JPS6368610A - Production of copolymer - Google Patents

Abstract

PURPOSE:To obtain a copolymer excellent in heat stability, solvent solubility, etc. and suitable for primer, etc., by radical-polymerizing a monomer mixture comprising vinyl chloride, vinylidene chloride and gamma,gamma'-dichloroisobutylene at a specified weight ratio. CONSTITUTION:An essential monomer mixture comprising vinyl chloride (A), vinylidene chloride (B), gamma,gamma'-dichloroisobutylene (C) and other radical- polymerizable monomers (D) (e.g., acrylic acid) which are optionally used are mixed with each other so that the component C content may be 0.1-20wt% based on the essential monomer mixture and that the total amount of components A and B may account for the major proportion of the monomer mixture. The obtained monomer mixture is radicalpolymerized to obtain the purpose copolymer. The obtained copolymer can be suitably used for primers used before application of coating agents, binders for magnetic recording media, printing ink binders, etc.

Description

Detailed Description of the Invention (a) Purpose of the Invention [Field of Industrial Application] The present invention is a combination of vinyl chloride and vinylidene chloride that has a high degree of thermal stability and is soluble in inexpensive solvents or plasticizers. This invention relates to a method for producing a polymer, and the copolymer obtained thereby can be used as a base material for magnetic paint, a resin for dispersing pigments, a resin for adhesion aid, etc.

[Conventional technology and problems]

Copolymers of vinyl chloride and vinylidene chloride have been studied for use in many fields, taking advantage of their characteristic properties, ie, gas barrier properties, flexibility, and adhesive properties.

However, due to the remarkable decomposition of this copolymer by heating, the lack of solubility in low-grade solvents, and the poor productivity of the copolymer due to non-uniformity of polymerization reactivity, there are many reasons why this copolymer is not practical. Its uses were extremely limited.

On the other hand, in JP-A No. 59-164514, a monomer mainly composed of vinyl chloride monomer and vinylidene chloride monomer and containing allyl chloride monomer or methallyl chloride monomer is disclosed. Vinyl chloride-vinyl chloride I, which has improved thermal stability and is soluble in inexpensive aromatic hydrocarbon solvents, is produced by radical polymerization of a polymer mixture.
Although methods for obtaining J-density copolymers have been proposed, such copolymers generally still have poor thermal decomposition resistance for use as base materials for magnetic paints, for example.

In addition, the base material for electron beam-curable paints has recently been attracting attention, and it has been proposed to use a vinyl chloride-vinyl chloride y-based copolymer into which an acryloyl group has been introduced as the base material. The vinyl chloride-vinylidene chloride copolymer used for production requires heating during the reaction to introduce the acryloyl group, so there is currently a need for even higher heat decomposition resistance than before. .

Furthermore, the vinyl chloride-vinylidene chloride copolymer described in JP-A-59-1154314 has insufficient solubility in inexpensive plasticizers such as dioctyl phthalate or dibutyl phthalate, It had limitations in its use as a pigment dispersion aid and adhesive.

[Problem that the invention seeks to solve]

The technical objective of the present invention is to improve the heat decomposition resistance and solubility in plasticizers of a vinyl chloride-vinylidene chloride copolymer.

(B) Structure of the Invention [Means for Solving the Problems] The present inventors have completed the present invention as a result of intensive study on the above-mentioned problems.

That is, the present invention provides vinyl chloride, vinylidene chloride and r,
A monomer mixture consisting of r'dichloroisobutylene and optionally other radically polymerizable monomers, wherein 0.1 of r,bidichloroisobutylene is present in the above essential monomer mixture.
A method for producing a copolymer, characterized in that the monomer mixture containing ~20% by weight and in which the total amount of vinyl chloride and vinylidene chloride constitutes the main component in the entire monomer mixture is subjected to radical polymerization. be.

