JPH04136057A - High-rigidity resin composition - Google Patents

Abstract

PURPOSE:To obtain a light-stable high-rigidity resin composition whose color tone changes little even when it is irradiated with ultraviolet rays by adding potassium titanate whiskers and a beta-diketone compound to a vinyl chloride resin. CONSTITUTION:A resin composition prepared by adding 10-30 pts.wt. potassium titanate whiskers and 0.1-2.0 pts.wt. beta-diketone compound to 100 pts.wt. vinyl chloride resin. A desirable potassium titanate whisker to be added is one having a mean fiber length of about 10-20mum. Examples of the beta-diketone compounds include dibenzoylmethane, stearoylbenzoylmethane and dihydroacetic acid. The change in the color tone of the potassium titanate whisker in the resin composition upon irradiation with light rays containing ultraviolet rays, such as sunlight, can be prevented by the light stabilization effect of the beta-diketone compound. Therefore, the change in the color tone of the high-rigidity resin composition can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a photostabilized, highly rigid resin composition that exhibits little change in color tone due to ultraviolet rays.

(Prior Art and Problems) Conventionally, potassium titanate whiskers have been used to increase the mechanical strength of resin materials such as vinyl chloride resin. There are sheets etc. obtained by adding 1 to 10 parts by weight of potassium titanate whiskers to 10 parts by weight of potassium titanate whiskers, and in JP-A-61-275357, 2 to 50 parts by weight of potassium titanate fiber 1i is added to 10 parts by weight of thermoplastic resin. A thermoplastic resin composition comprising 0.3 to 6 parts by weight of silicone oil is shown.

However, as mentioned above, when potassium titanate whiskers are simply added to vinyl chloride resin or other thermoplastic resins, when exposed to sunlight or other ultraviolet rays, the product, which is originally white, turns grayish-brown. The color tone changes easily, resulting in a deterioration in appearance quality.

The cause of the color change is not clear, but the irradiation energy of ultraviolet rays causes a certain reaction within potassium titanate molecules, liberating titanium.

It is presumed that this causes a change in color tone of the resin composition.

As a way to solve such problems, benzophenone-based,
A method of adding ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers is known, but if exposed to continuous heat and light, not only will the lasting performance of the ultraviolet absorbers decrease; Particularly when trying to obtain a white product, using a large amount of ultraviolet absorbent makes color adjustment difficult due to the color of the ultraviolet absorber itself.

Another possible method is to surface-treat the potassium titanate whiskers with a silane coupling agent, but the surface coating is not complete and this method cannot be said to be effective from the viewpoint of photostabilization.

Furthermore, there is a known method in which a resin composition containing potassium titanate whiskers is formed into a sheet, and then a UV blocking film, typified by acrylic resin, is attached to the surface of the sheet. In this method, there is a problem in that when a sheet is formed by a vacuum forming method or the like, the inherent molding performance of the resin composition is impaired due to the low molding performance of the film.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the inventors have conducted intensive research and found that the color tone of a highly rigid resin composition made by adding potassium titanate whiskers to vinyl chloride resin due to ultraviolet rays. In order to suppress the change, it was found that it is effective to further add a certain amount of a β-diketone compound, and this invention was completed.

That is, the present invention provides a light-stabilized high-rigidity product made by adding 10 to 30 parts by weight of potassium titanate whiskers and 0.1 to 20 parts by weight of a β-diketone compound to 100 parts by weight of a vinyl chloride resin. The main subject is resin compositions.

The main components and amounts used in the resin composition of the present invention will be described below.

First, vinyl chloride resin generally has an average degree of polymerization of 700.
~1300, and those made of a single polymer are preferably used.

Next, regarding the potassium titanate whisker added to impart rigidity to the vinyl chloride resin, it is preferable that the average fiber length is about 10 to 20 μm. and 10 to 30 parts by weight of potassium titanate whiskers. If the amount added is less than 10 parts by weight, no improvement in rigidity can be expected.
Furthermore, if the amount exceeds 30 parts by weight, an improvement in rigidity can be expected;
On the other hand, impact strength decreases, and sheet forming by extrusion or calendering becomes difficult. A particularly preferred amount of potassium titanate whiskers to be added is 15 to 25 parts by weight.

Furthermore, the β-diketone compound used in this invention is represented by -killing R'C'O・CH2・CO・Ro, and includes, for example, dibenzoylmethane (DBM), stearoylbenzoylmethane (SBM), dihydrocarbon Examples include acetic acid (D)Is). The amount of the β-diketone compound added is 0.00% relative to the potassium titanate whisker.
It is 1 to 2.0 parts by weight. If the amount added is less than 0.1 part by weight, the effect of suppressing color tone change due to ultraviolet rays, that is, the photostabilizing effect cannot be expected. On the other hand, if the amount exceeds 2.0 parts by weight, a photostabilizing effect against ultraviolet rays can be expected, but the addition Particularly suitable for β-diketone compounds, which are undesirable because it not only does not provide any effect commensurate with the amount, but also makes color adjustment difficult due to the color of the β-diketone compound. The amount added is 0.2 to 2.0 parts by weight.

