JPH08176374A - Amorphous polyolefin emulsion - Google Patents

Abstract

PURPOSE: To obtain an amorphous polyolefin emulsion consisting essentially of an acid-modified amorphous polyolefin and a surfactant, having small dispersed particles and good storage stability and having tacky film-forming ability after coating and drying. CONSTITUTION: This emulsion consists essentially of (A) an acid-modified amorphous polyolefin and (B) a surfactant. The component A is obtained by subjecting an amorphous polyolefin comprising polypropylene, propylene-ethylene copolymer, etc. and having <=10wt.% content insoluble in boiled n-heptane and 1500-100000 number-average molecular weight to graft polymerization with (anhydrous) maleic acid or (anhydrous) itaconic acid and has preferably 10-100 mgKOH/g acid value. The amount of the component B added is preferably 1-30 pts.wt. based on 100 pts.wt. of the component A. Furthermore, water content in the emulsion is generally 3-90wt.%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an amorphous polyolefin emulsion. More specifically, an emulsion having a high visco-adhesive film-forming ability after coating and drying, which is mainly composed of an acid-modified amorphous polyolefin, which can be preferably used for paper, fiber, leather, plastic molded products, wood, metal and the like. Regarding

[0002]

2. Description of the Related Art Conventionally, as an emulsion of crystalline polyolefin such as crystalline polyethylene or polypropylene, an emulsion of high molecular weight crystalline polyolefin is used as a heat sealant for paper, resin film, aluminum foil, etc. Crystalline polyolefin having a molecular weight, that is, an emulsion of wax is used as a release agent, an ink antiwear agent, a floor polish and the like. Since the polyolefins that compose these emulsions are crystalline, the coating obtained by coating and drying is tough and hard in the former at room temperature, and brittle and hard in the latter,
None of them have tackiness at room temperature. As an emulsion of low molecular weight crystalline polypropylene wax
No. 9236 discloses an emulsion of a maleic acid-modified crystalline polypropylene wax having a specific intrinsic viscosity and a specific amount of a maleic acid group. The obtained film is hard but brittle and has a viscous adhesive property at room temperature. do not do. On the other hand, as an emulsion of an amorphous polyolefin, an emulsion of atactic polypropylene is disclosed in Japanese Patent Publication No. 53-2652, and uses such as an adhesive, a waterproofing agent and a water repellent have been proposed. However, although the film obtained from this emulsion is flexible, its adhesiveness at room temperature is not sufficient, and its application is limited.

[0003]

Amorphous polyolefins are soft resins and are originally used as hot melt adhesives, sealing agents, tile carpet backing agents, and the like. Although it has a certain degree of tackiness at room temperature as compared with crystalline polyolefin, it is not at a level at which it can be widely used as an adhesive. When applying amorphous polyolefin to paper, fiber, leather, plastic molded products, wood, metal, etc.,
The amorphous polyolefin is preferably applied in the form of an emulsion, but an emulsion having a high ability to form a tacky adhesive film after coating and drying is desired. An object of the present invention is to provide an emulsion having such properties.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies for the above purpose, and as a result, an underwater emulsion characterized by comprising an acid-modified amorphous polyolefin and a surfactant is stable in storage. It has been found that the above-mentioned purpose is achieved with good sex. The amorphous polyolefin in the present invention is a homopolymer, a binary copolymer or a multicomponent copolymer selected from ethylene, propylene and α-olefins having a carbon number of C _{4 to} C ₈ . Particularly preferably, propylene homopolymer, propylene / ethylene copolymer, propylene / butene-1 copolymer, butene-1 / ethylene copolymer, propylene / hexene-1 copolymer, propylene-4-methyl- Pentene-1 copolymer, butene-1 / hexene-1
Copolymer, propylene / ethylene / butene-1 terpolymer, propylene / ethylene / hexene-1 terpolymer, propylene / ethylene-4-methyl-pentene-1
Terpolymer, propylene butene-1 hexene-1
Terpolymer, propylene / hexene-1 / octene-
1. Amorphous polyolefins containing a propylene component or a butene-1 component as a main component, such as a ternary copolymer and a propylene / hexene-1 / 4-methyl-pentene-1 terpolymer.

