JPS6322812A - Resin for antiblocking paint - Google Patents

Abstract

PURPOSE:To obtain the titled resin having excellent antiblocking property and film-forming property and giving a coating film having excellent properties and suitable for the coating of metals and inorganic building materials, by carrying out multi-stage emulsion polymerization of a carboxyl-containing polymerizable monomer in an aqueous medium. CONSTITUTION:The objective resin imparted with a film-forming property and a durability of coated film can be produced by carrying out a multi-stage emulsion polymerization of (A) 0.1-10(wt)% polymerizable monomer containing carboxyl group in the molecule and (B) 90-99.9% monomer preferably containing >=30% (meth)acrylic acid ester in an aqueous medium in a manner to give 20-90% 1st-stage polymer component having a Tg of >=30 deg.C and 10-80% final stage polymer component having a Tg of <=20 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a blocking-resistant paint resin. More specifically, when applied to various objects, it has good blocking resistance when loaded or left in a dry or semi-dry state, and has excellent blocking resistance with excellent film formation and coating performance. Round it to 84W4 for paint.

(Problem 6 to be solved by the prior art and the invention) Emulsion resins or paints using them have been used for coating various objects to be coated, such as metals, wood, paper, plastics, inorganic 1144, etc. It is being However, when the emulsion resin that has been used in the past comes into contact with other substances or the same M-coated object after painting, it blocks, causing damage to the coating film and destruction of the M-material itself, making it difficult to paint. It was not possible to achieve the original purpose of protecting the object to be coated and improving the aesthetic appearance. Furthermore, even if the object to be coated is coated under sufficient dry conditions, if a conventional emulsion resin or paint using a scraper is used, blocking will occur under tS temperature or load conditions. The above phenomenon occurs. This kind of blocking phenomenon can be solved by increasing the To of the polymer, but on the other hand, the film-forming properties are reduced, so it is necessary to use multiple film-forming aids during coating, or drying at temperature A is too slow. (This is done.) If a large amount of film-forming auxiliary agent is used, the auxiliary agent remains in the coating film even after film formation, so the anti-blocking property as expected may not be obtained, and the performance of the coating film may be deteriorated. In addition, as the film-forming agent evaporates after film formation, the flexibility of the resin is lost and cracks occur over time.Furthermore, drying at high temperatures is normally performed on factory lines. It is only used for painting in the paint, and the objects to be coated are limited to metals, inorganic building materials, etc. that can be dried at high temperatures, and this method also has the disadvantage that cracks occur in the paint film over time.

Another effective method for preventing the blocking phenomenon is to add a substance that imparts slipperiness to the coating film, such as a polyethylene wax emulsion or colloidal silica. However, when such a substance is used, the cohesive force of the coating film is lost, resulting in a decrease in durability and making it difficult to protect the coated object over a long period of time.

Furthermore, there is a method of crosslinking the resin in the coating film with metal ions to reduce the blocking phenomenon, but this method has the drawback of inducing a decrease in alkali resistance.

Therefore, it has excellent blocking resistance and film formability, and has long-term durability! i! ! At present, there is no known coating resin that provides l.

(Technical means for solving the problem) The present inventors
As a result of extensive research in view of the current situation, we have discovered that the above problems can be solved at once by using an emulsion resin with a specific composition and specific structure as a paint resin, and have completed the present invention. reached.

That is, the present invention provides a polymerizable σ-isomer (a) containing a carboxyl group in the molecule.
0.1 to 10% by weight and other polymerizable lit bodies (b)
90~99.9ffi% <[L,, (a) + (b
) is a at 100fflkn%. ) A multi-stage polymerization copolymer obtained by multi-stage emulsion polymerization of such polymerizable monomer components, and the To of the first stage polymer component is 30°C or more, and the final stage polymer This invention relates to a resin for blocking-resistant paints whose components have a To of 20°C or less.

Polymerizable isomer (a) containing a carboxyl group in the molecule used in the present invention (hereinafter referred to as 1ul1 isomer (a)
That's what it means. ) is a polymerizable t having a carboxyl group in the molecule.
Especially if it is in ttm type &! Not limited to 1, for example (meta)
Unsaturated carboxylic acids or derivatives thereof such as acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl fumarate, monoethyl fumarate, monomethyl maleate and monoethyl maleate can be mentioned, and these One type or two or more types can be used.

In the present invention, the single body (a) is used in an amount of 0.1 to 10% by weight based on the total polymerizable body components. Monomer (
If the amount of a) used is less than 0.1% by weight, the stability during multi-stage emulsion polymerization may decrease, and the adhesion to various coated materials may decrease; Both cases are unfavorable because the water resistance of the bound coating film decreases.

