JPS62151464A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition suitable for applications such as electric wire covering materials, etc., by incorporating a base resin with resin- encapsulized metal hydroxide to accomplish a large quantity of blending of said hydroxide without impairing moldability and mechanical strength. CONSTITUTION:The objective composition can be obtained by incorporating (A) 604n200(pref. 80-180)pts.wt. of a resin-encapsulized metal hydroxide prepared by, e.g. suspension polymerization, pref. in the presence of a compound capable of forming sulfite ion (e.g. aqueous sulfite solution) in an aqueous medium between (i) metal hydroxide(s) (pref. at least one kind of compound selected from aluminum hydroxide, magnesium hydroxide and zirconium hydroxide) and (ii) an encapsulizing resin monomer (pref. vinyl monomer such as ethyl acrulate) in (B) 100pts.wt. of a base resin (pref. ethylele resin) followed by kneading using e.g. Banbury mixer.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a resin composition in which a metal hydroxide is blended into a base resin, and the resin composition is mainly used for applications such as electric wire coating materials. relating to things.

[Prior Art] It is known that metal hydroxides are added to various base resins such as vinyl chloride resins, epoxy resins, and unsaturated polyester resins for various purposes, such as imparting flame retardance. There is. However, when such metal hydroxides are used as fillers, they are usually added between the rows of the base resin in order to exhibit various desired properties such as flame retardancy. However, if too much metal hydroxide is added, the moldability of the resulting resin composition deteriorates, and the mechanical strength also decreases. For this reason, when aluminum hydroxide is used as a metal hydroxide, the amount that can be blended into the base resin is at most 30 to 40% by weight, and if you try to blend more than 1 cum of this aluminum hydroxide, It becomes difficult to mix uniformly, making it impossible to produce a uniform molded product, and it is also impossible to improve its flame retardance.

For this reason, in the past, for example, a mixture of a metal hydroxide and a vinyl-based 'rJi, U body was polymerized in the presence of a radical catalyst to form a vinyl-based resin molded with 60 to 85 fflffi% of aluminum hydroxide. It has been proposed to manufacture a product (Japanese Unexamined Patent Publication No. 48-29.882).

[Problems to be solved by the invention] However, in the conventional method described above, the type of base resin is specified, and the type of base resin can be freely changed depending on the purpose and application of the molded product. The problem was that I couldn't choose.

In addition, metal hydroxides are hydrophilic and easily absorb moisture in the air, and even if a resin composition containing a large amount of metal hydroxide is sufficiently dried during production, it will gradually absorb moisture in the air. Since it absorbs water and causes foaming during molding, it is necessary to maintain it in a good dry state, which requires a great deal of cost and labor. In particular, when a large amount of metal hydroxide is blended into the ethylene resin used as a wire coating material, wet tree, chemical tree, electrochemical tree, etc. There has been a problem in that a so-called water tree phenomenon called bow tree tree occurs.

The present invention was devised in view of this point of view, and although a large amount of metal hydroxide is blended into the base resin, it has good moldability and mechanical strength, and can be used for long periods of time. The present invention also provides a resin composition that does not absorb moisture and does not cause foaming during molding.

[Means for Solving the Problems] That is, the present invention is a composition containing a base resin and a metal hydroxide as main components, and a resin-encapsulated metal hydroxide is used as the metal hydroxide. It is a resin composition made of

The base resin used in the present invention may be any resin as long as it can be molded, but preferably low density polyethylene, high density polyethylene,
Crosslinked polyethylene, ethylene resins such as ethylene-ethyl acrylate copolymer, acrylic resins such as polymethyl methacrylate, methacrylic acid-acrylic acid copolymer, general-purpose polystyrene, impact-resistant polystyrene, AB
Examples include styrene resins such as S resin, olefin resins such as polypropylene, nylon resins such as nylon 66, novolac type phenol resins, resol type phenol resins, and more preferably ethylene resins. These base resins can be used alone, and
It can also be used as a mixture of two or more types.

The metal hydroxide blended into the above base resin is blended as a resin-encapsulated metal hydroxide, and this resin-encapsulated total hydroxide is one whose surface is coated with a resin and encapsulated. be.

