JPS5986646A - Reinforced polyolefin resin composition - Google Patents

Abstract

PURPOSE:To provide a reinforced polyolefin resin compsn. which is excellent in mechanical and electrical properties and water repellency and has low specific gravity, by blending a reinforcing org. fiber, a reinforcing inorg. fiber or an inorg. filler with a specified modified polyolefin. CONSTITUTION:A reinforcing org. fiber, a reinforcing inorg. fiber or an inorg. filler is blended with a modified polyolefin or a mixture thereof with an unmodified polyolefin or other thermoplastic resin, said modified polyolefin being obtd. by reacting 0.05-0.8pts.wt. unsaturated carboxylic acid with 100pts.wt. polyolefin in the presence of benzoyl peroxide and 0.03-3pts.wt. org. peroxide derived from a dialkyl compd. or ketal having a decomposition temp. of 80 deg.C or higher to obtain a half life period of 10hr.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reinforced polyolefin resin composition having the following properties, low specific gravity, and excellent water repellency.

Recently, the use of thermoplastic composite materials for industrial purposes has been remarkable, and many materials are being used that take advantage of their various characteristics. Among them, polyethylene. Polyolefin resins such as polypropylene are used in large quantities in various fields because they have low specific gravity, excellent moldability and chemical resistance, and are inexpensive. However, polyolefin resins do not have sufficient physical properties for industrial applications that require mechanical properties, heat resistance, etc., and attempts have been made to incorporate various reinforcing agents and fillers, but Because it is resin. It has poor affinity with various reinforcing agents and fillers, and only those with low reinforcing effects were obtained. As a countermeasure against this, various methods have been reported to introduce polar groups into polyolefins to improve their affinity with reinforcing agents or fillers.
It is now possible to obtain items with a high reinforcing effect.

However, problems remain regarding moldability.
Especially for thin-walled molded products or large-sized molded products, the thickness and surface roughness of thin-walled parts can be improved by adding reinforcing agents or fillers.
Furthermore, it is often difficult to mold large molded products depending on their size and shape. The present inventors conducted studies to improve this point, and found that in the process of introducing polar groups into polyolefins, that is, during the grafting of unsaturated carboxylic acids onto polyolefins, a reaction initiator belonging to ketals or dialkyl groups was used, and the reduction was reduced by half. It has been found that when an organic peroxide having a decomposition temperature of 80 DEG C. or higher to obtain a 10-hour period is used, a material with good fluidity and excellent moldability can be obtained (Japanese Patent Application No. 112428/1982). However, even the molded articles obtained by this method did not necessarily have a satisfactory impact resistance. Therefore, the present inventors conducted further intensive studies and found that when grafting an unsaturated carboxylic acid onto a polyolefin, by using two or more specific organic peroxides together as a reaction initiator, excellent molding processability can be achieved. Moreover, mechanical properties.

In particular, it has been discovered that a composition with improved impact resistance can be obtained, and the present invention has been achieved. That is, the gist of the present invention is to provide a modified polyolefin obtained by reacting a polyolefin with an unsaturated carboxylic acid in the presence of an organic peroxide belonging to benzoylperols or dialkyls, or a modified polyolefin and an unmodified polyolefin. Or organic fibrous reinforcement in a mixture with other thermoplastic resins. A reinforced polyolefin resin composition containing at least one type of inorganic fibrous reinforcing agent or inorganic filler.

Methods for modifying the modified polyolefin used in carrying out the present invention include a method in which an unsaturated carboxylic acid and a polyolefin are melt-kneaded in the presence of an organic peroxide, and a solution reaction method in which the polyolefin is dissolved in a solvent. The former is mainly used to color polyolefins.

The latter method has the drawback of poor workability due to the long reaction time and complicated polymer recovery process, while the former method has the disadvantage of causing a significant decrease in the molecular weight of the polyolefin by reacting it under specific conditions. In particular, extrusion-based reaction methods are excellent because they can be modified without causing a significant decrease in their properties. The reaction in the extruder has the following three advantages.

Firstly, unlike the solution reaction method, the reaction can proceed in a short time by adding a small amount of modified side and a small amount of peroxide, secondly, it is economical, and thirdly, the grafting rate is low. Therefore, the homopolymer content is reduced, and the physical properties are good and the appearance of the molded product is good.

The method used to obtain the composition of the present invention is not particularly limited, but from the viewpoint of industrial practical value, it is desirable to carry out the reaction in an extruder under specific conditions.

That is, an unsaturated carboxylic acid and an organic peroxide are dissolved in a small amount of a low-boiling solvent and added to polyolefin powder, and the mixture is sufficiently mixed using a suitable mixer such as a Henschel mixer.
This method involves passing it through an extruder and reacting it.

