JPH05302299A - Composition for moisture and water proof processing - Google Patents

Abstract

PURPOSE:To obtain a composition for paper processing capable of preventing a trouble such as blowing and slipping at use, excellent in moisture and water proof and easy to separate at collecting of waste paper. CONSTITUTION:A composition for moisture and water proof processing of paper composed of an aqueous emulsion consisting of (A) 50-80wt. parts at dry base styrenic emulsion obtained by copolymerizing, as a main monomer composition, 80-97wt.% sum of styrene and other hydrophobic monomers having <=2g/100g water solubility at 25 deg.C and 3-10wt.%, alpha, beta ethylenic unsaturated carboxylic acid, (B) 10-40wt. parts at dry base emulsion of petroleum wax having 40-100 deg. melting point and (C) 10-40wt. parts at dry base emulsion of wax having carboxyl groups and 30-200 acid value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-proofing and waterproofing composition for paper, and more particularly, a moisture-proofing composition which can be easily recovered as waste paper.
The present invention relates to a processing composition that is useful for producing waterproof paper, and is particularly suitable for producing wrapping paper such as newspaper base paper and copy paper.

[0002]

2. Description of the Related Art Conventionally, packaging paper includes wax, general-purpose resin emulsion or coated paper coated with vinylidene chloride resin, and laminated paper laminated with a thermoplastic film such as polyethylene. In recent years, a large amount of waste paper has been collected and recycled due to the shortage of pulp raw materials, but the number of processed papers using the above-mentioned resins is increasing, and even if this waste paper is recovered, the resin component will not be sufficiently contained. It cannot be disintegrated, and undisintegrated fibers and resin pieces are mixed in the recovered paper material, which causes deterioration of the texture of the paper, pitch troubles, and the like.

When imparting moisture resistance to paper using wax, not only a certain amount of coating is required, but also the film is whitened during folding and the surface is very slippery. There is a problem that the anti-slip agent has to be applied because the paper tube is displaced inside. Also,
A general-purpose resin emulsion has a problem in terms of moisture proof performance, and paper coated with vinylidene chloride resin also exhibits excellent moisture proof performance, but it is often difficult to disintegrate waste paper when it is recycled. Recently, a coating agent that combines a wax emulsion and various emulsions has been developed, but it has all the necessary moisture resistance, waterproofness, easy disintegration for collecting waste paper, bending whitening prevention, slip prevention, and heat sealability. There is nothing to do yet, and this development was desired.

[0004]

In view of the above situation, the present invention is excellent in moisture proofing and waterproofing, easily disintegrates when collecting waste paper, and prevents troubles such as folding whitening and slippage during use, The present invention is intended to provide a processing composition capable of imparting a coating having heat sealability.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that a styrene emulsion having a monomer composition within a specific range, a petroleum wax emulsion, and a carboxyl group-containing polyethylene wax emulsion. It was found that there is a possibility of solving the problem by the composition containing the above, and further, the type and amount of the monomer and the type and amount of the wax emulsion were tested, and the present invention was accomplished.

That is, the present invention combines 80 to 97 of (a) styrene and other hydrophobic monomers having a solubility in water at 25 ° C. of less than 2 g / 100 g of water in 100 parts by weight of the total solid content. 50 to 80 parts by weight in terms of solid content, styrene emulsion obtained by copolymerizing 3 to 10% by weight and α, β ethylenically unsaturated carboxylic acid as a main component monomer composition, (b) melting point A petroleum wax emulsion at 40 to 100 ° C. has a solid content of 10 to 40.
Part by weight and (c) Carboxyl group-containing acid value 30 to 20
The present invention provides a composition for moisture-proofing and waterproofing paper, which is composed of an aqueous emulsion in which 10 to 40 parts by weight of a solid content of the polyethylene wax emulsion of No. 0 are mixed.

The present invention will be described in detail below. The dry film from the styrene-based emulsion which is the component (a) of the composition of the present invention is of course dense and has no pinholes or cracks, but this film has a low water vapor transmission rate, water,
Good alkali dissociation is an essential condition. For that purpose, the solid content derived from the styrene-based emulsion in 100 parts by weight of the total solid content of the composition is 50 to 80 parts by weight, and the solubility in water at 25 ° C. as a monomer for producing the emulsion is 25%. And a hydrophobic monomer having an amount of less than 2 g / 100 g of water and an α, β ethylenically unsaturated carboxylic acid are used.