By the above method, the present inventors have succeeded in producing a compound containing mainly a highly thermally stable and inexpensive aromatic hydrocarbon, while containing the total amount of vinyl chloride monomer units and vinylidene chloride monomer units as the main component. It has become possible to produce vinyl chloride-vinylidene chloride copolymers that are soluble in solvents or plasticizers such as dioctyl phthalate or dibutyl phthalate.

Next, the constituent elements of the method of the present invention will be sequentially explained.

It is necessary that the total amount of vinyl chloride and vinylidene chloride be the main components in the entire monomer mixture, and it is desirable that the content of each of vinyl chloride and vinylidene chloride is 4 to 95% by weight.

If the total amount of vinyl chloride and vinylidene chloride is not the main component in the total monomer mixture, the characteristics of the vinyl chloride-vinylidene chloride IJ-density copolymer, such as flexibility, adhesiveness, fluidity during molding, and heat resistance. Degradability and solubility in aromatic hydrocarbon-based solvents or phthalate ester plasticizers are poor.

If the vinyl chloride content is less than 4% by weight, the flexibility, adhesion, or fluidity during molding of the copolymer will be poor, and at the same time, the thermal decomposition resistance and polymerization reactivity of the monomer mixture will likely decrease. . If the weight exceeds 95%, the copolymer's flexibility, adhesion, or fluidity during molding will be poor, and at the same time, its solubility in aromatic hydrocarbon-based solvents or heptatalic acid ester plasticizers will deteriorate. This tends to cause a decrease in the polymerization reactivity of the polymer mixture.

If the vinyl chloride IJ density is less than 4% by weight, the copolymer's flexibility, adhesion, or fluidity during heat molding will be poor. The solubility in plasticizers and the polymerization reactivity of the monomer mixture tend to decrease. If it exceeds 95% by weight, the solubility in solvents mainly composed of aromatic hydrocarbons or phthalate plasticizers and fluidity during molding will be poor.

Next, it is necessary to mix r, r' dichloroin butylene in an amount of α1 to 20% by weight in the essential monomer mixture. α
If the amount is less than 1% by weight, the thermal decomposition resistance or weather resistance will be extremely poor, and at the same time, the flexibility, adhesion, or fluidity during molding will be poor. Solubility in phthalate plasticizers decreases. Moreover, when the content is 20% by weight, the polymerization reactivity is significantly reduced and the mechanical strength of the obtained copolymer is also significantly reduced.

Radically polymerizable monomers other than the above three types of monomers can also be used depending on the purpose. Among other radically polymerizable monomers, examples of monomers that can be used for the purpose of further increasing solubility in solvents or plasticizers and fluidity during molding include vinyl esters, vinyl ethers, and methane. Monomers that can be used to further enhance the adhesive properties or dispersibility of lyl chloride in magnetic powders include acrylic acid, hydroxyethyl acrylate, maleic anhydride, N-methylol acrylamide, glycidyl methacrylate. , 2-acrylamido-2-methylpropanol sulfonic acid, acrylic acid-2-
Examples include ethyl phosphate and the like. Such monomers can be used alone or in combination. The amount of these optionally copolymerized monomers to be used is desirably maintained at 0 to 40% by weight based on the above-mentioned essential monomer mixture. If it exceeds 40% by weight, it becomes difficult for the copolymer to exhibit the above-mentioned properties targeted by the present invention.

A more preferable blending ratio of the monomers used in the present invention is vinyl chloride 15 to 70% vinylidene chloride, vinylidene chloride 15 to 70%
% by weight, γ, γ' dichloroisobutyleph, 1 to 10% by weight, and other radically polymerizable monomers, based on the essential monomer mixture, 0 to 15% by weight.

In the present invention, various other polymerization reaction conditions may be suitably employed according to conventional methods, but industrially preferred are a polymerization temperature of 40 to 70°C and a polymerization time of 7 to 20 hours.

As the polymerization method, any of suspension polymerization, emulsion polymerization, and solution polymerization can be employed.