A wide range of things can be applied. In addition to the single polypropylene system, other polyolefins are used, namely polyethylene, poly(4-methyl-pentene-1), ethylene-vinyl acetate copolymer resin (PTA), ethylene-ethyl acrylate copolymer resin (EEA), ethylene-propylene. Rubber (EPR).

It is also possible to use ethylene-propylene-diene rubber (gpoM) in combination. There is no limit to the percentage of unsaturated carboxylic acids as long as they have a vinyl group, but specific examples include maleic acid, fumaric acid, acrylic acid,
methacrylic acid.

Examples include itaconic acid and these acid anhydrides.
Particularly suitable are acrylic acid and maleic anhydride. The blending amount of this unsaturated carboxylic acid/acid is 0.05 to 0.0, per 100 parts by weight of the polyolefin, and 0.1 to
Particularly preferred is 0.6 parts by weight. Next, the organic peroxide used as a reaction catalyst belongs to benzoyl peroxide (hereinafter referred to as BPO), peroxyketals, and dialkyl peroxides, and the decomposition temperature to obtain a half-life of 10 hours is 80°C or higher. belongs to.

In carrying out the present invention, it is an essential condition to use BPO in combination. The reason is that among various organic peroxides, B
Only PO has the specific effect of making the spherulites of polyolefin fine.

Generally, in crystalline polymers, spherulites are formed during the molding process, but if the spherulites are large, the strength and physical properties tend to decrease overall, and in particular impact resistance (9) is greatly affected. However, BPO significantly refines the spherulites of polyolefin molded products, thereby making it possible to obtain molded products with excellent impact resistance, which is a new fact discovered by the present inventors. However, B.P.
Since O has a low decomposition temperature, it does not have a large effect on improving the fluidity and processability of molded products that accompany the reduction of the molecular weight of polyolefins. Therefore, to improve this point, it is effective to combine organic peroxides belonging to the ketals or dialkyl groups, which have a high decomposition temperature. Limiting the organic peroxide used in combination with BPO to a specific compound such as ketal M or dialkyl allows the polyolefin to have a lower molecular weight effect to the maximum extent at the same time without inhibiting the unique nucleating agent effect of BPO.

Specific examples of organic peroxides belonging to ketals or dialkyls used in the present invention include 1,1-bis(
t-butylperoxy) 3,3゜5-trimethylcyclohexane, 1.1-bis(1-butylperoxy)cyclohexane, n-phr* thyl 4.4-bis(1-butylperoxy)valerate, 2 .2-bis(t-butylperoxy)butane, 2.
2-bis(1-butylperoxy)octane, di-t-
Butyl peroxide, -butylcumyl peroxide, dicumyl peroxide, α,α'-bis(t-butylperoxyinpropyl)benzene, 2,5-dimethyl-2,5-di(1-butylperoxy) ) hexane.

Examples include 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3. The total amount of organic peroxide is 0.03 to 3 parts by weight per 100 parts by weight of polyolefin.
The weight part is appropriate, preferably 0.05 to 1.0 weight part. In addition, the combined weight ratio of BPO and organic peroxide belonging to ketals or dialkyls used as a reaction initiator is suitably in the range of 1:10 to 10:1, preferably in the range of 1:6 to 6:1. It is. In these reactions, the temperature is preferably 150 to 280°C and the reaction time is preferably 1 to 20 minutes. Outside the above setting range, it is not very preferable because the polymer will be colored, the molecular weight will be markedly reduced, and unreacted unsaturated carboxylic acid will remain.The reactor is not particularly limited to an extruder. , any fusion crosstalk machine that satisfies the above conditions can be used regardless of its shape. Further, specific examples of the organic and inorganic fibrous reinforcing agent used in the present invention include glass fiber and aromatic polyamide fiber.

Silicon carbide fibers, vinylon fibers, metal fibers, etc. can be used. These can be used alone or in combination, but from the viewpoint of moldability of the composition of the present invention, it is preferable that the blending amount is 60% by weight, and from the viewpoint of reinforcing properties, it is preferable to use l'
i5 weight ratio or higher is preferable. Even when inorganic fillers and these fibrous reinforcing agents are used together, the total amount is 5 to 60%.
Weight ratio is preferred.1 Next, inorganic fillers used in the present invention include glass foil, talc, mica, clay, calcium carbonate, calcium sulfate, and magnesium oxide.

Examples include carbon black, titanium oxide, white carbon, and antimony trioxide. These can be used alone or in combination, but the amount added is 5 to 6 in the total composition.
It is in the range of 0 weight. Preferably, the total amount of the inorganic filler and the organic fibrous reinforcing agent or the inorganic fibrous reinforcing agent is 5 to 60% by weight in the entire resin composition. The matrix in the reinforced polyolefin resin composition of the present invention may be an unmodified polyolefin or a thermoplastic resin other than polyolefin, such as nylon 66°, nylon 6, if the modified polyolefin is 40 parts by weight or less in 100 parts by weight of the resin component. It can be blended with PBT etc.