As an amorphous polypropylene,
Atactic polypropylene produced as a by-product during the production of crystalline polypropylene may be used, or it may be produced directly from a propylene raw material. In addition, propylene or butene
The copolymer of 1 with other α-olefin can be produced by using the raw material so as to contain a predetermined propylene or butene-1 component. In the case of such production, it can be obtained, for example, by polymerizing a raw material monomer in the presence or absence of hydrogen using a titanium-supported catalyst supported on magnesium chloride and triethylaluminum. From the viewpoint of supply stability and quality stability, it is desirable to use the objectively produced amorphous polyolefin. Further, a suitable and suitable commercial product can be appropriately selected and used. Further, the amorphous polyolefin of the present invention,
The heat of fusion of crystals is preferably 20 Joule / g or less. When the amount of heat of fusion of crystals is out of the above range, the tackiness and adhesion are poor, which is not preferable.

The heat of crystal fusion was measured as follows. That is, this heat of crystal fusion is a value calculated using a straight line obtained by directly extrapolating the specific heat curve of the polymer in a completely molten state by a differential scanning calorimeter to the low temperature side as a baseline. The measurement was carried out using a DSC-50 manufactured by Shimadzu Corporation as a differential scanning calorimeter, and the sample amount was about 10 m.
g, a nitrogen atmosphere was used as a measurement atmosphere, and indium was used as a heat quantity standard. The heating program was as follows. That is, the sample was heated to 210 ° C. at a heating rate of 50 ° C./min, left at 210 ° C. for 5 minutes, and then
Cool to -42 ° C at a cooling rate of 0 ° C / min, and leave at -42 ° C for 5 minutes. After that, at a temperature rising rate of 20 ° C / min, -40
The measurement was performed from ℃ to 200 ℃.

The amorphous polyolefin of the present invention further has a boiling n-heptane insoluble content, that is, a Soxhlet extraction insoluble content by boiling n-heptane of 70% by weight or less,
Preferably 60% by weight or less, particularly preferably 10% by weight
The following are desirable: Boiling n-heptane insoluble matter 70
When the content is more than wt%, the ratio of the amorphous portion decreases, and it is not possible to impart the desired sufficient tacky adhesiveness to the resulting resin composition. The above-mentioned amorphous polyolefin preferably has a number average molecular weight of 1,000 to 200,
000, preferably 1,500 to 100,000. Here, the boiling n-heptane insoluble matter was measured by using a Soxhlet extraction method and using about 2 g of a dice-shaped sample of 3 to 5 mm square. In the present invention, the amorphous polyolefin may be used alone or in combination of two or more.

The acid-modified amorphous polyolefin of the present invention is
An unsaturated carboxylic acid is graft-polymerized to the amorphous polyolefin and has an acid value of 5 to 200 mgK.
OH / g. As the unsaturated carboxylic acid used in the graft polymerization, (meth) acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acid (trade name, endocis-bicyclo ( 2,2,1] Hept-5
-Ene-2,3-dicarboxylic acid), maleic anhydride, itaconic anhydride, citraconic anhydride and the like. Among these, maleic acid, maleic anhydride, itaconic acid, and itaconic anhydride are preferable. Graft polymerization is carried out by a known method. For example, the organic peroxide is added to a molten mixture of amorphous polyolefin and unsaturated carboxylic acid or to a solution using a solvent such as toluene or xylene. Further, ionizing radiation such as γ-rays may be irradiated without adding the organic peroxide. In any case, it is preferable to avoid mixing of air and oxygen in this graft polymerization, and it is preferable to carry out the graft polymerization in an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas.

The organic peroxide preferably has a decomposition temperature in the range of 70 to 270 ° C., which has a half-life of 1 minute, and includes, for example, acetylcyclohexylsulfonyl peroxide, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide. , The -tert-
Butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,1,4
-Bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butylperoxyacetate, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, tert-
Butyl peroxybenzoate, tert-butyl peroxylaurate, tert-butyl peroxyisobutyrate, tert-butyl peroxypivalate, cumyl peroxy octoate, tert-butyl peroxy (2-ethylhexanoate), tert-butyl hydroperoxide , Tert-butyl peroxyisopropyl monocarbonate, cumene hydroperoxide and the like.