In addition to the potassium titanate whisker and β-diketone compound used in this invention, stabilizers, plasticizers, lubricants, impact modifiers, processing aids, and titanium oxide commonly used for vinyl chloride resins There is no problem in using a white pigment such as exemplified by and a trace amount of an ultraviolet absorber in combination.

(Function) Since the highly rigid resin composition of the present invention is made by adding potassium titanate whiskers and a β-diketone compound to vinyl chloride resin as described above, it cannot be irradiated with light including ultraviolet rays such as sunlight. The color change of the potassium titanate whiskers in this case is suppressed by the photostabilizing effect of the β-diketone compound. Therefore, it is possible to prevent a change in color tone as a highly rigid resin composition.

(Example) Hereinafter, this invention will be explained according to examples.

First, 100 parts by weight of vinyl chloride resin with an average degree of polymerization of 800, potassium titanate whiskers (manufactured by Otsuka Chemical Co., Ltd., trade name "TISMO DJ") in the amounts shown in the table, and dibenzoylmethane (DBM) as a β-diketone compound. 5
3. Added together with appropriate amounts of other commonly used additives, heated and kneaded using a calendar method to obtain a sheet with a thickness of 0.5 mm, then stacked 6 sheets and heated and pressed using a press method. A white plate with a shadow thickness of 0 ■ was obtained (Example &
1-4).

Next, for each white plate obtained above, physical properties were measured (degree of discoloration (color difference), flexural modulus,
and Izot impact strength) and processability tests (sheeting property and ripening formability). The results are shown in the table. As a comparative example, a white plate with the added amounts of potassium titanate whiskers and dibenzoylmethane (DBM) as shown in the table, and a white plate with the addition amounts of potassium titanate whiskers and dibenzoylmethane (DBM>) were used. A plate without additives was obtained in the same manner as in the above example (Comparative example & 5
~9) 1. Measurement of physical properties and test of processability were also carried out. The results are also shown in the table. [Method of measuring physical properties] ■Degree of color change (color difference) Super energy irradiation tester (UE) manufactured by Suga Test Instruments Co., Ltd.
-IDEc) and 45 s+W/ on the surface of each sheet.
An amount of energy of cm2 was irradiated, and the color difference between the irradiated area and the non-irradiated area was measured using a color computer (SM-3) manufactured by the same company.

Here, the smaller the numerical value of the color difference, the less the change in color tone, and the larger the numerical value of the color difference, the more the change in the color tone.

■Bending elastic modulus (102kgf/-■2) ASTM D
Measured based on 790.

■Izotsu impact strength (kgf-c/c) ASTM
Measure based on D256.

[Processability Test - Sheeting Properties The situation was observed when the mixture of each component was heated and kneaded to form a sheet by the calender method.

Those that can be formed into a sheet shape very easily are rated 0, and those that can be formed into a sheet shape under normal conditions are rated x, and those that require a long time for O1 cross-connection and are difficult to form into a sheet shape are rated x.

■Aging shapeability (formable multiple) Each plate was formed into a cube with a 210 x 140 mm rectangular surface as a projection plane by vacuum forming, and the area ratio of the cube surface to the projected surface was determined as a moldable multiple. Here, the higher the value, the better the thermoformability.

(Margins below) As is clear from the results in the table, Examples of the present invention (&1
Regarding the physical properties of the white plate obtained from ~4), the color difference indicating the degree of discoloration is small, which indicates little change in color tone, and exhibits good appearance quality.

Furthermore, the flexural modulus is clearly improved compared to the sample without potassium titanate whiskers (&9). moreover,
The impact strength is that without potassium titanate whiskers (
Although it is inferior to NQ9>, it is clearly superior to Monoku&8), which has a large amount of addition.

Next, regarding processability, the examples were made without the addition of potassium titanate whiskers (&
Although it is slightly inferior in both sheeting property and thermoformability to 9), it is clearly superior in terms of sheeting property as compared to the material containing a large amount of potassium titanate whiskers (Na8).

(Effects of the Invention) As described above, in this invention, since potassium titanate whiskers and a β-dictone compound are added to vinyl chloride resin, the flexural modulus is significantly improved, the degree of discoloration (color difference) is reduced, and the color tone is It is possible to obtain a highly rigid resin composition that exhibits little change and is comparable to conventional compositions in terms of impact strength, sheeting properties, thermoformability, and other processability.

Therefore, according to the resin composition of the present invention, a highly rigid product with excellent photostability can be easily obtained.

that's all

Claims (1)

[Claims] A photostabilized high-rigidity resin composition obtained by adding 10 to 30 parts by weight of potassium titanate whiskers and further 0.1 to 2.0 parts by weight of a β-diketone compound to 100 parts by weight of vinyl chloride resin. .