Furthermore, various additives such as stabilizers against light or heat can be added to the reinforced resin composition of the present invention, if necessary.

Hereinafter, the present invention will be specifically explained with reference to Examples 0 Examples 1 to 6. Comparative Examples 1 to 6 To 100 parts by weight of polypropylene powder having an intrinsic viscosity of 1.5 (135°C, tetralin), the compounds shown in Table 1 as unsaturated carboxylic acids and organic peroxides were added in the proportions shown in Table 1, and the mixture was heated using a Henschel mixer. After mixing well with
φ extruder (t, 10 = 25) 230
Pellets were obtained by extrusion under conditions of residence at ℃ for 7 minutes.

In this case, the pento portion was degassed to remove unreacted unsaturated carboxylic acid. The obtained modified polypropylene mixture was used as a resin component, and at least one organic fibrous reinforcing agent, inorganic fibrous reinforcing agent, or inorganic filler was thoroughly mixed in a tumbler in the proportions shown in Table 1VC, and the mixture was mixed using the extruder described above. It was extruded into pellets at 220°C and molded using a 5-ounce screw in-line injection molding machine at a cylinder temperature of 22°C.
A molded article was obtained under molding conditions of 0°C and mold temperature of 60°C. Among the molded products, No. 1 dumbbell and 125 x 12.5 x 3.2 m +
and 125 x 12.5 x 6.4 square bars were used as test pieces for measuring physical properties, and the evaluation results are shown in Table 1.
Shown below. The bending strength 6 bending modulus in the table is ASTM-D
790, Izod impact strength is ASTM-D25/
+, Fluidity (MFI”) FiA8TM-D123
These are the values measured at 8K. For comparison, Table 2 also shows the results of molding evaluations of compositions other than those of the present invention using the same method.

As mentioned above, the composition of the present invention uses a combined system of BPO and an organic peroxide belonging to ketals or dialkyls as a reaction initiator and having a decomposition temperature of 80°C or higher to obtain a half-life of 10 hours. It can be seen that the material has excellent moldability, excellent mechanical properties, and particularly improved impact resistance.

Claims (1)

[Scope of Claims] A modified polyolefin obtained by reacting a polyolefin with an unsaturated carboxylic acid in the presence of an organic peroxide belonging to ketals or dialkyls at a temperature of 80°C or higher, or the modified polyolefin and unmodified polyolefin, or others. A reinforced polyolefin resin composition comprising a mixture with a thermoplastic resin and at least one of an organic fibrous reinforcing agent, an inorganic fibrous reinforcing agent, or an inorganic filler. 2. Polyolefin 100 as modified polyolefin
Use a mixture obtained by melting and reacting a mixture of 0.05 to 0.8 parts by weight of an unsaturated carboxylic acid and 0.03 to 3 parts by weight of a peroxide based on parts by weight using an extruder. The reinforced polyolefin resin composition according to claim 1, characterized in that: (5) The organic peroxide belonging to ketals or dialkyl is 1,1-bis(t-butylperoxy)5,3.5
-) Limethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, n-butyl 4,4-bis(1-butylperoxy)valerate, 2,2-bis(t-butylperoxy)butane , 2.2-bis(1-
(butylperoxy)octane, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α′-his(t-7” thylperoxyinpropyl)benzene, 2,5-dimethyl- 2,5
-di(1-butylperoxy)hexane, 2,5-dimethyl-2,5-di(1-butylperoxy)hexane-
The reinforced polyolefin resin composition according to claim 1, characterized in that the reinforced polyolefin resin composition is at least one selected from the group consisting of: 4. The weight ratio of benzoyl peroxide to an organic peroxide belonging to ketals or dialkyls with a decomposition temperature of 80°C or higher to obtain a half-life of 10 hours is 1:1.
~1o:1 and 5, the organic fibrous reinforcing agent or the inorganic fibrous reinforcing agent is glass fiber, metal fiber, or silicon carbide fiber. At least one type selected from aromatic polyamide fibers and vinylon fibers, and the proportion of the total composition is 5 to 5.
60% by weight, and the total amount of organic fibrous reinforcement or inorganic fibrous reinforcement and inorganic filler is 5 to 60% by weight.
The reinforced polyolefin resin composition according to claim 1, characterized in that: 6. The inorganic filler is at least one selected from glass foil, Merck, calcium carbonate, stone oxide, white carbon, antimony trioxide, magnesium oxide, clay, mica, carbon black, and titanium oxide. Claims characterized in that the proportion of the inorganic filler and the organic or inorganic fibrous reinforcement in the composition is in the range of 5 to 60% by weight, and the total amount of the inorganic filler and the organic or inorganic fibrous reinforcement is 5 to 60% by weight. The reinforced polyolefin resin composition described in item 1