Examples of metal hydroxides used for this purpose include aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, zinc hydroxide, antimony hydroxide, tin hydroxide, etc., and preferably It is one kind or a mixture of two or more kinds selected from aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

Furthermore, the encapsulating resin for covering the metal hydroxide may be any resin as long as it can perform resin encapsulation, but thermoplastic resins are preferred, particularly thermoplastic resins. Vinyl polymers or copolymers are preferred.

As a method for encapsulating the surface of the metal hydroxide with a resin, a commonly known interfacial polymerization method, in 5
itu polymerization method, in-liquid curing coating method, phase separation method from aqueous solution, phase separation method from organic solution, in-liquid drying method, melt dispersion cooling method, inclusion exchange method, powder bed method, in-air suspension coating method , spray drying method, vacuum evaporation method, electrostatic coalescence method, etc., but preferably, a vinyl monomer is graft-polymerized on the surface of the metal hydroxide, or a charge is imparted to the surface of the metal hydroxide. One or two types of thermoplastic resin latexes having opposite charges and adsorbing metal salts, surfactants, etc.
This method involves contacting a resin solution or dispersion containing at least one species.

As a method for graft polymerizing the vinyl spinning wheel base onto the surface of the metal hydroxide, various polymerization methods can be used in the presence of a radical polymerization initiator, such as bulk polymerization method, solution polymerization method, etc. Particularly preferred is a method in which a metal hydroxide and a vinyl spinning wheel matrix are subjected to suspension polymerization in an aqueous medium in the presence of a compound that generates sulfite ions, and water is generally used as the medium for suspension polymerization. Without being limited thereto, an aqueous medium such as a mixture of water and methanol can be used. In addition, as a polymerization initiator in suspension polymerization, a compound that generates hydrogen sulfite ions in an aqueous medium, such as blowing in sulfur dioxide gas, an aqueous sulfite solution, or subsulfite! Sulfites such as T-hydrogen soda and ammonium hydrogen sulfite, and persulfates such as potassium persulfate, sodium persulfate, and sodium persulfate can be used alone or in combination.

A preferred embodiment of the method for graft polymerizing the vinyl monomer onto the surface of the metal hydroxide is to treat the metal hydroxide with a surfactant in advance to selectively polymerize the surface of the metal hydroxide. By forming a molecular layer of a surfactant as a surface active agent, and then polymerizing a vinyl monomer on the surface of the metal hydroxide in the liquid dispersion medium, all or most of the surface of the metal hydroxide is converted into a vinyl-based monomer. It is better to coat it with a polymer.

As the surfactant that comes into contact with the metal hydroxide in the liquid dispersion medium to form a molecular layer that becomes a selective polymerized ring on its surface, most of the surfactants that are normally used are used. However, it is preferable that the vinyl monomers be polymerized together under the polymerization conditions so that the molecular layer formed on the surface of the metal hydroxide in the liquid dispersion medium becomes an excellent polymerized ring. Also, it is preferable to use a material that does not polymerize with vinyl monomers.

Specific examples of this surfactant include 1, for example, higher fatty acid alkali salts such as sodium oleate, alkyl sulfur [class A] such as sodium dodecyl@ate, alkyl sulfonates such as sodium stearyl sulfonate, sodium dodecylbenzenesulfonate, etc. alkylaryl sulfonates such as sulfosuccinate ester salts such as dioctyl sodium sulfosuccinate, anionic activators such as alkylamine oxides, higher alkylammonium salts such as dodecyl ammonium chloride, and quaternary salts such as dodecylpyridinium chloride. Quaternary N such as alkylpyridinium salts and dodecylpicolinium chloride
- Alkylpicolinium salts, quaternary alkyl ammonium salts such as cetyltrimethylammonium bromide, quaternary alkylimidazolinium salts, quaternary polyoxyethylene alkyldiammonium salts, quaternary polyoxyethylene alkyl ammonium salts, Cationic activators such as quaternary alkoxypropylammonium salts, organic acids or anionic acid salts of alkylpropylene diamines, and zwitterionic activators such as alkylglycines, alkylalanines, alkylbetaines, alkylimidacillins, etc. , alkyl polyoxyethylene ethers, alkylphenyl polyoxyethylene ethers, polyethylene glycol alkyl ethers, alkyl carbonyloxy polyethylenes, N,N-di(polyoxyethylene)alkanamides, N,N-di(alkaline) Examples include nonionic activators such as fatty acid polyhydric alcohol esters such as Norul fatty acid ester, sorbitan fatty acid ester, fatty acid monoglyceride, and fatty acid sucrose ester, and fatty acid polyhydric alcohol polyoxyethylene ethers. Two or more surfactants may be used in combination if necessary.Among these surfactants, those with particularly high critical micelle concentration give good results. When selecting an ionic active agent or a cationic active agent, a surfactant with the same charge as the surface charge of the metal hydroxide may be used as long as it has a strong adsorption power, but depending on the surface charge of the metal hydroxide used, Preferably, the material produces a charge opposite to the surface charge.

