JPS5819347A - Glass fiber-reinforced polypropylene resin composition - Google Patents

Abstract

PURPOSE:To obtain FRPP having a excellent high-temperature rigidity and impact strength of a weld, by specifying the viscosity of crystalline PP and using a specified rubbery polymer in a composition comprising crystalline PP, a modified PP and glass fiber. CONSTITUTION:FRPP is composed of crystalline PP(A) having an intrinsic viscosity eta of 1.25-1.45 in tetralin soln. at 135 deg.C, an oxygen-contg. unsaturated, org. compc.-modified PP(B), a silane compd.-treated glass fiber (C) and an ethylene/alpha-olfefin rubbery polymer (D) having an ethylene content of 60-79% and an intrinsic viscosity eta of 1.0-1.7 in xylene soln. at 70 deg.C. If component D is absent, no sufficient high-temperature rigidity can be obtd. If component A is absent, no sufficient impact strength of a weld can be obtd. Thus, the characteristics of FRPP can be obtd. only when components A and B are present in combination.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention focuses on mechanical strength, particularly rigidity at high temperatures, and impact strength of weld parts (weld parts are areas where molten resin flows from two or more directions and welds together). This invention relates to a glass fiber-reinforced propylene resin composition that has excellent properties. Due to its excellent mechanical strength and heat resistance, glass fiber-reinforced propylene resin is being actively applied to automobile parts, electrical parts, and the like.

However, glass fiber reinforced polypropylene resin (hereinafter abbreviated as FRFP) generally has a significantly lower impact strength, especially at the weld part, so it is not suitable for automotive parts such as instrument panels in the interior and mechanical parts in the engine compartment. Although it has excellent heat resistance, its application is often hindered. As a method for improving the impact strength of the weld part in FRPP, (1) the impact strength of the composition itself is increased. (2) Aspect ratio of glass fiber (
(8) To improve the fluidity of the 41 product. etc.

First, in order to increase the impact strength of the composition, it is possible to use an ethylene-propylene copolymer as the polypropylene, but on the other hand, the rigidity is greatly reduced, and the characteristics of FRPP are lost. Next, for example, if the aspect ratio of glass fibers is reduced, the weld strength will be slightly improved - by adding glass fiber rings! The resulting high temperature stiffness is impaired. Furthermore, it is qualitatively said that improving the fluidity of the composition increases the joining speed of the molten resin when forming the weld part and slightly improves the weld strength, but the actual effect is small. It was very difficult to achieve both high-temperature rigidity and impact strength of the welded part like Jin, which is the case with Genbo. The present inventors have developed a crystalline polypropylene which is the main component of a glass delicate reinforced propylene resin composition.

Although different kinds and amounts of modified polypropylene and glass fibers were used, and combinations thereof were also investigated, no significant effects were observed.

As mentioned above, it is true that the stiffness at high temperatures decreases when a rubbery polymer is further added, but as a result of various studies on the SGI* of the rubbery polymer and their amount It has been found that by paying attention to the combination with propylene, it is possible to obtain a FRFP with excellent rigidity at high temperatures and impact strength of the weld portion. In more detail, [11 (185°C, intrinsic viscosity of tetralin solution)
is 1.26 to 1.46, preferably '1·oo to 1·40
Crystalline propylene with an ethylene content of 4 or less and [11 (70°C, intrinsic viscosity of xylene solution) is LO ~ 1]
．． 7 Preferably 1.8 to 1.6 with an ethylene content of 60
A resin composition made by combining a rubber-like polymer of ~79q6 with polypropylene modified with a predetermined amount of an oxygen-containing unsaturated organic compound and glass finely treated with a silane compound has excellent rigidity at high temperatures. degree, and the impact strength of the weld area. The reason is not necessarily clear, but [-] is 1.26 to 1.45 and the ethylene content is 4.
Even if crystalline polypropylene with a crystallinity below excellent is used, the [1] of the rubbery polymer is 1.0 to 1.7 and the ethylene content is 60.
If it is outside the range of ~79 porridge, sufficient rigidity at high temperatures will not be obtained, and conversely, if [-] is 1.0 to 1.7 and the ethylene content is 60 to 79%, it will be rubbery. Considering that even if a polymer is used, sufficient weld strength cannot be obtained if the crystalline polypropylene deviates from the above-mentioned structure, it seems that this characteristic is only expressed when both components are present at the same time. It will be done. That is, [11 is 1.26~
1.46 Preferably 1.30 to 1.40 in crystalline polypropylene, polypropylene (2) modified with an oxygen-containing unsaturated organic compound, and glass fibers 0 and [-] surface-treated with a silane compound. A glass fiber-reinforced polypropylene resin composition consisting of a rubber-like polymer υ with O-1,7 and an ethylene content of 60 to 79% has excellent mechanical strength, particularly rigidity at high temperatures and impact strength of the weld part. It is especially suitable as a material for functional interior parts among automobile parts. The crystalline polypropylene used in the composition of the present invention includes polypropylene,
Examples include propylene ethylene copolymer [1] (1
85°C, the intrinsic viscosity of the tetralin solution is 1.20 to 1.
40 and has an ethylene content of 4% or less.Propylene is modified with the oxygen-containing unsaturated organic compound used in the composition of the present invention.Propylene is not particularly limited and any known propylene can be used, but in general polypropylene Homopolymers, polypropylenes such as ethylene-propylene copolymers, and oxygen-containing unsaturated compounds containing acid or acid anhydride units such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, etc. Copolymers or graft copolymers with organic compounds are used. and (1m/
A copolymer or graft copolymer of m-propylene and acrylic acid or maleic anhydride is preferred.6 Next, the glass fibers used in the composition of the present invention are those used in ordinary glass fine reinforced resins and are generally has a diameter of 6 to 20F and is surface treated with a silane compound, and the surface treatment agent used is β-(8,4-epoxycyclohexyl)-dityltrimethoxysilane.