Examples of such hydrophobic monomers include styrene, styrene derivatives, butadiene, isoprene,
Acrylic acid ester with alcohol having an alkyl group having 2 to 18 carbon atoms, methacrylic acid ester with alcohol having an alkyl group having 1 to 18 carbon atoms, vinyl chloride,
Vinylidene chloride and the like can be mentioned. Of these, styrene, which has excellent moisture resistance, is an essential component, but if it is used in an amount exceeding 60% by weight of the total amount of monomers, the coating film becomes hard and the texture is impaired or bent. Since whitening will occur, only one kind or a combination of two or more kinds is used from the other hydrophobic monomers. In order to achieve the object of the present invention, the total amount of styrene and other hydrophobic monomers is 80 to 97% by weight of the total amount of the monomers, preferably 9% by weight.
It is 0 to 97% by weight.

[0009] Another essential monomer component, α,
β-ethylenically unsaturated carboxylic acid is necessary for imparting water and alkaline disaggregation to the film, for example acrylic acid,
Methacrylic acid, crotonic acid, itaconic acid, maleic acid,
Examples thereof include fumaric acid, maleic anhydride, and maleic acid monoalkyl ester. Of these, only one kind may be used, or two or more kinds may be used at the same time.
When α, β ethylenically unsaturated carboxylic acid is used in a small amount, water and alkali dissociation properties are deteriorated.
The content is set to 10 to 10% by weight, preferably 4 to 7% by weight.

The styrene-based copolymer in the emulsion contains hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, (meth) acrylamide, N-.
Amido group-containing monomers such as methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide and N-butoxymethyl (meth) acrylamide, amino groups such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate Contained monomers, acrylonitrile, vinyl acetate, vinyl propionate, methyl acrylate, methoxyethyl (meth) acrylate,
If necessary, butoxyethyl (meth) acrylate or the like may be copolymerized in an amount of 10% by weight or less based on the total amount of the monomers in order to improve the mechanical stability and coatability of the emulsion.

The styrene emulsion used in the present invention can be produced by a known emulsion polymerization method using the above-mentioned monomers. That is, the monomers to be used are mixed, an emulsifier, a polymerization initiator and the like may be added thereto to carry out emulsion polymerization in an aqueous system, such as a method of batch charging polymerization and a method of polymerizing while continuously supplying each component. Various methods can be applied.

As the emulsifying agent for emulsion polymerization, anionic emulsifiers such as alkyl or alkylallyl sulfates, alkyl or alkylallyl sulfonates and dialkyl sulfosuccinates, cationic emulsifiers such as alkyl trimethyl ammonium chloride and alkyl benzyl ammonium chloride, Examples thereof include nonionic emulsifiers such as polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, and polyoxyethylene carboxylic acid ester. The amount of the emulsifier used may vary depending on the properties required for the emulsion, but generally, the amount of the emulsifier used will be improved for the purpose of improving the polymerization stability and improving the mechanical and chemical stability of the emulsion. In order to improve the water resistance of the dry film, it is desirable that the amount used is small. Usually, the amount is 1 to 10 parts by weight based on 100 parts by weight of the total amount of the monomers. The amount used depends on the purpose.

Examples of the polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, water-soluble types such as hydrogen peroxide, t-butyl hydroperoxide and azobisamidinopropane hydrochloride, benzoyl peroxide and cumene hydro. Examples thereof include oil-soluble types such as peroxide, dibutyl peroxide, diisopropyl peroxycarbonate, cumyl peroxy neodecanoate, cumyl peroxy octoate, and azobisisobutyronitrile. Further, if necessary, a redox system in which a reducing agent such as acidic sodium sulfite, Rongalite, L-ascorbic acid, saccharides, amines is used together can be used. The amount used may be about 0.01 to 3 parts by weight based on 100 parts by weight of the total amount of the monomers. The polymerization reaction is usually carried out at about 35 to 90 ° C., and the reaction time is usually set to about 3 to 10 hours.

