JP2000026539A - Fluorine-containing molding material, highly syndiotactic fluorine-containing polymer bearing fluoroalkyl groups as side chains therefor and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject fluorine-containing molding material that has excellent water-repelling and oil-repelling properties at elevated temperature and is useful as an optical material that is applicable to elevated temperature by constituting the material with a fluorine polymer of a specific three- dimensional structure bearing fluoroalkyl groups as side chains. SOLUTION: The objective molding material is obtained by constituting it with a fluoropolymer that includes the structural units bearing a fluoroalkyl group, preferably a group of the formula (Y is H, a halogen; m is 0-8; n is 1-25) as a side chain and has >=70%, preferably >=80% syndiotacticity in the stereoregularity of the main chain. This fluorine-containing polymer may comprises only the structural unit bearing the fluoroalkyl side-chains or may include other structural unit less than 90 mol.%, preferably less than 20 mol.%. As a fluoroalkyl side chain unit, are preferably cited an α-substituted olefin containing a fluoroalkyl group, particularly a fluoroalkyl α-substituted acrylic ester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorine-containing polymer having a novel steric structure having a fluoroalkyl group in a side chain and a fluorine-based molding material.

[0002]

2. Description of the Related Art A polymer having a fluoroalkyl group such as a perfluoroalkyl group in a side chain exhibits properties such as water and oil repellency and surface segregation derived from fluorine atoms contained therein, and is used as a surface modifier or coating. It is widely used as an agent. In order to express these unique properties to a higher degree, it is necessary to precisely control the three-dimensional structure of the main chain or the side chain in order to improve the orientation of the side chain fluoroalkyl group.

However, it is difficult to control such a steric structure by a conventional method for synthesizing a fluoroalkyl side chain-containing polymer mainly based on radical polymerization, and there is a limit in improving the performance of the polymer produced. Was.

[0004] Stereospecific anion polymerization using an alkyllithium or Grignard reagent as an initiator has been studied in detail in a system for polymerizing a methacrylate derivative monomer (Polymer Journal,
17, 977 (1985)). However, there is no example of a monomer containing fluorine in the alkyl side chain, except for a few studies, and a system for synthesizing a highly syndiotactic polymer has not yet been found.

Previously we had 65% syndiotacticity
Of poly (2-heptadecafluorooctyl) ethyl methacrylate was synthesized (Proceedings of the 39th Polymer Research Conference, P17 (1993)), but about 54% of syndiotactic polymers were obtained by conventional radical polymerization. It is hard to say that the difference is so significant in view of the fact that they have the itch.

[0006]

In addition, a polymer having a fluoroalkyl group in a side chain may precipitate during polymerization due to poor solubility in a general-purpose solvent due to the fluoroalkyl group. It was difficult to control the polymerization reaction.

[0007] Further, there have been few studies on a fluorine-containing compound solvent which can be a good solvent for a relatively fluorine-based polymer in the development of a polymerization system which provides a high degree of stereospecificity. The development of a catalyst system was an issue.

The present inventors have developed a conventional catalyst system capable of performing stereospecific polymerization in a polymerization system using a fluorine-containing solvent as a polymerization solvent, and have developed a side chain having a chain of 70% or more syndiotacticity. A polymer having a fluoroalkyl group was synthesized.

Furthermore, it has been found that the novel high syndiotacticity-containing fluoropolymer having such a fluoroalkyl side chain is useful as an optical material capable of improving water / oil repellency at high temperatures and usable at high temperatures.

[0010]

That is, the present invention relates to a fluoropolymer having a syndiotacticity containing a structural unit having a fluoroalkyl group in a side chain and having a stereoregularity of the main chain of 70%. And a fluorine-based molding material.

