiators that can be used in emulsion polymerization include:
A conventional water-soluble radical polymerization initiator is used. Examples include disuccinic acid peroxide, ammonium persulfate, potassium persulfate, t-butylperoxyisobutyrate, 2,2'-diguanyl-2,2'-azopropane dihydrochlorite, and the like. As the solvent, water alone or a mixed solvent of water and an organic solvent can be used. The organic solvent is t-butanol.

Difluoroethane, trichlorotrifluoroethane, etc. can be used, and as the chain transfer agent, those mentioned for solution polymerization can be used. As the emulsifier, fluorocarbon emulsifiers are desirable, such as C, F15C0ONH4, C,
F, , C00NI+4, etc.

The polymerization conditions in the various polymerization methods described in 1. are not particularly limited and can be adopted over a wide range, and specific polymerization methods, conditions, etc. are exemplified in the Examples below.

In the present invention, a polymer having a thermal decomposition point higher than the melting point of the first polymer is employed as the second polymer. If the thermal decomposition point of the second polymer is lower than the melting point of the first polymer, it is generally molded at a temperature higher than the melting point of the first polymer, which tends to cause problems with foaming and coloring during molding, which is not preferable. In particular, when the second polymer is a thermoplastic resin, the volumetric flow rate described later is 5 to 2 QOmm37
Polymers falling within the range of 1.5 seconds are preferred because they have excellent moldability and it is easy to obtain molded products with good appearance. The second polymer may be one type or two or more types.

Here, the volumetric flow rate of the second polymer is defined in the same way as for the first polymer, and the predetermined temperature is a temperature equal to or higher than the melting point of the second polymer by 10°C, and is a temperature range in which the second polymer can be molded. Recruited from within. For the second polymer in the present invention, the temperature employed when molding the composition of the present invention is selected as the predetermined temperature.

Specific examples of the second polymer include thermoplastic resins such as polyolefin resins, polyamide resins, polyacetal resins, polycarbonate resins, polyester resins, and acrylic resins, natural rubber, isoprene rubber, butadiene rubber, Synthetic rubbers such as chloroprene rubber, nitrile rubber, acrylic rubber, urethane rubber, silicone rubber, detrafluoroethylene-hexafluorobrobylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, Thermoplastic fluororesins such as detrafluoroethylene-ethylene copolymer, chlorotrifluoroethylene polymer, chlorotrifluoroethylene-ethylene copolymer, polyvinylidene fluoride, tetrafluoroethylene-vinylidene fluoride copolymer, Widely used in fluorine-containing elastomers such as tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, and tetrafluoroethylene-propylene copolymer. It is possible to give an example.

In the present invention, when a thermoplastic resin is employed as the second polymer, the molded product has extremely good heat resistance, chemical resistance, etc. Moreover, the effect that a molded article having high flame retardancy can be obtained is obtained. When natural rubber or synthetic rubber is used as the second polymer, molded products with excellent heat resistance, chemical resistance, and flame retardancy can be obtained, as in the case of thermoplastic resins, and the high-temperature strength of the molded products can also be improved. improves. When a thermoplastic fluororesin is employed as the second polymer, a molded article with excellent flexibility can be provided without impairing the properties of the fluororesin. Further, when a fluororesin having poor flame retardancy is used as the fluororesin, such as tetrafluoroethylene-ethylene copolymer or polyvinylidene fluoride, it is possible to impart flame retardance as well as the above-mentioned flexibility. Furthermore, when a fluorine-containing elastomer is employed as the second polymer, flame retardance can be imparted to the molded article, and the high temperature strength of the molded article is also improved. In particular, it is preferable to contain a fluorine-containing polymer such as a thermoplastic fluororesin or a fluorine-containing elastomer as the second polymer because it has particularly excellent heat resistance, solvent resistance, and the like.