For example, when using the simplest suspension polymerization method, partially saponified PVA, methyl cellulose, a copolymer of ethylene oxide and propylene oxide, or a copolymer of vinyl acetate and maleic acid can be used as the suspending agent. As the radical-generating catalyst, benzoyl peroxide, lauroyl peroxide, diterethylhexyl peroxydicarbonate, α,α'-dimethylvaleronitrile, etc. are used.

When emulsion polymerization or solution polymerization is employed, the objects of the present invention can be achieved by appropriately using water-soluble catalysts, oil-soluble catalysts, emulsifiers, and various general-purpose solvents.

The polymerization in the present invention is carried out in suspension polymerization, emulsion polymerization, or solution polymerization in the presence of aliphatic polycarbonate, aromatic polyester, or copolyamide in the medium used in these polymerization methods. The copolymer obtained by such polymerization partially contains a graft copolymer and can be used as a dispersant for magnetic powder and a hot melt adhesive.

The achievement of the object of the present invention is essentially attributable to the unique physical properties of the terpolymer of vinyl chloride, vinylidene chloride, and γ, γ′ dichloroisobutylene and its terpolymerizability. It is something.

[Examples and comparative examples]

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

In addition, each characteristic of the polymer obtained on each side was measured by the following method.

a) Thermal stability: The sample was kept in a gear oven at 80° C. for one month without adding a heat stabilizer, and the state of discoloration was visually observed.

b) Toluene/methyl ethyl ketone (80fEf/2
Solubility in a mixed solvent (hereinafter simply referred to as toluene solvent) consisting of 0 weight ts): 30 parts by weight of the copolymer was added to 70 parts by weight of toluene solvent, and after stirring at room temperature for 2 hours, the solution became cloudy. The presence or absence was observed.

C) Di-2-ethylhexyl phthalate (hereinafter referred to as DOP)
) Solubility in K: Add 20 parts by weight of copolymer to 80 parts by weight of DOP,
After stirring at °C for 2 hours, the temperature was returned to room temperature and the presence or absence of turbidity of the solution was observed.

d) Adhesion test: A 20wt% tetrahydrofuran solution of the copolymer was prepared, and the solution was applied to a mild steel plate at room temperature, followed by dry film formation, and the presence or absence of peeling was determined using the Erichsen test method of JISK-6744. observed.

e) Dispersibility of magnetic powder Barium ferrite fine powder 12 gr, copolymer 1.
4gr, urethane polymer with Tuboran 2604, Nippon Polyurethane) α6grs methyl ethyl ketone 16gr
,) A formulation consisting of 16 gr of luene and 80 gr of glass peas was shaken in a paint conditioner for 10 hours, and the solution obtained by filtering the glass peas was immediately applied to a polyester film with a doctor blade to a thickness of 100 μm. After coating and heating at 60℃ for 10 hours, the Nippon Denshoku Kogyo +11 Sigma 80 Color Measuring System (Σ80COLORMEA*5URING SYST) was applied.
The reflectance at 60° was measured by EM). High reflectance indicates good root dispersion.

f) Average degree of polymerization: A value converted to a vinyl chloride homopolymer was determined according to the viscosity method of JISK-6721.

Example t 5-e Vinyl chloride 10105O in autoclave.

390 gr of vinylidene chloride, 60 gr of r, r' dichloroin butylene, 7.5 gr of 0KS-7514 (saponification degree 40 mol - 0 partially saponified PVA, manufactured by Nippon Gosei Kagaku Kogyo ■) as a suspending agent, and Evan 485 (with ethylene oxide). Pro-copolymer with propylene oxide, Daiichi Kogyo Seiyaku ■
) 15gr, 5gr of 2-ethylhexyl peroxydicarbonate as a radical-generating catalyst, and 30gr of pure water.
00 gr and stirred at 500 rpm.
Suspension polymerization was carried out at ℃ for 13 hours. The centrifugal dehydration separation layer was dried, and as a result, a powder copolymer was obtained with a polymerization yield of 83% by weight. The properties of this copolymer were evaluated and the results are shown in Table 1.
It was shown to.

