JPH0347286B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a new graft body, and more specifically, to improve the mechanical strength, surface smoothness, and
The present invention relates to a method for producing a new graft body that improves surface gloss and imparts transparency to resin molded products. [Prior art and problems to be solved by the invention] Cellulose-based materials such as wood and pulp are difficult to thermoplasticize, and it has been difficult to thermo-press them into boards, sheets, etc. . Therefore, the use of wood powder and the like is limited to fields with low added value such as agricultural materials and fillers, and the current situation is that wood powder is not used at all and is incinerated. Therefore, various studies are underway regarding the advanced utilization of such cellulose-based materials. For example, a molding material made by melting and kneading a thermoplastic resin and wood flour is known, but its dispersibility, compatibility, and adhesiveness are insufficient. Therefore, sufficient mechanical strength, surface smoothness, and surface gloss have not been obtained. The present invention solves the above-mentioned problems and also provides a method for producing a new graft body that imparts excellent transparency to resin molded products. [Means for solving the problem] That is, the present invention grafts a modified polyolefin modified with an unsaturated carboxylic acid or a derivative thereof (component (B)) to a cellulose-based material containing at least cellulose (component (A)). The present invention provides a method for producing a novel graft body characterized by the following. In the present invention, it contains at least cellulose,
Cellulose-based materials include organic fibers consisting only of cellulose and organic fibers containing other components in addition to cellulose. For example, there are cellulose fibers, lignocellulose fibers, etc., specifically wood pulp, refiner, ground pulp (RGP), paper pulp, waste paper, pulverized wood chips,
Examples include wood flour, fruit flour, and various celluloses. As described above, the shape of the cellulose material in the present invention is not particularly limited, and may be fibrous, granular,
Cellulose-based materials such as powder can be used. Moreover, pulverized wood pulp, waste paper, etc. can also be used if necessary. Wood flour includes crushed products such as pine, fir, poplar, and Scots pine, sawdust, and canna shavings, and fruit flour includes crushed products of fruits such as walnuts, peanuts, and coconut. In addition, various types of cellulose include alpha fiber flock obtained by treating wood pulp with alkali and mechanically shredding it, cotton linters and cotton flock obtained from cotton seeds, and human silk flock obtained by shredding human silk. Among these, it is particularly preferable to use RGP and wood flour. In addition, when using wood flour, it is preferable to make it as fine as possible to eliminate entanglement between fibers, but it is difficult to work with,
Considering economic efficiency, etc., one having a capacity of about 20 to 400 meshes is usually used. Furthermore, even when RGP is used, it is preferable to use one that has been stirred with deionized water to loosen the entanglements between the fibers. In the present invention, cellulose may be partially chemically modified, such as esterification with lower or higher fatty acids such as acetylation and lauroylation; ethylation, propylation, allylation, benzylation, It may be modified by etherification such as carboxylation and hydroxylethylation; halogenation such as chlorination and bromination. Next, in the present invention, a modified polyolefin obtained by modifying a polyolefin with an unsaturated carboxylic acid or a derivative thereof is used as the component (B). Examples of modified polyolefins include (a) polyolefins obtained by heating and mixing polyolefins, resins, unsaturated carboxylic acids or derivatives thereof, and radical generators in the presence or absence of a solvent; (b) polyolefins Examples include those obtained by heating and mixing a resin, an unsaturated carboxylic acid or a derivative thereof, an elastomer, and a radical generator in the presence or absence of a solvent. In this invention, the amount of unsaturated carboxylic acid or its derivative added in any of the various modified polyolefins is preferably 0.1 to 14% by weight, particularly 0.5 to 10% by weight. The polyolefin resin that serves as the raw material for the modified polyolefin may be of any type, such as low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene,
Preferred examples include monoolefin polymers such as polybutene and poly-4-methylpentene-1, ethylene-propylene copolymers, and mixtures of these polymers. The elastomer is preferably a polymer containing a diene monomer as a main component and having a number average molecular weight of 500 to 10,000, and exhibits fluidity at room temperature. Examples of this include carboxyl groups, hydroxyl groups,
1,2- containing functional groups such as mercapto groups, halogen atoms, amino groups, aziridino groups, and epoxy groups
Polybutadiene, 1,4-polybutadiene, polyisoprene, polychloroprene, 1,2-polypentadiene, styrene-butadiene copolymer,
Elastomers such as acrylonitrile-butadiene copolymer, butadiene-isoprene copolymer, butadiene-pentadiene copolymer and terminally hydroxylated 1,2-polybutadiene, 1,
Unsaturated carboxylic acid half esters such as 4-polybutadiene or number average molecular weight without functional groups
500-10000 1,2-polybutadiene, 1,4-
Examples include polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, pyrolyzed rubber, ozonolyzed rubber, and mixtures of the above-mentioned elastomers. Examples of the unsaturated carboxylic acids or derivatives thereof include maleic acid, nadic anhydride, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, mesaconic acid, angelic acid, sorbic acid,
Acrylic acid, maleic anhydride, itaconic anhydride,
Citraconic anhydride and the like are preferred, and maleic anhydride is particularly preferred. Further, as the derivative of the unsaturated carboxylic acid, metal salts, amides, imides, esters, etc. of the unsaturated carboxylic acid can be used. Incidentally, as the unsaturated carboxylic acid and its derivatives used in this modified polyolefin, one or more of the above-mentioned ones can be used. The radical generator may be one that promotes the reaction between the polyolefin resin, an elastomer blended as necessary, and an unsaturated carboxylic acid or a derivative thereof, such as benzoyl peroxide, lauryl peroxide, azobisisomer, etc. Butyronitrile, cumene peroxide, α,α'-bis(t-butylperoxydiisopropyl)benzene, di-t-butylperoxide, 2,5-di(t-butylperoxy)hexane, etc. are preferably used. can do. Among these various modified polyolefins, in particular, polyethylene and/or polypropylene with a melt index (hereinafter abbreviated as MI) of 0.5 to 200 g/10 minutes, maleic anhydride, and terminal hydroxylated polybutadiene are combined with xylene,
Preferred is a resin to which 0.5 to 10% by weight of maleic anhydride is added, which is obtained by reaction using a radical generator such as benzoyl peroxide in a solvent such as toluene, heptane, or monochlorobenzene. The blending ratio of the above (A) component and (B) component is (A) component 10 to 95
The amount of component (B) is 5 to 90% by weight, preferably 10 to 85% by weight relative to the weight of component (B), preferably 15 to 90% by weight.
