JPS601236A - Production of glass fiber-reinforced polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled resin compsn. having greatly improved mechanical strength, by melt-kneading an unsaturated silane compd., an org. carboxylic acid, a free radical generating agent and a polyolefin to effect a reaction between the reactants, and melt-kneading glass fiber therewith. CONSTITUTION:In melt-kneading 50-99pts.wt. polyolefin with 1-50pts.wt. glass fiber, 1-50pts.wt. said fiber is added to a molten compsn. obtd. by melt-kneading 0.1-5pts.wt. (per 100pts.wt. glass fiber) unsaturated silane compd., 0.001- 5pts.wt. org. carbosylic acid or anhydride and 50-99pts.wt. said polyolefin to effect a reaction between the reactants, and the resulting mixture is further melt-kneaded. Preferred polyolefin resins include crystalline polyprolylene and a crystalline ethylen/propylene copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a glass fiber reinforced polyolefin resin composition having particularly excellent mechanical strength.

Glass fiber-reinforced polyolefin resins have superior mechanical properties, heat resistance, and dimensional stability than regular polyolefin resins, so they are increasingly being used in automobile parts, electrical appliance parts, and various industrial parts. .

Conventionally, various proposals have been made for achieving interfacial modification or interfacial adhesion between glass fibers and polyolefin resins in order to improve the physical properties of glass fiber reinforced polyolefin resin compositions. For example, (1) a method of coexisting an unsaturated silane compound and a radical generator (Japanese Patent Publication No. 49-41098
(2) A method of adding and mixing silane-treated glass fibers, a polyfunctional monomer capable of reacting with the silane, and a radical generator to a polyolefin resin (Japanese Patent Publication No. 49-410
No. 96, etc.) '131 A method of adding an organic carboxylic acid or its acid anhydride to glass fibers and polyolefins surface-treated with aminoalkylsilane compounds (Japanese Patent Publication No. 49-49029), (41 Unsaturated carboxylic acid) A method of adding and mixing glass fibers treated with a silane compound having two organic groups that react with acids to a polyolefin resin modified with an acid or its anhydride (Japanese Patent Publication No. 51-1
No. 0265, etc.). However, the conventional method (
Methods 1), (2), and (3) are simple, but the effect of improving mechanical strength is insufficient (and conventional method (4) is difficult to obtain a sufficient effect of improving mechanical strength. It requires a large amount of modified polyolefin resin, and it is also necessary to manufacture or manually prepare the modified polyolefin resin in advance, making the process complicated and economically expensive.

The present invention was completed based on the discovery that the mechanical strength of the composition can be dramatically improved by improving the conventional method with an extremely simple solution.

That is, in the present invention, when melt-kneading polyolefin (1,150 to 99 parts by weight) and 1 to 5 parts by weight of glass fiber (■), 1 to 5 parts by weight of unsaturated polyolefin to 100 parts by weight of the glass fiber (Ill) is melt-kneaded. Silane compound (al and 0.
01 to 5 parts by weight of an organic carboxylic acid or acid anhydride (BL), and 0.005 to 0.5 parts by weight of a radical generator (Cl and the polyolefin ([ A glass fiber-reinforced polyolefin resin characterized in that 1 to 50 parts by weight of the glass fiber (■) is added to a composition in a molten state obtained by subjecting 150 to 99 parts by weight to a melt-mixing reaction, and then further melt-kneaded. The present invention relates to a method for producing a composition.

The polyolefin resin (11) in the present invention is
Crystalline polypropylene, crystalline ethylene-zolopylene copolymer, polyethylene, polydetene, homopolymers of α-olefins such as poly-4-methylpentene-1, α-olefins and other α-olefins, aromatic olefins, dienes It is a copolymer with copolymerizable monomers such as
Mixtures of these, or mixtures with less than 50% by weight of nidistomers or other types of polymers are also possible. In particular, crystalline polyethylene and crystalline ethylene-propylene copolymer are suitable.

The unsaturated 7-rane compound (al) in the present invention is a specific silane having an ethylenic double bond and a group capable of forming a silanol group in the molecule, such as vinyltriethoxysilane, vinyltriethoxysilane, γ -Methacryloyloxyzolopyltrimethoxysilane, γ-acryloyloxypropyltrimethoxysilane, etc. are preferred, and a mixture of two or more volumes is also possible.The amount of these unsaturated silane compounds to be used is based on 100 parts by weight of glass fiber. The amount is in the range of 0.1 to 5 parts by weight, more preferably 0.3 to 6 parts by weight.Below the above range, no improvement in mechanical strength is obtained, and above the above range, the rate of improvement in mechanical strength is The size is small, the cost is high, and heat resistance is decreased and discoloration is likely to occur.

