JPS61275311A - Curable fluoroolefin copolymer and its production - Google Patents

Abstract

PURPOSE:To produce the titled copolymer in good yields, by copolymerizing a fluoroolefin with a carboxylic acid vinyl ester, a vinyl ether and a hydroxyl group-containing vinyl ether in specified conditions. CONSTITUTION:A copolymer of 10-70mol% fluoroolefin, 5-70mol% carboxylic acid vinyl ester of the structure of formula II, 5-70mol% 1-8C alkyl-containing vinyl ether and 3.5-30mol% hydroxyl group-containing vinyl ether of the structure of formula III is obtained by carrying out copolymerization at -20-130 deg.C in the presence of a radical initiator, a solution of a feed composition which satisfies the relationship IV [wherein a(mol%) is a fluoroolefin, b(mol%) is a vinyl ether, c(mol%) is a hydroxyl group-containing vinyl ether, and d(mol%) is a carboxylic acid vinyl ester]. In the formulas, X is H, Cl, F, CF3, OCF3 or OC3F7, R1 is a 1-17C aliphatic, aromatic or alicyclic hydrocarbon, and R2 is a 1-6C alkyl.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel crosslinkable curable fluoroolefin copolymer and a method for producing the same. The present invention relates to possible fluoroolefin copolymers. The present invention also relates to a method for producing this copolymer with high yield by utilizing the copolymerization reactivity of each monomer.

(Prior art and its problems) Fluoroolefin polymers are widely used because they have properties such as chemical resistance, heat resistance, abrasion resistance, and non-adhesion, but on the other hand, they have a high melting point. , requires melting and baking at high temperatures. Furthermore, since it is not soluble in solvents, it can only be used in the form of an emulsion or dispersion, making it unsuitable for paints with good storage stability. In order to improve these drawbacks and improve the crosslinking curability, for example, in JP-A No. 57-34107, a copolymer consisting of fluoroolefin, cyclohexyl vinyl ether, alkyl vinyl ether, and hydroxyalkyl vinyl ether was mixed with isocyanate, melamine, etc. A method of curing has been proposed. However, such copolymers do not necessarily have satisfactory compatibility with curing agents such as incyanate, and the raw material cyclohexyl vinyl ether is a special monomer that is generally difficult to obtain.

(Means for Solving the Problems) As a result of repeated research to improve the drawbacks of fluoroolefin polymers, the present inventors have found that fluoroolefins,
Using a quaternary copolymer of a specific composition consisting of carboxylic acid vinyl ester, vinyl ether, and hydroxyl group-containing vinyl ethyl, we discovered an inexpensive copolymer with crosslinking and curable properties, and in the process of producing this copolymer, It was discovered that the yield can be increased by specifying the composition of each monomer charged, leading to the present invention.

The present invention comprises 10 to 70 mol% of a fluoroolefin having a structure represented by the following general formula (A), 5 to 70 mol% of a carboxylic acid vinyl ester having a structure represented by the following general formula (B), and an alkyl having 1 to 8 carbon atoms. 5 to 70 mol% of vinyl ethers having a group and 6,5 to 30 hydroxyl group-containing vinyl ethers having a structure of the following general formula (C), a viscosity of α05 to 2.0 dl/77, and a hydroxyl value of 17 to 30.
200 to KOH/II, and the fluoroolefin A mol%, the vinyl ether 6 mol%, the hydroxyl group-containing vinyl ether C mol%,
In the case of the carboxylic acid vinyl ester d mol% Toshita, a solution satisfying [17(b+c)≦a+d<3.5 (b+c) is heated at -20°C to 16°C in the presence of a radical initiator.
The present invention provides a method for producing the fluoroolefin copolymer, which is characterized in that the fluoroolefin copolymer is polymerized at a temperature of 0°C.

H 0 is a hydrogen group. ) The fluoroolefins used in the present invention are represented by the general formula ().