Examples 2 to M and Comparative Examples 1 to 3 In Example 1, polymerization was carried out by changing the monomer composition and keeping the other polymerization conditions the same, and the properties of the obtained copolymers were evaluated. The results are shown in Table 1. Example 9 52 900 gr of vinyl chloride was placed in an autoclave.

Vinylidene chloride 495 gr, maleic anhydride 45 gr
, γ, γ'-dichloroisobutylene 45 gr.

As a suspending agent e) 7.5 gr of KS-7514 (partially saponified polyvinyl alcohol with a degree of saponification of 45 molar, manufactured by Nippon Gosei Kagaku Kogyo ■) and Epan 485 (a block copolymer of ethylene oxide and propylene oxide, the first (manufactured by Kogyo Seiyaku ■) 15 gr, 2-ethylhexyl silver oxydicarbonate (2-ethylhexyloxydicarbonate) 5 gr as a radical generating catalyst, and pure water 5 gr.
000 gr and stirred at 500 rpm at 60°C.
Suspension polymerization was carried out for 13 hours. After centrifugal dehydration, the copolymer was dried to obtain a powdery copolymer.

Comparative Example 4 By using the same amount of methacrylic chloride in place of γ,γ'-dichloroisobutylene used in Example 4, and using the same charging ratios of other raw materials and polymerization conditions as in Example 4, polymerization was carried out. , a powdery copolymer was obtained.

The number average molecular weight, solubility in various solvents, and heat meltability were evaluated, and the results are shown in Table 2.

Note that the evaluation method for the above characteristics is as follows.

O number average molecular weight: Based on Kel permeation chromatography method, the number average molecular weight is expressed as a polystyrene equivalent.

The copolymer was added so that the solid content concentration was 601f% with respect to the 0-solubility solvent, and after stirring at room temperature for 60 minutes, the state of the liquid was visually evaluated.

The copolymer that melts under zero heat was dispersed under pressure on a thin iron plate so that the powders would not overlap, and after being placed in an open oven at 130°C for 3 minutes, the powder was taken out and the melting state of the powder was visually evaluated. Those that were completely melted were judged as good, and those that had some lumps remaining were judged as somewhat poor.

Table 2 [Note] 1) Toluene and methyl ethyl ketone are 1=1 (
This indicates a solvent mixed in a ratio of (weight ratio).

From Example 9 and Comparative Example 4, the vinyl chloride-vinylidene chloride copolymer obtained by copolymerizing γ, γ'-dichloroinbutene is better than the vinyl chloride-vinylidene chloride copolymer obtained by copolymerizing methacrylic chloride. It can be seen that it is superior in solubility in solvents and heat-melting properties compared to polymers.

In addition, r,γ'-dichloroisobutyne belongs to the second petroleum class under the Fire Service Act, and methacrylic chloride belongs to the class petroleum class, so γ r/-dichloroisobutyne is easier to handle. It is preferable.

(c) Effects of the invention The copolymer obtained by the invention has excellent thermal stability, solubility in solvents, adhesion, and dispersibility in magnetic powder or pigments, so it can be used in various fields. For example, primers used before applying various coatings to concrete, metal materials and synthetic resins, binders for magnetic recording media, binders for printing inks, vehicles for paint, resins for powder coatings, gas barrier packaging materials, magnetic It is suitable as a sealer containing powder, a pigment dispersant for paste vinyl chloride sol, etc.

Claims (1)

[Claims] 1. A monomer mixture consisting of vinyl chloride, vinylidene chloride, γ, γ' dichloroisobutylene, and optionally other radically polymerizable monomers, wherein γ, γ' dichloroisobutylene is present in the above essential monomer mixture. .1-20% by weight
and the total amount of vinyl chloride and vinylidene chloride accounts for the main component in the entire monomer mixture,
A method for producing a copolymer characterized by radical polymerization.