JP3032884B2 - Cellulose-based composite resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cellulosic composite resin composition.

[0002]

2. Description of the Related Art Hitherto, as a cellulosic composite resin composition, a composite resin composition comprising an unmodified polyolefin resin, a cellulosic material and a modified polyolefin resin has been known (for example, JP-A-62-39642). ).

[0003]

However, the conventional cellulose-based composite resin composition has a problem that the mechanical properties are not sufficient.

[0004]

Means for Solving the Problems In view of the above problems, the present inventors have conducted intensive studies to obtain a cellulosic composite resin having good mechanical properties, and as a result, have reached the present invention.

[0005] That is, the present invention relates to an MF based on mass.
100 parts of unmodified polyolefin resin (A) having R of 0.1 to 300, and cellulose-based material (B) 20 to 150
Parts, 0.1 to 15 parts of an oxide (C) of an alkali metal and / or alkaline earth metal, and a number average molecular weight of 700
Acid modified low molecular weight polyolefin resin (D) obtained by acid modification of low molecular weight polyolefin (d1)
It is a composite resin composition consisting of 0.1 to 15 parts.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The unmodified polyolefin resin (A) in the present invention includes an ethylene-based polymer [high-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene and at least one other vinyl compound (for example, α
-Copolymers with olefins, vinyl acetate, methacrylic acid, acrylic acid, etc.), propylene polymers [polypropylene, copolymers of propylene with one or more other vinyl compounds, etc.], ethylene / propylene Examples include polyolefins such as copolymers, polybutene, and poly-4-methylpentene-1. Among these, polyethylene, polypropylene and ethylene / propylene copolymer are preferred. The MFR (melt flow rate; JIS K7210) of (A) is usually 0.1 to 300, preferably 0.1 to 100. If the MFR is less than 0.1 or more than 300, the moldability is reduced and it is not practical.

The cellulosic material (B) used in the present invention includes corn starch, paper, pulp, wood flour, straw, rice hull, crushed waste paper, cardboard and the like. The shape of (B) may be any shape, but it is preferable that the shape has been reduced by passing through a wire mesh of at least 10 mesh. The water content of the cellulosic material (B) is controlled to 15% by mass or less, preferably 10% by mass or less.

In the present invention, the alkali metal or alkaline earth metal oxide (C) is one or two selected from lithium oxide, sodium oxide, potassium oxide, cesium oxide, magnesium oxide, calcium oxide and barium oxide. The above mixture is used. Of these, preferred are sodium oxide, potassium oxide,
Calcium oxide and mixtures of two or more of these. By mixing (C), foaming components such as moisture contained in the cellulosic material can be reduced, and mechanical properties such as flexural modulus of the molded product can be improved.

The low molecular weight polyolefin resin (d1) constituting the acid-modified polyolefin resin (D) in the present invention
Examples include ethylene polymers [high-density polyethylene, medium-density polyethylene, low-density polyethylene, copolymers of ethylene with one or more other vinyl compounds (eg, α-olefin, vinyl acetate, methacrylic acid, acrylic acid, etc.). Polymers, etc.], propylene-based polymers [polypropylene, copolymers of propylene with one or more other vinyl compounds, etc.],
Ethylene propylene copolymer, polybutene and poly-
And polyolefins such as 4-methylpentene-1. Among these, polyethylene, polypropylene and ethylene / propylene copolymer are preferred.

The number average molecular weight of the (d1) GPC method is usually 70,000 or less, preferably 700 to 20,
000. If it is less than 700, the strength of the composite resin decreases, and if it exceeds 70,000, the amount of the unsaturated dicarboxylic acid and / or anhydride (d2) added becomes small, so that the performance is inferior. The (d1) can be obtained by a polymerization method or a thermal degradation method, but the one produced by the thermal degradation method is preferable in that the added amount of (d2) can be increased.

