JP2009203445A - Crosslinkable polytetrafluoroethylene aqueous dispersion, manufacturing method for polytetrafluoroethylene crosslinker-impregnated molding, paint composition, and manufacturing method for polytetrafluoroethylene crosslinker-coated molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crosslinkable PTFE (polytetrafluoroethylene) aqueous dispersion, capable of saving labors and times for application work and impregnation work, when using the crosslinkable PTFE aqueous dispersion as a paint or an impregnation liquid, a manufacturing method for a PTFE crosslinker impregnated molding, a paint composition, and a manufacturing method for a PTFE crosslinker-coated molding. <P>SOLUTION: This crosslinkable PTFE aqueous dispersion contains 30-70 wt.% of crosslinkable PTFE having at least one reactive functional group selected from the group comprising a cyano group (-CN), a first functional group expressed by formula (1) -C(=NR1)R2, and a second functional group expressed by formula (2) -C(=O)R1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a crosslinkable polytetrafluoroethylene aqueous dispersion, a method for producing a crosslinked polytetrafluoroethylene-impregnated molded article, a coating composition, and a method for producing a crosslinked polytetrafluoroethylene-coated article.

In the past, “crosslinkable PTFE in which a reactive functional group is introduced into polytetrafluoroethylene (hereinafter abbreviated as“ PTFE ”) has been reported (see, for example, Patent Documents 1 and 2). It has been clarified that this crosslinkable PTFE exhibits moldability, mechanical properties, surface characteristics and the like superior to conventional PTFE after the completion of the crosslinking reaction.
International Publication No. 2007/52664 Pamphlet JP-T-2006-511660

  By the way, this crosslinkable PTFE is obtained by emulsion polymerization or suspension polymerization as in the case of conventional PTFE, and when used as a paint or an impregnating liquid, it is used in the state of an aqueous dispersion.

  However, the existing cross-linkable PTFE aqueous dispersion has a low cross-linkable PTFE concentration of about 18% to 24% by weight, and when used as a paint or an impregnating liquid, it must be re-applied. It took a lot of work.

  An object of the present invention is to save time and effort of coating and impregnation work when a crosslinkable PTFE aqueous dispersion is used as a paint or an impregnation liquid.

  The crosslinkable PTFE aqueous dispersion according to the first invention includes a cyano group (—CN) and a first functional group represented by the general formula (1):

（Ｒ¹およびＲ²は各々独立に水素原子、ハロゲン原子、−ＯＲ³，−Ｎ（Ｒ³）₂，−Ｒ³であり、Ｒ³は炭素数１〜１０のフッ素を含んでもよいアルキル基または水素原子である）、および一般式（２）で表される第２官能基：

(R ¹ and R ² are each independently a hydrogen atom, a halogen atom, —OR ³ , —N (R ³ ) ₂ , —R ³ , and R ³ is an alkyl group which may contain fluorine having 1 to 10 carbon atoms. Or a hydrogen atom), and the second functional group represented by the general formula (2):

（Ｒ¹は水素原子、ハロゲン原子、−ＯＲ³，−Ｎ（Ｒ³）₂，−Ｒ³であり、Ｒ³は炭素数１〜１０のフッ素を含んでもよいアルキル基または水素原子である）より成る群から選択される少なくとも１種の反応性官能基を有する架橋性ＰＴＦＥが３０〜７０重量％含まれる。なお、この架橋性ＰＴＦＥ水性分散液には、架橋性ポリテトラフルオロエチレンの反応性官能基と反応可能な架橋剤が添加されていてもよい。

(R ¹ is a hydrogen atom, a halogen atom, —OR ³ , —N (R ³ ) ₂ , —R ³ , and R ³ is an alkyl group which may contain fluorine having 1 to 10 carbon atoms or a hydrogen atom) 30 to 70% by weight of crosslinkable PTFE having at least one reactive functional group selected from the group consisting of: In addition, the crosslinking agent which can react with the reactive functional group of crosslinkable polytetrafluoroethylene may be added to this crosslinkable PTFE aqueous dispersion.

  Incidentally, such a crosslinkable PTFE aqueous dispersion can be prepared by a phase separation method using a nonionic surfactant with a crosslinkable PTFE aqueous emulsion having a crosslinkable PTFE concentration of 20 mass% to 40 mass% as a starting material. It can be obtained by applying a membrane separation method using an outer filtration membrane.

  The method for producing a PTFE crosslinked body-impregnated molded body according to the second invention includes an impregnation step, a drying step, and a firing and crosslinking step. In the impregnation step, the article to be treated is impregnated with the crosslinkable PTFE aqueous dispersion according to the first invention. In the drying step, the crosslinkable PTFE aqueous dispersion impregnated in the treatment object in the impregnation step is dried. In the firing and crosslinking step, the crosslinkable PTFE is fired while being crosslinked. Note that the drying step and the firing and crosslinking step may be performed simultaneously.

  The crosslinkable PTFE is present in a high concentration in the crosslinkable PTFE aqueous dispersion or coating composition according to the present invention. For this reason, when apply | coating or impregnating to-be-processed object the crosslinkable PTFE aqueous dispersion and coating composition which concern on this invention, the frequency | count of application | coating or impregnation can be reduced conventionally. Therefore, if the crosslinkable PTFE aqueous dispersion or coating composition according to the present invention is used, the labor of coating and impregnation can be saved.

  Further, in the method for producing a PTFE crosslinked body-impregnated molded body or the method for producing a PTFE crosslinked body-coated molded body according to the present invention, a crosslinkable PTFE aqueous dispersion or coating composition in which a crosslinkable PTFE is present in a high concentration is applied or impregnated. Used for. For this reason, in the manufacturing method of the PTFE crosslinked body impregnated molded body and the manufacturing method of the PTFE crosslinked body-coated molded body according to the present invention, the number of times of application or impregnation can be reduced more than before. Therefore, if the method for producing a PTFE crosslinked body-impregnated molded body or the method for producing a PTFE crosslinked body-coated molded body according to the present invention is used, the labor of coating and impregnation work can be saved.

  The crosslinkable PTFE aqueous dispersion according to the present invention contains 30 to 70% by mass of crosslinkable PTFE. In the present application, the crosslinkable PTFE concentration (P) is the residue (Z) after about 1 g (X) of a sample in an aluminum cup having a diameter of 5 cm is dried at 100 ° C. for 1 hour and subsequently at 300 ° C. for 1 hour. Is measured based on the formula: P = Z / X × 100 (% by weight).

  Hereinafter, the crosslinkable PTFE aqueous dispersion, and the PTFE crosslinked body-impregnated molded body and the PTFE crosslinked body-coated molded body obtained by using the crosslinkable PTFE aqueous dispersion will be described in detail.

<Chemical structure of crosslinkable PTFE>
As the crosslinkable PTFE, those having a cyano group (—CN group) and a crosslinkable reactive group represented by the following general formulas (1) and (2) are preferably exemplified as the site capable of crosslinking reaction.

（Ｒ¹およびＲ²は各々独立に水素原子、ハロゲン原子、−ＯＲ³，−Ｎ（Ｒ³）₂，−Ｒ³であり、Ｒ³は炭素数１〜１０のフッ素を含んでもよいアルキル基または水素原子である）

(R ¹ and R ² are each independently a hydrogen atom, a halogen atom, —OR ³ , —N (R ³ ) ₂ , —R ³ , and R ³ is an alkyl group which may contain fluorine having 1 to 10 carbon atoms. Or a hydrogen atom)

（Ｒ¹は水素原子、ハロゲン原子、−ＯＲ³，−Ｎ（Ｒ³）₂，−Ｒ³であり、Ｒ³は炭素数１〜１０のフッ素を含んでもよいアルキル基または水素原子である）

(R ¹ is a hydrogen atom, a halogen atom, —OR ³ , —N (R ³ ) ₂ , —R ³ , and R ³ is an alkyl group which may contain fluorine having 1 to 10 carbon atoms or a hydrogen atom)

  Among these, a cyano group or a functional group represented by the general formula (1) is more preferable from the viewpoint of reactivity. Further, from the viewpoint of easy production, the functional group represented by the general formula (2) is more preferable, and a carboxyl group is particularly preferable.

In addition, the substituent R ³ in the functional group represented by the general formula (1) is more preferably a hydrogen atom from the viewpoint of reactivity.

  This functional group reacts with one or a plurality of functional groups within or between the crosslinkable PTFE molecules to form a crosslinked structure.

  The following two types of crosslinking reactions can be considered.

(1) π-electron deficient heterocyclic cyclization reaction In this type of crosslinking reaction, azole, triazole, azine, diazine, triazine and the like are formed. An example of such a crosslinking reaction is a crosslinked structure formed through a triazine cyclization reaction (see chemical reaction formula (A)).

  Further, for example, a cyano group as a functional group and a cyano group derivative of the following formula

の２種が共存する場合には、下記の化学反応式（Ｂ）で示されるイミダゾール環化反応を経て形成される架橋構造が一例として挙げられる。なお、化式４および５において−ＯＭｅが−ＯＲ³や−Ｎ（Ｒ³）₂であってもかまわない。

When these two types coexist, a crosslinked structure formed through an imidazole cyclization reaction represented by the following chemical reaction formula (B) is given as an example. In Chemical Formulas 4 and 5, -OMe may be -OR ³ or -N (R ³ ) ₂ .

(2) Radical decarboxylation / de-CO reaction When heated to 150 ° C or higher, COOH and COOMe cause de-CO ₂ to generate radicals. In the case of CHO or COCl, de-CO is generated to generate radicals. These radicals are coupled to form a crosslinked structure (see chemical reaction formulas (C) and (D)).

  A PTFE crosslinked product can be obtained by appropriately utilizing the above two crosslinking reactions.

  When a heterocyclic cyclization reaction is used, it is preferable to use a triazine cyclization reaction using a cyano group from the viewpoints of polymerizability, identification of crosslinking reactivity, and functional group stability. When utilizing the reaction, a crosslinking reaction by decarboxylation / coupling using a carboxylic acid is preferred from the viewpoints of polymerizability, crosslinking reactivity, and functional group stability.

  The crosslinkable site may be introduced into PTFE by a polymer reaction, or tetrafluoroethylene (hereinafter abbreviated as “TFE”) and a monomer that provides a crosslinkable site. It may be introduced by polymerization. As a method for introducing a functional group into PTFE by a polymer reaction, a dry method in which PTFE is treated with radiation, laser, electron beam, plasma, corona discharge or the like to introduce a functional group, electrochemically, or Li metal is used. A wet method for reduction with a / naphthalene complex has been conventionally known. In addition, it is preferable to employ the latter method because it is easy to manufacture.

  In the crosslinkable PTFE, the content of the monomer that gives a crosslinking site is preferably 0.01 mol% or more, more preferably 0.03 mol% or more, still more preferably with respect to TFE as an essential monomer. Is 0.06 mol% or more, preferably 20 mol% or less, more preferably 10 mol% or less, and still more preferably 5 mol% or less. If the content of the monomer giving a site capable of crosslinking reaction is 0.01 mol% or less, a sufficient effect cannot be obtained, and if the monomer content is 20 mol% or more, a polymer can be obtained. This is because it becomes difficult.