Other polymerizable monomers (b) used in the present invention
(It is called tlrII body (b) under IX.) Toshi is l1
If the l1m form is copolymerizable with the m form (a), the eyes will not be closed, for example, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-
(Meth)acrylic acid esters such as ethylhexyl (meth)acrylate and cyclohexyl (meth)acrylate; Aromatic unsaturated monomers such as styrene, α-chlorostyrene, and vinyltoluene; Halogens such as vinyl fluoride and vinyl chloride unsaturated cyanide compounds such as (meth)acrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate; tJI11
unsaturated acid amides or derivatives thereof such as (meth)acrylamide and N-methyl(meth)acrylamide; unsaturated 01 organisms containing amino groups such as dimethylaminoethyl (meth)acrylate, nidivinylbenzene , polyfunctional unsaturated trlfI 1-forms such as ethylene glycol di(meth)acrylate; glycidyl group-containing unsaturated 4-forms such as glycidyl (meth)acrylate and allylglycidyl needle; these 1
14 or 2 or more types can be used. Monomer (b
) is fully polymerizable It! It is used in a range of 99.9% to 99.9% of the total adult component. Furthermore, in the present invention, from the viewpoint of weather resistance, it is desirable that 30fJ1% or more of the monomer (b) be (meth)acrylic esters.

The anti-blocking paint resin of the present invention contains the monomer (a
) and (b) polymerizable III! 1 body (a) component is bound by multi-stage emulsion polymerization in an aqueous medium, and in this case, the To of the first stage of the composite component is 30°C or higher, preferably 45°C or higher, and the final stage is T of the polymer component of the eye
g is required to be 20°C or less, preferably 0°C or less. The multi-stage emulsion polymerization referred to here means that first, some of the polymerizable monomer components have a polymer To of 3.
A part of the components is emulsion polymerized using a known emulsion polymerization method as the first stage, and in the presence of the obtained polymer component, the remaining monomer components are used in the first step. This is a method in which emulsion polymerization of 2g and subsequent stages is carried out sequentially. At this time, from the second stage onwards, use the entire amount of the remaining monomer components used in the first stage to achieve 2F! 11 polymerization, or appropriately divided into 3 polymerizations.
Polymerization may be carried out in stages or more. It is sufficient that the Tg of the polymer component in the second stage of R is 20° C. or less. For multi-stage polymerization, a combination of two to three stages is usually used. Even if the polymerization is carried out in more than one stage, the performance will not be particularly improved.
However, this only increases the complexity during manufacturing.

In the anti-blocking paint resin of the present invention, the TQ of each of the first stage polymer component and the last stage polymer component must be as defined above. If the Tg of the first stage polymer component is 30°C or less, blocking resistance will not be developed, and the To of the last stage polymer component will be 20°C.
In the above cases, use this! l#! Both are undesirable because the film-forming properties of the coating material decrease, a film-forming aid is required during coating film formation, and high temperatures are required for drying. Furthermore, when obtaining a blocking-resistant paint resin, the first stage polymer component is preferably 20 to 90% by weight in the copolymer.
More preferably, the amount is 35 to 70% by weight, and the final stage polymer component is preferably 10 to 80% by weight in the copolymer.
, more preferably 30 to 65% polymerization. By setting a small amount of the polymer component in the first stage and the polymer component in the second stage of Nil within this range, it is possible to achieve both high levels of blocking resistance and film formability of the coating film, which in turn improves durability. MAWR for anti-blocking coatings with significantly improved coating performance including 1η.

In the present invention, examples of the polymerization initiator used in the multistage emulsion polymerization include known water-soluble or oil-soluble initiators such as ammonium persulfate, potassium persulfate, hydrogen peroxide, and butyl hydroperoxide. Further, at this time, sodium bisulfite, di-asunilupic acid, or the like may be used as a redox initiator as a reducing agent. Also, as an emulsifier, lauryl fJlil! Anionic activators such as sodium and nonionic activators such as polyoxyethylene alkyl ether are used, but depending on the case, polymerization can also be carried out in the absence of an emulsifier. In the present invention, a chain transfer agent such as laurylmethylmecabutane may be used for the purpose of molecular fi1m linkage during preparation.

The anti-blocking paint resin of the present invention polymerized according to the above procedure may be neutralized with a basic compound if necessary.

Examples of basic compounds that can be used include ammonia, triethylamine, morpholine, and sodium hydroxide.

Furthermore, known additives such as film-forming aids, pigments, fillers, DOBU-1 wet AJ agents, antistatic agents, etc. may be added to the anti-blocking paint resin of the present invention as necessary. .

(Effects of the Invention) The anti-blocking paint resin of the present invention has a multi-stage polymer component in which the first stage polymer component has a Tg of 30°C or higher and the last stage polymer component has a To of 20°C or lower. Because it is a polymeric co-protein, it has high blocking resistance and sufficient film forming properties, and it has excellent film formation properties. The ψ membrane with little change in Jm over time is bound.

