JPH07216132A - Light-resistant resin and / or rubber composition - Google Patents

Abstract

PURPOSE:To obtain a resin and/or rubber compsn. which has an improved light resistance and hardly undergoes tk discoloration, degradation in strengths, etc., due to light or ultraviolet rays. CONSTITUTION:This compsn. contains a flaky zinc oxide powder with a mean thickness of 0.1-0.5mum, a mean diameter of 0.1-100mum, and a ratio of mean diameter to thickness of 3-1.000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin and / or rubber composition having light resistance which is unlikely to cause deterioration such as discoloration or reduction in strength due to light or ultraviolet rays.

[0002]

2. Description of the Related Art As is well known, organic polymer materials such as resins and rubbers undergo physical and chemical actions under the influence of light, ultraviolet rays, etc., and lose their inherent physical properties, causing discoloration and strength reduction. There is an inconvenience.

In order to prevent the deterioration due to light or ultraviolet rays, an organic ultraviolet absorber such as a benzotriazole type, a salicylate type, a benzophenone type or a cyanoacrylate type is added and kneaded to absorb the ultraviolet rays which have an adverse effect, and to absorb a resin or rubber. It is widely practiced to suppress the deterioration of.

However, it is hard to say that the organic ultraviolet absorber is at a satisfactory level in terms of heat resistance, weather resistance, volatility, etc., and there is a problem in long-term use and application to high heat resistant resin. was there.

In response to this problem, it has been widely attempted to add an inorganic powder, which is more durable than an organic ultraviolet absorber, to a resin and / or rubber and knead them to absorb or scatter ultraviolet rays to improve light resistance. Has been done. For example, it has been proposed to use a plastic film sheet in which fine particles of zinc oxide, cerium oxide, or the like are dispersed in order to prevent a decrease in luminance and a decrease in chromaticity of an EL luminescent material due to ultraviolet rays.
In addition, Zinc Research Digest
Digest) 36,74 (1978) was excellent in outdoor exposure test of polypropylene by using 0.11 μm fine particle zinc oxide in combination with vulcanization accelerator such as zinc diethyldithiocarbamate and alkyl phosphite, and antioxidant. It has been reported to show weather resistance.

However, since the inorganic powder used in the above proposal is fine particles, when the addition amount is increased, the strength of the molded product is lowered and the viscosity at the time of molding is increased. As a result, the fluidity of the resin and / or rubber is lowered, and there is a problem in that a good molded product cannot be obtained.

[0007]

In view of such circumstances, in view of the above circumstances,
The present inventor has conducted extensive studies to obtain a resin composition or a rubber composition that is resistant to deterioration such as discoloration or strength reduction even when irradiated with light or ultraviolet rays, and as a result, has found that flaky zinc oxide powder is used as a resin and / or rubber. A resin that suppresses deterioration due to light and ultraviolet rays when added to and kneaded with and has good moldability
Further, they have found that a rubber composition can be obtained, and completed the present invention.

[0008]

That is, according to the present invention, the average thickness is 0.1 μm to 0.5 μm, and the average transfer diameter is 0.1 μm.
˜100 μm, ratio of average delivery diameter / average thickness is 3 to 10
The present invention provides a light-resistant resin and / or rubber composition, which comprises the flaky zinc oxide powder No. 00.

The present invention will be described in detail below. In the present invention, the average thickness is 0.1 μm to 0.5 μm, the average delivery diameter is 0.1 μm to 100 μm, and the average delivery diameter / average thickness is for the purpose of suppressing the deterioration of the resin or rubber due to light or ultraviolet rays. 20 to 350 parts by weight of flaky zinc oxide powder having a ratio of 3 to 1000 is added and mixed with 100 parts by weight of resin and / or rubber. Since the shape (size) of the flakes is not constant here, the average thickness in the present invention is the thickness of all the flakes that can be read within the field of view of the scanning electron micrograph, and the average thickness is taken as the arithmetic mean. . The average delivery diameter of the thin pieces is an average value of (maximum delivery diameter + minimum delivery diameter) / 2 of 100 pieces.

Zinc oxide is widely known as a material that absorbs ultraviolet rays because of its electronic structure. In the present invention,
Since zinc oxide has a flaky shape, in addition to the ultraviolet ray absorbing performance of zinc oxide, effects such as good moldability due to the flaky shape and improvement of the strength of the molded body can be exhibited.