The graft polymerization temperature when an organic peroxide is used depends on the softening point of the amorphous polyolefin and the decomposition temperature of the organic peroxide, but is generally 80 to 220 ° C. The blending amount of unsaturated carboxylic acid and organic peroxide, and the temperature and time of graft polymerization are such that the acid value of the obtained acid-modified amorphous polyolefin is 5 to 200 mgKOH / g, preferably 10 to 100 mgKOH / g. It is selected appropriately. Here, the acid value is the number of mg of KOH required for neutralization per 1 g of the polymer, and in this case, it is a measure of the concentration of carboxylic acid groups and / or carboxylic acid anhydride groups in the acid-modified amorphous polyolefin. Equivalent to. If the acid value of the acid-modified amorphous polyolefin is less than 5, the hydrophilicity is too low.
When it exceeds 00, the hydrophilicity is too high, and the stability of the obtained emulsion is poor.

The surfactant in the present invention is an anionic type,
Either a cation type or a nonion type may be used, and the addition amount thereof is 0.1% with respect to 100 parts by weight of the acid-modified amorphous polyolefin.
It is 1 to 40 parts by weight, preferably 1 to 30 parts by weight.
If it is less than 0.1 part by weight, the acid-modified amorphous polyolefin will not be emulsified, and if it exceeds 40 parts by weight, the visco-adhesiveness of the film after coating and drying will be impaired.

Examples of the anionic surfactants include primary higher fatty acid salts, secondary higher fatty acid salts, primary higher alcohol sulfate ester salts, secondary higher alcohol sulfate ester salts, and primary higher alkyl sulfones. Acid salt, secondary higher alkyl sulfonate, higher alkyl disulfonate, sulfonated higher fatty acid salt, higher fatty acid sulfate ester salt, higher fatty acid ester sulfonate salt, higher alcohol ether sulfate ester salt, higher alcohol ether sulfone salt Examples thereof include acid salts, alkylated sulfuric acid ester salts of higher fatty acid amides, alkylbenzene sulfonates, alkylphenol sulfonates, alkylnaphthalene sulfonates, and alkylbenzimidazole sulfonates.

Examples of cationic surfactants include amine salt type and quaternary ammonium salt type.

Examples of nonionic surfactants include, for example:
Polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene alkyl Aryl ethers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate,
Sorbitan fatty acid esters such as sorbitan monooleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monopalmitate and other polyoxyethylene sorbitan fatty acid esters,
Examples thereof include polyoxyethylene glycol monolaurate, polyoxyethylene glycol monostearate, and other polyoxyethylene glycol fatty acid esters.

Further, a multi-chain type high molecular weight nonionic surfactant can also be used. The multi-chain type high molecular weight nonionic surfactant has one or more, preferably three or more active hydrogens in its molecule, and has alkylene oxide added to the active hydrogens. It is due to an amino compound (group) or a polyhydric alcohol. A specific example is an ethylene oxide / propylene oxide addition polymer, which may be a block polymer or a random polymer, and the addition weight% of ethylene oxide in the polymer is 20 to 80% by weight. As the compound to which alkylene oxide is added, one or more, preferably three or more active hydrogens in one molecule of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine and the like are preferable. It is an amine or a compound thereof. Alternatively, polyhydric alcohols such as glycerin, trimethylolpropane, pentaerythritol and the like or derivatives thereof such as polyhydric alcohols having one or more, preferably three or more active hydrogens in one molecule.

The emulsion of the present invention is obtained by simultaneously kneading the acid-modified amorphous polyolefin, the surfactant and water using an emulsifying machine such as a heating and pressurizing kneader, homomixer, colloid mill, or the like. The acid-modified amorphous polyolefin and the surfactant are kneaded, water is added to the mixture, and the mixture is further kneaded. Then, the mixture is cooled to near room temperature and taken out. The temperature of this heat kneading is 220 ° C. from the softening point of the acid-modified amorphous polyolefin, and is generally 100 to 200 ° C.
The obtained emulsion is apparently solid when the water content in the emulsion is low, and creamy to milky when the water content is high. When the former, apparently solid product, is poured into water, it is easily diluted into water to form a creamy to milky product. Therefore, the amount of water in the emulsion is set according to the purpose. Generally, the water content is 3 to 90 wt% (solid content 10 to 97 wt%). The average particle size of the obtained emulsion is 10 μm or less. In the emulsion of the present invention, various auxiliary materials that can be usually used in emulsions such as dispersant, stabilizer, wetting agent, thickener, foaming agent, defoaming agent, coagulant, gelation Agent, anti-aging agent, softener, plasticizer,
It goes without saying that a filler, a coloring agent, a flavoring agent, etc. may be used in combination.

