JPS58215406A - Copolymer, film formable composition and surface coating method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of the Invention] The present invention relates to a copolymer comprising a polymerizable ester of an unsaturated carboxylic acid into which a hydrazide group has been introduced, and an aqueous copolymer containing this copolymer. The present invention relates to a film-forming composition and a method of coating a surface with the composition.

[Problems with conventional technology and -t]

Polymers and copolymers comprising esters of unsaturated carboxylic acids having hydrazide groups as substituents are known. For example, JP-A-51-69489 discloses a urea scavenger in which a copolymer of this type is reacted with formaldehyde or glyoxal. However, we have recently discovered that a type of copolymer consisting of a polymerizable ester of an unsaturated carboxylic acid into which a hydrazide group has been introduced is water-soluble and can be used to form an aqueous film. It has been found that the present invention has film-forming properties that make it useful in sexual compositions.

[Purpose of the invention]

Accordingly, it is an object of the present invention to provide a copolymer, a film-forming composition containing the entire copolymer, and a method for coating surfaces with the composition.

[Key points of the invention]

According to the invention, therefore, a copolymer into which a hydrazide group of a polymerizable ester of an unsaturated carboxylic acid has been introduced contains a large proportion of monomer units which are methyl acrylate or methyl methacrylate; a small proportion of one comonomer unit which is an alkyl ester of acrylic acid or methacrylic acid or higher;
Alkyl groups are characterized in that they have at least 4 carbon atoms.

A monomer unit can be methyl acrylate or methyl methacrylate, or a mixture of both. Similarly, a comonomer unit can be a mixture of acrylic esters and/or methacrylic esters.

Preferably, the alkyl group of one unit of the comonomer has 4 to 12 carbon atoms. Suitable comonomers are butyl,
Includes pentyl, hexyl and lauryl acrylic acid and methacrylic cough esters and their branched enzyme derivatives.

Preferably, the ratio of one unit of monomer to one unit of comonomer in the co-merger is 20:1 to 10:8, more preferably 4:
The ratio is 1 to 3:2.

A copolymer into which a hydrazide group is introduced can be produced by a conventional polymerization method. Preferably, solution polymerization is used. Azobisisobutyronitrile is a suitable polymerization initiator.

The hydrazide group can be introduced into the copolymer using a known method. For example, a suitable method consists of dissolving or dispersing the copolymer in a water-soluble alcohol, such as methanol, or in a mixed water-alcohol solution. If the copolymer is prepared by solution polymerization with alcohol as the solvent, it can be subjected to the hydrazide step immediately after the polymerization is complete. The solution or suspension is stirred and heated to a temperature of 50° to 80°C and hydrazine hydrate gold is added. The reaction is exothermic, so the hydrazine hydrate is preferably added slowly. Adding hydrazine hydrate all at once will make temperature control difficult and side reactions will occur.

The amount of hydrazide groups that need to be incorporated into the copolymer to make it water-soluble depends on the monomers used to make the copolymer. Preferably the hydrazide content is 1
It is more than 0 to 20 moles. Typically, the hydrazide content of copolymers having butyl acrylate as a common unit is 11 to 17 moles.

The copolymers with hydrazide-based substituents preferably have a molecular weight of 500 to 10,000. For example, a chain transfer agent such as butanethiol can be added to the monomers prior to polymerization to control the molecular weight of the copolymer.

The copolymer is water soluble and the present invention includes an aqueous solution of the copolymer. Water-soluble copolymers are suitable for use in water-based protective coatings.

It has been found that the adhesion properties of coatings made from copolymers can be improved by including other heptamers of the following types. Accordingly, the present invention provides fixing comonomers selected from the group consisting of hydroxyethyl acrylate, hydroxyethyl methacrylate, water-soluble derivatives of hydroxyethyl acrylate or hydroxylethyl methacrylate, and unsaturated carboxylic acids, such as acrylic acid or methacrylic acid. Copolymers further comprising: Preferably, the amount of fixing monomer contained in the co-9-^r polymer is from 5 to 24% by weight based on the weight of methyl acrylate or methyl methacrylate monomer.

The present invention includes a film-forming composition comprising the above copolymer and a crosslinking agent, wherein the crosslinking agent is a water-soluble aldehyde or an organic thermosetting resin containing all methylol groups or methoxy groups; The polymer and crosslinker are dissolved or dispersed in an aqueous medium, and the amounts of copolymer and crosslinker are such that when applied to a surface, a film is formed.

Bathable aldehydes can be divalent.