Particularly preferred are tetrafluoroethylene, chlorotrifluorotetraethylene, and fluoropropylene. Its content in the copolymer is 10 to 70 mol%, preferably 20 to 60 mol%. If the content is less than 10 mol%, weather resistance will be insufficient, and if it exceeds 70 mol%, the gloss of the cured product will be low. As the carboxylic acid vinyl ester, those represented by general formula (B) are used.

0 It is an elementary group. ) Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl bivalate, vinyl caproate, vinyl versatate (vinyl ester of C9-,0 carboxylic acid), vinyl laurate, vinyl stearate, vinyl benzoate. , vinyl pt-butylbenzoate, vinyl salicylate, vinyl cyclohexanecarboxylate, etc., and preferably vinyl versatate, vinyl cyclohexanecarboxylate, vinyl benzoate, and vinyl cyclohexanecarboxylate, which improve coating hardness in small amounts. Vinyl benzoate is used.

Its content in the copolymer is 5 to 70 mol%, preferably 10 to 60 mol%. If the amount is less than 5 mol%, the rigidity and hardness of the coating film will be low and the adhesion of dust will be significant. Moreover, when it exceeds 70 mol%, weather resistance becomes low.

Examples of vinyl ethers having an alkyl group having 1 to 8 carbon atoms include evamethyl vinyl ether, ethyl vinyl ether, n-7' lobil vinyl ether, inglobil vinyl ether, n-7'' til vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, n- -pentyl vinyl ether, n-hexyl vinyl ether,
One or more types of n-octyl vinyl ether, 2-ethylhexyl vinyl ether, etc. are used. Its content is 5 to 70 mol% in the copolymer, preferably 7
~60 mol%.

If the amount is less than 5 mol %, the conversion rate of fluoroolefin during production of the copolymer will be low, which is not preferable. Moreover, if it exceeds 70 mol%, the fluorine content in the copolymer will be low, and the function as a fluoropolymer will be low.

As the hydroxyl group-containing vinyl ether, those represented by general formula (C) are used.

Examples include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, 6-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 4-hydroxybutyl vinyl ether, 2-hydroxy-2-methylpropyl Vinyl ether, 5-hydroxypentyl vinyl ether, 6
-Hydroxyethyl vinyl ether and the like, the content of which is 3.5 to 60 mol%, preferably 5 to 2 mol%.
It is 5 mol%. If the amount is less than 3.5 mol%, the crosslinking curing time increases and the chemical resistance, solvent resistance, stain resistance, etc. of the coating film decreases. Moreover, if it exceeds 30 mol %, the solubility of the copolymer in the bath agent OJ decreases, and when mixed with a hardening agent, the gelation time decreases, resulting in a decrease in paint application and workability.

The copolymers of the present invention are limited to those having an intrinsic viscosity of α05 to 2.0 dl/g, preferably a2 to at7t), as measured in tetrahydrofuran at 25°C. A copolymer with an intrinsic viscosity of less than [105 dll/11] has a low molecular weight and a low mechanical strength. 2. Copolymers exceeding Odl/I have high molecular weights, and when made into a solution,
The viscosity is too high, making coating operations difficult. Also,
The copolymer of the present invention has a hydroxyl value of 17 to 200 a9
KOH/I, preferably 20-120WKOH/1
It is. If the hydroxyl value is less than 17 my KOi (/y), the cured product has low thinner resistance, and 200~KOH/l
If it exceeds /, the curing time becomes too short, coating and workability deteriorate, and the cured product becomes brittle, which is not preferable.

In order to produce the copolymer of the present invention in good yield, it is preferable to select the following charging composition. That is, this is a case where the following formula is satisfied, with fluoroolefin a mol %, vinyl ether 6 mol %, hydroxyl group-containing vinyl ether C mol %, and carboxylic acid vinyl ester 46 mol %.