In addition, regarding the amount of this surfactant used, the surface active agent that suppresses the formation of polymer at places other than the surface of the metal hydroxide, and provides a selective polymerization site on the surface of the metal hydroxide. In order to form a molecular layer of the surfactant, the concentration of the surfactant is preferably 5 to 100% of the critical micelle concentration of the surfactant in the polymerization system. If the amount of surfactant used is too small, it will be difficult to form an effective molecular layer of surfactant that will serve as a selective polymerization site on the surface of the metal hydroxide; becomes difficult to suppress. The critical micelle concentration of the surfactant in the polymerization system referred to herein refers to the critical micelle concentration of the surfactant in a liquid dispersion medium to which a metal hydroxide, a vinyl yarn Tsumer 1 polymerization catalyst, etc. are added.

Formation of a molecular layer of a surfactant, which serves as a selective polymerization site, on the surface of the metal hydroxide can be performed by bringing the metal hydroxide and the surfactant into contact in a liquid dispersion medium.

In addition, the vinyl spinning wheel, which coats the surface of the metal hydroxide by protein on the surface of the metal hydroxide, contains acrylic acid, methacrylic acid, α-chloroacrylic acid, itaconic acid, maleic anhydride, and maleic acid. acids, ionically dissociable vinyl monomers such as unsaturated carboxylic acids such as fumaric acid, vinyl halides such as vinyl chloride and vinyl fluoride, styrene compounds such as styrene and α-methylstyrene, and vinyl acetate. , nonionically dissociable vinyl monomers such as aliphatic vinyl esters such as vinyl progonate, and unsaturated carboxylic acid esters such as butyl acrylate, butyl acrylate, methyl methacrylate, glycidyl methacrylate, and lauryl methacrylate. Quantities can be mentioned. When the resin is encapsulated on the surface of the metal hydroxide by graft polymerization, the amount of resin is 0.0% relative to the metal hydroxide.
It is 1 to 50% by weight, preferably 0.5 to 40% by weight. The resin-encapsulated metal hydroxide thus obtained is
A portion of a vinyl resin produced by a polymerization reaction is chemically grafted to active sites for free radicals on the surface of a metal hydroxide.

In addition, the thermoplastic resin latex includes not only latex synthesized by emulsion polymerization, but also dispersions in which polymeric substances are dispersed in an aqueous medium by appropriate means, and the medium also includes water. In addition, it may be an aqueous medium consisting of water mixed with an organic solvent.
In addition, plasticizers, stabilizers, ultraviolet absorbers,
Latex containing other additives may also be used.

Specifically, rubber latex such as styrene-butadiene rubber latex, polyisoprene latex, polychloroprene latex, methyl methacrylate-butadiene rubber latex, polyurethane aqueous dispersion, polymethyl methacrylate latex, methyl methacrylate, etc. -Styrene copolymer latex, methyl methacrylate-
Polyacrylate emulsions such as butyl methacrylate copolymer latex, polyvinyl acetate emulsions such as polyvinyl acetate latex, ethylene-vinyl acetate copolymer latex, polyvinyl chloride latex, vinyl chloride-vinylidene chloride, etc. Examples include polyvinyl chloride emulsions such as polymer latex, polyolefin emulsions and dispersions such as polyethylene emulsions, polybutene emulsions, and polytetrafluoroethylene dispersions, and other polystyrene latexes and silicone emulsions. They may be used alone or in combination of two or more.