As an example of the method for producing a low molecular weight polyolefin (d1) by the above thermal degradation method, the number average molecular weight is 70,
000 to 200,000 or more high molecular weight polyolefin resin in an inert gas, usually 300 to 4
A method of thermally degrading at 50 ° C. for 0.5 to 10 hours (for example, a method described in Japanese Patent Application Laid-Open No. 3-62804) can be mentioned.

The amount of double bonds per 1,000 carbon atoms in (d1) is usually 0.2 to 5 or more, preferably 0.5 to 4. When the number is less than 0.2, the addition of the unsaturated dicarboxylic acid or its anhydride (d2) becomes insufficient,
Poor performance.

The unsaturated dicarboxylic acid or its anhydride (d2) used for the modification of (d1) includes dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid, and anhydrides thereof. Among them, particularly preferred is maleic anhydride.

As an example of the method for producing the acid-modified polyolefin resin (D), an unsaturated dicarboxylic acid and / or its anhydride (d2) may be added to a low molecular weight polyolefin (d1) in the presence of an organic peroxide, if necessary, by a solution method or A method in which the reaction is performed by any of the melting methods. The added amount of (d2) in (D) is usually 0.2 to 20% by mass, preferably 1 to 20% by mass based on the mass of (D).

The composite resin composition of the present invention comprises (A)
It is obtained by mixing (B), (C) and (D) simultaneously or sequentially. The mixing temperature is a temperature at which (A) and (D) melt, and is usually 50 to 250 ° C, preferably 90 to 220 ° C. If the temperature is lower than 50 ° C., a sufficient mixed state cannot be obtained.

The mixing ratio of (A), (B), (C) and (D) is based on the mass,
(B) 20 to 150 parts, (C) 0.1 to 15 parts,
(D) is 0.1 to 15 parts, preferably (A) 10
(B) 20 to 100 parts, (C) 0.1
To 5 parts, and (D) is 0.8 to 8 parts. (B) is 150
If the amount is more than 10 parts, the fluidity of the composite resin composition is reduced and molding becomes difficult. (C) exceeds 15 parts or 0.1
If the amount is less than the part, the mechanical properties of the resin are undesirably reduced. If (D) exceeds 15 parts, the heat resistance of the composite resin composition decreases, and if it is less than 0.1 part, there is no effect of the addition and neither is preferable.

The method of mixing (A), (B), (C) and (D) may be carried out by using an apparatus used for producing an ordinary composite resin. These devices include:
For example, a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, a kneader ruder, and a combination of two or more of these are exemplified.

In addition, other known resin additives can be optionally added to the resin composition of the present invention according to various uses, as long as the properties of the composition are not impaired. Examples of the additives include pigments, dyes, fillers, nucleating agents, glass fibers, lubricants, plasticizers, release agents, antioxidants, flame retardants, and ultraviolet absorbers.

[0019]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. “Parts” and “%” in the examples are parts by mass and mass%, respectively.

Production Example 1 90 parts of polypropylene (ethylene random copolymer type) having a number average molecular weight of 4000 obtained by thermal degradation and 10 parts of maleic anhydride were melted at 180 ° C., and 2 parts of dicumyl peroxide was dissolved. A 50% xylene solution was added dropwise over 15 minutes, and after aging for 1 hour, the solvent was removed to obtain an acid-modified polyolefin resin (D-1) having a maleic anhydride content of 9.3%.

Production Example 2 A number average molecular weight of 18,000 was obtained in the same manner as in Production Example 1.
An acid-modified polyolefin resin (D-2) having a maleic anhydride content of 4.1% was obtained from the above polypropylene (homo type).

Production Example 3 In the same manner as in Production Example 1, an acid-modified polyolefin resin (D-3) having a maleic anhydride content of 5.2% was obtained from low-density polyethylene having a number average molecular weight of 3000.