If an aldehyde having at least 6 carbon atoms in the molecule, excluding the carbon atoms in the aldehyde group, is used,
A longer curing time can be obtained.

Aldehydes suitable for use as crosslinking agents include formaldehyde, glyoxal and glutaraldehyde. The relative number of aldehyde groups to hydrazide groups in the composition may range from 5:1 to 1:5, preferably from 4:1 to 1:1.

Organic thermosetting resins containing methylol groups and/or methoxy groups are known. Preferably, these resins are soluble or dispersible in aqueous media, alcohols or water/alcohol mixtures. Suitable resins are:
For example, phenol-formaldehyde resin, urea-
Formalgahyde resin, o-, m-5 or p-cresol-formaldehyde resin, resorcinol-formaldehyde resin, thiourea-formaldehyde resin,
Includes guanidine-formaldehyde resins, daanamine-formaldehyde resins, melamine-formaldehyde resins, hexamethoxymelamine resins and cardol-formaldehyde resins. Kaldol is an alkyl-substituted resorcinol derived from cashew kernel oil.

Particularly suitable resins are methylated resins, such as methylated hexamethoxymelamine resins and methylated melamine-bormaldehyde resins.

The relative number of methoxy or methylol groups in the resin to hydrazide groups in the copolymer is preferably 1:1. In practice, the number of methylol or methoxy groups in a particular resin need not be known, and only simple experimentation is required to determine the required resin and copolymer cap.

The aqueous medium in which the copolymer and crosslinking agent are dissolved or dispersed is preferably fresh water. The concentration of comonomers in water is
Preferably 20 to 60 weight i' based on the total weight of the copolymer solution.
I am in charge.

Preferably, the composition should be usable for at least 8 hours after being made.

The "use life" of a composition depends on factors such as the particular copolymer and crosslinking agent used, their degree of strength in the composition, temperature, and the hydrazide content of the copolymer.

Generally, the copolymer and crosslinker are stored separately and the composition is made up as needed. The copolymer and crosslinker are stored as a concentrate, optionally mixed with water, or
Alternatively, one or both components can be stored as an aqueous solution or dispersion.

The compositions according to the invention may also contain other substances such as pigments, corrosion inhibitors, viscosity modifiers, etc.

The present invention also encompasses a method of coating a surface, which method comprises applying the composition described above (by any known method, such as brushing or spraying) onto the surface and then cracking and cracking the surface. It is successful to heat the mixture at 120 to 180° C. for 5 minutes to 4 hours.

The film-forming properties of the copolymers make it possible to form a complete υ coating by applying an aqueous solution of the copolymer to a surface and heating it without the presence of a crosslinking agent. However, this type of coating is cross-linked with a suitable aldehyde or methylol or methoxy group resin, requires prolonged heating and is less stable. low. The method of the present invention produces a water-insoluble coating from an aqueous composition containing a water-soluble copolymer.

[Embodiments of the invention]

The present invention will be explained below using examples.

Mix the following ingredients and carry out the polymerization at 70 °C under nitrogen atmosphere.
Polymerization initiator: azobisisobutyronitrile 5F, methyl acrylate 100! , butyl acrylate 50f, methacrylic acid 20y, water 400117, industrial methylated spirit 600tj0 The copolymer solution was maintained at 70 °C and without isolating the copolymer.
120 mj (2,47 mol) of hydrazine hydrate total 20
Add gradually over a period of minutes. Turn off the heat and let the mixture come to room temperature (
The mixture was stirred for a further 6 hours until the temperature returned to about 22°C. The solvent was then removed using a mouth-to-tal evaporator.

The polymer yield was 117y, and the hydrazide content was 11x. The viscosity of a 36% solution of the polymer measured using a Brookfield viscometer (29 rpm, spindle A5) was 6800 centipoise (Xl 0 1j/m).
s ), and the viscosity of a 10% solution (100 rpm, spindle A2) is 660 centipoise (X 1OK?/m
s).

A 40 weight S solution was obtained by dissolving the copolymer in water and 10 excellent solutions of different aldehydes 061 were added and mixed with sample 5d of this copolymer solution. The composition was then brushed onto a cold rolled mild steel plate of thickness Q, f3 sn and heated at 120° C. for 2 hours. All compositions gave a clear pale yellow coating on the board. These test tubes were subjected to the König-Pensulam hardness test and the conical mandrel test (AS
TM D522-60) to measure the elongation of the coating. The results are shown in Table 1. The result of the König-Italian hardness test is shown as excellent, which is the hardness ratio of the glass.