[17 (b+c) 4a+d<3.5 (b+c) If this range is exceeded, the copolymer targeted by the present invention may not be obtained or the yield may be poor, and it may be difficult to obtain an industrially desired copolymer. Undesirable. That is, fluoroolefins (C moles) and carboxylic acid vinyl esters (d moles)
If the phase (a + d) is smaller than α7 times the sum (b + e) of vinyl ether (b mol) and hydroxyl group-containing vinyl ether (C mol), the content of vinyl ether and hydroxyl group-containing vinyl ether in the copolymer may become low, Also, 3
．． When it exceeds 5 times, the conversion rate of fluoroolefins becomes low.

This relational expression shows that fluoroolefins and vinyl ethers copolymerize alternately, and that when fluoroolefins and vinyl carboxylates copolymerize, and when vinyl ethers and vinyl carboxylates, vinyl carboxylates copolymerize preferentially. It is something.

In the production method of the present invention, each of the above-mentioned monomers is mixed in the presence of a radical initiator using known techniques such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization in a batch, semi-continuous, or continuous manner. It is done.

Examples of radical initiators include diacyl peroxides such as acetyl peroxide and benzoyl peroxide, ketone peroxides such as methyl ethyl ketone peroxide and cyclohexane peroxide, hydrogen peroxide, t-butyl hydroperoxide, and cumene hydroperoxide. hydroperoxides such as di-t-butyl peroxide, dialkyl peroxides such as dicumyl peroxide, alkyl peroxides such as t-butyl peroxyacetate and t-butyl peroxypivalate, and optionally hydrogen sulfite. ) 17
Inorganic reducing agents such as sodium chloride, sodium pyrosulfite, and organic reducing agents such as cobalt naphthenate and dimethylaniline are used.

Reaction fit during copolymerization reaction! The temperature is usually -20℃~1
The radical initiator is selected in the range of 30° C. and has a moderate decomposition rate at that temperature. In addition, the reaction pressure is usually 1~
10 Q h/cx”, preferably 5 to 60 yu/c
rrL”.

The copolymer of the present invention includes acetone, methyl ethyl ketone,
It is soluble in ketones such as methyl isobutyl ketone, and organic solvents such as ethyl acetate, propyl acetate, and isobutyl acetate. In addition, in the copolymer of the present invention, the hydroxyl group in the hydroxyl group-containing vinyl ether unit becomes a crosslinking site, and the melamine curing agent,
It can be cured by heating using a urea resin curing agent, a polybasic acid curing agent, or the like. Melamine curing agents include butylated melamine, methylated melamine, epoxy-modified melamine, etc., urea resin curing agents include butylated urea, methylated urea, etc., and polybasic acid curing agents include long-chain aliphatic Examples include dicarboxylic acids, aromatic polycarboxylic acids, and block polyisocyanates. Further, examples of polyvalent isocyanates that can be cured at room temperature with the copolymer of the present invention and polyvalent isocyanates include tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate. aromatic incyanate,
Aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexane diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4-(or 2,6-
) diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,3-di(incyanatomethyl)-cyclohexane, preferably hexamethylene diisocyanate, Non-yellowing diisocyanates such as diisocyanate and blocked products thereof are used.

Furthermore, curing can be accelerated by cooling a catalyst such as dibutyltin dilaurate.

When curing at room temperature using the copolymer of the present invention and the incyanate 1, the blending ratio of the hydroxyl group-containing vinyl ether unit and the polyvalent incyanate is OH/NC0=1
/CL2 to 1/2 (equivalent ratio) is appropriate.

(Effects of the invention and industrial fields of application) The copolymer of the present invention has excellent weather resistance, water repellency, non-adhesiveness, stain resistance, and chemical resistance, and has lubricity on the bottom surface, so it can be used for steel materials, etc.
It is particularly excellent as a surface coating for wood products, ceramic products, glass products, and glass products, a water-repellent oil agent for textile processing, non-adhesive coatings, optical fiber sheath materials for sliding bearings, solar collectors, and materials for physical, chemical, and medical applications. Furthermore, as a paint, it is particularly excellent as a baking paint for metals, a paint for the exterior of buildings, a paint for roofs in areas with heavy snowfall, and a seasoning agent for ships, automobiles, and aircraft. Further, the production method of the present invention is industrially advantageous because the conversion rate of each monomer introduced into the polymer can be 80% or more by specifying the monomer composition to be charged.