In the present invention, the blending ratio of the base resin and the resin-encapsulated metal hydroxide varies depending on the types of the base resin, metal hydroxide and encapsulation resin used, the use of the obtained resin composition, etc. However, the resin-encapsulated metal hydroxide is in an amount of 60 to 200 parts by weight, preferably 80 to 180 parts by weight, per 100 parts by weight of the base resin. Regarding the group containing the metal hydroxide in the resin composition,
From the viewpoint of its addition effect and moldability, it is usually 50 to 2
00% by weight, preferably within the range of 60 to 180% by weight.

As a method for manufacturing a resin molded article using the resin composition obtained by the present invention, any molding method such as calendar molding, extrusion molding, compression molding, lamination molding, injection molding, etc. can be adopted, It can be selected as appropriate depending on the shape of the resin molded product.

Furthermore, when producing a molded article from the resin composition obtained according to the present invention, a kneading operation using commonly used means such as a Banbury mixer, a co-kneader, or a mixing roll may be performed before the above-mentioned molding step. Depending on the intended use, various plasticizers, stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, colorants, lubricants, etc. are often added to the resin composition at that time and/or during the molding operation. Various additives can also be added.

[Function] The resin composition of the present invention contains the metal hydroxide, which is required to be blended in a large amount in the base resin, as a resin turntable metal hydroxide, so the resin composition may become non-uniform as a whole. It is possible to incorporate a large amount of metal hydroxide without impairing formability and mechanical strength. Furthermore, the hygroscopicity of the resin composition disappears, probably because the hydrophilicity of the surface of the metal hydroxide changes to lipophilicity due to resin encapsulation.

[Example 1] Hereinafter, the resin composition of the present invention will be specifically explained based on Examples and Comparative Examples.

Example 1 10,000 weights of aluminum hydroxide (trade name: Hygilite H-42M manufactured by Showa Denko ■) were suspended in 50,000 weights of water, and 3 parts by weight of ethyl acrylate monomer and Sw
2 parts of t% sulfite aqueous sulfite was added, and polymerization was carried out at 60°C for 3 hours with stirring. The resulting reaction mixture was filtered, washed with water, dried and powdered with resin encapsulated aluminum hydroxide (up to 2.9% resin) coated with ethyl acrylate resin.
3 parts by weight were obtained.

This powder was stored for 3 days under conditions of 23° C. and 50% humidity, and its water absorption ω was determined under drying conditions of 105° C. and 1 hour. As a result, the water absorption rate was 0.06%.

Next, 120 parts by weight of the resin-encapsulated aluminum hydroxide powder was blended with 100 parts by weight of high-density polyethylene having an average molecular weight of 136,000 ff, and the mixture was kneaded in a Panbury mixer to form pellets. Using this pellet, a sheet with a thickness of 300 μm (aluminum hydroxide content δ153% by weight) was molded using an extrusion molding machine. The surface of the obtained sheet was smooth and its moldability was good. In addition, as a result of measuring the bending strength (ASTH 0790) and tensile strength (ASTH0638) of the obtained sheet, the bending strength was 750Kg/ci, and the tensile strength was 520K.
g/cIIi.

Further, the above seal 1- was stored in a constant temperature and humidity chamber at 23° C. and 50% humidity for 10 days, and the moisture content was measured after that, and the weight was 0.01717. Also, this sheet has 6
．． 30 under water with a voltage of 7KV/#.

When the voltage was applied for 1,000 hours and the occurrence of so-called water trees was observed using an electron microscope, no occurrence of water trees was detected.

Comparative Example 1 The water absorption rate of the aluminum hydroxide used in Example 1 was measured in the same manner as that measured for the resin-encapsulated aluminum hydroxide powder in Example 1, and the water absorption rate was 1.0% by weight. Met.

Next, pellets and sheets (containing 853% by weight of aluminum hydroxide) were prepared in the same manner as in Example 1, using 117 parts by weight of the above aluminum hydroxide in place of the resin-encapsulated aluminum hydroxide powder in Example 1. Prepared.