Further, a novel polymer which provides the fluorine-based molding material, that is, formula (I): CH ₂ ＣＲCR ¹ —COO— (CH ₂ ) _m — (CF ₂ ) _n —Y (I) , R ¹ is a hydrogen atom, a halogen atom or a methyl group, Y is a hydrogen atom or a halogen atom, m is an integer of 0 to 8, and n is an integer of 1 to 25) And CH ₂ CR ² —COO—R ³ (II) (wherein R ² is a hydrogen atom, a halogen atom or a methyl group, and R ³ is a C 1-10 Which is an alkyl group having a syndiotacticity of 70% or more.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The fluorine-containing molding material of the present invention has a fluoroalkyl group on the side chain, preferably of the formula (III):

[0013]

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Wherein Y is a hydrogen atom or a halogen atom, m is an integer of 0 to 8 and n is an integer of 1 to 25, and the syndiotacticity is 70% It comprises at least 80% of the fluoropolymer. The fluorinated polymer may be composed of only the structural unit having the fluoroalkyl side chain, or may contain another structural unit of 90 mol% or less, preferably 20 mol% or less. Other structural units may be those that do not reduce syndiotacticity, and specific examples will be described later.

The structural units having a side chain fluoroalkyl group may be the same or different (for example, a mixture of fluoroalkyl groups having different carbon numbers), but the same type is preferred from the viewpoint of improving the crystallinity. Preferred structural units include
Examples thereof include fluoroalkyl group-containing α-substituted olefins, and among them, fluoroalkyl α-substituted acrylates are preferred. A specific example will be described later.

In the fluorine-based molding material of the present invention, the stereoregularity of the main chain is highly syndiotactically controlled. Therefore, when the fluorine-based molding material is amorphous, the glass transition temperature thereof has a stereoregular structure. 3 to 30 ° C compared to none
It rises by about ℃.

In the fluorine-containing molding material of the present invention, even when a fluoroalkyl group (for example, a fluoroalkyl group having 7 or more carbon atoms) crystallizes between side chains, the stereoregularity of the main chain is high. , The melting point derived from the side chain increases by about 3 ° C. to about 30 ° C. as compared with those having no stereoregular structure.

Furthermore, when the main chain has crystallinity, the stereoregularity of the main chain is highly syndiotactically controlled, so that the melting point of the main chain is 3 times higher than that without a stereoregular structure. It rises by about 150 ° C from ° C.

In any case, improvement in mechanical properties at high temperatures, water and oil repellency, gas barrier properties, etc. can be expected due to the rise in melting point and glass transition temperature.

For example, when a side-chain crystalline fluoropolymer is used, it can be used as a coating material utilizing water / oil repellency at high temperatures and as a packaging material utilizing gas barrier properties at high temperatures. When an amorphous fluoropolymer is used, it can be used as an optical material usable at high temperatures.

The present invention also relates to a novel fluoropolymer.

As described above, the novelty of the present invention lies not in the repeating units constituting the fluoropolymer but in the stereoregularity of the main chain of the polymer. That is, a fluoropolymer having a fluoroalkyl group in the side chain and having a syndiotacticity of the main chain of 70% or more was not synthesized. More specifically, the above formula (I)
A fluorine-containing polymer obtained by polymerizing one or more of the monomers alone, or one or two of the monomers (I)
Fluorine-containing copolymers of at least one species and the monomer (II) of the formula (II) are mentioned.

Specific examples of the monomer (I) include:

[0024]

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And the like.

Further, specific examples of the monomer (II) include:

[0027]

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And the like.

The copolymerization molar ratio of the monomer (I) and the monomer (II) is from 10/90 to 100/0, preferably from 80/20 to
100/0.

The fluoropolymer of the present invention has a syndiotacticity of 70% or more, preferably 80% or more. The higher the syndiotacticity, the higher the melting point or glass transition temperature, which is advantageous for use at high temperatures.

The high syndiotactic fluorine-containing polymer of the present invention comprises a monomer (I) or a monomer mixture of the monomers (I) and (II) containing a fluorine-containing solvent. It is obtained by adding a bulky alkyl aluminum in an amount of 2 equivalents or more to 1 equivalent of the initiator in the polymerization solvent in the presence of an anionic polymerization initiator and polymerizing.