In the present invention, the ratio of the first polymer to the second polymer is not particularly limited, and the effect can be recognized even if the first polymer is in a very small amount. Practically, it is preferable that the first polymer is contained in an amount of about 5% by weight or more based on the total amount of the first polymer and the second polymer. As the proportion of the first polymer increases, the physical properties of the silicate approach those of the first polymer. 1st
Although the upper limit of the proportion of the polymer is not particularly limited, it is practically preferable to set it to about 95% by weight or less. In particular, the first polymer IQ is preferably 90% by weight. Further, the ratio of the first polymer to the second polymer can be appropriately selected depending on the purpose. For purposes where heat resistance, solvent resistance, flame retardance, etc. are particularly required by taking advantage of the characteristics of the first polymer, the proportion of the first polymer is preferably about 48 to 90% by weight. On the other hand, when the purpose is to improve the second polymer, for example, when the second polymer is a rubber or elastomer and is intended to impart mechanical properties, heat resistance, solvent resistance, and flame retardance, the first polymer The ratio of 10
The content is preferably about 60% by weight.

The composition of the present invention may contain fillers, additives, etc. in addition to the first polymer and second polymer described above. Such fillers include silica.

Inorganic fillers such as alumina, bronze, and carbon black; heat stabilizers such as copper, copper compounds, tin, and tin compounds;
Examples include light absorbers such as ultraviolet absorbers or light stabilizers, colorants such as pigments and dyes, antioxidants, and lubricants. Further, when natural rubber, synthetic rubber, or fluorine-containing elastomer is used as the second polymer, it is preferable that a compounding agent for vulcanization is included. The compounding agent for vulcanization can be appropriately selected depending on the vulcanization system, such as peroxide type, amine type, or polyol type. −・Generally, as a compounding agent for vulcanization,
A vulcanizing agent, a vulcanization accelerator, a vulcanizing catalyst, and if necessary an acid acceptor are used. In addition, when the film forming temperature is high, there is a problem that vulcanization accelerator etc. volatilizes during forming and causes environmental pollution, but in the composition of the present invention,
Since molding can be performed at relatively low temperatures, there are almost no problems such as those mentioned above. Furthermore, the problems mentioned in item 2 may be solved by using a compound which is prepolymerized and has a high volatilization start temperature as a vulcanization accelerator. Also,
As the vulcanization method, conventionally known vulcanization methods such as thermal vulcanization and vulcanization with energy beams such as electron beams and radiation may be appropriately employed.

A molded article having a specific composition of the present invention includes a first polymer,
After mixing the second polymer and optional fillers and additives, it can be molded using a conventional molding machine such as an extrusion molding machine, a pressure molding machine, or an injection molding machine. Alternatively, the mixture may be heated and mixed in advance using a brushender, extruder, etc., and then molded using a double molding machine. Since the composition of the present invention has excellent moldability, molded products with good appearance without coloring or foaming can be obtained, and can be used for various molded products such as films, sheets, tubes, and O-rings. Can be done. It can also be applied to composite molded products such as wire coatings.

[Example] In the examples shown below, the melting point, thermal decomposition point, copolymer composition 7, oxygen index, and melt flow rate were measured by the methods shown below.

Using a DT-3D model manufactured by Kairan-Zenbunno Shishimajiru Seisakusho, the temperature was raised from room temperature at a heating rate of 10°C/min, and the maximum value of the melting curve was taken as the melting point, and the thermogravimetric curve began to decrease. The point was taken as the thermal decomposition point.

The composition of the nine-grained copolymer was calculated from the fluorine content and chlorine content of the copolymer. The fluorine content and chlorine content were each measured by the following methods.

That is, the fluorine content was measured by trapping fluorine generated by thermal decomposition of the copolymer in an aqueous solution and using a fluoride ion selective electrode (No. 476042, manufactured by Corning, USA). In addition, the chlorine content was determined by molding the copolymer into a sheet and using a fluorescent X-ray analyzer (IKF manufactured by Rigaku Denki).
3064M type).

The test was carried out according to the method of JIS K7201-1972 on lentils using Kigindle method combustion tester No. 606 manufactured by Toyo Seiki Co., Ltd.

62.6 kg of trichlorotrifluoroethane and 56.1 kg of trichlorofluoromethane were added to an evacuated and stirred 120Q stainless steel autoclave of 1 thfm, and then chlorotrifluoroethylene 6.4.6kg
, 260 g of ethylene, 12.1 g of tetrafluoroethylene
kg were added to each. The temperature of the autoclave was increased to 65°C under stirring, and 41.6 g/Q of t-butylperoxyisobutyrate was added to trichlorotrifluoroethane.
500 mQ of the solution dissolved in was added. The pressure at this time is
It was 12kg/cm2. As the polymerization started, a mixed gas having a composition of 50 mol% of tetrafluoroethylene, 20 mol% of chlorotrifluoroethylene, and 30 mol% of ethylene was continuously added so that the pressure was kept constant.

