JPH1143562A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition useful as e.g. a construction material with high mechanical strength by kneading a wood-based material with a polypropylene-based resin, a polyolefin resin modified with a polybasic acid anhydride, and the like. SOLUTION: This composition is obtained by including (A) 50-80 pts.wt. of a polypropylene-based resin 0.1-2 g/10 min in melt flow rate at 230 deg.C under a load of 2.16 kg, (B) a polyethylene-based resin 3.5-15 dL/g in intrinsic viscosity composed of an ultra-high-molecular polyethylene 10-40 dL/g in intrinsic viscosity determined in decalin solvent at 135 deg.C and 15-40 wt.% based on the ultra-high- molecular polyethylene, of a low- to high-molecular polyethylene, (D) 0.1-10 pts.wt. of a polyolefin-based resin modified with 0.1-20 wt.% of a polybasic acid anhydride, and (C) such an amount, based on a total of 100 pts.wt. of the components A and B, of a lignocelluslose-based material so as to be (90:10) to (30:70) in the weight ratio (A+B)/C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition which can be easily formed into an arbitrary shape in molding such as extrusion molding and has good mechanical strength as a molded product.

[0002]

2. Description of the Related Art The technique of using a wood-based material as a filler in polypropylene is disclosed in JP-B-59-30176, and it has been pointed out that there is a problem in moldability due to a decrease in fluidity and the like.

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a method of kneading a polypropylene resin which is a thermoplastic resin and wood powder of a woody material, by mixing a polypropylene resin and a polyethylene resin modified with a polybasic anhydride. Addition thereof provides a thermoplastic resin composition having good extrusion moldability, excellent surface smoothness, capable of forming with little edge swelling, and having good mechanical strength as a molded product.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the following composition has been found to provide a composition having an improved interface bonding property between resin and wood flour. They have found that they can be adjusted without loss and arrived at the present invention. That is, the present invention provides the following compounds. (A) A polypropylene resin 50 having a melt flow rate (MFR; ASTM D1238-65T) of 0.1 to 2 g / 10 minutes at 230 ° C. and a load of 2.16 kg.
To 80 parts by weight, (B) an ultrahigh molecular weight polyethylene having an intrinsic viscosity of 10 to 40 dl / g measured in a decalin solvent at 135 ° C. and 1 to the ultrahigh molecular weight polyethylene
A polyethylene resin having an intrinsic viscosity of 3.5 to 15 dl / g substantially consisting of 5 to 40% by weight of 0.1 to 5.0 dl / g of low to high molecular weight polyethylene (D) polybasic anhydride modification amount Is 0.1 to 20% by weight, and 0.1 to 10 parts by weight of the modified polyolefin resin and 100 parts by weight of (A) + (B), the lignocellulosic and cellulosic substances are added to ((A) +
(B)) / (C) is added in a weight ratio of 90/10 to 30/70. The polypropylene resin (A) used in the present invention has 230
° C, melt flow rate at 2.16 kg load (M
FR; ASTM D1238-65T) 0.01 to 2
g / 10 minutes, preferably 0.05 to 1 g / 10 minutes, and polypropylene and 20 mol% or less of ethylene and / or a C3-C20 α-olefin copolymer. Preferably it is C3-C8. The polyethylene resin (B) used in the present invention has a temperature of 135 ° C.
The intrinsic viscosity measured in a decalin solvent is 10 to 40 dl /
g of ultrahigh molecular weight polyethylene and 15 to 40% by weight of 0.1 to 5.0% based on the ultrahigh molecular weight polyethylene.
A polyethylene resin having an intrinsic viscosity of 3.5 to 15 dl / g consisting essentially of low molecular weight to high molecular weight polyethylene of dl / g, and copolymerization of polyethylene and ethylene with 10 mol% or less of a C3-C20 α-olefin. Means coalescence. Preferably it is C3-C8. Lignocellulose and cellulosic substances (woody materials) are wood flour, woody pulp and the like, and the raw wood and tree species are not particularly limited. It is also possible to carry out a neutralization treatment of wood acid with urea or the like. Lignocellulosic and cellulosic substances (C) are ((A)
+ (B)) / (C) in a weight ratio of 90/10 to 30/70. Polybasic acid-modified olefin resins include maleic anhydride, dimethyl maleate,
Polypropylene resin, polyethylene resin, polybutene resin, poly-4 modified with diethyl maleate, acrylic acid, methacrylic acid, tetrahydrophthalic acid, glycidyl methacrylate, hydroxy methacrylate, etc.
-Methylpentene resin and the like. The modification amount of the polybasic acid anhydride is 0.1 to 20 wt%, and the addition amount is 1 to 10 parts by weight. It is preferable that the amount of modification and the amount of addition are large, but the amount of addition of the modified polyolefin is determined in consideration of the effect in consideration of economy. The method of kneading is not particularly limited, and examples thereof include a blender, a kneader, a mixing roll, a Banbury mixer, a single-shaft or twin-shaft granulator, and the like. For example, the set temperature of the kneading zone is set to 150 ° C. to 200 ° C., preferably 160 ° C.
A method of obtaining a kneaded composition at 200 ° C. can be mentioned.
When the temperature is 210 ° C. or higher, a gas is generated due to decomposition of the woody material, so that it is necessary to lower the granulation temperature. In the present invention, an inorganic filler such as talc, calcium carbonate or the like, or an organic filler such as polyester,
Various additives such as a flame retardant, a stabilizer, an ultraviolet absorber, an antioxidant, a plasticizer and the like, and a coloring agent such as a face dye can be added in addition to a polyamide fiber and the like. Also, a measure for improving MT can be achieved by using a crosslinking agent and a peroxide together.

