KR810001985B1 - Process for preparing the polymer for coating - Google Patents

Abstract

Nitryl polymer for coating metal is prepd. by graft copolymg. acrylonitrile(I) and Me acrylate(II) or styrene with latexes of nitrile rubber of SBR, resp. Thus, a 31.1% solid rubber latex was prepd. by polymn. of 40 parts I with 60 parts 1,3-butadiene in water in the presence of AIBN tert- dodecyl mercaptan and emulsifier, and 31.9 parts of the rubber latex was polymd. with 75 parts I and 25 parts II in water in the presence of K2S2O8, in emulsifier, n-dodecyl mercaptan, and EDTA to give 33% solids copolymer latex.

Description

Manufacturing method of coating polymer

The present invention relates to a method for producing a nitrile polymer having excellent fluid barrier properties and useful as a can or a metal surface treatment product.

Prior to the present invention, polymer latex was used as a can coating, which was practically problematic. Cans made of metals such as tinned iron and aluminum are usually covered with a corrosion resistant coating to protect its contents for a long time. The storage of food and beverages in particular requires cans with such treatments. Coatings using polymeric latex as the coating cannot be coatings lacking pinholes, voids and the like and are therefore usually used with organic solvents to coat the cans.

However, the use of such organic solvents is expensive and toxic.

The inventors have found that protective coatings with good chemical resistance can be prepared using a kind of nitrile copolymer latex which is described in detail later.

The most useful polymer latex of the present invention is most useful as it is made by effluent polymerization in the presence of parasitic rubbery material based on olefinic unsaturated nitrile and other monomer components copolymerizable with the nitrile.

Such latex of the present invention (or blend of latex) generally contains 20 to 45% solids, the average particle diameter is 500 to 3000mm 3.

The most useful polymers in the process of the present invention are made by reacting a large amount of mono-unsaturated nitrile (e.g. acrylonitrile) with a small amount of monovinyl monomer (which must be copolymerizable during emulsion polymerization with nitrile). The diene rubber produced by copolymerizing or monopolymerizing the conjugated diene monomer may optionally be reacted in the presence of.

Feed diene monomers used in the present invention include butadiene-1, 3-isoprene, chloroprene, bromoprene, cyanoprene, 2, 3-dimethylbutadiene-1, 3- and the like. Among them, butadiene 1, 3- and isoprene which are more suitable for the purpose of the present invention are easily available and have excellent polymerizability.

인 알파, 베타-올레핀성 불포화모노니트릴이 있다. 이때의 R은 수소, 탄소수 1 내지 4의 저급알킬, 할로겐이며 이와 같은 화합물로는 아크릴로니트릴, 알파-클로로 아크릴로니트릴, 알파-플루오로아크릴로니트릴, 메타크릴로니트릴, 에타크릴로니트릴 등등이 있다. 이와 같은 화합물 중에서도 본 발명에 더욱 적합한 것은 아크릴로니트릴, 메타크릴로니트릴 또는 이것들의 혼합물이 있다.As the olefinically unsaturated nitriles used in the present invention, the structural formula is

Phosphorus alpha, beta-olefinically unsaturated mononitrile. In this case, R is hydrogen, lower alkyl having 1 to 4 carbon atoms, halogen, and such compounds include acrylonitrile, alpha-chloro acrylonitrile, alpha-fluoroacrylonitrile, methacrylonitrile, ethacrylonitrile and the like. There is this. Among such compounds, more suitable for the present invention are acrylonitrile, methacrylonitrile or mixtures thereof.

As mentioned above, the monovinyl monomer copolymerizable with olefinically unsaturated nitriles and conjugated dienes includes esters of olefinically unsaturated carboxylic acids, vinyl esters, alpha-olefins, vinyl aromatic monomers and the like.

을 갖는 화합물을 포함한다.The aforementioned olefinically unsaturated carboxylic acid ester has a structural formula

It includes a compound having a.

However, at this time, R ₁ is hydrogen, alkyl having 1 to 4 carbon atoms, halogen and R ₂ is alkyl having 1 to 6 carbon atoms. Such compounds include methyl acrylate, amyl acrylate, hexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, methyl alpha- Chloroacrylate, ethyl alpha-chloroacrylate and the like. Among these compounds, more suitable compounds for the present invention include methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and the like.