Organic carboxylic acid or its acid anhydride (
Various types of b) are possible, including aliphatic carboxylic acids, aromatic carboxylic acids, monocarboxylic acids, dicarboxylic acids, and saturated carboxylic acids. It can be an acid or an unsaturated carbic acid (,
It may also have other types of functional groups. For example, acetic acid, propionic acid, capric acid, lauric acid, stearic acid,
Acrylic acid, methacrylic acid, oleic acid, cono-phosphoric acid,
Adipic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, lactic acid, citric acid, phthalic acid,
Typical examples include benzoic acid and toluic acid. Particularly preferred are carboxylic acids having 3 to 10 carbon atoms. These acid anhydrides are also possible, but maleic acid,
Acid anhydrides such as cono-phosphoric acid, 7-talic acid, and citraconic acid are useful. The above acids and acid anhydrides may be used alone, or may be used as a mixture of two or more. The amount of the organic carboxylic acid or its acid anhydride used is in the range of 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight of glass fiber. In addition, a weight ratio of 1/λo-2o/1 to the unsaturated silane compound is satisfactory, but a sufficient improvement effect can be obtained even in the range of 1/10-5A.The above usage amount If it is less than the above range, the mechanical strength improvement effect will not be sufficient, and if it is more than the above range, the rate of increase in the improvement effect will be small and discoloration, odor, etc. will easily occur.

Examples of the radical generating agent (Cl) in the present invention include organic peroxides and azo compounds. Particularly suitable are organic peroxides whose decomposition temperature is 120°C or higher at which the half-life of decomposition is 1 minute. For example, benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2.
5-dimethyl-2゜5-di(t-butylperoxy)hexyne-3,1,6-bis(t-butylperoxyisopropyl)benzene, 1,4-bis(t-butylperoxyisopropyl) Examples include benzene, di-t-butyl peroxide, cumene hydroperoxide, and t-deterperpenzoate, and they can also be used as a mixture of two or more. The lid used for these radical generators varies depending on the type of polyolefin, amount of glass fiber, amount of unsaturated silane compound, and crosstalk conditions, but usually polyolefin 100
It is in the range of 0.005 to 0.5 parts by weight, more preferably 0.01 to 0.1 parts by weight. If the amount is less than the above range, the mechanical strength improvement effect will not be sufficient, and if it is more than the above range, too many polymer radicals will be generated, resulting in crosslinking and main chain scission, resulting in poor physical properties and moldability. I also don't like it.

The glass fibers used in the present invention ([1] are commercially available glass fibers, which are usually surface-treated with aminorane, epoxy silane, vinyl silane, or acrylic silane, but can be treated with any of them. can also be processed, and may not be processed.

Usually, the glass fibers are preferably chopped strands cut into 3 mm, 6 lengths, etc., but long fibers may also be supplied in the form of rovings and broken during kneading.

In the composition of the invention, the concentration of glass fibers is between 1 and 50
It is more preferably in the range of 6 to 40% by weight.

If the amount is less than the above range, the reinforcing effect of the glass fibers will be small, and if it is more than the above range, the reinforcing effect will be saturated and the moldability, appearance of the molded product, etc. will deteriorate.

In the production method of the present invention, glass fiber fll'a? The present invention can also be produced by a batch method such as a pan-grill mixer, but it can also be produced by single-screw or multi-screw extrusion having a vent hole that allows continuous supply of glass fibers. A method of continuous production using a multi-stage extruder, etc., which has a separate melt-kneader section and a granulation/extrusion section, is industrially simple and preferred. +11 and (al
. (11 or (11 and (al,
The mixture of (bl and (c)) is fed to the above-mentioned single-screw or multi-screw extruder or Banbury mixer, etc., at a temperature above the melting point of the polyolefin and below the decomposition temperature, preferably 1.
80~280'C1, preferably 200~250℃
The melt crosstalk reaction is carried out at a temperature of . Glass fiber +Ill is added and mixed into this molten state to further melt and mix the wires. (11) may be added continuously through the vent hole of the extruder, or may be added to the hopper on the granulation extruder side of a multi-stage extruder (or may be directly mixed in a batch system). .

(11 and (al, tb+, It is possible to obtain a composition with much better mechanical strength than by melt-kneading at the same time.Of course, glass fibers break during kneading, but the average fiber length in the composition is preferably 0.3. or more, more preferably 0.5 s+m or more.Even if the average fiber length in the composition by the conventional method is longer than that of the present invention, the composition of the present invention has far superior mechanical strength. .

The composition obtained by the present invention can be formed by injection molding, extrusion molding,
It is molded into various molded products, sheets, rods, and pipe-shaped products by commonly used melt molding methods such as compression molding.