  In the present embodiment, the monomer that gives a crosslinking site has an ethylenically unsaturated bond, and is represented by a cyano group (—CN group) as a functional group and the following general formulas (1) and (2). Any compound can be used as long as it has a functional group and has a copolymerizability with TFE.

（Ｒ¹およびＲ²は各々独立に水素原子、ハロゲン原子、−ＯＲ³，−Ｎ（Ｒ³）₂，−Ｒ³であり、Ｒ³は炭素数１〜１０のフッ素を含んでもよいアルキル基または水素原子である）

(R ¹ and R ² are each independently a hydrogen atom, a halogen atom, —OR ³ , —N (R ³ ) ₂ , —R ³ , and R ³ is an alkyl group which may contain fluorine having 1 to 10 carbon atoms. Or a hydrogen atom)

（Ｒ¹は水素原子、ハロゲン原子、−ＯＲ³，−Ｎ（Ｒ³）₂，−Ｒ³であり、Ｒ³は炭素数１〜１０のフッ素を含んでもよいアルキル基または水素原子である）

(R ¹ is a hydrogen atom, a halogen atom, —OR ³ , —N (R ³ ) ₂ , —R ³ , and R ³ is an alkyl group which may contain fluorine having 1 to 10 carbon atoms or a hydrogen atom)

  As the monomer, any of linear and cyclic compounds can be used. If the monomer is a cyclic compound, cyclopentene having a functional group and derivatives thereof, norbornene and derivatives thereof, polycyclic norbornene and derivatives thereof, vinylcarbazole and derivatives thereof, and part or all of hydrogen atoms of these compounds As an example, a compound in which is substituted with a halogen atom, particularly a fluorine atom, or a fluorine-containing alkyl group can be given. From the viewpoint of polymerizability, the monomer is preferably a chain compound. Among the chain compounds, a monomer represented by the following general formula (3) is preferable.

CY ¹ Y ² = CY ³ (O) _m (R ⁸ ) _n −Z ¹ (3)
Wherein Y ^{1 to} Y ³ are each independently a hydrogen atom, a halogen atom, —CH ₃ , or —CF ₃ , R ⁸ is a divalent organic group, n is 0 or 1, m Is 0 when n is 0, 0 or 1 when n is 1, and Z ¹ is any of the above functional groups)

Among these, from the viewpoint of polymerizability, Y ¹ to Y ³ are preferably hydrogen atoms or halogen atoms, and fluorine atoms are particularly preferable among the halogen atoms. Specifically, CH ₂ = CH-, CH ₂ = CF-, CFH = CF-, CFH = CH-, and CF ₂ = CF- are mentioned as preferred structures. In particular, a structure of CH ₂ = CH-, CH ₂ = CF-, CF ₂ = CF- is more preferable. When n = 0, CH ₂ = CHCN, CH ₂ = CHCOOR,

、ＣＦ₂＝ＣＦＣＮ、ＣＦ₂＝ＣＦＣＯＯＲ、

, CF ₂ = CFCN, CF ₂ = CFCOOR,

といった化合物が架橋可能な単量体として例示し得る。

Can be exemplified as monomers capable of crosslinking.

When n = 0, m = 0, but when n = 1, m may be 0 or 1. When m is 1, CH ₂ = CHO-, CH ₂ = CFO-, CFH = CFO-, CFH = CHO-, CF ₂ = CFO- are listed as preferred structures. In particular, CH ₂ ═CHO—, CH ₂ ═CFO—, and CF ₂ ═CFO— are listed as preferred structures.

R ⁸ can be selected from any divalent organic group, but an alkylene group that may contain an ether bond having 1 to 100 carbon atoms is preferred from the viewpoint of ease of synthesis and polymerization. In addition, as for carbon number, it is more preferable that it is 1-50, and it is further more preferable that it is 1-20. In such an alkylene group, some or all of the hydrogen atoms may be substituted with halogen atoms, particularly fluorine atoms. This is because if the number of carbon atoms is 100 or more, polymerization becomes difficult, and preferable characteristics cannot be obtained even if crosslinking is performed. The alkylene group may be a linear or branched alkylene group. An example of the minimum structural unit constituting such a linear or branched alkylene group is shown below.
(I) Linear minimum structural unit:

_{-CH 2 -, - CHF -,} - CF 2 -, - CHCl -, - CFCl -, - CCl 2 -
(Ii) Branched minimum structural unit:

When the alkylene group represented by R ⁸ does not contain an ether group, an alkylene group, these minimum structural units alone, or a straight-chain type (i) with each other, branched-chain represented by R ⁸ (ii) It is configured by combining them appropriately. Also, when the alkylene group represented by R ⁸ contains an ether group, an alkylene group represented by R ^8, these minimum structural units alone and an oxygen atom, or a straight-chain type (i) with each other, the branch The chain type (ii) and oxygen atoms can be combined with each other or an appropriate combination thereof, but the oxygen atoms are not bonded to each other. In the above examples, the alkylene group represented by R ⁸ is preferably composed of a constitutional unit not containing Cl because it does not cause a deHCl reaction with a base and is more stable.

R ⁸ is a structure represented by —R ¹⁰ —, — (OR ¹⁰ ) —, or — (R ¹⁰ O) — (R ¹⁰ is an alkylene group which may contain fluorine having 1 to 6 carbon atoms). It is further preferable to have Preferable specific examples of R ¹⁰ include the following linear or branched types.

As those of _{linear, -CH 2 -, - CHF -} , - CF 2 -, - CH 2 CH 2 -, - CF 2 CH 2 -, - CH 2 CF 2 -, - CF 2 CF 2 -, _{-CH 2 CH 2 CH 2 -,} - CF 2 CH 2 CH 2 -, - CH 2 CF 2 CH 2 -, - CH 2 CH 2 CF 2 -, - CF 2 CF 2 CH 2 -, - CF 2 CH 2 _{CF 2 -, - CH 2 CF} 2 CF 2 -, - CF 2 CF 2 CF 2 -, - CH 2 CH 2 CH 2 CH 2 -, - CH 2 CF 2 CH 2 CF 2 -, - CH 2 CF 2 CF ₂ CF _2- , -CH ₂ CH ₂ CF ₂ CF _2- , -CH ₂ CF ₂ CH ₂ CF ₂ CH _2- , -CH ₂ CF ₂ CF ₂ CF ₂ CH _2- , -CH ₂ CF ₂ CF ₂ CH _{2 CH 2 -, - CH 2} CH 2 CF 2 CF 2 CH 2 -, - CH 2 CF 2 CF 2 CF 2 CF 2 -, - CH 2 CF 2 CH 2 CF 2 CH 2 CH 2 -, - _{H 2 CH 2 CF 2 CF 2} CH 2 CH 2 -, - CH 2 CF 2 CF 2 CF 2 CH 2 CH 2 - , etc. can be exemplified, as the branched type,

などを挙げることができる。また、上記の構成から、下記の化合物が一例として例示し得る。
ＣＨ₂＝ＣＨ−（ＣＦ₂）_n−Ｚ² （４）
（式中、ｎは２〜８の整数）
ＣＹ⁴ ₂＝ＣＹ⁴（ＣＦ₂）_n−Ｚ² （５）
（式中、Ｙ⁴は水素原子またはフッ素原子、ｎは１〜８の整数である）
ＣＦ₂＝ＣＦＣＦ₂Ｒ_f ⁴−Ｚ² （６）
（式中、

And so on. Moreover, the following compounds can be illustrated as an example from said structure.
_{CH 2 = CH- (CF 2)} n -Z 2 (4)
(Where n is an integer from 2 to 8)
CY ⁴ ₂ = CY ⁴ (CF ₂ ) _n −Z ² (5)
(Wherein Y ⁴ is a hydrogen atom or a fluorine atom, and n is an integer of 1 to 8)
^{_{CF 2 = CFCF 2 R f 4}} -Z 2 (6)
(Where

であり、ｎは０〜５の整数である）
ＣＦ₂＝ＣＦＣＦ₂（ＯＣＦ（ＣＦ₃）ＣＦ₂）_m
（ＯＣＨ₂ＣＦ₂ＣＦ₂）_nＯＣＨ₂ＣＦ₂−Ｚ² （７）
（式中、ｍは０〜５の整数であり、ｎは０〜５の整数である）
ＣＦ₂＝ＣＦＣＦ₂（ＯＣＨ₂ＣＦ₂ＣＦ₂）_m
（ＯＣＦ（ＣＦ₃）ＣＦ₂）_nＯＣＦ（ＣＦ₃）−Ｚ² （８）
（式中、ｍは０〜５の整数であり、ｎは０〜５の整数である）
ＣＦ₂＝ＣＦ（ＯＣＦ₂ＣＦ（ＣＦ₃））_mＯ（ＣＦ₂）_n−Ｚ² （９）
（式中、ｍは０〜５の整数であり、ｎは１〜８の整数である）
ＣＦ₂＝ＣＦ（ＯＣＦ₂ＣＦ（ＣＦ₃））_m−Ｚ² （１０）
（式中、ｍは１〜５の整数である）
ＣＦ₂＝ＣＦＯＣＦ₂（ＣＦ（ＣＦ₃）ＯＣＦ₂）_nＣＦ（−Ｚ²）ＣＦ₃ （１１）
（式中、ｎは１〜４の整数である）
ＣＦ₂＝ＣＦＯ（ＣＦ₂）_nＯＣＦ（ＣＦ₃）−Ｚ² （１２）
（式中、ｎは２〜５の整数である）
ＣＦ₂＝ＣＦＯ（ＣＦ₂）_n−（Ｃ₆Ｈ₄）−Ｚ² （１３）
（式中、ｎは１〜６の整数である）
ＣＦ₂＝ＣＦ（ＯＣＦ₂ＣＦ（ＣＦ₃））_nＯＣＦ₂ＣＦ（ＣＦ₃）−Ｚ² （１４）
（式中、ｎは１〜２の整数である）
ＣＨ₂＝ＣＦＣＦ₂Ｏ（ＣＦ（ＣＦ₃）ＣＦ₂Ｏ）_nＣＦ（ＣＦ₃）−Ｚ² （１５）
（式中、ｎは０〜５の整数である）、
ＣＦ₂＝ＣＦＯ（ＣＦ₂ＣＦ（ＣＦ₃）Ｏ）_m（ＣＦ₂）_n−Ｚ² （１６）
（式中、ｍは０〜５の整数、ｎは１〜３の整数である）
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＯＣＦ（ＣＦ₃）−Ｚ² （１７）
ＣＨ₂＝ＣＦＣＦ₂ＯＣＨ₂ＣＦ₂−Ｚ² （１８）
ＣＦ₂＝ＣＦＯ（ＣＦ₂ＣＦ（ＣＦ₃）Ｏ）_mＣＦ₂ＣＦ（ＣＦ₃）−Ｚ² （１９）
（式中、ｍは０以上の整数である）
ＣＦ₂＝ＣＦＯＣＦ（ＣＦ₃）ＣＦ₂Ｏ（ＣＦ₂）_n−Ｚ² （２０）
（式中、ｎは１以上の整数である）
ＣＦ₂＝ＣＦＯＣＦ₂ＯＣＦ₂ＣＦ（ＣＦ₃）ＯＣＦ₂−Ｚ² （２１）
ＣＦ₂＝ＣＦ−（ＣＦ₂Ｃ（ＣＦ₃）Ｆ）_n−Ｚ² （２２）
（式中、ｎは、１〜５の整数である）、
ＣＦ₂＝ＣＦＯ−（ＣＦＹ⁵）_n−Ｚ² （２３）
（式中、Ｙ⁵はＦまたは−ＣＦ₃であり、ｎは１〜１０の整数である）
ＣＦ₂＝ＣＦＯ−（ＣＦ₂ＣＦＹ⁶Ｏ）_m−（ＣＦ₂）_n−Ｚ² （２４）
（式中、Ｙ⁶はＦまたは−ＣＦ₃であり、ｍは１〜１０の整数であり、ｎは１〜３の整数である）
ＣＨ₂＝ＣＦＣＦ₂Ｏ−（ＣＦ（ＣＦ₃）ＣＦ₂Ｏ）_n−ＣＦ（ＣＦ₃）−Ｚ² （２５）
（式中、ｎは０〜１０の整数である）
ＣＦ₂＝ＣＦＣＦ₂Ｏ−（ＣＦ（ＣＦ₃）ＣＦ₂Ｏ）_n−ＣＦ（ＣＦ₃）−Ｚ² （２６）
（式中、ｎは１〜１０の整数である）
（一般式（４）〜（２６）中、Ｚ²は、上記官能基のいずれかである）