인 탄소수 4 내지 10의 올레핀류가 좋다. 이때의 R¹과 R＂는 탄소수 1 내지 7의 알킬이며, 이와 같은 화합물로서 적절한 것은 이소부틸렌, 2-메틸부텐-1-, 2-메틸펜텐-1-, 2-메틸헥센-1-, 2-메틸헵텐-1-, 2-메틸옥텐-1-, 2-에틸부텐-1-, 2-프로필펜텐-1- 등등이 있으며 가장 좋기로는 이소부틸렌이다.Alpha-olefins of the present invention is a structural formula

Olefin having 4 to 10 phosphorus carbons is preferable. R ¹ and R 'at this time are alkyl having 1 to 7 carbon atoms, and suitable as such compounds are isobutylene, 2-methylbutene-1-, 2-methylpentene-1-, 2-methylhexene-1-, 2-methylheptene-1-, 2-methyloctene-1-, 2-ethylbutene-1-, 2-propylpentene-1- and the like, most preferably isobutylene.

As the above-mentioned vinyl ethers, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, methyl isopropenyl ether, ethyl isopropenyl ether and the like are used.

In addition, the above-mentioned vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate and the like, with vinyl acetate being preferred.

In addition, the vinyl aromatic monomar as described above includes styrene, alpha-methylstyrene, vinyltoluene, vinylxylene, and the like, of which styrene is more preferable.

What is suitable as a polymer of this invention is that what made the total amount of following (A) + (B) 100 weight part, and made following (C) 0-40 weight part exists. At this time

인 하나이상의 니트릴을 (A)+(B)량의 60 내지 90중량%로 하고(A) is a structural formula

One or more nitriles of phosphorus are 60 to 90% by weight of the amount of (A) + (B)

(B) is selected from the following components (1)-(5) to be 10 to 40% by weight of the amount of (A) + (B)

인 에스테르(1) structural formula

Phosphorus ester

인 알파-올레핀(2) structural formula

Phosphorus alpha-olefin

(3) Vinyl ether selected from methyl vinyl ether, ethyl vinyl ether, propofyl ether, butyl vinyl ether, etc.

(4) vinyl acetate

(5) styrene

(C) is a rubbery polymer of a conjugated diene monomer selected from butadiene and isoprene, to which a comonomer selected from styrene, a structural nitrile, and a ester of structural formula can be optionally added before polymerization. The constitution comprises 50 to 100 wt% of the conjugated diene monomer and 0 to 50 wt% of the comonomer.

The polymer latex of the present invention is made by an emulsion polymerization method, and the process is carried out by a batch method, a continuous method, an interruption method, and the like, and monomers are supplied by each method. Such polymerization is carried out by adding an emulsifier and a free radical polymerization initiator in an aqueous medium to maintain 0 to 100 ° C. in a state where oxygen is removed.

The process for producing the latex of the present invention is described in detail in US Pat. Nos. 3,426,102,358,673,37,377, and the like.

The new latex of the present invention uses a doctor knife, a wire bar, a roller coater, a spray gun, or immerses the metal in latex, or a latex on a metal surface in a degreased metal can to be coated. The cloth is coated with a coating technique such as shedding.

After drying by applying a latex coating as described above, it is dried by maintaining a temperature of 200 to 300 ℃, the metal at this time refers to iron plate, tin-plated iron, aluminum and the like.

Next, the following examples have been described in order to describe the present invention in detail, but it will be apparent that the examples do not limit the scope of the present invention and all parts are parts by weight.

Example 1

A. The rubbery latex to be used in the present invention is prepared by stirring and polymerizing the following components under conditions of removing oxygen at 45 ° C.

Prior to starting the reaction, the mixture was adjusted to pH 8 with KOH and the polymerization was carried out for 22.5 hours so that the conversion was 92% and the total solids 33.1%.

B. Highly impact resistant gas tight resins are prepared by polymerizing a mixture of the following components:

At this time, the pH was adjusted to 0.7 with KOH, and the polymerization reaction was carried out at a temperature of 60 ° C. for 20 hours while removing oxygen to obtain a conversion ratio of 97% and a solid amount of latex 33%.

