JPH0841263A - Production of chlorinated polypropylene emulsion - Google Patents

Abstract

PURPOSE:To obtain the emulsion, containing neither organic solvent substance nor polymeric substance, excellent in anchoring properties in a substrate, capable of providing a coating excellent in gloss of the film surface and useful for automotive parts, etc., by dissolving a chlorinated polypropylene in d-limonene, then adding the resultant solution to another aqueous solution and stirring the mixture solution. CONSTITUTION:This method for producing a chlorinated polypropylene emulsion is to dissolve (i) a chlorinated polypropylene in (ii) d-limonene, provide (A) a solution of the chlorinated polypropylene, then add the component (A) to (B) an aqueous solution separately prepared by using the component (i), (iii) a surfactant and (iv) water as essential components and stir the resultant mixture solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an emulsion of chlorinated polypropylene which is useful as a raw material for water-based paints of polyolefin moldings used for automobile parts and the like.

[0002]

2. Description of the Related Art Chlorinated polypropylene highly chlorinated grade products are used as coating materials for marine applications, heavy duty anticorrosion paints and inks, and low chlorinated grade products are primers for polypropylene moldings such as car bumpers. It is widely used as a raw material for paints and paints, and as an adhesive, but in reality, these primers, paints and adhesives are generally used as a toluene solution. However, due to global environmental issues, solvent-free paints and development of water-based paints have been called for, and various methods for manufacturing water-based paints have been studied for chlorinated polypropylene. For example, a method of dissolving chlorinated polypropylene in toluene and emulsifying the toluene solution or a method of dissolving chlorinated polypropylene in an acrylic monomer to form a solution, and suspending the solution in water in the presence of a catalyst and an emulsifier, A general method is to obtain an emulsion of chlorinated polypropylene by suspension polymerization.
However, the emulsion obtained by this method contains toluene or is a mixture of polyacrylic acid ester and chlorinated polypropylene, and is not an emulsion of chlorinated polypropylene alone, but has various restrictions in use and formulation. is there. Emulsion coatings of polymer compounds obtained by using an emulsifier generally have the drawbacks of poor anchoring to the substrate and poor gloss of the coating film surface.

[0003]

[Problems to be Solved by the Invention] An organic solvent such as toluene is not used in the emulsification of chlorinated polypropylene, and an emulsion is obtained which does not contain a polymer substance such as polyacrylic acid ester, which is a constraint in the formulation of paint. That was the challenge. In addition, it is excellent in anchoring to the base material,
It was also an issue to make a chlorinated polypropylene emulsion that gives a coating having excellent gloss on the surface of the coating film.

[0004]

In order to achieve the above object, as a result of earnest research, it was found that chlorinated polypropylene was soluble in d-limonene, which is a kind of terpene compound, and the terpene compound was already applied. The inventors of the present invention have come to the present invention by knowing that they are used as gloss improvers for films. That is, an emulsion can be easily obtained by dropping the d-limonene solution in which chlorinated polypropylene is dissolved into an aqueous solution of separately prepared d-limonene, a surfactant and a large amount of water while stirring. The intended purpose has been reached. The obtained emulsion is an O / W type, and the chlorinated polypropylene is in a state of being dissolved in water in a form of being dissolved in d-limonene. The emulsion can be easily mixed with a general polymer emulsion and is stable. The d-limonene used in the present invention is
It is a compound contained in citrus fruits such as orange, and is used in large quantities as a raw material for scientific substances, fragrances, and cleaning agents.
Chlorinated polypropylene has a chlorine content of 20-40 wt.
% Low chlorinated polypropylene and 40 wt% or more high chlorinated polypropylene. Generally, low chlorinated grades are used for resins for plastic coatings, primers for car bumpers and polypropylene adhesive tapes, etc., while high chlorinated polypropylenes are used for marine coatings and land heavy food. Next, an example will be described in detail.

[0005]

【Example】

(Basic solution I) 400 g of chlorinated polypropylene having a chlorine content of about 40 wt% and a molecular weight of about 20,000 is d-
In addition to 600 g of limonene, the mixture was stirred with a dissolver to prepare a d-limonene solution of chlorinated polypropylene.
The resulting solution was a pale yellow liquid and had a viscosity of 4,150 centipoise (25 ° C).

(Basic solution II) d-limonene 15 wt
%, Nonionic surfactant 14 wt%, boiling point about 24
15wt of higher alcohol with 5 ℃ and flash point of 140 ℃
% Water 56 wt% was mixed and stirred to obtain a colorless transparent liquid. The obtained liquid had a pH of 9.1 (25 ° C).

Example 1 500 cc of the base solution II was mixed with 50 ml of the base solution I while stirring at high speed with a homomixer.
0 cc was dropped. The obtained milky white emulsion is p
H: 7-8, viscosity: 1,660 centipoise (25 ° C)
Met. The stability was examined by leaving it at room temperature, but it was stable, and no separation or increase in viscosity was observed.

(Example 2) Similar to Example 1, the basic solution I
An emulsion was prepared from 750 cc of I and 250 cc of base solution I. The pH was 7 to 8, the viscosity was 5,100 centipoise (25 ° C.), and the stability with time was excellent.

[0009]

INDUSTRIAL APPLICABILITY The method for producing a chlorinated polypropylene emulsion of the present invention can easily obtain a chlorinated polypropylene useful as a primer for a polypropylene molded article or a paint by using d-limonene, and the d-limonene can be applied to It is characterized by improving the anchoring property and surface gloss of the film.

Claims (1)

[Claims] 1. A chlorinated polypropylene is dissolved in d-limonene to form a limonene solution of chlorinated polypropylene, and the solution is added to an aqueous solution prepared separately by using d-limonene, a surfactant and water as essential components. A method for easily obtaining a chlorinated polypropylene emulsion by stirring.