[0005]

The molded articles which can be used in the present invention are suitable for use in many fields such as electric insulating materials, industrial parts materials and building materials. In particular, housing materials, building materials, skirting boards, surface decorative boards, door materials, outer wall materials, vanities,
Counter materials, foundation backing plates, window frames, wall materials, surrounding margins, handrails, handles, structural materials, civil engineering timber, pillars, floor pillars, decorative pillars,
Earthquake-resistant materials, wallpaper fitting ceiling materials, base materials, tatami mats, floors, concrete panels, scaffolding materials, shielding boards, sound insulation boards, furniture box ceilings,
Door, front board back board, shelf board, sleeve board, curtain board, deck, back board, seat board,
Kitchen parts, waterproofing materials, antifungal materials, preservatives, shutter boards, sleeve boards,
Hips, side plates, bath units, floor pans, bus ceilings, bath walls, baths, tubs, porcelain appliances, toilet seats, toilet lids, home appliances, radio TV receivers, cabinets, stereo cabinets, amplifier cabinets, speakers, piano organs Useful for parent boards, large roofs, rolled roofs, upper and lower scroll boards, etc. Further, the present invention has an advantage that wood materials and unused wood materials as industrial wastes in the wood industry can be effectively used, and is extremely industrially effective.

[0006]

Next, an embodiment of the present invention will be described. << Method of Manufacturing Composition >> Biaxial extruder (TEX30, manufactured by Nippon Steel Works Co., Ltd.) Barrel setting temperature: 160 ° C. At 110 rpm screw speed, the resin temperature was set to 180 ° C. at the extruder outlet. Extrusion kneading amount: 6 kg / 1 hour Raw materials are uniformly mixed in advance using a Henschel mixer at room temperature, and then granulated. << Press sheet molding method for evaluating physical properties >> A hot-press molding machine is used. 70-ton press molding machine manufactured by Shinto Metal Industry Co., Ltd. Heating temperature 180 ° C Preheating time 5 minutes Pressing pressure 50kgf / cm ² Heating compression time 5 minutes Cooling time 5 minutes 50kgf / cm ² Temperature 23 ° C Molded sheet thickness 2mm << Physical properties Measurement method for evaluation >> MFR 190 ° C., 2.16 kg load Tensile strength ASTM D 638 Flexural strength ASTM D 638 Flexural modulus ASTM D 638 Izod impact strength ASTM D 256 Evaluation of formability L-shaped molded product with 50 mm extruder Were prototyped, and the moldability and appearance were evaluated. Molding temperature 190 ° C

[0007]

Example 1 Polypropylene (MFR 0.5 g / 10
Min, homopolypropylene, specific gravity 0.91) 1.75k
g, intrinsic viscosity in decalin solvent at 135 ° C is 10 dl / g
0.75 kg of polyethylene (consisting of 70% by weight of a polyethylene resin having an intrinsic viscosity of 1 to 3 dl / g and 30% by weight of an ultrahigh molecular weight polyethylene resin having an intrinsic viscosity of 25 to 35)
And wood flour 2.5kg, modified polypropylene (maleic acid addition 3wt%) (135

℃, in decalin solvent

[Η] = 0.5 dl / g) 100 g of the mixture was stirred at room temperature with a Henschel mixer for 3 minutes and blended.
A mixed composition was obtained at an extrusion rate of 6 kg / hour at ℃.
The resin temperature at the die outlet at this time was 190 ° C. The above mixed composition was molded by a press sheet molding method, and the obtained molded article was measured for tensile strength, flexural strength, flexural modulus and impact strength, and the results are shown in Table 1. In addition, Tanabe Seisakusho 5
An L-shaped molded product was molded at a molding temperature of 190 ° C. using a 0 mm extruder. The appearance and moldability were evaluated.

[0009]

Example 2 The same operation as in Example 1 was performed except that (A) 1.25 kg of a polypropylene resin and (B) 1.25 kg of a polyethylene resin. Table 1 shows the results.

[0010]

Example 3 The same operation as in Example 1 was performed except that (A) 2.0 kg of polypropylene and (B) 0.5 kg of polyethylene resin. Table 1 shows the results.

[0011]

Comparative Example 1 The same operation as in Example 1 was performed except that (A) polypropylene of MFR (10 g / 10 min) and (B) 0.5 kg of polyethylene resin of MFR (5 g / 10 min) were used. As a result, no satisfactory molded product was obtained in which the surface roughness and creaking in the extrusion molding were remarkable.

Claims (1)

[Claims] 1. A melt flow rate (MFR; ASTM D1238) at 230 ° C. under a load of 2.16 kg.
(B) an ultrahigh molecular weight polyethylene having an intrinsic viscosity of 10 to 40 dl / g measured at 135 ° C. in a decalin solvent; 15 to 40% by weight of the ultra-high molecular weight polyethylene is 0.1 to 5.0 dl / g.
(D) a modified polyolefin resin having a polybasic anhydride modification amount of 0.1 to 20% by weight; a polyethylene resin having an intrinsic viscosity of 3.5 to 15 dl / g consisting essentially of a low molecular weight to high molecular weight polyethylene; With respect to 1 to 10 parts by weight and 100 parts by weight of (A) + (B), (C) a lignocellulose-based material and a cellulosic-based material were added to ((A) +
(B)) / (C) is added in a weight ratio of 90/10 to 30/70.