Furthermore, by making the first stage polymer component and the last stage polymer component have a gloss within a specific range, durability can be improved! ! !
The membrane performance has been significantly improved. Therefore, when a paint containing the anti-blocking paint resin of the present invention is applied to, for example, general Ti materials, plastics, paper, wood, etc. and dried at room temperature, it quickly forms a film and exhibits anti-blocking properties. It develops and forms a coating film with excellent durability. In addition, in the field of factory line lli, the coating is applied to objects such as metals and inorganic building materials, dried at the eroded B temperature, and has excellent blocking resistance of 6 degrees even when the objects are loaded before completely cooling down. It showed no coating film performance.

(Examples) The present invention will be described in detail below with reference to Examples, but the present invention is not limited to the following Examples. In addition, parts in the examples are by weight unless otherwise specified.

Example 1 11 equipped with a stirrer, a reflux condenser, a dropping tube, and a thermometer
500 parts pure, 8 parts sodium lauryl sulfate in a separable flask. ! After charging No. 11, the temperature was raised to 70° C. with stirring while blowing nitrogen gas. Thereafter, a polymerizable monomer mixture (A) (glass transition temperature: 60°C) consisting of 80 parts of methyl methacrylate, 80 parts of styrene, 36 parts of butyl acrylate, and 114 parts of methacrylate was uniformly added dropwise over 1 hour as a first stage. did.

At the same time, 10 parts of a 10% ammonium persulfate aqueous solution was uniformly dropped over 1 hour.

After aging for 1 hour, methyl methacrylate 8
0 parts, butyl acrylate i i 6i.

Polymerizable 1-body mixture (8) consisting of 4 parts of methacrylic acid
(Glass transition temperature: -8°C) was added dropwise uniformly over 1 hour as the last step. At this time, 10% excess l1
10 parts of AII12 ammonium aqueous solution was uniformly dropped over 1 hour. The mixture was aged for 1 hour. After cooling, 6.3 parts of 25% aqueous ammonia was added to effect neutralization. The paint resin (1) thus obtained has a non-volatile content of 43.
5%, PH9.0, viscosity 95cps (B type, viscosity = 1,
N0010-tar, 30 rpm, 25°C), minimum construction II
The special value at temperature of 25°C is shown. The obtained paint resin (1
11Q For part Q, add film-forming agent C8-12 (Ziso ■
Add 3 parts of glume and mix until uniform. After spraying the coating resin (1) containing this film-forming agent onto two flexible boards at a rate of 1000/d,
The sample was dried in a hot air dryer for 5 minutes (wind speed: 1 nL/S) to obtain a test piece for blocking resistance test. Leave these two test pieces at room temperature for another 2 minutes until the surface temperature reaches 7.
When the temperature reached 0°C, the coated surfaces of the coating resin +1) were placed on top of each other, and a pressure of 5/d was applied using a press at 70°C for 30 minutes.

The two flexible boards pressurized in this manner peeled off without resistance after the pressurization was completed, and there was no am on the painted surface. Further, the results of the coating film performance test of the test piece coated under the same conditions as used in the blocking resistance test are shown in Section 1''a.

Example 2 Pure 5 was added to the same separable flask as used in Example 1.
After charging 00 parts, the temperature was raised to 75°C with stirring while blowing in nitrogen gas. I did m. 92,120 parts of streaks prepared beforehand, 20 parts of acrylonitrile,
58 parts of ethyl acrylate, Itacon Is! 22 parts (glass transition temperature of the above polymerized RP hull mixture 53°C), 6 parts of a 25% aqueous solution of Lebenol WZ (manufactured by Kao@, polyoxyethylene nonylphenyl ether sulfate) and thorium,
4 parts of 25% aqueous solution of Noniball 200 (Sanyo Chemical [J Polyoxyethylene Nonylphenyl Ether), PerwKM
A pre-emulsion mixture (C) consisting of 1 part of ammonium 7 ammonium and 69 parts of deionized water was uniformly dropped over 1 hour as a first stage. During this time, 5 parts of a 10% aqueous sodium bisulfite solution was added in equal portions every 10 minutes. After aging for 1 hour, 64 parts of styrene, 35 parts of butyl acrylate, 11 parts of acrylic W (glass transition temperature of the above polymerizable m-helical mixture 25°C), 23 parts of Repenol W, 2 parts of 25% aqueous Noniball 200, A pre-emulsion mixture (D) consisting of 0.5 parts of ammonium persulfate and 34.5 parts of deionized water was uniformly added dropwise over 30 minutes as a second stage. 2.5 parts of this sodium bisulfite extract containing 10% WA was added in equal portions every 10 minutes. After aging for 30 minutes, 50 parts of styrene, 48 parts of 2-ethylhexyl acrylate, 2 parts of methacrylic acid (
Glass transition temperature of the above polymerizable 1ffi mixture -7°C
), a pre-emulsion mixture (E
) was added dropwise uniformly over 30 minutes as the last step. During this time, add 2.5 parts of 10% sodium bisulfite aqueous solution to 10%
Addition was made in equal portions every minute. The ja was aged for 60 minutes. cold! J] and 6 parts of 25% aqueous ammonia were added to neutralize the mixture.