Such flaky zinc oxide powder generates zinc salts and ammonia or ammonium ions, as shown in, for example, Japanese Examined Patent Publications Nos. 54-35197, 54-19235 and 54-38298. The compound can be obtained by mixing the above compounds to prepare flaky basic zinc and firing it. Further, flaky zinc oxide having a small particle size is disclosed in JP-A-1-230431.
It can also be obtained by mixing zinc ions and a base in a specific pH range.

It is desirable that the flakes have high strength when added to or mixed with a resin or rubber, but metal atoms of aluminum and / or iron are added in an amount of 0.0001 mol to 1 mol of zinc per mol of zinc.
Flake-shaped zinc oxide containing 0.5 mol is particularly desirable because it has excellent flake strength.

The flaky zinc oxide powder containing aluminum and / or iron metal atoms can also be produced as follows. Aluminum sulfate, iron sulfate, aluminum nitrate, iron nitrate, aluminum chloride, iron chloride, aluminum acetate, zinc salt solution such as zinc sulfate, zinc nitrate, zinc chloride,
A compound containing aluminum and / or iron atoms such as iron acetate, aluminum phosphate, iron phosphate and ammonium alum is dissolved, and a solution containing ammonium or a compound that decomposes to generate an ammonium ion is mixed and neutralized. Flake-shaped zinc hydroxide is precipitated, and the precipitate is filtered, washed, dried, and fired in an oxidizing atmosphere to obtain flaky zinc oxide powder.

In the present invention, the average thickness is from 0.1 μm to
0.5 μm, average delivery diameter is 0.1 μm to 100 μm,
The average differential delivery diameter / average thickness ratio is 3 to 1000, and from the viewpoint of handleability of powder and maintenance of working environment, the average thickness is preferably 0.1 μm to 0.5 μm, and the average delivery diameter is 1 μ to 80 μm.
A flaky zinc oxide having a ratio of m, average delivery diameter / average thickness of 5 to 300 is used. When the delivery diameter is 0.1 μm or less, there is not much difference from zinc oxide which is substantially granular, and the effect derived from the flaky shape is not exhibited. On the other hand, the delivery diameter is 100μ
If it exceeds m, the fluidity and mechanical strength of the resin will be impaired, so 100 μm or less is preferable.

Examples of the resins and rubbers used in the present invention include polyethylene, polypropylene, copolymers of ethylene and other α-olefins; ethylene-ethyl acrylate copolymers, ethylene-vinyl acetate copolymers, Copolymers of ethylene and other monomers such as ethylene-acrylic acid copolymers and ethylene-propylene copolymers; polybutene, polystyrene, polyvinyl chloride, polyvinyl acetate, polyacrylate, polymethacrylate,
Thermoplastic resin such as polyamide, polyester, polyether, polyurethane; phenol resin, melanin resin,
Examples thereof include thermosetting resins such as epoxy resins, unsaturated polyester resins, and alkyd resins; EPDM, SBR, NBR, butyl rubber, isopropylene rubber, silicone rubber; and the like, but are not limited thereto.

In the present invention, the compounding amount of flaky zinc oxide with respect to the resin and / or rubber is appropriately selected depending on the type of resin and / or rubber, the delivery diameter of the flakes, the thickness, the shape of the molded product, and the like. , Resin and / or rubber 100
The amount is about 20 to about 350 parts by weight, preferably about 30 to 300 parts by weight, based on parts by weight. When the blending amount of flaky zinc oxide is less than the above range, the light resistance becomes insufficient, and conversely, when the blending amount exceeds the above range, mechanical properties such as Izod impact strength and tensile strength are deteriorated. Since there is a risk of causing the disadvantage of (4), it is preferable to appropriately select it within the above-mentioned blending range.

There is no particular restriction on the method of mixing and kneading the resin and / or rubber with the flaky zinc oxide, and any mixing means capable of uniformly mixing the two can be adopted. Examples include single or twin screw extruders, rolls, Banbury mixers, kneaders and the like. There is no particular restriction on the molding method, and any known molding means can be arbitrarily used depending on the type of resin and / or rubber, the type of desired molded product, and the like. For example, injection molding, extrusion molding, blow molding,
These are press molding, rotational molding, calender molding, sheet forming molding, transfer molding, laminated molding, vacuum molding and the like.