It is to be noted that, by adding a basic substance at the start or after the end of emulsion polymerization to adjust the pH, the polymerization stability, freeze stability, mechanical stability, chemical stability, etc. of the emulsion are improved. You can In this case, it is preferable to adjust the pH of the obtained emulsion to 5 or more. As the basic substance, ammonia, ethylamine, diethylamine, triethylamine, ethanolamine, triethanolamine, diethylethanolamine, caustic soda, caustic potash, etc. Can be used.

The emulsion of the petroleum wax as the component (b) is added in order to impart moisture resistance and waterproofness to the film, and the petroleum wax having a melting point in the range of 40 to 100 ° C. is dissolved in water by an anionic emulsifier. It is an aqueous dispersion dispersed in. When the melting point of petroleum wax is higher than 100 ° C, the general condition for drying the processing composition applied on the paper surface is 130 ° C x several tens of seconds, and the petroleum wax does not melt sufficiently, so that a uniform coating is obtained. If the temperature is lower than 40 ° C., the petroleum wax will penetrate into the fibers of the paper, so that sufficient moisture resistance cannot be obtained. Therefore, a petroleum wax emulsion having a melting point range of 40 to 100 ° C. is used.
A preferred melting point range is 45 to 65 ° C.

Examples of the petroleum wax include paraffin wax, microcrystalline wax, petrolatum, and paraffin wax to which a zirconium compound is added. Paraffin wax is preferable. If the blending amount of the component (b) is too small, sufficient moistureproofness and waterproofness cannot be obtained, and if it is too large, an excessive whitening phenomenon appears at the time of bending or the disintegration property is significantly impaired. The solid content from the petroleum wax emulsion in 100 parts by weight is 10 to 40 parts by weight, preferably 15 to 25 parts by weight.

The polyethylene wax emulsion as the component (c) is added for the purpose of imparting moisture-proofing property and waterproofing property of the film as well as improving disaggregation property and slip resistance. Although this polyethylene wax has a carboxyl group and an acid value of 30 to 200, the molecular weight is preferably in the range of 2,000 to 20,000. If the compounding amount of the component (c) is too small, sufficient disintegration cannot be obtained, and if it is too large, sufficient moisture resistance and slip resistance cannot be obtained, so polyethylene in 100 parts by weight of the total solid content of the composition is not obtained. The solid content of the system wax emulsion is 10 to 40 parts by weight, preferably 15 to 25 parts by weight.

[0018]

EXAMPLES Next, synthetic examples of styrene-based emulsions and specific examples and comparative examples using the emulsions will be shown, but the present invention is not limited to these examples. In addition, part and% in an example show a weight part and weight%, respectively.

Synthesis Example 1 (Synthesis of Emulsion P-1) 275 parts of deionized water was charged into a polymerization vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet, and the atmosphere was replaced with nitrogen. The temperature was raised. On the other hand, 138 parts of deionized water, 253 parts of styrene, acrylic acid-2-
2. A solution in which 253 parts of ethylhexyl, 11 parts of hydroxyethyl acrylate, 19 parts of methacrylic acid, 14 parts of acrylic acid, 3.8 parts of sodium lauryl sulfate and 12.3 parts of polyoxyethylene nonylphenyl ether were mixed and emulsified with a homogenizer; 8% ammonium persulfate aqueous solution 42
And 3 parts were separately dropped into the above polymerization vessel over 3 hours, and the mixture was further reacted at 82 ° C. for 2.5 hours to complete the polymerization. The obtained copolymer emulsion (hereinafter referred to as P
-1) was a solid content concentration of 55%.

Synthesis Examples 2 to 6 (emulsions P-2 to P-
Synthesis of 6) In the same manner as in Synthesis Example 1, copolymerization was performed in an amount based on the types and composition% of the monomers shown in Table 1 to obtain a solid content concentration of 54 to 55.
% Copolymer emulsion (P-2 to P-6) was obtained.

[0021]

[Table 1]

Example 1 110 parts of emulsion P-1 obtained in Synthesis Example 1 (60 parts solid content) and 45 parts of petroleum wax emulsion (paraffin wax, solid content concentration 45%, melting point 57 ° C.) (solid content) 20 parts of conversion) and polyethylene wax emulsion E-1 (solid content concentration 25%, molecular weight 15,000,
80 parts of acid value 150) (20 parts of solid content) were put into a container, and mixed by stirring for 30 minutes at room temperature.