The resin for paint (2) thus obtained has a non-volatile content of 42.2
%, PH9.0, viscosity 250C1)S (B type viscometer, N
o, 2[]-ter, 30 r Dm.

25°C) and a minimum film forming temperature of 23°C. Using this paint resin C), a paint was prepared with the following formulation.

Mixture
(Part) Water
64.6 Demol EP (Kao■
) 2.0 Antifoam agent Nobuco 8034 (manufactured by San Nopco ■) 0.3 Titanium oxide (rutile type) 54.0 Kaolin 6.0 Paint resin (2) 173.8C3-
12 (manufactured by Chisso@) 5.2 Hydroxylethyl cellulose 3χ aqueous solution 3.0 go
Total 308.9 (P
45% WC, 43.4% N, V) The obtained paint was applied to flexible board, lauan material, corrugated iron, ABS resin, and high-quality paper with a brush at 100Q/g, and dried at 4°C for 3 days to obtain anti-blocking properties. A test piece for testing was obtained.

The blocking resistance of these test pieces was determined by JIs.
When a test was conducted based on the inviscosity test method described in 6.8 of K-5400, all test pieces showed good results. Behind the test piece above,
Table 1 shows the results of the coating film performance test on the test piece using the flexible board.

Comparative Example 1 In Example 1, the polymerization 111-interval mixture (
Comparative resin (1) was obtained by repeating the same operation as in Example 1 except for using B) and the polymerizable monomer mixture (A) in the last stage. The characteristic values of the obtained comparative resin (1) were non-volatile content 43.3%, pH 9.0, and viscosity 110 cps.
11n low-forming M1mB exhibited a temperature of 55°C. This comparative resin (
8 parts of C3-12 was added to 11,100 parts and stirred well to make it uniform. A test piece coated with this in the same manner as in Example 1 was used for a blocking resistance test and t!
Membrane performance tests were conducted. As a result of the blocking resistance test,
Blocking occurred and the two painted plates could not be peeled off.

Further, the coating film performance test results were as shown in Table 1.

Comparative Example 2 In Example 2, the second stage with pre-emulsion mixtures (D) and (E) and j! Only the pre-emulsion mixture (C) used in the first stage without polymerizing the intrusion stage (at this time, the pre-emulsion mixture (C) used in Example 2)
The amount was twice that of C). Comparative MA fat (2) was obtained by repeating the same operation as in Example 2, except for polymerizing .

This comparative resin (2) had a nonvolatile content of 42.3%, a pH of 9,
It showed the special values of 0, Fl+a180cps, It low tm temperature 83°C. This comparative resin (2) is a3 in Example 1.
I couldn't form a film with the same formulation as Ruru paint, so I used the following formulation with increased film-forming agent C3-12! tTn was adjusted to rJ4.

Mixture
(Part) Water
646 Demol EP (manufactured by Kao ■)
2゜81 foam agent Nobuco 8034 (2゜81 foam agent Nobuco I)
0.3 titanium oxide (rutile type) 54
．． 0 Kaolin 6.0 4M fat for paint +21 173.
8C3-12 (made by Chisso!!1) 261 Total 327.8
(PWC45X, N, V 4G, 9%) The same test as in Example 2 was conducted using the obtained paint. As a result of the Plotki jig resistance test, gauze marks remained in all cases. Further, the coating film performance test results were as shown in Table 1.

Table 1: Coating film performance test results All test boards used flexible boards.

Note 1) Soaked in warm water at 60°C for 5 days.

Note 2) 1.00 on Sunshine Weather-O-meter
0:18! The appearance of the coating film after 1 hour was examined.

Note 31: 100 cycles were performed based on method B described in ASTM C-666, and the state of the coating film was examined.

Procedural amendment (voluntary) 1986
August 5th

Claims (1)

[Claims] 1. A polymerizable monomer containing a carboxyl group in the molecule (
a) 0.1 to 10% by weight and other polymerizable monomers (b)
) 90 to 99.9% (However, (a) + (b) is 100% by weight.) A multistage polymerized copolymer bound by multistage emulsion polymerization of a polymerizable monomer component, A blocking-resistant paint resin, characterized in that the first stage polymer component has a Tg of 30°C or higher, and the last stage polymer component has a Tg of 20°C or lower. 2. In the multi-stage copolymer, the first stage polymer component is 20
The blocking-resistant coating resin according to claim 1, wherein the proportion of the last stage polymer component is in the range of 10 to 80% by weight.