And n is an integer from 0 to 5)
CF ₂ = CFCF ₂ (OCF (CF ₃ ) CF ₂ ) _{m
(OCH 2 CF 2 CF 2)} n OCH 2 CF 2 -Z 2 (7)
(In the formula, m is an integer of 0 to 5, and n is an integer of 0 to 5).
CF ₂ = CFCF ₂ (OCH ₂ CF ₂ CF ₂ ) _m
(OCF (CF ₃ ) CF ₂ ) _n OCF (CF ₃ ) -Z ² (8)
(In the formula, m is an integer of 0 to 5, and n is an integer of 0 to 5).
_{CF 2 = CF (OCF 2 CF} (CF 3)) m O (CF 2) n -Z 2 (9)
(In the formula, m is an integer of 0 to 5, and n is an integer of 1 to 8.)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m -Z 2 (10)
(Where m is an integer of 1 to 5)
_{CF 2 = CFOCF 2 (CF (} CF 3) OCF 2) n CF (-Z 2) CF 3 (11)
(In the formula, n is an integer of 1 to 4)
_{CF 2 = CFO (CF 2)} n OCF (CF 3) -Z 2 (12)
(Wherein n is an integer of 2 to 5)
_{CF 2 = CFO (CF 2)} n - (C 6 H 4) -Z 2 (13)
(Where n is an integer from 1 to 6)
_{CF 2 = CF (OCF 2 CF} (CF 3)) n OCF 2 CF (CF 3) -Z 2 (14)
(Where n is an integer of 1 to 2)
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) n CF (CF 3) -Z 2 (15)
(Wherein n is an integer from 0 to 5),
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -Z 2 (16)
(In the formula, m is an integer of 0 to 5, and n is an integer of 1 to 3)
_{CH 2 = CFCF 2 OCF (CF} 3) OCF (CF 3) -Z 2 (17)
_{CH 2 = CFCF 2 OCH 2 CF} 2 -Z 2 (18)
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m CF 2 CF (CF 3) -Z 2 (19)
(Where m is an integer of 0 or more)
_{CF 2 = CFOCF (CF 3)} CF 2 O (CF 2) n -Z 2 (20)
(Where n is an integer of 1 or more)
_{CF 2 = CFOCF 2 OCF 2 CF} (CF 3) OCF 2 -Z 2 (21)
_{CF 2 = CF- (CF 2 C} (CF 3) F) n -Z 2 (22)
(Wherein n is an integer from 1 to 5),
^{_{CF 2 = CFO- (CFY 5)}} n -Z 2 (23)
(Wherein Y ⁵ is F or —CF ₃ , and n is an integer of 1 to 10)
_{CF 2 = CFO- (CF 2 CFY} 6 O) m - (CF 2) n -Z 2 (24)
(Wherein Y ⁶ is F or —CF ₃ , m is an integer of 1 to 10, and n is an integer of 1 to 3)
_{CH 2 = CFCF 2 O- (CF} (CF 3) CF 2 O) n -CF (CF 3) -Z 2 (25)
(In the formula, n is an integer of 0 to 10)
_{CF 2 = CFCF 2 O- (CF} (CF 3) CF 2 O) n -CF (CF 3) -Z 2 (26)
(Where n is an integer from 1 to 10)
(In General Formulas (4) to (26), Z ² is any one of the above functional groups)

In the case the Z ² is COOR ^{1, to 1} group -COOR acts as a crosslinking site is preferably ¹ group -COOR is a structure easily react with the reactive functional groups of the crosslinking agent. That is, it is preferable that R ¹ is easily desorbed. Examples of such R ¹ include sulfonyl esters such as toluenesulfonic acid, nitrotoluenesulfonic acid, and trifluoromethanesulfonic acid, phosphate esters, and organic phosphate esters. However, the sulfonyl ester is not preferred because the sulfonic acid to be removed has a high acidity and may corrode a metal (for example, a mold of a molding machine). Therefore, R ¹ is preferably an alkyl group that may contain an ether bond or an aromatic ring. In this case, the number of carbon atoms is preferably 1-20, more preferably 1-10, and even more preferably 1-6. A hydrogen atom partially substituted with a halogen atom is preferable because of its high detachability. When R ¹ is an alkyl group that may contain an ether bond or an aromatic ring, R ¹ is specifically exemplified by methyl group, ethyl group, propyl group, isopropyl group, butyl group, phenyl group, 1,1,1 -Trifluoroethyl group, 1,1,1,2,2-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoroisopropyl group and the like can be mentioned. However, it is preferably —COOH because it can be de-CO ₂ at low temperature and can be efficiently coupled without chain transfer.

  In the monomers represented by the general formulas (4) to (26), any of the above functional groups becomes a crosslinking site, and the crosslinking reaction proceeds.

As the monomer represented by the general formula (5), specifically,
_{CF 2 = CF-CF 2 -CN} , CF 2 = CF-CF 2 CF 2 -CN,

、

,

、ＣＦ₂＝ＣＦ−ＣＦ₂−ＣＯＯＨ、ＣＦ₂＝ＣＦ−ＣＦ₂ＣＦ₂−ＣＯＯＨ、
ＣＦ₂＝ＣＦ−ＣＦ₂−ＣＯＯＣＨ₃、ＣＦ₂＝ＣＦ−ＣＦ₂ＣＦ₂−ＣＯＯＣＨ₃、
などが挙げられるが、架橋反応性の点で、
ＣＦ₂＝ＣＦ−ＣＦ₂−ＣＮ、ＣＦ₂＝ＣＦ−ＣＦ₂ＣＦ₂−ＣＮ

_{, CF 2 = CF-CF 2} -COOH, CF 2 = CF-CF 2 CF 2 -COOH,
_{CF 2 = CF-CF 2 -COOCH} 3, CF 2 = CF-CF 2 CF 2 -COOCH 3,
In terms of crosslinking reactivity,
_{CF 2 = CF-CF 2 -CN} , CF 2 = CF-CF 2 CF 2 -CN

、

,

であることが好ましく、重合反応性が優れている点で、
ＣＦ₂＝ＣＦ−ＣＦ₂−ＣＯＯＨ、ＣＦ₂＝ＣＦ−ＣＦ₂ＣＦ₂−ＣＯＯＨ、
ＣＦ₂＝ＣＦ−ＣＦ₂−ＣＯＯＣＨ₃、ＣＦ₂＝ＣＦ−ＣＦ₂ＣＦ₂−ＣＯＯＣＨ₃であることが好ましい。

In terms of excellent polymerization reactivity,
_{CF 2 = CF-CF 2 -COOH} , CF 2 = CF-CF 2 CF 2 -COOH,
Is preferably _{CF 2 = CF-CF 2 -COOCH} 3, CF 2 = CF-CF 2 CF 2 -COOCH 3.

As the monomer represented by the general formula (22), specifically,
CF ₂ = CFCF ₂ C (CF ₃ ) FCN, CF ₂ = CF (CF ₂ C (CF ₃ ) F) ₂ CN,

、

,

、ＣＦ₂＝ＣＦＣＦ₂Ｃ（ＣＦ₃）ＦＣＯＯＨ、
ＣＦ₂＝ＣＦ（ＣＦ₂Ｃ（ＣＦ₃）Ｆ）₂ＣＯＯＨ、
ＣＦ₂＝ＣＦＣＦ₂Ｃ（ＣＦ₃）ＦＣＯＯＣＨ₃、
ＣＦ₂＝ＣＦ（ＣＦ₂Ｃ（ＣＦ₃）Ｆ）₂ＣＯＯＣＨ₃、
などが挙げられるが、重合反応性という点で、ＣＦ₂＝ＣＦＣＦ₂Ｃ（ＣＦ₃）ＦＣＯＯＨであることが好ましい。

, CF ₂ = CFCF ₂ C (CF ₃ ) FCOOH,
CF ₂ = CF (CF ₂ C (CF ₃ ) F) ₂ COOH,
CF ₂ = CFCF ₂ C (CF ₃ ) FCOOCH ₃ ,
CF ₂ = CF (CF ₂ C (CF ₃ ) F) ₂ COOCH ₃ ,
In view of polymerization reactivity, CF ₂ = CFCF ₂ C (CF ₃ ) FCOOH is preferable.

As the monomer represented by the general formula (23), specifically,
CF ₂ = CFOCF ₂ CF ₂ CF ₂ CN, CF ₂ = CFOCF ₂ CF ₂ CN,
CF ₂ = CFOCF ₂ CN,

、

,

、

,

、ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ₂ＣＦ₂ＣＯＯＨ、ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ₂ＣＯＯＨ、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＯＯＨ、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ₂ＣＦ₂ＣＯＯＣＨ₃、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ₂ＣＯＯＣＨ₃、ＣＦ₂＝ＣＦＯＣＦ₂ＣＯＯＣＨ₃
などが挙げられるが、架橋反応性、重合反応性という点で、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ₂ＣＦ₂ＣＯＯＨ、ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ₂ＣＯＯＨ、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ₂ＣＦ₂ＣＯＯＣＨ₃、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ₂ＣＯＯＣＨ₃であることが好ましい。

CF ₂ = CFOCF ₂ CF ₂ CF ₂ COOH, CF ₂ = CFOCF ₂ CF ₂ COOH,
CF ₂ = CFOCF ₂ COOH,
CF ₂ = CFOCF ₂ CF ₂ CF ₂ COOCH ₃ ,
CF ₂ = CFOCF ₂ CF ₂ COOCH ₃ , CF ₂ = CFOCF ₂ COOCH ₃
In terms of crosslinking reactivity and polymerization reactivity,
CF ₂ = CFOCF ₂ CF ₂ CF ₂ COOH, CF ₂ = CFOCF ₂ CF ₂ COOH,
CF ₂ = CFOCF ₂ CF ₂ CF ₂ COOCH ₃ ,
It is preferable that CF ₂ = CFOCF ₂ CF ₂ COOCH ₃ .