In the case of obtaining the above-mentioned anionic polymerization, the polymerization solvent is preferably one in which the monomers ((I) and (II)) and the obtained polymer are sufficiently dissolved and do not coagulate even at a low polymerization temperature. A fluorinated solvent alone or a mixed solvent thereof with a non-fluorinated solvent is used.

If no fluorine-containing solvent is contained, the polymerization may not proceed or the desired syndiotacticity may not be obtained.

Preferred fluorinated solvents include, for example, 1,3-bistrifluorobenzene (m-XHF), C
_{4 H 9 OCH 3, HCFC-} 141b, HCFC-134
and non-fluorinated solvents to be mixed therewith include aromatics such as toluene, diethyl ether, T
Ethers such as HF are preferred. To increase the syndiotacticity 70% or more, and m-XHF or C ₄ H ₉ OCH ₃ as essential components, preferably toluene as the non-fluorinated solvent to be mixed therewith.

As the anionic polymerization initiator, a known anionic initiator having an alkali metal or an alkaline earth metal as a counter cation is suitable. Among them, t-C ₄ H ₉ MgB
Grignard reagents such as r, alkyl lithium such as t-C ₄ H ₉ Li is preferably mentioned.

The bulky aluminum alkyl coordinates the active terminal of the polymerization without leakage, imparts syndiotacticity of the obtained polymer, and acts to increase its stereoregularity. The compounding amount is at least 2 equivalents to 1 equivalent of the polymerization initiator,
It is particularly preferable to use an excess of 3 to 5 equivalents. Specific examples include bis (2,6-di-t-butylphenoxy) methylaluminum [MeAl (ODBP) ₂ ] and bis (2,6-di-t-butylphenoxy) ethylaluminum] [EtAl (ODBP) ₂ ]. EtAl (O 2) is used to increase syndiotacticity.
DBP) ₂ is preferred.

The polymerization temperature is 0 ° C. or lower, preferably -80 to
A temperature at which the polymerization solvent is not frozen in a range of -40 ° C is employed.

The polymerization method may be a batch charging method, a split charging method, or a continuous charging method. Particularly, when two or more monomers are copolymerized, one or more of the monomers may be divided or continuously charged. By polymerizing, a polymer having a homogeneous composition is obtained.

The molecular weight of the fluorine-containing polymer of the present invention is 2,000 to 1,000,000, preferably 10,000 to 500,000, in number average molecular weight.

In the present invention, a fluorine-containing multi-segmented polymer containing the fluoropolymer having a fluoroalkyl side chain and having a syndiotacticity of 70% or more as one segment may be used. The multi-segmented polymer may be in the form of a block copolymer or a graft polymer.

The multi-segmented polymer of the present invention necessarily contains a segment of high syndiotacticity corresponding to the fluoropolymer of the present invention. In the case of a block copolymer, the other segment may be the monomer (II)
Polymer segment, or syndiotacticity is 7
Less than 0% of the fluoropolymer segment of the monomers (I) and (II). The proportion of high syndiotacticity segments is 5-95% by weight, preferably 30-80% by weight. The production method is, for example, that a monomer mixture of the monomer (II) and, if necessary, further the monomer (I) is usually added to the high syndiotactic fluoropolymer produced as described above. What is necessary is just to copolymerize by the method. In this case, the stereospecificity need not be particularly considered.

In the case of a graft copolymer, a fluoropolymer unit having high syndiotacticity may constitute the main chain, or may be a graft chain. Other units are
The polymer unit of the monomer (II) or the fluorine-containing polymer unit of the monomers (I) and (II) having a syndiotacticity of less than 70% is exemplified. The proportion of units with high syndiotacticity is 5 to 95% by weight, preferably 3%.
0 to 80% by weight.

The molecular weight of the fluorine-containing multi-segmented polymer of the present invention can be arbitrarily changed depending on other polymer segments and units, and is, for example, about 10,000 to 500,000.

[0044]

Next, the present invention will be described based on examples, but the present invention is not limited to only these examples.