Production Examples 4 to 6 Cellulose-based material pieces shown in Table 1 were finely pulverized with a pulverizer and selected with a wire mesh having an aperture of 10 mesh.
And dried for 12 hours in a cellulosic material powder (B
-1) to (B-3) were obtained.

[0024]

Table 1------------------------Production example Raw material Product moisture------------------------------------------------------------- −−−−− 4 Newspaper B-1 3% 5 Wood chip B-2 6% 6 Rice husk B-3 4% −−−−−−−−−−−−−−−−−−−−−−−−−

Examples 1 to 7, Comparative Examples 1 to 5 Predetermined parts by weight of each component shown in Tables 2 and 3 were added to a kneader and kneaded to obtain pellets of a composite resin composition. After preparing a predetermined test piece with an injection molding machine using these pellets, evaluation of resin properties was performed. The evaluation method is as follows. Flexural modulus; according to JIS K7203 Tensile strength: according to JIS K7113

[0026]

Table 2 Composite resin composition Resin physical properties---------------------------- −−−−−−−−−−−−−−−−−−−−−−−−−−−− Component (A) (B) (C) (D) Flexural modulus Tensile strength Mixing ratio 100 100 5 6 (MPa) (MPa) (parts by mass) −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Example 1 PP− 1 B-1 CaO D-1 5600 49 2 PP-1 B-1 CaO D-2 5500 52 3 PP-1 B-2 CaO D-1 4700 38 4 PP-1 B-3 CaO D-1 4600 36 5 LDPE B-1 CaO D-3 1100 22 6 PP-2 B-1 CaO D-1 5500 48 −−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−− Comparative Example 1 PP-1 B-1 None None 5000 25 2 PP-1 B-2 None None 4100 24 3 PP-1 B-3 None None 4200 24 4 PP-1 B-1 None D-1 5300 38 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ------ Table in PP-1: MFR10 polyps Ropi Len resin (homo-type) PP-2: MFR10 polyps Ropi Len resin (ethylene Koh Bu beam copolymer type) LDPE: MFR9 low density po Riechiren resin CaO: Calcium oxide

[0027]

Table 3 Composite resin composition Resin physical properties------------------------------------ −−−−−−−−−−−−−−−−−−−−−−−−−−−−− Components (A) (B) (C) (D) Flexural modulus Tensile strength Mixing ratio 100 25 2 2 (MPa) (MPa) (parts by mass) −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Example 7 PP− 1 B-1 CaO D-1 2500 31 Comparative Example 5 PP-1 B-1 None None 2200 25 −−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−− PP-1 in the table: Polyfluororesin resin of MFR10 (homo type) CaO: Calcium oxide

[0028]

The cellulosic composite resin composition of the present invention has excellent mechanical properties as compared with conventional ones. Because of the above effects, the resin composition of the present invention
Housing for OA equipment, automotive parts, building boards,
It can be suitably used as various molding materials such as plastic containers for daily use.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 23:26)

Claims (4)

(57) [Claims] 1. MFR is 0.1 to 30 based on mass
0 unmodified polyolefin resin (A) 100 parts, cellulosic material (B) 20-150 parts, alkali metal and / or alkaline earth metal oxide (C) 0.1-1
A composite resin composition comprising 5 parts and 0.1 to 15 parts of an acid-modified low molecular weight polyolefin resin (D) obtained by acid-modifying a low molecular weight polyolefin (d1) having a number average molecular weight of 700 to 20,000. 2. The composite resin composition according to claim 1, wherein (D) is an acid-modified low molecular weight polyolefin obtained by modifying (d1) with an unsaturated dicarboxylic acid and / or an anhydride thereof (d2). 3. The method according to claim 1, wherein (d1) is obtained by thermally degrading a high molecular weight polyolefin, and has at least 0.2 double bonds per 1000 carbon atoms.
Or the composite resin composition of 2 above. 4. The composite resin composition according to claim 2, wherein (d2) is maleic anhydride.