The emulsion of the present invention comprises cement, mortar,
It is used as a modifier by directly mixing it with powder or granules such as gypsum. In addition, it is applied to the surface of paper, fiber, leather, plastic molded products, wood, metal, etc. and dried to form a highly viscous adhesive film, which has high adhesiveness, water resistance, oil resistance, chemical resistance on the base material. Used to impart sex. It is also used as a heat sealant. Such an emulsion is
Since water is used as the dispersion medium, it is very advantageous compared to the solvent type in terms of flammability problems, working environment problems, and handleability, and is used in a wide range of fields.

[0018]

[Examples and Comparative Examples]

Example 1 A 1-liter pressure type kneader was charged with an amorphous polyolefin (Ubetack UT-2115 manufactured by Ube Lexen Co., Ltd.).
(Softening point 152 ° C)) maleic anhydride modified product (acid value:
35 mg KOH / g) 100 g and nonionic surfactant 20% aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Discol N)
-518, HLB = 18) (50 g) was charged and kneaded at 170 ° C for 10 minutes. Then, 70 g of hot water was added while applying a back pressure, the kneading was continued for another 30 minutes, and then the mixture was cooled to room temperature and the emulsion was taken out. Solid content of emulsion is 50%, p
H was 6.8, the average particle size of the particles was 2 μm, and the emulsion was stable even after 1 month without separation. The emulsion was applied to an aluminum foil (thickness 20 μm) in an amount such that the film thickness after drying was about 10 μm, and dried at 100 ° C. for 3 minutes. When the dried film was touched with fingers of the hand, tackiness was recognized. Further, the above-mentioned aluminum foils on which the emulsion was applied and dried were brought into contact with each other on the application surface side, and heat-pressed at 150 ° C., a pressure of 3 kg / cm ² , and a pressure of 5 seconds. The T peel strength of the obtained adhesive aluminum foil was measured at a pulling speed of 200 mm / mi.
It was measured by n. The T-peel strength was 600 g / 25 mm, which was cohesive failure. Table 1 shows the composition, the pressure kneader temperature, and the physical properties of the emulsion.

[0019]

[Table 1]

Examples 2 and 3 In the same manner as in Example 1 except that the acid value of the maleic anhydride-modified amorphous polyolefin was changed to change the charged amount of the surfactant aqueous solution and the charged amount of additional water. went. The results are shown in Table 1.

Examples 4 and 5 The procedure of Example 1 was repeated, except that the maleic anhydride-modified amorphous polyolefin was changed and the pressure kneader temperature was changed. The results are shown in Table 1.

Comparative Examples 1 and 2 In Examples 1 and 5, except that an unmodified amorphous polyolefin was used in place of the maleic anhydride modified amorphous polyolefin, and the surfactant aqueous solution charging amount and the additional water charging amount were changed. Was performed in the same manner as in Examples 1 and 5, respectively. The average particle size of the emulsion particles was large and the stability after one month was poor, and it was not worth considering the application to aluminum foil. The composition, pressure kneader temperature and emulsion physical properties are shown in Table 2.

[0023]

[Table 2]

Comparative Example 3 The procedure of Example 3 was repeated except that the maleic anhydride-modified amorphous polyolefin having an acid value of 250 mgKOH / g was used. The pH of the emulsion is 6.
4. The average particle size of the particles was 1 μm, but the stability after 1 month was poor, and it was not worth considering the application to aluminum foil.

[0025]

The emulsion of the present invention has small dispersed particles, good storage stability, and has the ability to form a tacky adhesive film after coating and drying.

Claims (3)

[Claims] 1. An emulsion having the ability to form a tacky adhesive film after coating and drying, which comprises an acid-modified amorphous polyolefin and a surfactant as essential components. 2. The amorphous polyolefin is ethylene,
Ropylene, carbon number C _Four~ C₈Selected from α-olefins
A homopolymer, a binary copolymer, or a multicomponent copolymer
The emulsion according to claim 1, which is present. 3. The acid-modified amorphous polyolefin is the amorphous polyolefin of claim 2 graft-polymerized with an unsaturated carboxylic acid, and has an acid value of 5 to 200 mgK.
The emulsion according to claim 1, which is OH / g.