Example 1 A solution of 5.87 mg (0.0917 mmol) of t-BuLi in heptane and 207 mg of MeAl (ODBP) ₂
(0.459 mmol) of toluene solution and 5 ml of a mixed solvent (6/4) of 1,3-bistrifluorobenzene (m-XHF) and toluene were placed in a glass ampoule and kept at -78 ° C. under a stream of dry nitrogen. Was. to this

[0046]

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1 g (4.59 mmol) was added to initiate polymerization. After 24 hours, a small amount of hydrochloric acid in methanol was added to stop the polymerization, and the reaction solution was poured into a large amount of methanol to precipitate a polymer. I let it. The resulting precipitate was collected by filtration, washed, and dried under vacuum to obtain the fluoropolymer of the present invention.

The number average molecular weight of the obtained fluoropolymer,
The molecular weight distribution, stereoregularity, and thermal properties (crystal melting point, glass transition temperature) were examined by the following methods. Table 1 shows the results.

(Number average molecular weight) 500 MHz ¹ HN
MR (Varian Unity INOVA500)
At 70 ° C. in C ₆ F ₆ / C ₆ D ₆ = 19/1 (containing tetramethylsilane). From the initiator terminal t-C ₄ H ₉
Signal intensity around 1.3 ppm from the group and 1.9 ppm and 2.5 p due to CH ₂ present in the side chain
The ratio between the monomer unit and the terminal group in the polymer was calculated from the signal intensity around pm.

(Molecular weight distribution) It was confirmed by GPC. H
The measurement was performed at room temperature using CFC225 as a solvent and PL gel 5 μm mini mix D (4.6 × 250 mm) as a column. The chromatogram was calibrated using a sample of standard PMMA.

(Stereoregularity) Regarding how to determine the stereoregularity of polymethacrylate, see Nishioka (JP
olym. Sci. , 45, 232 (1960)) and B
ovey (J. Polym. Sci., 44, 173)
(1960)) et al., And again used that method. That is, 1p in ¹ H-NMR
The triad tacticity fraction was determined as iso, hetero, and syndio in order from the low magnetic field using three absorptions based on the proton of the α-methyl group appearing near pm (mm: isotactic triad, mr: hetero). Tactic triad, rr: syndiotactic triad).

(Thermal Characteristics) DSC (SEIKO-RD)
The sample, cooled from 200 ° C. to 0 ° C. at a rate of 10 ° C./min at C220), was measured for crystal melting point and glass transition temperature at 10 ° C./min.

Example 2 As a monomer

[0054]

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1 g (2.07 mmol), 2.66 mg (0.0415 mmol) of t-BuLi as an initiator and EtAl (OD
BP) ₂ (96.5 mg, 0.207 mmol), m-XHF (5 ml) as a polymerization solvent, and the polymerization temperature was -40.
C. and radical polymerization was carried out in the same manner as in Example 1 to obtain a fluorinated polymer of the present invention.
It investigated similarly to. Table 1 shows the results.

Comparative Example 1 5 g (22.9 mmol) of 5FM as a monomer and azobisisobutyronitrile (AIBN) as a polymerization initiator
Was used in the same manner as in Example 1 except that 37.6 mg (0.229 mmol) of m-XHF and 25 ml of m-XHF were used as a polymerization solvent, and no alkyl aluminum was used.
For 24 hours to obtain a fluorinated polymer, and the physical properties were examined in the same manner as in Example 1. Table 1 shows the results.

COMPARATIVE EXAMPLE 2 1 g (10.4 mmol) of 17FM as a monomer, 17.1 mg (0.104 mmol) of AIBN as a polymerization initiator, 25 ml of m-XHF as a polymerization solvent, and alkyl aluminum were used. Radical polymerization was performed at 60 ° C. for 24 hours in the same manner as in Example 1 except that the fluorinated polymer was obtained, and the physical properties were examined in the same manner as in Example 1. Table 1 shows the results.