Table 1 also shows the results of tests carried out on coatings made of polymer solutions in the absence of aldehydes. The hardness and elongation of this coating were similar to coatings produced using all aldehyde crosslinkers, but showed lower resistance to water and solvents.

Table 1: Hardness and Elongation of the Coating Produced in Example 1 The coatings crosslinked using aldehydes were immersed in water, acetone, and toluene for 24 hours, but no signs of coating dissolution or deterioration were observed. It was not shown. 15-coatings crosslinked in the absence of aldehydes swelled and the film became wet when immersed in water.

Example 2 The following ingredients were all mixed and the polymerization was carried out at 70°C under nitrogen atmosphere.
for 5 hours; azobisisobutyronitrile 5y, methyl acrylate 100F.

Lauryl methacrylate 10y, methacrylic acid 20y, industrial methylated spirit 100f The CJO copolymer clear liquid was maintained at 70 °C, and 180M (3,7 mol) hydrazine hydrate was added without first separating the copolymer. was added over 20 minutes. Heating was declined and the mixture was stirred for 6 hours until the temperature had cooled to room temperature (approximately 22°C).

The mixture was added to a 6-fold excess of cold acetone to precipitate the copolymer as a white powder. The yield was 122P.

30p of copolymer 1iH7[+1j was dissolved in water, and this solution 5d was mixed with 0.5F (0.8 x 10 mol) of a 5% by weight solution of formaldehyde.

This composition was brush-coated onto a mild steel plate and placed in an oven at 100°C for 4 hours. The composition formed a beautiful ribbed film on the metal surface. König-Benschram & degree of coating 1tib2%, conical mandrel test (A
The elongation rate measured by STM D522-60 is 30
%.

Example 6 The following ingredients were completely mixed and polymerization was carried out at a temperature of 7° C. for 6 hours under nitrogen atmosphere; azobisisobutyronitrile 5y as polymerization initiator
.

Methyl acrylate 100F.

Butyl acrylate 50y1, methacrylic acid 201, water 4001, industrial methylated spirit 6ool! l, butanethiol as chain transfer agent 2.5j.

The copolymer solution was maintained at 70 °C and without isolating the copolymer (120 m (2,47 mol) of hydrazine hydrate was slowly added over 20 minutes. Heating was interrupted. ,
The mixture was then stirred for a further 6 hours until it returned to room temperature (approximately 22°C). This solution was then removed using a rotary evaporator.

A 50% solution of the copolymer has a diameter of 660 centibore (X10
It showed a viscosity of 1 &/or 1. This inclusion of chain transfer agent reduces the molecular weight of the polymer, which is evidenced by the lower viscosity of the polymer solution compared to the similar polymer prepared in Example 1.

2F of a 50% solution of formaldehyde was added to 105g of a 50% solution of the copolymer, and the composition was brushed onto a mild steel plate. The plates were subjected to different heat treatments and a König-Pensulam hardness test and a conical mandrel test (A8'i'MD522-60) were carried out for each inoculum. The results are shown in Table 2.

Table 2 Example 4 The following ingredients were mixed and the polymerization was carried out at 70°C under a nitrogen atmosphere.
for 6 hours at a temperature of: 2.5 f of azobisisobutytetranitrile as polymerization initiator.

Methyl methacrylate 1oop.

Butyl acrylate 50P1 Methacrylic acid 20F, Industrial Methylated Subirit) 10100O.

Butanethiol 2.511j.

The copolymer solution was maintained at 70° C. and without isolating the entire copolymer (120II7 (2.47 mol) in hydrazine water was added slowly over a period of 20 minutes. Heating was interrupted. , and stirred for an additional 6 hours until the mixture returned to total room temperature (approximately 22° C.). The solvent was then removed using a rotary evaporator. The polymer yield was 160 F, and the hydrazide weight was 13%. .

The isolated co-electropolymer was dissolved in water to form solutions of various concentrations. The viscosity at 26°C was measured using a Brookfield viscosity needle. The results are shown in Table 6.

The striped 6-table copolymer was dissolved in water to obtain a 27 weight heritable solution. Various resins 1j''Ik with methylol groups were added and mixed with 51 samples of 27qb polymer solution.

The resins used were as follows: Resin 1: Methylated melamine-formaldehyde resin sold by Ciba Geigy under the trade name Melorum ML1767.

Resin 2: Methylated hexamethoxymelamine resin sold by Ciba Naka Geigy under the trade name Shihamin ML1000.

Resin 6: Modified melamine-formaldehyde resin sold by BASF under the tradename Urecol 8MV.