(Example) Next, the present invention will be further explained by examples.

Examples 1 to 5, Comparative Examples 1 to 2 Methyl in butyl ketone (abbreviated as MIBK) 50ee and perbutyl pv (NOF ■#riQ, 5# and the amounts listed in Table 1 were placed in a stainless steel pressure-resistant tube with an internal volume of 1001III). Ethyl vinyl ether (abbreviated as E V E), hydroxybutyl vinyl ether (abbreviated as HBVE), C
, a carboxylic acid vinyl ester having an alkyl group [trade name Gueovar 9 (abbreviated as VV-9), manufactured by Shell Chemical ■] or benzoic acid vinyl ester (abbreviated as BZVE), and heated to -70°C in a dry ice-methanol bath. The tube was cooled to 100 mL, and nitrogen gas was blown into the tube to remove oxygen from the pressure tube. Then, the liquefied hexafluoropropylene (RFP
) or chlorotrifluoroethylene (CTF)
(abbreviated as E) was charged in a specified amount and sealed in a tube. In addition, in the case of tetrafluoroethylene (abbreviated as TFE), use a pressure-resistant tube with pulp, and after preparing it in the same manner as above,
After pressurizing and sealing TFE from the cylinder, the pulp was tightened and weighed. These pressure-resistant tubes were placed in a rotary constant-temperature water bath heated to 60°C, and after reacting for 16 hours, the contents were precipitated in 10 times the volume of methanol, and after drying with ventilation at 80°C for 12 hours, the yield was measured. did. Furthermore, this polymer is 100-
After dissolving in acetone, reprecipitate with methanol in step 11,
The purified and dried product was subjected to measurements of fluorine content, NMR, intrinsic viscosity, hydroxyl value, and glass transition point.

The fluorine content was measured by colorimetric determination of fluorine using the Alizarin Combrecran method, and the amount of fluoroolefin components was calculated based on the measurement.

NMR measurements were performed using JNM-MH60fi manufactured by JEOL Ltd., using tetramethylsilane as an internal standard substance. As a result, the sum of the 10-protons of alkyl vinyl ether and hydroxybutyl vinyl ether jik(b+
c) appeared at 3.9-4.6-C-4,6-5.9 PPM.

Therefore, b + c / d (molar ratio) = (3,9 ~
Peak area of 4.6)/Peak area of (4,6-5.9)・・・・・・・・・(1) c+d=100-(a+b)=(2
) Substituting this into (21) gives 100-(a+b).

From the above formula, C (hydroxybutyl vinyl ether ik) and d (vinyl carboxylate-fit) are determined.

Intrinsic viscosity was measured at 25°C using a 1% solution of tetrahydrofuran.
It was measured using a Kuperod viscometer.

The hydroxyl value was measured by an acetylation method using anhydrous vinegar [K]. Based on this, the amount of hydroxybutyl vinyl ether was calculated.

Moreover, the glass transition temperature was measured by TGA-DSC.

(Note) HFP: Hexafluoropropylene, CTFE:
Chlorotrifluoroethylene, TFE: Tetrafluoroethylene, EVE: Ethyl vinyl ether, HBVE
: Hydroxybutyl vinyl ether, VV-9: Ueover-9 (carboxylic acid vinyl ester), BZVE: Pinyl benzoate The above polymers include ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, tetrahydrofuran, carbon tetrachloride, toluene, xylene, etc. It was soluble in organic solvents.