In addition to the above-mentioned components, the composition produced by the method of the present invention contains additives such as a heat stabilizer, an ultraviolet absorber, an antistatic agent, a lubricant, a photonic agent, a flame retardant, a coloring agent, and a crystal nucleating agent. May contain.

The present invention will be explained in more detail below using Examples and Comparative Examples. All parts in Examples and Comparative Examples are parts by weight.
Express weight%.

In addition, mechanical strength was measured by measuring tensile strength and bending properties. The measurement method was as follows.

Tensile strength: ASTM' D6 to 8, in units! ? /c+
n” strength: ASTM D79L1. a-kg
/c7n2 Flexural modulus: ASTM D790, unit 9/Crn2 Examples 1-1 to 6 MFI 4.0 crystalline polypropylene (11,
l, maleic acid (tel, 2,5-dimethyl-2,5-
After thoroughly mixing di(t-butylperoxy)hexane (cl) in the proportions listed in Table 1, it was fed in an extrusion mode set at 200 to 250°C. The vent hole was located 2/3 from the hopper side, and the glass fiber (■) was continuously supplied from this vent hole at the ratio shown in Table 1.The screw of this extruder It had a Dalmage-type crosstalk zone just before it. Chopped strands with a length of 3 vyr and a diameter of 16 μm, surface-treated with γ-aminopropyltrimethoxysilane, were used as the glass fibers.The resulting pellets A test piece was prepared by injection molding from 5, and its mechanical strength was measured.The results are shown in Table 1.

Comparative Example 1-rt: Composition pellets were produced in the same manner as in Example 1 except that the proportions of each component were set as shown in Table 1, and the mechanical strength was measured. .

The results are shown in Table 1.

Comparative Example 2 Same composition ratio as Example 1-5, (II, (a), (b)
), (after premixing cl and fIll, Example 1
It is supplied from a portion of the extruder used in . However, 1
The screw used for this prevention was different from that in Example 1, and was a full-flight type screw. Results - The average fiber length of the lath fibers in the resulting composition pellets was measured and was found to be between 0.6 and 0.6.

The average fiber length of Example 1-5 was approximately CJ-6 mm. The results of measuring mechanical strength are shown in Table 1.

Comparative Example 6 M! I 8
A pellet composition was prepared by extruding 70 parts of crystalline polypropylene and 60 parts of glass fiber in the same manner as in Example 1, and then evaluated. The results are shown in Table 1.

(All white below) Example 2 Composition pellets were produced in the same manner as in Example 1-5, except that various organic carboxylic acids and acid anhydrides were used instead of maleic acid. The mechanical strength was determined to be 1. The results are shown in Table 2.

Table 2 Example 6 In Example 1-5, the procedure was the same as in Example 1-5 except that ^density polyethylene of M 20 and density 0.962 was used instead of crystalline polyzolopyrene. Composition pellets were manufactured using the same method, and their mechanical strength was measured. The tensile strength is 870 kl/cm' and the bending strength is 1290 kl?
/cr/12.

Comparative Example In Example 6, composition pellets were produced in the same manner as in Example 6 except that only cylindrical density polyethylene and glass fiber were used, and the mechanical strength was measured. Tensile strength is 560 kg/cIrL2, bending strength is 690 kg/
It was cx2.

The composition of the present invention has excellent mechanical strength, and particularly exhibits extremely high tensile strength and bending strength. According to the present invention,
By filling the glass fibers with 2[chi], it is possible to develop tensile strength and bending strength values that are similar to those of conventional compositions that require 30% glass fiber filling. The fact that the amount of glass fiber filling can be lowered means that
There are many benefits, including cost reduction, less molding wear, better appearance of molded products, lighter weight, and less anisotropy.

Moreover, the composition of the present invention can be produced by a simple method.

Patent applicant: Asahi Kasei Kokuri Co., Ltd.

Claims (1)

[Claims] (1) When melt-kneading polyolefin + 1,150 to 99 parts by weight and 1 to 50 parts of glass fiber (■), 0.1 to 5 parts by weight of unsaturation per 100 parts by weight of the glass fiber (■). 7 run compound (al and 0.01 to 5 N parts of organic carboxylic acid or its acid anhydride (b), and the polyolefin (Jlloo: 0, OO' 5 to 0.5 parts by weight per part of ff1-1iir) Adding 1 to 50 parts by weight of the glass fiber (1) to a composition in a molten state obtained by subjecting the radical generator tc+ and the polyolefin + 1,150 to 99 parts by weight to a melt-mixing reaction, and then further melt-kneading. Method for producing glass fiber reinforced polyolefin resin composition