Example 2

The method of Example 1B is repeated except for latex A component.

The result was a latex copolymer of acrylonitrile and methyl acrylate.

Example 3

The acrylonitrile-styrene copolymer is prepared in the presence of the latex (butadiene 72% styrene 28%) of the rubbery butadiene-styrene copolymer using the following components.

The copolymerization was carried out under nitrogen pressure, the reaction temperature was 60 ℃, the molar ratio of acrylonitrile / styrene was 20/1, the reaction time was 130 minutes, and 53 parts of styrene was added to the reaction mixture during the reaction. As a result, a polymer having a yield of 73% was obtained, and the nitrogen content of the obtained polymer was 11.19%, indicating that the molar ratio of acrylonitrile / styrene of the copolymer was 1.44 / 1.

Example 4

A latex of acrylonitrile-styrene copolymer was prepared by the method of Example 3, excluding butadiene-styrene latex.

Example 5

A. The resulting polymer latex of Example 1B is filtered through a coarse filter paper to filter out all polymer particles (including pre-flock). 0-3 parts by weight of distilled water is added per 1 part by weight of filtered latex to dilute the latex.

Three parts of water are usually added per part of the latex, and the diluted latex is placed in a nebulizer (Vinx 26).

The latex is used to coat tin coated iron plates and aluminum plates.

In the bending process, the oil or fat foil present on the metal surface is first removed. Carbon tetrachloride or similar solvents are used as cleaning agents.

The final clean and dried metal surface is spray coated with latex, which is then brightly and finely coated with a spray gun. If the latex coating on the metal surface is good, each coating is air dried for about one minute before the next coating is used, and when the outermost part is roughly dried, it is left in a circulating air oven maintained at 200 to 200 ° C for 1 to 2 minutes.

This iron plate is taken out of the oven and cooled to room temperature.

Overexposure of the coating should be avoided as degradation will occur if the polymer is exposed to high temperatures for a long time.

The thickness of the final cladding was 0.5 ± 0.1 mils and typically the thickness of this coating is 0.1 to 1 mil. For another experiment a 5 x 8 x 4 to 7 mil board was coated and the thickness of the coating could be varied.

B. The strength and adhesion of the polymer coating coated on the test metal layer according to the method of A described above can be measured by the bending test. For the bending test, a metal coated with a polymer is hung on a vise, bent to the opposite side of the coated surface, removed from the vise, bent in the same direction, and doubled to overlap the coating layer. The cut and fragments of the polymer coated on the metal surface are examined at this time.

The metal plate coated with the polymer is then hooked back to the vise and folded to the other side to bend the coated surface itself.

It is bent 180 degrees again to bring the metal layer into contact with the coating surface.

The cut and fragments of the polymer coated on the metal surface are examined at this time. In all cases of the three kinds of metal sheets (for example, iron sheet, tinned iron sheet, and aluminum) used in the test, no cutting or chipping of the coating was found.

C. A faster and more rigorous test was designed to test the perforation than the bending test of B above. In the puncture test, the coated metal layer of B is placed on a metal plane with a slightly loose vise or hole. A hard, solid surface is then placed under the coating layer (there is a hole under the coating layer).

The covering layer on the hole is punched sharply with a hammer to make a perforation. Examine the polymer coating around the cut and slit holes. No cuts or pieces mean this coating is excellent. Poor coatings can be seen that the surface around the hole is cut, chipped, and split, even on the backside 1/8 to 4/1 from around the hole.

The drilling test can be carried out in two ways: the first outermost surface and the second surface of the bottom layer.

In the first test the perforation took place under the coating and in the second test the perforation occurred on the coating.

Samples of the coated metal layer prepared in B did not show any cuts, chips or cracks and proved to have good coatings in this test.

C. The pinhole test is carried out even if the polymer coating on the test layer referred to in B is free of diaphragms and there are no pinholes and voids on the coating surface.

For the pinhole test, make 2% by weight CuSO ₄ ㆍ 5H ₂ O solution in distilled water and use this solution with a small amount of H ₂ SO ₄ to make pH 1 and put the coated metal test plate into this solution. Iron plate, tin foil iron plate) is plated with copper in a short time. On the other hand, if there are no pinholes, voids or slits in the coated surface, no plating of copper is produced. If the polymer cladding has pinholes, voids and slits, a small metal surface is exposed and copper metal adheres to the exposed surface. When making fine crushing a part of fine polymer coatings, the crushing appears as a regular, delicate reddish red line on the coated iron plate surface or tin plated iron plate layer.