This mixture was applied to the surface of untreated kraft paper with a bar coater so that the dry film thickness was 10 g / m ^2, and then dried at 130 ° C. for 30 seconds to give a test piece. About the obtained test piece, moisture permeability, waterproofness, disaggregation,
Bending whitening resistance, slip resistance, and heat sealability were measured. The results are shown in Table 3.

The characteristics were measured as follows. a. Moisture Permeability The moisture permeability was measured by a water vapor permeability test method (JIS Z0208) by a cup method under constant temperature and constant humidity conditions (40 ° C., 90% RH). b. A box having a length of 5 cm, a width of 5 cm, and a height of 2.5 cm was made using the waterproof test piece, and 40 ml of deionized water was placed in the box, and the exudation state of water after standing for 24 hours was examined and evaluated in four levels. ◎: No bleeding, ○: Almost no bleeding, △: Partially bleeding, ×: Bleeding

C. Water disintegration property A test piece was placed in water at 45 ° C so that the pulp concentration became 0.5%, and the disintegration state after stirring this for 2 minutes with a juicer mixer was evaluated by visual and microscopic observation in four grades. ⊚: Complete disaggregation, ○: Almost disaggregation, Δ: Partial disaggregation, ×: No disaggregation d. Alkaline disaggregation A test piece was put into a 1% caustic soda aqueous solution at 45 ° C so that the pulp concentration became 0.5%, and the disaggregated state after stirring this for 45 minutes with a stirrer (rotation speed 200 rpm) was visually and microscopically observed. It was evaluated in four levels. ◎: Complete disaggregation, ○: Almost disaggregation, △: Partial disaggregation, ×: Not disaggregation

E. Folding whitening property The whitening state of the coating film at the fold portion when the test piece was bent was visually evaluated in three levels. ◯: No whitening, Δ: Partial whitening, ×: Whitening f. Slip resistance The static friction coefficient was measured by the inclination method of the friction coefficient test method (JIS P8147). Depending on the type of coated paper,
Generally, those having a coefficient of static friction of 0.6 to 1.2 are preferable. g. Heat-sealing property The coated surface of the test piece is overlaid on the coated surface, and a heat inclination tester is used at 160 to 180 ° C. × 4 kg / cm ² × 10 sec.
After thermocompression bonding under the conditions described above, the presence or absence of the heat-sealing property of the coating film was visually evaluated in three stages. ○: Heat sealable, △: Heat sealable but weak in strength, ×: No heat sealable

Examples 2 to 7 and Comparative Examples 1 to 4 In the same manner as in Example 1, except that the types and amounts of the styrene emulsion, petroleum wax emulsion and polyethylene wax emulsion shown in Table 2 were changed, A test piece was prepared in the same manner by stirring and mixing. The characteristics of the obtained test piece were measured in the same manner as in Example 1,
The results are shown in Table 3. The polyethylene wax emulsion E-2 had a solid content concentration of 30% and a molecular weight of 5,000.
0 and an acid value of 60.

Comparative Example 5 Commercially available polyethylene laminated paper (resin layer polyethylene 20
μ, kraft paper 75 g / m ² ) was measured by the same method as in Example 1, and the results are shown in Table 3.

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

EFFECT OF THE INVENTION The novel moisture-proof and waterproof composition of the present invention provides a coating film to be formed on the paper with excellent moisture-proof and waterproof properties, and has no drawbacks such as folding whitening and slippage.
Since it imparts good heat-sealing properties and easily disintegrates when recovering waste paper, it is extremely useful for paper processing because it also has such characteristics.

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Claims (1)

[Claims] 1. The solubility of (a) styrene and others at 25 ° C. in water is 2 g / 10 water in 100 parts by weight of the total solid content.
80-97% by weight of hydrophobic monomers less than 0 g and α, β ethylenically unsaturated carboxylic acid 3-1
A styrene emulsion obtained by copolymerizing 0% by weight as a main component monomer composition is 50 to 80 parts by weight in terms of solid content, and (b) a petroleum wax emulsion having a melting point of 40 to 100 ° C is in terms of solid content. 10-40 parts by weight and (C)
An emulsion of a polyethylene wax having a carboxyl group and an acid value of 30 to 200 has a solid content of 10 to 40.
A composition for moisture-proofing and waterproofing paper, which comprises an aqueous emulsion in which each part by weight is blended.