As the monomer represented by the general formula (24), specifically,
CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CN,

、ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ（ＣＦ₃）ＯＣＦ₂ＣＦ₂ＣＯＯＨ、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ（ＣＦ₃）ＯＣＦ₂ＣＦ₂ＣＯＯＣＨ₃、
などが挙げられるが、反応性の点で、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ（ＣＦ₃）ＯＣＦ₂ＣＦ₂ＣＮ、

_{, CF 2 = CFOCF 2 CF (} CF 3) OCF 2 CF 2 COOH,
CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ ,
In terms of reactivity,
CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CN,

であることが好ましく、製造が容易な点で、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ（ＣＦ₃）ＯＣＦ₂ＣＦ₂ＣＯＯＨ、
ＣＦ₂＝ＣＦＯＣＦ₂ＣＦ（ＣＦ₃）ＯＣＦ₂ＣＦ₂ＣＯＯＣＨ₃、
であることが好ましい。

It is preferable that it is easy to manufacture,
CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOH,
CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ ,
It is preferable that

As the monomer represented by the general formula (25), specifically,
CH ₂ = CFCF ₂ OCF (CF ₃ ) CN,
CH ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) CN,
CH ₂ = CFCF ₂ O (CF (CF ₃ ) CF ₂ O) ₂ CF (CF ₃ ) CN,

、

,

、

,

、ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＨ、
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＨ、
ＣＨ₂＝ＣＦＣＦ₂Ｏ（ＣＦ（ＣＦ₃）ＣＦ₂Ｏ）₂ＣＦ（ＣＦ₃）ＣＯＯＨ、
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＣＨ₃、
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＣＨ₃、
ＣＨ₂＝ＣＦＣＦ₂Ｏ（ＣＦ（ＣＦ₃）ＣＦ₂Ｏ）₂ＣＦ（ＣＦ₃）ＣＯＯＣＨ₃、
などが挙げられるが、重合反応性という点で、ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＮ、
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＮ、

, CH ₂ = CFCF ₂ OCF (CF ₃ ) COOH,
_{CH 2 = CFCF 2 OCF (CF} 3) CF 2 OCF (CF 3) COOH,
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) 2 CF (CF 3) COOH,
CH ₂ = CFCF ₂ OCF (CF ₃ ) COOCH ₃ ,
CH ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOCH ₃ ,
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) 2 CF (CF 3) COOCH 3,
In terms of polymerization reactivity, CH ₂ = CFCF ₂ OCF (CF ₃ ) CN,
CH ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) CN,

、

,

、ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＨ、
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＨ、
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＣＨ₃、
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＣＨ₃、
であることが好ましい。

, CH ₂ = CFCF ₂ OCF (CF ₃ ) COOH,
_{CH 2 = CFCF 2 OCF (CF} 3) CF 2 OCF (CF 3) COOH,
CH ₂ = CFCF ₂ OCF (CF ₃ ) COOCH ₃ ,
CH ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOCH ₃ ,
It is preferable that

As the monomer represented by the general formula (26), specifically,
CF ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) CN,

、ＣＦ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＨ、
ＣＦ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＣＨ₃、
などが挙げられるが、反応性の点で、
ＣＦ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＮ、

CF ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOH,
CF ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOCH ₃ ,
In terms of reactivity,
CF ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) CN,

であることが好ましく、製造が容易な点で、
ＣＦ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＨ、
ＣＦ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＣＦ₂ＯＣＦ（ＣＦ₃）ＣＯＯＣＨ₃であることが好ましい。

It is preferable that it is easy to manufacture,
CF ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOH,
CF ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOCH ₃ is preferred.

Further, in general, the reactive functional group is more than —CF ₂ —CN, rather than being bonded to a branched alkylene group such as —CF (CF ₃ ) —CN or —CF (CF ₃ ) —COOR. A bond to a linear alkylene group such as —CF ₂ —COOR is preferable because of high reactivity.

In the crosslinkable PTFE according to the present embodiment, the above-mentioned reactive functional group-containing monomer can be used as a copolymerization component, and at the same time, any monomer can be used as a copolymerization component. Monomers other than the monomer that gives the crosslinking site are not particularly limited, and examples thereof include fluorine-containing monomers other than TFE and fluorine-free monomers. Such a copolymerizable monomer may have a functional group that does not react with the crosslinking agent. Examples of functional groups that do not react with the crosslinking agent include hydroxyl group, sulfonic acid group, phosphoric acid group, sulfonic acid imide group, sulfonic acid amide group, phosphoric acid imide group, phosphoric acid amide group, carboxylic acid amide group, and carboxylic acid imide. Groups and the like. When a monomer having a functional group that does not react with the cross-linking agent is used as a copolymerization component, effects such as improved adhesion and improved dispersibility are expected. In addition, when such a monomer containing no functional group is introduced as a copolymerization component, it is possible to adjust the particle size, the melting point, and the mechanical properties. Examples of the “fluorine-containing monomer” include fluoroolefins, cyclic fluorinated monomers, and fluorinated alkyl vinyl ethers. Examples of the fluoroolefin include hexafluoropropylene (HFP), vinyl fluoride, vinylidene fluoride (VDF), trifluoroethylene, chlorotrifluoroethylene, hexafluoroisobutylene, and perfluorobutylethylene. Examples of the cyclic fluorinated monomer include perfluoro-2,2-dimethyl-1,3-dioxole (PDD), perfluoro-2-methylene-4-methyl-1,3-dioxolane. (PMD). Examples of the fluorinated alkyl vinyl ether include, for example, the general formula CY ⁷ ₂ = CY ⁸ OR ¹² or CY ⁷ ₂ = CY ⁸ (OR ¹³ ) _n OR ¹² (Y ⁷ is the same or different and is H or F, Y ⁸ is H or F, R ¹² is an alkyl group having 1 to 8 carbon atoms in which part or all of the hydrogen atoms may be substituted with fluorine atoms, or an alkyl group having a functional group at the end, and R ¹³ Are the same or different, and an alkylene group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms, and n is an integer of 0 to 10). It is done. In addition, as said fluorinated alkyl vinyl ether, perfluoro (methyl vinyl ether) (PMVE), perfluoro (ethyl vinyl ether) (PEVE), perfluoro (propyl vinyl ether) (PPVE) is preferable, for example. The “fluorine-free monomer” is not particularly limited as long as it has a copolymerizability with the TFE, and examples thereof include hydrocarbon monomers. The hydrocarbon monomer may have a halogen atom other than fluorine, an element such as oxygen or nitrogen, various substituents, and the like. Examples of the hydrocarbon monomers include alkenes, alkyl vinyl ethers, vinyl esters, alkyl allyl ethers, alkyl allyl esters, and the like.

  As the “fluorine-containing monomer” and “fluorine-free monomer”, among those described above, fluoroolefin and perfluorovinyl ether usually used for modification of PTFE are more preferable, and HFP, chlorotrifluoroethylene, Hexafluoroisobutylene, VDF, PMVE, PEVE, and PPVE are particularly preferable. The amount of modification may be any amount as long as the basic properties as crosslinkable PTFE are not impaired, but in the case of fluoroolefin, it is preferably 0.01 mol with respect to TFE as an essential monomer. % Or more, more preferably 0.1 mol% or more, preferably 7 mol% or less, more preferably 5 mol% or less, particularly preferably 2 mol% or less. In the case of perfluorovinyl ether, an essential monomer Preferably it is 0.01 mol% or more with respect to TFE which becomes, More preferably, it is 0.1 mol% or more, Preferably it is 1 mol% or less.

<Method for producing crosslinkable PTFE aqueous dispersion>
The crosslinkable PTFE aqueous dispersion according to the present invention can be obtained by concentrating a crosslinkable PTFE aqueous emulsion obtained by emulsion polymerization. In addition, the crosslinkable PTFE concentration of the crosslinkable PTFE aqueous emulsion is usually 20 to 40% by mass.

(1) Emulsion polymerization The polymerization conditions (temperature, time, etc.) for emulsion polymerization may be appropriately determined in consideration of the type of monomer.

  A wide range of emulsifiers can be used for the emulsion polymerization. From the viewpoint of suppressing chain transfer reaction to the emulsifier molecules that occur during the polymerization, a carboxylic acid having a fluorocarbon chain or a fluoropolyether chain is used. Salts are preferred. An alternative emulsifier may be used as the emulsifier.

As the polymerization initiator, for example, a persulfate such as ammonium persulfate (APS) or an organic peroxide such as disuccinic acid peroxide (DSP) or diglutaric acid peroxide may be used alone or in the form of a mixture thereof. Can do. In addition, as the polymerization initiator, a redox-based one shared with a reducing agent such as sodium sulfite may be used. Preferably, a carboxyl group or a group capable of forming a carboxyl group (for example, acid fluoride, acid chloride, —CF ₂ OH, etc., all of which generate a carboxyl group in the presence of water) is present at the end of the main chain. What can be made is preferable. Specific examples include ammonium persulfate (APS) and potassium persulfate (KPS).

  Moreover, you may use the chain transfer agent normally used for adjustment of molecular weight. Such a compound acting as a chain transfer agent is composed of at least one of a hydrocarbon, a halogenated hydrocarbon, and a water-soluble organic compound. The chain transfer agent may be any of hydrocarbons and halogenated hydrocarbons, halogenated hydrocarbons and hydrocarbons, and hydrocarbons and fluorinated hydrocarbons. In addition, one or two or more of hydrocarbons, halogenated hydrocarbons, and water-soluble organic compounds can be used. The chain transfer agent is at least one selected from the group consisting of methane, ethane, butane, HFC-134a, HFC-32, methanol, and ethanol in terms of good dispersibility and uniformity in the reaction system. It is preferable that it consists of one.

Furthermore, by using a compound having an iodine or bromine atom, a compound having a narrow molecular weight distribution can be obtained, and the molecular weight can be easily adjusted. Examples of such a chain transfer agent having an iodine atom include the following compounds represented by the general formulas (27) to (35).
I (CF ₂ CF ₂ ) _n I (27)
ICH ₂ CF ₂ CF ₂ (OCF (CF ₃ ) CF ₂ ) _m OCF (CF ₃ ) -Z ³ (28)
ICH ₂ CF ₂ CF ₂ (OCH ₂ CF ₂ CF ₂ ) _m OCH ₂ CF ₂ —Z ³ (29)
I (CF ₂ ) _n Z ³ (30)
I (CH ₂ CF ₂ ) _n Z ³ (31)
_{ICF 2 CF 2 OCF 2 CF (} CF 3) OCF 2 CF 2 -Z 3 (32)
_{ICH 2 CF 2 CF 2 OCH 2} CF 2 -Z 3 (33)
ICF ₂ CF ₂ OCF ₂ CF ₂ -Z ³ (34)
_{ICF 2 CF 2 O (CF 2} ) n OCF 2 CF 2 -Z 3 (35)
A compound represented by the formula (wherein Z ³ is any one of the above functional groups, m is an integer of 0 to 5, and n is an integer of 1 or more) can be used. Among these, the chain transfer agents represented by the general formulas (28) to (35) are preferable from the viewpoint of having a crosslinking site capable of reacting with the crosslinking agent.

  The crosslinkable PTFE used in the present invention can convert a group such as a metal salt or ammonium salt of a carboxylic acid present in the polymerization product into a carboxyl group by treating the polymerization product with an acid. As the acid treatment method, for example, washing with hydrochloric acid, sulfuric acid, nitric acid or the like, or a method of bringing the mixture system after polymerization reaction with these acids to pH 3 or less is suitable.