50 g of each of the polymers of Examples 1 to 5 and Comparative Examples 1 to 2 was mixed with 25 g of toluene and 1 methyl inoptyl compound f-y251 to obtain a colorless and transparent solution. Add Thai Bake CR- to this solution.
90 (manufactured by Ishihara Sangyo ■) 271 and milled in a ball mill to 24
A white mill base was produced by mixing for a period of time. Parnock DN-950 (hexamethylene diisocyanate type, manufactured by Dainippon Ink Chemical Co., Ltd.) was added to this so that the hydroxyl groups and incyanate groups of the polymer were equivalent, and a JIS G-3) 41 steel plate was degreased with methyl ethyl ketone. The coating was applied to the surface using an applicator, baked and cured at 80° C. for 30 minutes, and then left to stand for 2 days before being subjected to physical property tests. The thickness of the reed film was 35 to 40 μm, and the results shown in Table 2 were obtained.

The coating films of Examples 1 to 5 exhibit good physical properties, but Comparative Example 1 has poor solvent resistance, and Comparative Example 2 has a coating film that is too flexible, has adhesion of outdoor natural MF dust, and is unable to maintain gloss. is inferior.

Examples 6 to 9 Target copolymers were obtained in the same manner as in Examples 1 to 5 from the monomers shown in Table 3. The properties of the obtained copolymers are shown in the same table. In addition, cured coating films were obtained from each of the synthesized polymers in exactly the same manner as in Examples 1 to 5. The coating performance was good as shown in Table 4.

Claims (1)

[Scope of Claims] 1) 10 to 70 mol% of a fluoroolefin having a structure represented by the following general formula (A), 5 to 70 mol% of a carboxylic acid vinyl ester having a structure represented by the following general formula (B), and a carbon number of 1 Vinyl ethers with up to 8 alkyl groups 5-
It has a composition of 70 mol% and 3.5 to 50 mol% of a hydroxyl group-containing vinyl ether having the structure of the following general formula (C), and the intrinsic viscosity of the copolymer is 0.05 to 2.0 dl/g.
, a fluoroolefin copolymer having a hydroxyl value of 17 to 200 mgKOH/g. Note (A) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (X is H,
They are Cl, F, CF_3, OCF_3, and OC_3F_7. ) (B) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_1 is a hydrocarbon group selected from aliphatic, aromatic, and alicyclic groups with 1 to 17 carbon atoms.) (C) ▲ Numerical formulas, chemical formulas , tables, etc. ▼ (R_2 is an alkylene group having 1 to 6 carbon atoms.) (2) The carboxylic acid vinyl ester has 9 to 10 carbon atoms.
The fluoroolefin copolymer according to claim 1, which is a vinyl ester of an aliphatic carboxylic acid. (3) The fluoroolefin copolymer according to claim 1, wherein the vinyl carboxylate ester is vinyl cyclohexanecarboxylate. (4) The fluoroolefin copolymer according to claim 1, wherein the carboxylic acid vinyl ester is vinyl benzoate. (5) The carboxylic acid vinyl ester is para-tert.
The fluoroolefin copolymer according to claim 1, which is vinyl -butylbenzoate. (6) 10 to 70 mol% of a fluoroolefin having the structure represented by the general formula (A) above, 5 to 70 mol% of a carboxylic acid vinyl ester having the structure represented by the following general formula (B), and an alkyl group having 1 to 8 carbon atoms. Vinyl ether with 5~
In producing a copolymer containing 70 mol and 3.5 to 30 mol % of a hydroxyl group-containing vinyl ether having the structure of the following general formula (C), the charging composition was changed to fluoroolefin a.
When mol%, vinyl ether b mol%, hydroxyl group-containing vinyl ether c mol%, and carboxylic acid vinyl ester d mol%, a solution satisfying 0.7 (b + c) ≦ a + d < 3.5 (b + c) is a radical initiator. A method for producing a copolymer, comprising polymerizing at a temperature of -20°C to 130°C in the presence of a copolymer.