Resin 4 A phenolic resin sold by BP Chemicals under the trade name Niresol J2226S.

Resin 5: Urea-formaldehyde resin sold by BASF under the trade name Urekol S.

Resin 1.2.6 and 5 were dispersed in water to give 35 weight 1
I gave the article 11's Seishinkai. Resin 4 was dispersed in n-propanol to the same concentration. These compositions were brush-coated onto a mild steel plate and heated at 180°C. 5 of these samples
15 minutes or 30 minutes. The coating was subjected to the König-Benschram hardness test and the conical mandrel test (
The elongation of the coating was measured using a heavy metal test (ASTM D522-60). All coatings had conical mandrel elongations of 30 or better. The results of the König e-Pensulam Hard Maro test are shown in Table 4.

Table 4 Coated König-Pensulam Hardness Coated steel sheets heated for 15 minutes or 30 minutes were immersed in water for three days and showed no signs of dissolution, swelling or deterioration of the coating.

Example 5 The following paraboloids were mixed and the polymerization was carried out at 70°C under nitrogen atmosphere.
for 4 hours at a temperature of 2.5 F; azobisisobutyronitrile as the polymerization initiator.

Methyl methacrylate 75P.

Methyl acrylate 25P1 Butyl acrylate 50F, Methacrylic acid 20F, Butanethiol 2.51j.

Water 400m? .

(Industrial Methylated Spirits) 100auO co-plate combined solution was maintained at 70°C for 4 hours and 15M (0.3 mol) of hydrazine hydrate was added to 2 without isolating the copolymer.
Added over 0 minutes. Heating was continued with stirring for an additional 70 minutes, then heating was discontinued and the mixture was brought to room temperature (
The mixture was stirred for an additional 6 hours until cooled to approximately 22°C.

The hydrazide content of the copolymer was >15.

An aqueous solution was prepared with a copolymer content of over 26% by weight.

The viscosity of this solution at 23°C is 80 cp (X10
It was a taste/m-). A 50% dispersion of Sipanne ML 1000, methylated hexamethoxymera, sold by Ciba 9 Geigy, in water was added to the copolymer solution at a resin solution to copolymer solution ratio of 1:5 by weight. Ta.

This composition was sprayed onto a number of mild steel plates and
Heated at a temperature ranging from 150°C for 15-60 minutes. The transparent pale yellow coating had a film thickness in the range of 10-15 microns.

The coated plates were exposed to industrial methylated spirits, acetone, toluene/and chloroform for 24 hours. No deterioration in appearance or physical properties of the coating was observed.

The coating a on several plates was scraped off until the metal was exposed, and these plates f: A8TM B117-76 were subjected to a salt spray test for 660 hours. Rust on the plate was evaluated using the visual test of the Philadelphia Coating Industry Association. The area of rust on the plate is Q, 3 to 1 attack, which is on a scale of 0 to 10 (10
is a good result) and 0 is a bad result).
~ Corresponds to the evaluation of Party B. The maximum spread of corrosion caused by maximum cut back or scratching under the film was 15 to 2.51111 for the plates tested. This is on a scale of Ω ~ 1o (10 is good and 0#'i
Corresponds to a rating of 8 to 7 on the Psell scale of corrosion creep (poor).

Example 6 The following ingredients were mixed and the polymerization was carried out at 70°C under nitrogen atmosphere.
Azobisin butyronitrile was used as a polymerization initiator. 2.
5 p.

Methyl acrylate 100F, butyl acrylate 50y1 hydroxyethyl methacrylate 20p1 butanethiol 2.5 m, industrial methylated spirit 1000M.

60 ml (12 mol) of hydrazine hydrate was maintained at 70°C and without isolating the copolymer.
Add gradually over 0 minutes.

Heating was discontinued and the mixture was stirred for approximately 6 hours in a cooling chamber to room temperature (approximately 22°C). By removing the solvent υ
The copolymer was isolated. The polymer yield was 168j1,
The hydrazide content was 13 parts.

The isolated copolymer was dissolved in water to form a 25% weight solution. The viscosity at 26°C is 40 cp (X1
It was 0.6/msl. 516 liquid of formaldehyde was added to 10 p of the IFt-copolymer solution, and the composition was brushed onto a mild steel plate. Some of the plates were heated to 180℃.
It was heated for 5 minutes and for 60 minutes. 1
König-Pensulam hardness of coating heated for 5 minutes: 1
d, b4q6. All plates had conical mandrel test elongation greater than 30%.