Epoxysilanes such as γ-glycidoxypropyltrimethoxysilane, vinylsilanes such as vinyltriethoxysilane and vinyltrichlorosilane, and r-aminopropyltriethoxysilane.

A method for performing surface treatment using at least one treatment agent selected from aminosilanes such as N-β-(aminoethyl)-r-aminopropyltrimethoxysilane is usually performed using a solution of a surface treatment agent using a silane compound. A method of soaking and then drying is used. Finally, rubber polymers used in the composition of the present invention include ethylene-brone monomer copolymers and ethylene-butene copolymers, which have an [η] of 1.0 to 1.7 and contain ethylene. amount is 6
0 to 79 gruel 0 In the present invention, when mixing the aforementioned crystalline polypropylene, modified polypropylene, glass fiber, and rubbery polymer, it is necessary to disperse each component as uniformly as possible, and for this purpose. A Banbury mixer, screw extruder, roll mill, etc. can be used for this purpose. In addition, various general antioxidants, stabilizers such as ultraviolet absorbers, general pigments, inorganic fillers, etc. can be optionally added to the composition of the present invention. This will be explained in more detail using bite examples.

*Example 1 Crystalline polypropylene A (Cη) = 1.8, ethylene content 1q6), B (['2"l = -1, a5
, ethylene content 8.5%) or 0 ((tl = 1
．． s.

Ethylene content O), modified polypropylene (Riboside 1001 manufactured by Nippon Reichhold Co., Ltd.), glass fiber (RE806-TP87 manufactured by Nippon Glass Fibers) and rubbery polymer A (C'l]-1,4, containing ethylene. Amount 70%
ethylene proprene copolymer), B [[η] = 1.8
゜Ethylene-containing 1i78q6 ethylene-butene copolymer) or C(r'?) = 1. L ethylene content 65
% ethylene propylene copolymer) and an antioxidant for 2 minutes in a powder mixer.1. temperature 220
A screw extruder (screw 66-0.
(1, R, = 8.01 was used to create extruded pellets.The resulting composition was heated at a resin humidity of 280°C and a pressure of
b/cd.

A predetermined test piece was prepared under injection molding conditions with a total cycle of 40 seconds, and a physical property test was conducted.

However, the IZOVT impact test piece had gates at both ends of the test piece and a weld part was formed in the center, and the IZOVT impact test was conducted by adjusting the weld part to make it harder with a hammer.

The results obtained are summarized in Table 1. Samples 1.2 and 8 in the examples in which crystalline polypropylene A or B and rubber polymer or B are simultaneously present in the composition are shown in Table 1. It is clear from comparison with the comparative example (sample 4.5) that it has excellent properties in terms of rigidity and weld strength.

Claims (1)

[Scope of Claims] (1) (Crystalline polypropylene whose 11 (intrinsic viscosity of tetralin solution at 185°C) is 1.26 to 1.46 and polypropylene modified with an oxygen-containing unsaturated organic compound) and silane Glass fibers surface-treated with chemical compounds (
L) and [η] (70°C, intrinsic viscosity of xylene solution)
is 1. o~! , 7 and 0 of an ethylene-5-olefin rubber-like polymer having an ethylene content of 60 to 79q6. (2) [7] is 1.80 to 1.40 Ten2f L/
Crystalline polypropylene with a content of 4 or less
t] of 1.8 to 1.6 and an ethylene content of 68 to 76. (8) Crystalline polypropylene (2) 80-70% by weight 11%
and polypropylene modified with oxygen-containing unsaturated organic compounds@
10-20% by weight, 15-86% by weight of glass fiber (0) surface-treated with a silane compound, and 0% by weight of rubbery polymer.
The glass fiber reinforced polypropylene resin composition according to claim 1, comprising a weight of 5 to 1.6.