(The surface of the sheet was rough and uneven, and the formability was not good. Also, the bending strength (ASTH 0790) measured in the same manner as in Example 1 was 450:9/car, and the tensile strength ( ASTH D638) is 280
It was K9/ci.

Furthermore, the moisture content determined in the same manner as in Example 1 was 0.
05% by weight, and the number of water trees determined in the same manner as in Example 1 was as high as 14 pieces/mm3.

Example 2 Resin-encapsulated magnesium hydroxide coated with ethyl acrylate resin in the same manner as in Example 1, using magnesium hydroxide (Kyowa Kagaku Co., Ltd. product name: Kismer) in place of aluminum hydroxide in Example 1. 103 parts by weight of powder (resin amount: 2.9% by weight) was obtained. The water absorption rate of this powder was measured in the same manner as in Example 1, and the water absorption rate was 0.04%.

Next, pellets and sheets (magnesium hydroxide content: 53 wt ω%) were molded in the same manner as in Example 1.

The surface of the obtained sheet was smooth and its moldability was good. In addition, the bending strength (A
STH0790) is 710 Kyl~, and the tensile strength (
ASTHD638) was 9/ci at 480.

Furthermore, the moisture content determined in the same manner as in Example 1 was 0.
014% by weight, and as a result of examining the occurrence of water tree in the same manner as in Example 1, no occurrence of water tree was observed.

Comparative Example 2 The water absorption rate of the magnesium hydroxide used in Example 2 was measured in the same manner as that measured for the resin-encapsulated magnesium hydroxide powder in Example 2, and the water absorption rate was 0.5% by weight. Met.

Next, pellets and sheets (magnesium hydroxide content: 53 Weight a%) was prepared.

The surface of the obtained sheet was rough and its moldability was not very good. In addition, the bending strength (ASTH0790) measured in the same manner as in Example 1 was 430 Kg/cr.
A, and the tensile strength (ASTH0638) is 270 K
It was y/ci. Further, the moisture content determined in the same manner as in Example 1 was 0.03% by weight, and the state of occurrence of water trees determined in the same manner as in Example 1 was 6 pieces/#llll3.
Met.

[Effects of the Invention] According to the present invention, by using a resin-encapsulated metal hydroxide, the entire resin composition does not become non-uniform, and the moldability and mechanical strength are not impaired. It becomes possible to blend a large amount of metal hydroxide into the base resin, and the effect of this metal hydroxide blend can be effectively brought out. In addition, since a resin composition with no hygroscopicity can be obtained, quality control of this resin composition is extremely easy, and there is no need for equipment or equipment for quality control. This method can solve the so-called water tree phenomenon, which is a problem in the use of electric wire coating materials using ethylene resin.

Patent Applicant: Shinnichito Chemical Co., Ltd. Agent Patent Attorney: Katsuo Naruse (2 others) Procedural Amendment February 3, 1985 Director General of the Patent Office Michibe Uga 1, Indication of Case 1985 Patent Application No. 292174 2, Name of the invention Resin composition 3, Relationship with the case of the person making the amendment Patent applicant address 5-13-16 Ginza, Chuo-ku, Tokyo Name (6
64) Nippon Steel Chemical Co., Ltd. 4, Agent 105 Telephone (433) 4420 Address 3-8-8-5 VifTbashi, Minato-ku, Tokyo Date of amendment order Voluntary amendment 6, Invention increased by amendment 7. Section 8 of “Detailed Description of the Invention” of the amended sealed specification, Contents of the amendment

Claims (4)

[Claims] (1) A resin composition comprising a base resin and a metal hydroxide as main components, characterized in that a resin-encapsulated metal hydroxide is used as the metal hydroxide. (2) The resin composition according to claim 1, wherein the base resin is an ethylene resin. (3) The resin composition according to claim 1 or 2, wherein the metal hydroxide is one or a mixture of two or more selected from aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide. (4) The resin composition according to any one of claims 1 to 3, wherein the encapsulating resin covering the metal hydroxide is a vinyl polymer or copolymer.