  Moreover, PTFE containing iodine or bromine can be oxidized with fuming nitric acid to introduce a carboxyl group.

  Furthermore, as a method for introducing a cyano group, a carboxyl group, or an alkoxycarbonyl group, the method described in International Publication No. 00/05959 pamphlet can also be used.

  The average primary particle size of the crosslinkable PTFE particles obtained by emulsion polymerization is usually 0.05 to 0.5 μm, preferably 0.1 to 0.35 μm. In addition, this average particle diameter is the transmittance | permeability of the projection light of 550 nm with respect to the unit length of crosslinkable PTFE aqueous emulsion (reference) which adjusted the crosslinkable PTFE density | concentration to 0.22 mass%, and in a transmission electron micrograph. It is determined on the basis of a calibration curve created from the average particle diameter determined by measuring the constant direction diameter.

  The aqueous medium used for the preparation of the crosslinkable PTFE aqueous emulsion is not particularly limited as long as it is a liquid containing water, and may contain an organic liquid. The organic liquid is not particularly limited, and examples thereof include lower alcohols such as 1-butanol and diacetone alcohol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2- Butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-butene-1,4-diol, glycerin, 2-ethyl-2-hydroxymethyl-1,3-propanediol Polyhydric alcohols such as 1,2,2,6-hexanetriol, ketones such as methyl isobutyl ketone and methyl ethyl ketone, esters such as butyl acetate, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, Amides such as N, N-dimethylformamide, toluene, xylene, trimethylbenzene, methyl ether Rubenzen, propylbenzene, aromatic hydrocarbons such as butyl benzene, ethers, and paraffin waxes, and the like. These organic liquids can be used alone or in combination of two or more.

  Moreover, the crosslinkable PTFE concentration of the crosslinkable PTFE aqueous emulsion is usually 20 to 40% by mass as described above. If the crosslinkable PTFE concentration is less than 20% by mass, it may be difficult to phase separate the crosslinkable PTFE aqueous emulsion. On the other hand, if the crosslinkable PTFE concentration exceeds 40% by mass, the crosslinkable PTFE aqueous solution may be difficult. This is because it may be difficult to remove the fluorine-containing anionic surfactant present in the emulsion. The preferable lower limit of the crosslinkable PTFE concentration is 22% by mass, the more preferable lower limit is 25% by mass, the preferable upper limit is 35% by mass, and the more preferable upper limit is 30% by mass.

(2) Concentration of crosslinkable PTFE aqueous emulsion Examples of the concentration method of the crosslinkable PTFE aqueous emulsion include a phase separation method and a membrane separation method such as an ultrafiltration membrane. From the viewpoint of simplicity and productivity, A separation method is preferred.

  In the phase separation method, an acid component is added to the crosslinkable PTFE aqueous emulsion so that the pH of the crosslinkable PTFE aqueous emulsion is 2 to 3, and then a nonionic surfactant is added to the crosslinkable PTFE aqueous emulsion. Added. Then, the crosslinkable PTFE aqueous emulsion undergoes phase separation, and the crosslinkable PTFE collects in the lower phase. When the upper phase (supernatant) is removed in this state, the crosslinkable PTFE aqueous dispersion according to the present invention is obtained. The solid content concentration of the crosslinkable PTFE aqueous dispersion at this time is 30 to 70% by mass.

  As the nonionic surfactant used in the present invention, known ones can be used, for example, ether type nonionic surfactants such as polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkylene alkyl ether and the like. Agents, polyoxyethylene derivatives such as ethylene oxide / propylene oxide block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, and other ester types Nonionic surfactants, amine-based nonionic surfactants such as polyoxyethylene alkylamines and alkylalkanolamides can be mentioned.

  The nonionic surfactant may be any of an aromatic compound, a linear compound, and a compound having a branched chain, but is a linear compound having no alkylphenol in the structure or a compound having a branched chain. Preferably having a polyoxyethylene alkyl ether structure, more preferably having a polyoxyethylene alkyl ether structure having an alkyl group having 10 to 20 carbon atoms, and polyoxyethylene having an alkyl group having 10 to 15 carbon atoms Those having an alkyl ether structure are more preferred. Examples of the nonionic surfactant having a polyoxyethylene alkyl ether structure include polyoxyethylene alkyl ether type nonionic surfactants such as Neugen TDS-80 (Daiichi Kogyo Seiyaku Co., Ltd.).

  In the present invention, the nonionic surfactant is preferably added in an amount of 10 to 40 parts by mass with respect to 100 parts by mass of the crosslinkable PTFE in the aqueous emulsion.

  When the nonionic surfactant is less than 10 parts by mass with respect to 100 parts by mass of the crosslinkable PTFE, the phase may not clearly separate, whereas when it exceeds 40 parts by mass with respect to 100 parts by mass of the crosslinkable PTFE, This is because economic efficiency may be impaired. In the present application, the content (N) of the nonionic surfactant is about 1 g (X) of a sample taken in an aluminum cup having a diameter of 5 cm, dried at 100 ° C. for 1 hour, and further heated (Y). Was determined based on the formula: N = (Y−Z) / X × 100 (%) from the heating residue (Z) dried at 300 ° C. for 1 hour.

  In the present application, “phase separation” means a state where the crosslinkable PTFE-free phase and the crosslinkable PTFE-containing phase are in an equilibrium state or an unbalanced state. However, when the crosslinkable PTFE aqueous emulsion contains a fluorine-containing anionic surfactant, the concentration of the fluorine-containing anionic surfactant in the non-crosslinkable PTFE-containing phase is within the range described below. The separated state is preferable, and it is more preferable that it is in an equilibrium state in terms of reproducibility during production and process control.

  The phase separation in the present invention can be performed by, for example, the method described in International Publication No. 2003/078479.

  The phase separation is preferably performed at a temperature equal to or higher than the cloud point of the nonionic surfactant, more preferably performed at a temperature higher than the cloud point by 5 ° C or higher, and performed at a temperature higher than the cloud point by 10 ° C or higher. More preferably. The “cloud point” means that when the nonionic surfactant aqueous solution is heated to make the nonionic surfactant aqueous solution a white turbid liquid, the white turbid liquid is gradually cooled. It is the temperature at which it becomes transparent. In the present application, the cloud point is determined according to ISO 1065 (Method A) when 15 mL of a measurement diluted sample is placed in a test tube and heated until it becomes completely opaque, and then the measured diluted sample is gradually cooled with stirring. It is measured as the temperature at which the entire liquid becomes transparent.

  Moreover, it does not specifically limit as a method of removing a crosslinkable PTFE non-containing phase, It can carry out by conventionally well-known methods, such as a decantation.

(3) Additives In the crosslinkable PTFE aqueous dispersion according to the present invention, a crosslinking agent, a binder resin, a film forming aid, a leveling agent, a solid lubricant, water powder, quartz sand, carbon black, Diamond, tourmaline, germanium, alumina, silicon nitride, fluorite, clay, talc, extender pigment, extender, conductive filler, glitter material, pigment, filler, pigment dispersant, anti-settling agent, moisture absorber, surface conditioning Agent, thixotropy imparting agent, viscosity modifier, anti-gelling agent, UV absorber, light stabilizer, plasticizer, anti-coloring agent, anti-skinning agent, anti-scratch agent, anti-mold agent, antibacterial agent, anti-antibacterial agent An erosion agent, an antioxidant, an antistatic agent, a silane coupling agent, an antifoaming agent, a desiccant, a repellency inhibitor, an antioxidant, an activator, and the like can be added.

  Although it does not specifically limit as a crosslinking agent, The thing which reacts with 1 or several reactive functional group of crosslinkable PTFE, and can form a cyclic structure is preferable, and it reacts with 1 or several reactive functional group of crosslinkable PTFE. It is more preferable to form a heterocyclic ring. Moreover, as this crosslinking agent, those that cause a π-electron deficient heterocyclic cyclization reaction are particularly preferable. In this case, a π-electron deficient heterocyclic ring (azol, triazole, azine, diazine, triazine, etc.) excellent in oxidation resistance and chemical resistance is formed during the crosslinking reaction. As such a crosslinking reaction for forming a π-electron deficient heterocyclic ring, for example, a known reaction described in “New edition of heterocyclic compounds, basic edition, applied edition, Yamanaka et al., Kodansha Scientific 2004” can be used. . As a finally formed crosslinked structure, for example, a crosslinked structure formed by a triazine cyclization reaction from a crosslinkable PTFE containing a cyano group and a crosslinking agent containing a plurality of cyano groups, containing a cyano group Containing crosslinkable PTFE and guanidine containing crosslinkable structure, acid halide group, carboxyl group, or alkoxycarbonyl group formed from a crosslinkable PTFE and a crosslinker containing a plurality of hydrazine groups via a triazole cyclization reaction By a triazole cyclization comprising a crosslinkable PTFE containing an acid halide group, a carboxyl group, or an alkoxycarbonyl group and a crosslinker containing a plurality of amidrazones. Examples include a crosslinked structure. Among these, it is particularly preferable to utilize a ring synthesis reaction of 1,3 azole utilizing a ring closing reaction by 1,2 bond formation as a crosslinking reaction. In addition, by introducing a heterocyclic ring as a crosslinking point, there is also an effect that adhesion with other materials of the PTFE crosslinked body is improved.

  Examples of such a crosslinking agent include bisdiaminophenyl compounds, bisaminophenol compounds, and bisaminothiophenol compounds containing at least two crosslinkable reactive groups represented by the following general formula (51), as well as the general formula The compound is selected from the group consisting of a bisamidrazone compound and a bisamidoxime compound represented by formula (52), a bisamidrazone compound represented by formula (53), and a bisamidoxime compound represented by formula (54) Preferably it is at least one compound.

（式中、Ｒ¹は、同じかまたは異なり、−ＮＨ₂、−ＮＨＲ²、−ＯＨまたは−ＳＨであり、Ｒ²は、フッ素原子または１価の有機基である）

(Wherein R ¹ is the same or different and is —NH ₂ , —NHR ² , —OH or —SH, and R ² is a fluorine atom or a monovalent organic group)

（式中、Ｒ³は、−ＳＯ₂−、−Ｏ−、−ＣＯ−、炭素数１〜６のアルキレン基、炭素数１〜１０のパーフルオロアルキレン基、又は単結合手であり、

(Wherein R ³ is —SO ₂ —, —O—, —CO—, an alkylene group having 1 to 6 carbon atoms, a perfluoroalkylene group having 1 to 10 carbon atoms, or a single bond,

（式中、Ｒ_f ¹は炭素数１〜１０のパーフルオロアルキレン基である）

(Wherein R _f ¹ is a C 1-10 perfluoroalkylene group)

（式中、ｎは１〜１０の整数である）

(Where n is an integer from 1 to 10)

  The compound having at least two crosslinkable reactive groups represented by the general formula (51) preferably has 2 to 3 crosslinkable reactive groups, and more preferably has two. When the number of crosslinkable reactive groups represented by the general formula (51) is less than 2, crosslinking cannot be performed.

The substituent R ² in the crosslinkable reactive group represented by the general formula (51) is a monovalent organic group other than a hydrogen atom or a fluorine atom. The N—R ² bond is preferable because it has higher oxidation resistance than the N—H bond.