In addition to flaky zinc oxide, various conventional additives may be added to the light-resistant resin and / or rubber composition of the present invention, if necessary. For example, antistatic agents, pigments, paints, plasticizers, fillers, flame retardants and the like can be added.
The flaky zinc oxide powder can be used as it is by mixing it with a resin or rubber, but higher fatty acids, anionic surfactants, phosphorus and the like are used for the purpose of improving dispersibility and compatibility in the resin or rubber. It may be surface-treated with at least one selected from the group consisting of acid esters, coupling agents (silane-based, titanate-based, aluminum-based, etc.) and esters of polyhydric alcohols and fatty acids.

[0019]

The light-resistant resin and / or rubber composition thus obtained does not cause discoloration, deterioration such as strength reduction, etc. even when irradiated with light or ultraviolet rays. Is extended and the life of the molded product is extended, and the industrial value thereof is extremely large.

[0020]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. In addition, "part" in the examples means "part by weight" unless otherwise specified. Further, in the examples, the impact strength and color difference (ΔE) of the molded product were measured by the following methods. -Impact strength: Notched Izod impact strength measured according to ASTM, D256 was used.・ ΔE (color difference): Iwasaki Electric Co., Ltd.
per) UV tester, wavelength from 290nm to 45
From the two sets of L ^* value, a ^* value and b ^* value obtained from the two sets of test pieces before and after exposure to ultraviolet rays having an intensity of 100 mW / cm ² at 63 ° C. for 100 hours in the range of 9 nm, the CIE
These are values calculated according to the 1976 L ^* , a ^* , b ^* color difference formula. The test piece was prepared by injection-molding a 40 × 40 × 3 mm plate, and the color was measured by a spectrocolorimeter (Mcbis Color Eye MS2020 +) manufactured by Macbis Corporation.

Example 1 Poly (2,6-dimethyl-1,4-phenylene ether) (PPE: Nippon Polyether Co., H-4
6) was fed to the feed throat of a 50 mm Toshiba twin screw extruder equipped with a cylinder temperature of 260 ° C and equipped with a downstream feed port. 90 parts by weight of polyamide-6 (PA: manufactured by Allied Signal Co., CAPRON XPN-154
6) and 5 parts by weight of average transfer diameter 5 μm, average thickness 0.2
A premixed product composed of flaky zinc oxide powder of μm was supplied to the downstream supply port while maintaining the mixing ratio of the resin after melting to PPE / PA = 10/90. The extruded strands were cut into pellets and injection molded into test pieces (40 x 40 x 3 mm). Table 1 shows the impact strength and ΔE of the test pieces.

Examples 2 to 7 and Comparative Examples 1 to 5 Resin compositions were obtained in the same manner as in Example 1 except that the kinds and amounts of the resins and inorganic powders shown in Table 1 were used as raw materials, and the tests were carried out. A piece was prepared and the impact strength and ΔE were measured. The results are shown in Table 1. In the examples using maleic anhydride (MAH) as the compatibility improver, MAH was used after being premixed with PPE by a super mixer.

[0023]

[Table 1] (Note) * 1: Al / Zn (atomic ratio) = 0.3 / 100 Average delivery diameter 5μ
m, thickness 0.2 μm * 2: Al / Zn (atomic ratio) = 0/100 average crossover diameter 5 μm, thickness 0.2 μm * 3: average particle size 0.2 μm * 4: average particle size 0.05 μm

Claims (3)

[Claims] 1. A flaky zinc oxide powder having an average thickness of 0.1 μm to 0.5 μm, an average transfer diameter of 0.1 μm to 100 μm, and an average transfer diameter / average thickness ratio of 3 to 1000. A light-resistant resin and / or rubber composition characterized by: 2. A flaky zinc oxide powder is aluminum and / or
Alternatively, the metal atom of iron is 0.0001 per mol of zinc atom.
The resin and / or rubber composition according to claim 1, wherein the resin and / or rubber composition is contained in an amount of 0.5 to 0.5 mol. 3. The resin and / or the resin composition according to claim 1, wherein the flaky zinc oxide is added and mixed in an amount of 20 to 350 parts by weight with respect to 100 parts by weight of the resin and / or rubber.
Or a rubber composition.