Samples of polymer coated aluminum layers are required for the pinhole test. The pH of the above-described sulfated goji solution is made to hydrochloric acid rather than sulfuric acid so that the pH is 1. When the specimen is immersed in this solution, the copper is better covered with aluminum.

This copper sulfate pinhole test can also be carried out on a polymer coating layer subjected to a bending or puncture test. The polymer coating metal layer described in B was found to have a good barrier-free coating in this copper sulfate pihol test.

Example 6

The polymer latex sample prepared in Example 1B was filtered well through coarse filter paper and used without dilution.

The aluminum layer is coated by dipping in filtration latex.

At this time, the aluminum plate from which the oil is removed is immersed in the latex at room temperature, and the immersion time is about 5 to 10 seconds.

After this treatment, the aluminum plate is taken out of the latex to remove excess latex over 5 to 15 seconds and then air dried for 5 minutes.

Thereafter, the coating layer is left to circulating air for 1 to 2 minutes at 200 to 220 캜. In Example 5A, only one side was spray-coated, but both sides were coated here. The thickness of the coating at this time is measured by a micrometer.

The thickness of this coating was on average 0.3-0.4 mil on both sides. However, in such a deposition coating method, the thickness of the plate is different. The upper end of the layer is the thinnest and the lower layer (the removed latex collects) is the thickest.

Therefore, in order to eliminate this problem, a method of rotating the metal plate during air drying is required. The immersion coated aluminum layer produced by this method was found to have a good coating in the test of Example 5B.

Example 7

The latex made in Example 1B is filtered and diluted as in Example 5A. The latex is used to coat a clean iron plate and a tin plated iron plate layer using a roller.

This coating layer is placed on a flat surface to bind the two ends. The dilution ratio causes the distilled water: filtration latex to be 1: 1 (medium).

A small amount of diluted latex was poured at one end of the metal plate and the layer was pushed with a roller. Slowly roll the rubber roller onto the layer so that a thin latex wave is pressed in front of the roller. After the roller passed, a thin layer of latex was coated on the metal surface. The coating is allowed to air dry at room temperature for some time and the coating layer is heated at 200-220 ° C. in reflux air.

Example 8

The latex prepared in Example 2 was coated on the iron plate, tin iron plate, aluminum plate, etc. according to the method of Example 1, and showed an excellent effect.

Example 9

The latex prepared in Example 3 was coated on the iron plate, tin iron plate, aluminum plate, etc. according to the method of Example 1, and showed an excellent effect.

Example 10

The latex prepared in Example 4 was coated on the iron plate, tin iron plate, aluminum plate, etc. according to the method of Example 1, and showed an excellent effect.

Claims (1)

The content of the following (A) + (B) component to 100 parts by weight of the following (C) component by the presence of 0 to 40 parts by weight of the polymerization to prepare a polymer material, characterized in that for producing a polymer. At this time (A) is a general diet

One or more nitriles of phosphorus are 60 to 90% by weight of the amount (B) is selected from the following components (1)-(5) to be 10 to 40% by weight of the amount of (A) + (B) (1) general diet

Phosphorus ester (2) general diet

Phosphorus alpha-olefin (3) Vinyl ether selected from methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, etc. (4) vinyl acetate (5) styrene (C) is a rubbery polymer of a conjugated diene monomer selected from butadiene and isoprene, which are optionally styrene and

Phosphorus nitrile, general dietary

The comonomer selected from the phosphorus esters can be added, and the constitution of the rubbery polymer is 50 to 100% by weight of the conjugated diene monomer and 0 to 50% by weight of the comonomer. (Wherein R is hydrogen, alkyl of 1 to 4 carbon atoms, halogen, R ₁ is hydrogen, alkyl of 1 to 4 carbon atoms, halogen and R ₂ is alkyl of 1 to 6 carbon atoms, R 'and R ＂Is alkyl having 1 to 7 carbon atoms).