Examples of the monovalent organic group include, but are not limited to, an aliphatic hydrocarbon group, a phenyl group, or a benzyl group. Specifically, for example, at least one -CH ₃ of ^{_{R 2, -C 2 H 5,}} -C 3 carbon atoms, such as H ₇ 1 to 10, especially 1 to 6 lower alkyl group; -CF _3, - Fluorine atom-containing lower alkyl group having 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms such as C ₂ F ₅ , —CH ₂ F, —CH ₂ CF ₃ , —CH ₂ C ₂ F ₅ ; phenyl group; benzyl group; _{C 6 F 5, -CH 2 C} 6 F 5 phenyl or benzyl 1-5 hydrogen atoms with fluorine atoms is substituted, such _{as; -C 6 H 5-n (} CF 3) n, -CH 2 _{C 6 H 5-n (CF} 3) n (n is an integer of 1 to 5), such as, 1 to 5 hydrogen atoms in -CF ₃ and the like phenyl or benzyl group substituted.

Of these, a phenyl group and —CH ₃ are preferred because they are particularly excellent in heat resistance, have good crosslinking reactivity, and are relatively easy to synthesize.

  Moreover, as a crosslinking agent, the compound shown by the following general formula (55) is preferable from the point that a synthesis | combination is easy.

（式中、Ｒ¹は上記Ｒ¹と同じ、Ｒ⁵は、−ＳＯ₂−、−Ｏ−、−ＣＯ−、炭素数１〜６のアルキレン基、炭素数１〜１０のパーフルオロアルキレン基、単結合手、または、

(In the formula, R ¹ is as defined above R ^1, R ⁵ _{is, -SO 2 -, - O -} , - CO-, an alkylene group having 1 to 6 carbon atoms, perfluoroalkylene group having 1 to 10 carbon atoms, Single bond hand, or

で示される基である）

Is a group represented by

  Preferable specific examples of the alkylene group having 1 to 6 carbon atoms include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, and the like. As the perfluoroalkylene group having 1 to 10 carbon atoms, Is

などが挙げられる。なお、これらの架橋剤は、特公平２−５９１７７号公報、特開平８−１２０１４６号公報などで、ビスジアミノフェニル化合物の例示として知られているものである。

Etc. These crosslinking agents are known as examples of bisdiaminophenyl compounds in JP-B-2-59177, JP-A-8-120146, and the like.

  Among these, a more preferable crosslinking agent is a compound represented by the general formula (56).

（式中、Ｒ⁶は、同一であるか又は相違し、いずれも水素原子、炭素数１〜１０のアルキル基；フッ素原子を含有する炭素数１〜１０のアルキル基；フェニル基；ベンジル基；フッ素原子および／または−ＣＦ₃で１〜５個の水素原子が置換されたフェニル基またはベンジル基である）

Wherein R ⁶ is the same or different and both are hydrogen atoms, alkyl groups having 1 to 10 carbon atoms; alkyl groups having 1 to 10 carbon atoms containing fluorine atoms; phenyl groups; benzyl groups; A phenyl group or a benzyl group in which 1 to 5 hydrogen atoms are substituted with a fluorine atom and / or —CF ₃ )

  As the crosslinking agent, those that can utilize the ring synthesis reaction of 1,3 benzoazole utilizing the ring closing reaction by 1,2 bond formation as described above as the crosslinking reaction are particularly preferable. This is because the introduction of benzoazole and an aromatic ring improves the adhesion between PTFE and other materials.

  Specific examples include, but are not limited to, 2,2-bis (3,4-diaminophenyl) hexafluoropropane, 2,2-bis [3-amino-4- (N-methylamino) phenyl] Hexafluoropropane, 2,2-bis [3-amino-4- (N-ethylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N-propylamino) phenyl] hexafluoro Propane, 2,2-bis [3-amino-4- (N-phenylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N-perfluorophenylamino) phenyl] hexafluoro Examples include propane and 2,2-bis [3-amino-4- (N-benzylamino) phenyl] hexafluoropropane. Among these, 2,2-bis (3,4-diaminophenyl) hexafluoropropane is more preferable from the viewpoint of excellent heat resistance and particularly good crosslinking reactivity.

  These bisamidoxime crosslinkers, bisamidrazone crosslinkers, bisaminophenol crosslinkers, bisaminothiophenol crosslinkers, bisdiaminophenyl crosslinkers, etc. are cyano groups possessed by PTFE used in the present invention. , React with a carboxyl group, an alkoxycarbonyl group and an acid halide group to form an oxazole ring, a thiazole ring and an imidazole ring, to give a PTFE crosslinked product.

  The addition amount of the crosslinking agent is preferably 0.01 to 20 parts by weight and more preferably 0.03 to 10 parts by weight with respect to 100 parts by weight of the crosslinkable PTFE. If the cross-linking agent is less than 0.01 parts by weight, there is a tendency that practically sufficient mechanical strength, heat resistance and chemical resistance cannot be obtained, and if it exceeds 20 parts by weight, it takes a long time to cross-link. This is because the PTFE crosslinked body tends to be brittle. Moreover, the physical property of a PTFE molded object can be changed by adjusting the addition amount of a crosslinking agent. For example, an amount of a crosslinking agent capable of reacting with all of the reactive functional groups introduced into the crosslinkable PTFE may be added, or reacting with all of the reactive functional groups introduced into the crosslinkable PTFE. Alternatively, an amount of a cross-linking agent intended for an effect derived from a functional group such as improvement of adhesion with other materials may be added while leaving an uncrosslinked site.

  In addition, when a crosslinking agent is added to the crosslinkable PTFE aqueous dispersion according to the present invention, the content of the monomer that gives a crosslinking site of the crosslinkable PTFE is preferably relative to TFE that is an essential monomer. Is 0.01 mol% or more, more preferably 0.03 mol% or more, further preferably 0.06 mol% or more, preferably 50 mol% or less, more preferably 20 mol% or less, still more preferably 5 mol% or less. It is. If the content of the monomer giving the cross-linked site is 0.01 mol% or less, a sufficient effect cannot be obtained, and if the content of the monomer is 50 mol% or more, it is difficult to obtain a polymer. Because it becomes.

  The binder resin is not particularly limited, and examples thereof include polyphenylene sulfide, polyamide, polyamideimide, polyamic acid, and polyimide. The polyamide is not particularly limited, and examples thereof include aliphatic boramides such as nylon 6, nylon 66, nylon 11, and nylon 12, aromatic boramides such as polyparaphenylene terephthalamide and polymetaphenylene isophthalamide, and the like. Is mentioned.

  Although it does not specifically limit as a film-forming auxiliary agent, Depolymerizable acrylic resin, urethane resin, etc. are mentioned.

  The bright material is not particularly limited, and examples thereof include mica, metal powder, glass beads, glass bubbles, glass flakes, and glass fibers.

  The metal powder is not particularly limited, and examples thereof include powders of simple metals such as aluminum, iron, tin, zinc, gold, silver, and copper, and powders of alloys such as aluminum alloy and stainless steel. The shape of the metal powder is not particularly limited, and examples thereof include particles and breaks. When the crosslinkable PTFE aqueous dispersion contains such a bright material, the crosslinkable PTFE aqueous dispersion can form a coating film having an excellent appearance. The content of the glittering material is preferably 0.1 to 10.0% by mass with respect to the solid content of the crosslinkable PTFE aqueous dispersion.

  The viscosity modifier is not particularly limited, and examples thereof include methyl cellulose, alumina sol, polypinyl alcohol, and carboxylated vinyl polymer.

  Although it does not specifically limit as an antifoamer, For example, nonpolar solvents, such as toluene, xylene, a C9-C11 hydrocarbon type, silicone oil, etc. are mentioned.

  Although it does not specifically limit as a desiccant, For example, a cobalt oxide etc. are mentioned.

  Although it does not specifically limit as an antioxidant, Polyarylene sulfide, a nitrogen containing compound, tin, metals, such as zinc and phosphorus, sulfur, etc. are mentioned.

<Manufacture of PTFE crosslinked body-impregnated molded body>
The PTFE crosslinked body-impregnated molded body according to the present invention is manufactured through an impregnation step, a drying step, and a firing and crosslinking step.

  In the impregnation step, the cross-linkable PTFE aqueous dispersion is impregnated into the object to be treated. In the drying step, the crosslinkable PTFE aqueous dispersion impregnated in the treatment object in the impregnation step is dried. In the firing and crosslinking step, the crosslinkable PTFE is fired while being crosslinked by heat treatment or the like. Note that the drying step and the firing and crosslinking step may be performed simultaneously.

  The material to be treated is not particularly limited, and examples thereof include a fiber base material, a woven / nonwoven fabric, and a sintered metal. Moreover, it does not specifically limit as a fiber base material, For example, glass fiber, a vinyl fiber, carbon fiber, an aramid fiber (Kevlar fiber etc.) is mentioned. Moreover, the PTFE crosslinked body-impregnated molded body according to the present invention is preferably used for, for example, a roof material (tent film) of a membrane structure building, a conveyor belt, a high-frequency printed circuit board, a packing, a sintered metal bearing, and the like. it can. The PTFE crosslinked body-impregnated molded body usually has a thickness of about 10 to 100 μm, although it depends on the shape and thickness of the object to be treated.

  Drying can be performed by a conventionally known method. For example, the drying may be performed at a temperature of room temperature to 150 ° C. for 5 to 20 minutes.

  Firing needs to be performed at a temperature equal to or higher than the melting temperature of the crosslinkable PTFE, and is usually preferably performed at a temperature of 340 to 415 ° C for 5 to 60 minutes, more preferably at 360 to 400 ° C for 10 to 30 minutes. .

<Manufacture of PTFE crosslinked body-coated molded body>
The PTFE crosslinked body-coated molded body according to the present invention is manufactured through an application process, a drying process, and a crosslinking reaction process. In the application step, the coating composition is applied to the object to be processed. In the drying process, the coating composition applied to the object to be processed in the application process is dried. In the crosslinking reaction step, the crosslinkable PTFE is crosslinked. In addition, a drying process and a crosslinking reaction process may be performed simultaneously.

  In the present application, the coating composition refers to a composition in which at least a binder resin is added to the crosslinkable PTFE aqueous dispersion. The binder resin is preferably a heat resistant resin.

  As an example of the coating composition, as a coating composition containing a fluororesin and a heat-resistant resin in the past, for example, a coating composition containing a fluororesin, mica or metal flake, a depolymerizable acrylic resin, and a liquid carrier (see Patent Document 3) )), A coating composition (see Patent Document 4 and Patent Document 5) containing a fluororesin and a specific polyether-based urethane resin has been proposed.

  In addition, as a coating composition having improved paintability in such a coating composition, a coating composition comprising a melt-processable fluororesin having a specific melt viscosity and an acrylic copolymer having a decomposition temperature of 40 ° C. or lower (Patent Document 6) And a coating composition comprising a fluororesin particle, a high-boiling polyhydric alcohol, a depolymerizable acrylic resin and a nonionic surfactant, and an aqueous medium (see Patent Document 7).