After 3 hours of polymerization, the product was collected and dried at 150° C. for 9 hours to obtain 151 kg of polymer. The composition of this polymer was determined by the measurement method described above and was found to be TFE/CT F E/ E T = 4.
5/24/31 (mol%).

Furthermore, the melting point, thermal decomposition point, etc. were measured and are shown in Table 1. Using a similar procedure, Polymer II having a different composition was obtained by selecting the initial charge composition ratio and the additional charge composition ratio as shown below.

Example 1 and Comparative Example 1 50 parts by weight of polymethyl methacrylate (volume flow rate 35 mm 37 seconds at 200°C, thermal decomposition point 235°C) and 150 parts by weight of the polymer shown in Table 1 were melt-kneaded at 200°C. It was press-molded into a sheet.

Table 2 shows the results of evaluating the solvent resistance and oxygen index of this sheet and the polymethyl methacrylate single sheet.

Table 2 O indicates that there was no change, △ indicates that a small amount of rack occurred, and × indicates that it was dissolved.

Example 2 and Comparative Example 2 Ethylene-tetrafluoroethylene copolymer (ET/T
FE copolymer) (volume flow rate 50 at 300°C
mm"/sec, thermal decomposition point 355 °C) and 150 parts by weight of the polymer shown in Table 1 were melt-kneaded at 300 °C and press-formed into a sheet at 300 °C. Table 3 shows the results of measuring the oxygen index and flexural modulus of the single polymer sheet.

Table 3 Example 3 and Comparative Example 3.4 Tetrafluoroethylene-propylene copolymer (TFE
/P copolymer) (thermal decomposition point 400°C) 50 parts by weight and the first
After kneading 50 parts by weight of the polymer Tl shown in the table, 5 parts by weight of triallylisocyanurate, and 1 part by weight of a-a'-bis-(t-butylperoxy)p-diisopropylbenzene (beloxylin) at 170°C, It was press-molded into a sheet at ℃. Also, instead of polymer 11, ET/T
Using FE copolymer, kneading at 280°C and heating at 300″C
A sheet was obtained in the same manner except that it was press-molded. Table 4 shows the results of evaluating the tensile strength (according to ASTM D63B) and appearance at room temperature and 100°C. In addition, the formulation using the ET/TFE copolymer instead of the polymer TI was kneaded at 170°C and
Press molding at 00°C was not possible.

Table 4 Example 4 and Comparative Example 5 Ethylene-propylene rubber (EP rubber) (thermal decomposition point 28
0 °C), Polymer II, carbon black 50, zinc white, stearic acid, peroxide compound (Samberox DCP: trade name) and triallyl isocyanurate shown in Table 1 were blended in the composition shown in Table 5. ,
After kneading at 170°C, the mixture was press-molded into a sheet at 200°C. Regarding this sheet-like material, room temperature and 100°C
Table 5 shows the results of measuring the tensile strength (according to ASTM D638) and evaluating the appearance.

Table 5 [Effects of the Invention] As explained above, the composition of the present invention has excellent properties such as heat resistance and solvent resistance, and has a good appearance without coloring or foaming during molding. A molded article having the following properties can be obtained.

In particular, the first polymer contains 10 to 60% of tetrafluoroethylene, chlorotrifluoroethylene, and ethylene, respectively.
By using a ternary copolymer copolymerized at a ratio of 20 to 60 mol% and 20 to 40 mol%, the effect becomes particularly remarkable and a composition with excellent flame retardance can be obtained. Can be done. Furthermore, when natural rubber, synthetic rubber, or fluorine-containing elastomer is employed as the second polymer, in addition to the above-mentioned effects, there is also the effect that mechanical properties are improved.

Claims (1)

[Claims] 1. A first polymer which is a terpolymer of tetrafluoroethylene, chlorotrifluoroethylene and ethylene, and at least one polymer having a thermal decomposition point higher than the melting point of the first polymer. A fluoropolymer composition comprising a second polymer. 2, tetrafluoroethylene, chlorotrifluoroethylene and ethylene are each 10 to 60 mol%, 20
2. The composition according to claim 1, which is a copolymer in which the copolymer is copolymerized in amounts of ~60 mol% and 20-40 mol%.