[0058]

[Table 1]

As is evident from Table 1, the high syndiotactic fluoropolymer of the present invention has increased both the crystal melting point and the glass transition temperature. It can be expected that oil properties, gas barrier properties and optical properties can be exhibited in a higher temperature range.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichi Right Hand 31-25-301 Machikaneyamacho, Toyonaka City, Osaka Prefecture (72) Inventor Tatsuki Kitayama 5-8-207 Makiraku, Minoo City, Osaka Prefecture (72) Inventor Koichi Hatada 3-4-1, Asahioka, Ikeda-shi, Osaka F-term (reference) 4J002 BG031 BG041 BG051 BG061 BG081 GG02 GH01 4J015 DA02 DA03 DA05 4J100 AL03Q AL04Q AL08P AL24Q AL26P BB12P19 CA32 FA01

Claims (9)

[Claims] 1. A fluorine-containing molding material comprising a fluoropolymer having a syndiotacticity containing a structural unit having a fluoroalkyl group in a side chain and having a stereoregularity of the main chain of 70% or more. 2. The fluorine-containing molding material according to claim 1, wherein the fluoropolymer comprises only a structural unit having a fluoroalkyl group in a side chain. 3. The fluorine-containing molding material according to claim 1, wherein the side chain fluoroalkyl group of the fluoropolymer is the same group. 4. The compound of the formula (II)
I): — (CH ₂ ) _m — (CF ₂ ) _n —Y (III) (where Y is a hydrogen atom or a halogen atom, and m is 0-8)
And n is an integer of 1 to 25). The fluorine-based molding material according to any one of claims 1 to 3. 5. The fluorine-based molding material according to claim 1, wherein the structural unit having a fluoroalkyl group in a side chain is derived from a fluoroalkyl group-containing α-substituted olefin. 6. The fluorine-containing molding material according to claim 5, wherein the fluoroalkyl group-containing α-substituted olefin is a fluoroalkyl α-substituted acrylate. 7. Formula (I): CH ₂ ： CR ¹ —COO— (CH ₂ ) _m — (CF ₂ ) _n —Y (I) wherein R ¹ is a hydrogen atom, a halogen atom or a methyl group, Y is a hydrogen atom or a halogen atom, m is an integer of 0 to 8, n is an integer of 1 to 25), and 10 to 100 mol% of a monomer having a fluoroalkyl side chain represented by the formula (II): CH ₂ ＣＲCR ² —COO—R ³ (II) (wherein R ² is a hydrogen atom, a halogen atom or a methyl group, and R ³ is an alkyl group having 1 to 10 carbon atoms) A fluorine-based molding material comprising a fluoropolymer having a syndiotacticity of 70% or more by mole of 90% or more. 8. Formula (I): CH ₂ ： CR ¹ —COO— (CH ₂ ) _m — (CF ₂ ) _n —Y (I) wherein R ¹ is a hydrogen atom, a halogen atom or a methyl group, Y is a hydrogen atom or a halogen atom, m is an integer of 0 to 8, n is an integer of 1 to 25), and 10 to 100 mol% of a monomer having a fluoroalkyl side chain represented by the formula (II): CH ₂ ＣＲCR ² —COO—R ³ (II) (wherein R ² is a hydrogen atom, a halogen atom or a methyl group, and R ³ is an alkyl group having 1 to 10 carbon atoms) Fluorine-containing polymer having a syndiotacticity of 70% by mole or more consisting of ９０90 mol%. 9. Formula (I): CH ₂ ： CR ¹ —COO— (CH ₂ ) _m — (CF ₂ ) _n —Y (I) wherein R ¹ is a hydrogen atom, a halogen atom or a methyl group, Y is a hydrogen atom or a halogen atom, m is an integer of 0 to 8, n is an integer of 1 to 25), and 10 to 100 mol% of a monomer having a fluoroalkyl side chain represented by the formula (II): CH ₂ ＣＲCR ² —COO—R ³ (II) (wherein R ² is a hydrogen atom, a halogen atom or a methyl group, and R ³ is an alkyl group having 1 to 10 carbon atoms) 9. The fluorine-containing polymer according to claim 8, wherein bulky alkyl aluminum is added in an amount of at least 2 equivalents to 1 equivalent of the anionic polymerization initiator in the presence of an anionic polymerization initiator in an amount of about 90 mol% in a fluorine-containing solvent. Polymer production method.