These coating compositions can be generally prepared by adding an aqueous resin dispersion or the like to a fluororesin-containing aqueous dispersion.
JP-A-52-13531 International Publication No. 97/40112 Pamphlet International Publication No. 99/21927 Pamphlet Japanese National Patent Publication No. 11-513052 International Publication No. 2003/011991 Pamphlet

  Furthermore, the fluorine-containing polymer, on the other hand, has a problem of poor adhesion to an object to be treated (object to be coated) due to its non-adhesiveness. For the purpose of improving the adhesion, a primer containing a binder resin such as a heat-resistant resin and a fluorine-containing polymer is preliminarily coated on an object to be coated as an undercoat.

As an aqueous primer containing a fluoropolymer and a heat-resistant resin, a coating composition containing a fluoropolymer, colloidal silica and a specific polyamic acid and a liquid carrier (see, for example, Patent Document 8), polyethersulfone, Polyamideimide and / or polyimide, line, PTFE or other fluororesin having a specific content ratio (see, for example, Patent Document 9), heat-resistant resin, fluoropolymer, and specific amount of non-alkylphenol type nonionic surfactant And a coating composition comprising an aqueous dispersion containing an agent (for example, see Patent Document 10).
JP 52-14630 A International Publication No. 99/64523 Pamphlet JP 2004-204073 A

  The material to be treated is not particularly limited, and the cross-linkable PTFE has excellent heat resistance, chemical resistance, water / oil repellency, releasability, slidability, and the like. [OA] Household appliances such as equipment rolls and irons, and kitchen appliances such as frying pans and hot plates. Moreover, this crosslinkable PTFE is suitably used as a coating material in the fields of food industry, electrical industry, machine industry and the like.

  The material of the object to be processed is not particularly limited, and examples thereof include metals such as aluminum, stainless steel (SUS), iron, copper, etc., heat-resistant resins, enamels, glass, ceramics, and the like. Is preferred. The metal may be a single metal or an alloy, and may be an oxide film rapid-forming metal such as stainless steel, copper, copper alloy, or gold in terms of good adhesion to the resulting coating film. Alternatively, an oxide film slow-forming metal such as aluminum or iron may be used. Further, the object to be processed may have any shape. In addition, in order to uniformly apply the coating composition on the object to be processed and to improve the adhesion of the coating composition to the object to be processed, the object to be processed is previously subjected to a surface treatment such as a degreasing process or a roughening process. It is preferable to carry out. The surface roughening treatment method is not particularly limited, and examples thereof include chemical etching with acid or alkali, anodization (alumite treatment), sandblasting, and the like.

  The coating composition may be applied directly to the object to be processed, or may be applied to the object to be processed through a primer layer in order to improve adhesion to the object to be processed. The primer layer preferably has a film thickness of 1 to 100 μm.

  As a coating method of the coating composition, a known coating method such as a dipping method, a spray method, a roll coating method, a doctor blade method, a flow coating method (spin flow method or curtain flow method) can be employed.

  Drying can be performed by a conventionally known method. For example, the drying may be performed at a temperature of room temperature to 150 ° C. for 5 to 20 minutes.

  Firing needs to be performed at a temperature equal to or higher than the melting temperature of the crosslinkable PTFE, and is usually preferably performed at a temperature of 340 to 415 ° C for 5 to 60 minutes, more preferably at 360 to 400 ° C for 10 to 30 minutes. .

  When the primer layer is provided on the object to be processed, the baking may be performed after the primer layer is applied, dried and baked (2-coat 2-bake method), or the primer layer is applied and dried. The coating composition may be applied and dried (two-coat one-bake method).

  In addition, the coating film formed on a to-be-processed object is although it does not specifically limit, It is preferable that it is 10-100 micrometers.

  In addition, the application of the coating composition according to the present invention is not particularly limited, and the coating composition is a coating material for various electric wires such as heat-resistant enamel wires, information equipment parts (paper separation claw, printer guide, gear, bearing). Connectors, Verniin sockets, IC sockets, oil field electrical components, relays, electromagnetic shielding, relay cases, switches, covers, terminal board buses, metal foil coatings, valve seats, hydraulics Seals, backup rings, piston rings, wear bands, vanes, ball bearing retainers, rollers, cams, gears, bearings, labyrinth seals, pump parts, mechanical linkages, bushings, fasteners, spline liners, brackets, hydraulic pistons, chemical pumps Casing, valve, valve, joint, tower packing, co Lvobin, packing, connectors, gaskets, valve seals, buried bolts, buried nut casings, oil seals, covering materials for parts such as antenna caps, thrust washers, seal rings, gears, bearings, tappets, engine parts (pistons) , Piston rings, valve steers), transmission parts (spool valves, ball check valves, sealing), covering materials for vehicle industry parts such as rocker arms, jet engine parts (bushings, washers, spacers, nuts), and power control Clutch, door hinge bearing, connector, tube clamp, bracket, hydraulic component, antenna, radome, frame, fuel system component, compressor component, boiler component, rocket engine component, wear strip, co Kuta shelf, coating materials for aerospace industry parts such as space structures, coating materials for semiconductor parts such as semiconductor factory ducts, kitchen knives, rice cookers, rice bowls, oven linings, electric pots, hot plates, frying pans, Home bakery, pan tray, gas table top plate, pan top plate, gas table, pan (grill pan, pressure cooker), kettle, coating material for cooking utensils such as ice tray, kneading roll, rolling roll, chute, conveyor, die, Can be used as a covering material for food industry parts such as hoppers, iron bottom plates, snow shovels, plows, saws, files, drills, scissors, kitchen knives, etc., molds, molds, iron making Pin covers, plating equipment parts, nuclear power parts, ultrasonic transducers, potentiometer shafts, faucet parts, etc., stirring blades , Tank inner surface, vessel, tower, centrifuge, pump, valve, piping, heat exchanger, plating jig, tank lorry inner surface, anticorrosion coating such as screw conveyor, OA roll, OA belt, OA separation claw, papermaking It can also be used as a release coating material for rolls, calendar rolls for film production, injection molds, pipes, ship bottoms, and the like.

<Other usage modes>
A molded body such as a film, fiber, or block may be formed from the crosslinkable PTFE aqueous dispersion according to the present invention. Moreover, the crosslinkable PTFE aqueous dispersion according to the present invention may be mixed with an activator or the like into a paste and used as a battery binder (binder).

  Hereinafter, examples of the crosslinkable PTFE aqueous dispersion will be described in detail.

(1) Production of crosslinkable aqueous PTFE emulsion (Synthesis Example 1)
Into a stainless steel reactor with a stirrer having a content volume of 6 L, 3580 g of deionized water, 94 g of paraffin wax and 5.4 g of ammonium perfluorooctanoate were placed. The reactor contents were then aspirated while heating to 70 ° C. and simultaneously purged with TFE monomer to remove oxygen in the reactor. Thereafter, 14.7 g of perfluoro [3- (1-methyl-2-vinyloxy-ethoxy) propiontonyl] (hereinafter abbreviated as CNVE) was added to the reactor, and the contents were stirred at 280 rpm.

  TFE monomer was added into the reactor until a pressure of 0.73 MPa was reached. 0.72 g ammonium persulfate (APS) initiator dissolved in 20 g deionized water was injected into the reactor and the reactor was brought to a pressure of 0.83 MPa. A pressure drop occurred after the injection of the initiator and the onset of polymerization was observed. TFE monomer was added to the reactor to maintain pressure and polymerization was continued until about 1.1 Kg of TFE monomer had reacted. Thereafter, the reactor was evacuated and the contents were removed from the reactor and cooled. Thereafter, the supernatant paraffin wax was removed from the aqueous dispersion.

  The obtained crosslinkable PTFE aqueous dispersion had a solid content concentration of 26.5% by weight and an average primary particle size of 0.21 μm. The average primary particle size is determined by the transmittance when light having a wavelength of 550 nm is incident on a predetermined cell into which a crosslinkable PTFE aqueous dispersion prepared to have a solid content of 0.15% by weight is injected, and a transmission electron microscope. After obtaining the correlation with the number average primary particle diameter calculated by measuring the unidirectional diameter from the photograph, it was obtained by applying the above transmittance measured for the obtained sample to the above correlation (calibration curve Law).

The resulting crosslinkable PTFE aqueous dispersion was diluted with deionized water to a solids concentration of about 15% by weight and coagulated under high speed stirring conditions. The coagulated powder was dried at 145 ° C. for 18 hours. At this time, the CNVE modification amount of the crosslinkable PTFE powder was 0.125 mol%. The amount of denaturation was determined by a ¹⁹ F-MAS NMR (manufactured by BRUKER) measurement method employing measurement conditions of probe diameter: 4.0 mm, measurement rotation speed: 13 to 15 KHz, measurement atmosphere: nitrogen, measurement temperature: 150 ° C. The peak derived from TFE and the peak derived from the denaturing agent (peak of -77 to -88 ppm) were detected and determined from the area ratio of these peaks. Moreover, although this crosslinkable PTFE powder was heated to 380 degreeC, crosslinkable PTFE powder did not show fluidity | liquidity.

(Synthesis Example 2)
A 6L stainless steel reactor with a stirrer was charged with 3560 g deionized water, 94 g paraffin wax and 5.4 g ammonium perfluorooctanoate dispersant. The reactor contents were then aspirated while heating to 70 ° C. and simultaneously purged with TFE to remove oxygen in the reactor. Thereafter, 0.17 g of ethane gas and 15.2 g of perfluoro [3- (1-methyl-2-vinyloxy-ethoxy) propionic acid] (hereinafter abbreviated as “CBVE”) were added to the reactor. The material was stirred at 280 rpm. TFE was added into the reactor until a pressure of 0.73 MPa was reached. 0.36 g of ammonium persulfate (hereinafter abbreviated as “APS”) initiator dissolved in 20 g of deionized water was injected into the reactor to bring the reactor to a pressure of 0.83 MPa. A pressure drop occurred after the injection of the initiator and the onset of polymerization was observed. TFE was added to the reactor to maintain the pressure and polymerization was continued until about 1.1 kg of TFE had reacted. Thereafter, the reactor was evacuated and the contents were removed from the reactor and cooled. Thereafter, the supernatant paraffin wax was removed from the crosslinkable PTFE aqueous emulsion.

  The obtained crosslinkable PTFE aqueous emulsion had a solid content concentration of 23.5% by weight and an average primary particle size of 0.08 μm. The average primary particle size is determined by the transmittance when 550 nm light is incident on a predetermined cell into which a crosslinkable PTFE aqueous emulsion prepared to a solid content of 0.15% by weight is injected, and a transmission electron microscope. After obtaining the correlation with the number average primary particle diameter calculated by measuring the unidirectional diameter from the photograph, it was obtained by applying the above transmittance measured for the obtained sample to the above correlation (calibration curve Law).

The obtained crosslinkable PTFE aqueous emulsion was diluted with deionized water to a solid content concentration of about 15% by weight and coagulated under high-speed stirring conditions. The coagulated powder was dried at 145 ° C. for 18 hours. The CBVE modification amount of the crosslinkable PTFE powder at this time was 0.26 mol%. The amount of denaturation was determined by a ¹⁹ F-MAS NMR (manufactured by BRUKER) measurement method employing measurement conditions of probe diameter: 4.0 mm, measurement rotation speed: 13 to 15 KHz, measurement atmosphere: nitrogen, measurement temperature: 150 ° C. The peak derived from TFE and the peak derived from the denaturing agent (peak of -77 to -88 ppm) were detected and determined from the area ratio of these peaks.