The coated plate was immersed in water for 24 hours and 1'15, but the coating bath
27 = Generate a cover.

showed no signs of deterioration or deterioration.

〔Effect of the invention〕

A water-soluble copolymer of a terminating ester of an unsaturated carboxylic acid having a hydrazide group as a substituent comprises a large proportion of one monomer unit being methyl acrylate and/or methyl methacrylate and a large proportion of monomer units being methyl acrylate and/or methyl methacrylate. 1
and a small proportion of comonomer units which are species or more alkyl esters, where the alkyl group has at least 4 carbon atoms. The copolymers exhibit useful film-forming properties for use in protective coatings. The present invention includes a film-forming composition comprising a copolymer and a crosslinking agent,
The crosslinker is an organic thermosetting resin containing aldehyde or methylol or methoxy groups, and the copolymer and crosslinker are combined in an aqueous medium in an amount such that a film is formed when applied to the surface. be dissolved. This composition is applied to the entire surface and heated at 120 to 180°C for 5 minutes to 4 hours to form a water-insoluble wave from the aqueous composition containing the water-soluble copolymer.

Claims (1)

[Scope of Claims] (1) A copolymer made of a polymerizable ester of an unsaturated carboxylic acid into which a hydrazide group has been introduced, which copolymer is composed of a monomer of methyl acrylate or methyl methacrylate. copolymer consisting of a large proportion of units and a small proportion of one comonomer unit which is one or more alkyl esters of acrylic acid or methacrylic acid, the alkyl group having at least 4 carbon atoms; Combined. (2) Acrylic acid or methacrylic acid with an alkyl group in which one comonomer unit has 4 to 12 carbon atoms.
The copolymer according to claim 1, which is an alkyl ester of fi or more. -1-^ (6) The copolymer according to claim 1 or 2, wherein the ratio of 1 unit of hexamer to 1 unit of comonomer in the copolymer is 20:1 to 10:8. (4) The copolymer according to claim 3, wherein the ratio of one unit of the comonomer to one unit of the comonomer in the copolymer is from 4:1 to 3:2. (5) The copolymer according to any one of claims 1 to 4, which has a hydrazide content of 10 to 20 moles. (6) A patent claim further comprising a fixing comonomer selected from the group consisting of hydroxylethyl acrylate, hydrodiethyl methacrylate, bathable derivatives of hydroxylethyl acrylate and hydroxyethyl methacrylate, and unsaturated carboxylic acids. A copolymer containing 6 in any one of items 1 to 5 of the range. (C) To a patent in which the copolymer contains a hereditary fixing comonomer in 5 to 24 for the superposition of methyl acrylate or methyl methacrylate monomers.
-2-Claim No. 6
Copolymer described in section. (A composition suitable for use in a film-forming composition comprising an aqueous solution of a copolymer according to any one of claims 1 to 7 of the Scope of Claims 1 to 7 of the 81 Patent dII). (9) Claim 1 It consists of a copolymer according to any one of Items 1 to 7 and a crosslinking agent, and the crosslinking agent is a water-soluble aldehyde or an organic thermosetting resin containing a methylol group or a methylol group. C. A film-forming composition in which a copolymer and a crosslinking agent are dissolved or dispersed in an aqueous medium such that the amount of copolymer and crosslinking agent forms a film when applied to a surface. (10) The film-forming composition according to claim 9, wherein the aldehyde is selected from the group consisting of formaldehyde, glyoxal and glutaraldehyde. (11) An organic thermosetting composition containing a methylol group or a methoxy group. phenol-formaldehyde resin, urea-formaldehyde resin, 0-lm- or p
-Cresol-formalphyde resin, guanidine-formaldehyde resin, guanamine-formaldehyde resin, melamine-formaldehyde resin, hexamethoxymelamine resin, and cardol-formaldehyde resin. The film-forming composition described. (12) The film-forming composition according to claim 9 or 11, wherein the organic resin is a methylated resin. (16) The film-forming composition according to claim 9 or 10, wherein the ratio of hydrazide groups to aldehyde groups in the copolymer is 5=1 to 1:5. (14) The ratio of hydrazide groups to aldehyde groups is 4=1
14. The film-forming composition of claim 13, wherein the ratio is ˜1:1. (15) The film according to any one of claims 10 to 14, wherein the amount of copolymer in the composition is in the range of 25 to 60% by weight based on the total weight of the copolymer solution. Formable composition. (16) The composition according to any one of claims 8 to 13 is applied to a sound surface, and the coated surface is heated to 120 to 180 °C for 5 minutes to 4 hours. A surface coating method characterized by heating over a period of time.