(Synthesis Example 3)
Polymerization was performed in the same manner as in Synthesis Example 2 except that 15.2 g of CBVE in Synthesis Example 2 was changed to 14.6 g of CNVE.

  The solid content concentration of the crosslinkable PTFE aqueous emulsion obtained at this time was 23.1% by weight, and the average primary particle size was 0.17 μm. Further, the CNVE modification amount of the crosslinkable PTFE powder at this time was 0.14 mol%.

(Synthesis Example 4)
In the synthesis example 2, 0.17 g of ethane gas was replaced with 0.03 g of ethane gas, and 15.2 g of CBVE was replaced with 15.7 g of perfluoro [3- (1-methyl-2-vinyloxy-ethoxy) propionate] Polymerization was carried out in the same manner as in Synthesis Example 2 except that “RVEE” was used.

  The solid content concentration of the crosslinkable PTFE aqueous emulsion obtained at this time was 23.8% by weight, and the average primary particle size was 0.18 μm. Moreover, the RVEE modification amount of the crosslinkable PTFE powder at this time was 0.20 mol%.

(Synthesis Example 5)
A 6L stainless steel reactor with a stirrer was charged with 3560 g deionized water, 94 g paraffin wax and 5.4 g ammonium perfluorooctanoate dispersant. The reactor contents were then aspirated while heating to 70 ° C. and simultaneously purged with TFE to remove oxygen in the reactor. Thereafter, 0.17 g of ethane gas and 16.6 g of perfluorobutenoic acid (hereinafter abbreviated as “PFBA”) were added to the reactor, and the contents were stirred at 280 rpm. TFE was added into the reactor until a pressure of 0.73 MPa was reached. 0.36 g of APS initiator dissolved in 20 g of deionized water was injected into the reactor and the reactor was brought to a pressure of 0.83 MPa. A pressure drop occurred after the injection of the initiator and the onset of polymerization was observed. TFE was added to the reactor to maintain the pressure and polymerization was continued until about 1.1 kg of TFE had reacted. Thereafter, the reactor was evacuated and the contents were removed from the reactor and cooled. After that, the supernatant paraffin wax was removed from the crosslinkable PTFE aqueous emulsion.

  The obtained crosslinkable PTFE aqueous emulsion had a solid content concentration of 23.7% by weight and an average primary particle size of 0.22 μm. The average primary particle size is determined by the transmittance when 550 nm light is incident on a predetermined cell into which a crosslinkable PTFE aqueous emulsion prepared to a solid content of 0.15% by weight is injected, and a transmission electron microscope. After obtaining the correlation with the number average primary particle diameter calculated by measuring the unidirectional diameter from the photograph, it was obtained by applying the above transmittance measured for the obtained sample to the above correlation (calibration curve Law).

The obtained crosslinkable PTFE aqueous emulsion was diluted with deionized water to a solid content concentration of about 15% by weight and coagulated under high-speed stirring conditions. The solidified crosslinkable PTFE powder was dried at 145 ° C. for 18 hours. The amount of PFBA modification of the crosslinkable PTFE powder at this time was 0.28 mol%. The amount of denaturation was determined by a ¹⁹ F-MAS NMR (manufactured by BRUKER) measurement method employing measurement conditions of probe diameter: 4.0 mm, measurement rotation speed: 13 to 15 KHz, measurement atmosphere: nitrogen, measurement temperature: 150 ° C. , A peak derived from TFE and a peak derived from a denaturant (-179 to -190 ppm for PFBA, -77 to -88 ppm for CBVE and CNVE) were detected, and the peak area ratio was detected. Asked.

(Synthesis Example 6)
Polymerization was conducted in the same manner as in Synthesis Example 5 except that the amount of PFBA in Synthesis Example 5 was changed to 6.6 g.

  The solid content concentration of the crosslinkable PTFE aqueous emulsion obtained at this time was 23.8% by weight, and the average primary particle size was 0.20 μm. Further, the amount of PFBA modification of the crosslinkable PTFE powder at this time was 0.14 mol%.

(Synthesis Example 7)
Polymerization was performed in the same manner as in Synthesis Example 5 except that the amount of PFBA in Synthesis Example 5 was 6.6 g and the amount of ethane was 3.0 ml.

  The solid content concentration of the crosslinkable PTFE aqueous emulsion obtained at this time was 23.7% by weight, and the average primary particle size was 0.23 μm. Moreover, the amount of PFBA modification | denaturation of the crosslinkable PTFE powder at this time was 0.12 mol%.

  In this synthesis example, since the amount of ethane added as a chain transfer agent is less than that of synthesis examples 5 and 6, the PTFE obtained in this synthesis example is more than the molecular weight of PTFE obtained in synthesis examples 5 and 6. Become big. Incidentally, this is confirmed by the standard specific gravity [SSG] measured by an underwater substitution method using a sample prepared according to ASTM D 4895-89.

(Synthesis Example 8)
Polymerization was performed in the same manner as in Synthesis Example 5 except that the amount of PFBA in Synthesis Example 5 was 1.7 g and the amount of ethane was 3.0 ml.

  The solid content concentration of the crosslinkable PTFE aqueous emulsion obtained at this time was 23.2% by weight, and the average primary particle size was 0.20 μm. Moreover, the amount of PFBA modification | denaturation of the crosslinkable PTFE powder at this time was 0.03 mol%.

(Synthesis Example 9)
3380 g of deionized water was placed in a 6 L stainless steel reactor with a stirrer. The reactor contents were then aspirated while heating to 70 ° C. and simultaneously purged with TFE to remove oxygen in the reactor. Thereafter, 0.51 g ethane gas and 6.6 g PFBA were added to the reactor and the contents were stirred at 700 rpm. TFE was added into the reactor until a pressure of 0.73 MPa was reached. 0.68 g APS initiator dissolved in 20 g deionized water was injected into the reactor and the reactor was brought to a pressure of 0.83 MPa. A pressure drop occurred after the injection of the initiator and the onset of polymerization was observed. TFE was added to the reactor to maintain the pressure and polymerization was continued until about 0.8 Kg of TFE had reacted. The reactor was evacuated and cooled to room temperature, and the resulting crosslinkable PTFE powder was washed with deionized water and filtered.

  The resulting crosslinkable PTFE powder was dried at 145 ° C. for 18 hours. The amount of PFBA modification of the crosslinkable PTFE powder at this time was 0.20 mol%.

(Synthesis Example 10)
Polymerization was performed in the same manner as in Synthesis Example 9 except that 6.6 g of PFBA in Synthesis Example 9 was changed to 15.2 g of CBVE.

  The crosslinkable PTFE powder obtained at this time was dried at 145 ° C. for 18 hours. Further, the CBVE modification amount of the crosslinkable PTFE powder at this time was 0.45 mol%.

(Synthesis Example 11)
Polymerization was conducted in the same manner as in Synthesis Example 9 except that 6.6 g of PFBA in Synthesis Example 9 was changed to 15.2 g of CBVE, the amount of APS initiator was changed to 0.07 g, and ethane was not used.

  The crosslinkable PTFE powder obtained at this time was coarsely pulverized and then dried at 145 ° C. for 18 hours. Then, it grind | pulverized until the average particle diameter became 10-150 micrometers with the fine grinder, and the crosslinkable PTFE powder for shaping | molding was obtained. The CBVE modification amount of the crosslinkable PTFE powder at this time was 0.35 mol%.

(Synthesis Example 12)
Polymerization was performed in the same manner as in Synthesis Example 5 except that 16.6 g of PFBA in Synthesis Example 5 was changed to 14.6 g of CNVE.

  The solid content concentration of the crosslinkable PTFE aqueous emulsion obtained at this time was 23.1% by weight, and the average primary particle size was 0.17 μm. Further, the CNVE modification amount of the crosslinkable PTFE powder at this time was 0.14 mol%.

(Synthesis Example 13)
Polymerization was conducted in the same manner as in Synthesis Example 5 except that 16.6 g of PFBA in Synthesis Example 5 was changed to 15.7 g of RVEE, and the amount of ethane gas was changed to 0.17 g of 0.07 g.

  The solid content concentration of the PTFE aqueous emulsion thus obtained was 23.5% by weight, and the average primary particle size was 0.18 μm. Further, the amount of RVEE modification of the PTFE powder at this time was 0.25 mol%.

  (2) Concentration of crosslinkable concentrated PTFE aqueous dispersion

The non-ionic surfactant RO (CH ₂ CH ₂ O) _n H (R: tridecyl group) was added to the crosslinkable PTFE aqueous dispersion (crosslinkable PTFE solid content concentration 26.5% by weight) obtained in Synthesis Example 1. (Daiichi Kogyo Seiyaku Co., Ltd. product name: Neugen TDS-80C) was added in an amount of 18% by weight based on the solid content of the crosslinkable PTFE, and the resulting aqueous dispersion was gently stirred for several minutes.

  The aqueous dispersion was heated in a warm bath at 70 ° C. and allowed to stand for 20 hours. Then, when the resulting transparent supernatant layer was removed, a crosslinkable PTFE concentrated dispersion having a solid content concentration of 60% by weight was obtained. The TDS-80C content was 4.4% with respect to the solid content of PTFE.

  Further, TDS-80C was further added to the crosslinkable PTFE concentrated dispersion so that the content of TDS-80C was 6% by weight with respect to the solid content of PTFE.

  In addition, the crosslinkable PTFE aqueous dispersion obtained in Synthesis Examples 2 to 13 can be concentrated by the same method as in the above Examples.

  The crosslinkable PTFE aqueous dispersion and coating composition according to the present invention have a feature that the crosslinkable PTFE is present at a high concentration, and contributes to the efficiency of the coating operation and the impregnation operation.

  In addition, the method for producing a cross-linked PTFE-impregnated molded body and the method for producing a cross-linked PTFE-coated body according to the present invention use a cross-linkable PTFE aqueous dispersion or coating composition in which cross-linkable PTFE is present in a high concentration. And contributes to the efficiency of application work and impregnation work.

Claims (2)

Cyano group (—CN), first functional group represented by general formula (1):

(R ¹ and R ² are each independently a hydrogen atom, a halogen atom, —OR ³ , —N (R ³ ) ₂ , —R ³ , and R ³ is an alkyl group which may contain fluorine having 1 to 10 carbon atoms. Or a hydrogen atom), and the second functional group represented by the general formula (2):

(R ¹ is a hydrogen atom, a halogen atom, —OR ³ , —N (R ³ ) ₂ , —R ³ , and R ³ is an alkyl group which may contain fluorine having 1 to 10 carbon atoms or a hydrogen atom) A crosslinkable polytetrafluoroethylene aqueous dispersion containing 30 to 70% by mass of a crosslinkable polytetrafluoroethylene having at least one reactive functional group selected from the group consisting of: An impregnation step of impregnating the object to be treated with the crosslinkable polytetrafluoroethylene aqueous dispersion according to claim 1;
A drying step of drying the crosslinkable polytetrafluoroethylene aqueous dispersion impregnated in the object to be treated in the impregnation step;
The manufacturing method of a polytetrafluoroethylene bridge | crosslinking body impregnation molded object provided with the baking and bridge | crosslinking process of baking, making the said crosslinkable polytetrafluoroethylene crosslink.