Here, if the content of component (A) exceeds 95% by weight, the rigidity decreases, which is not preferable. In addition, if the amount of component (A) is less than 10% by weight, strength, transparency, and glossiness decrease, which is not preferable. The novel graft body targeted by the present invention is obtained by kneading and grafting the above-mentioned components. That is, by kneading the above-mentioned components, a grafting reaction is caused by ester bonds between the hydroxyl groups of cellulose and the carboxyl groups of the modified polyolefin resin. The kneading may be carried out using a conventionally known method, such as a mixer such as a Banbury mixer or a Henschel mixer, a kneader, or various extruders. Further, the kneading may be performed in a solvent. In any case, it is preferable to conduct the heating under moderate heating. In addition, kneading is carried out at 140 to 200℃ using a kneader or Banbury mixer, for example.
It is preferably carried out at a temperature of 150 to 190°C for 10 to 30 minutes, preferably 15 to 20 minutes. In addition, the rotation speed of the kneader etc. at this time is usually 50 to 200 rpm, preferably
70~150rpm. During kneading, a catalyst that enhances the grafting reaction can be added if necessary. Examples of the catalyst include carbonates, oxides, hydroxides, carboxylates of alkali metals or alkaline earth metals, amine compounds such as N,N-dimethylbenzylamine and triethylamine, pyridine, dimethylaniline, etc. can be added. The novel graft material targeted by the present invention is obtained by grafting a modified polyolefin modified with an unsaturated carboxylic acid or a derivative thereof onto a cellulose-based material containing at least cellulose. There is no particular restriction on the proportion, but it is usually 3% by weight or more,
Preferably it is 4% by weight or more. If the grafting ratio is low, the thermoplasticity of the cellulose material and the dispersibility and compatibility with the thermoplastic resin will be insufficient, which is not preferable. Various molded products can be produced by molding the resin composition containing the novel graft body obtained in this way into an appropriate shape by means such as pressure molding, film molding, extrusion molding, and injection molding. [Effects of the Invention] The molded article of the resin assembly containing the new graft body obtained by the method of the present invention has extremely excellent mechanical strength, and also has excellent transparency, smoothness, and
It has luster. Therefore, molded products containing the novel graft body obtained by the method of the present invention can be used as materials for film and sheet materials, furniture, building materials (surface finishing materials, structural materials), automobiles, housings for home appliances, interior materials, acoustic materials, etc. It is effectively used as [Example] Hereinafter, the present invention will be explained in detail with reference to Examples. Preparation Example 1 Preparation of RGP New Zealand radiata pine and dehydrated ionized water were stirred in a home appliance mixer for 1 minute to loosen the fibers, and then collected by filtration and mixed with methanol,
By then washing with ether and drying
Got RGP. Preparation Example 2 Preparation of acetylated RGP RGP obtained in Preparation Example 1 was pretreated with tetralin acetate solution, and reacted at 140°C for 24 hours using acetic anhydride as an acetylating agent, potassium acetate as a catalyst, and tetralin as a solvent. Acetylated RGP by
I got it. Preparation Example 3 Preparation of Acetylated Wood Flour Acetylated wood flour was obtained in the same manner as in Preparation Example 2, except that 200 mesh wood flour was used instead of RGP. Preparation Example 4 Preparation of benzylated RGP 50g of RGP was dissolved in a sodium hydroxide aqueous solution (prepared with 50g of sodium hydroxide and 500ml of water) at 100~
After reacting at 102°C for 3 hours, the mixture was vacuum filtered.
Benzyl chloride (20 ml/water 0.5) was added to this filtered product and reacted at 102°C for 5 hours, followed by vacuum filtration and then dried at 80°C for 8 hours to obtain benzylated RGP. Examples 1 to 13 and Comparative Examples 1 to 6 A cellulose-based material in a predetermined proportion shown in Table 1 as component (A) was introduced into a kneader (Laboplast Mill manufactured by Toyo Seiki Co., Ltd.) whose temperature was controlled at 160°C, and the rotation speed was 90r・
After kneading for about 10 minutes at pm, add a predetermined amount of maleic anhydride-modified polypropylene (hereinafter abbreviated as MAH-modified PP) or unmodified polypropylene (hereinafter abbreviated as unmodified PP) as component (B). Kneaded for a minute. The total weight of the components (A) and (B) was 24 g, which corresponded to the capacity of the mixing section of the device. The obtained kneaded product was pressure-molded at 170°C to produce a film with a thickness of 0.3 mm. 80mm× from this film
A 5 mm rectangular specimen was prepared and its physical properties were evaluated using the following method. The evaluation results are shown in Table 1. Evaluation method 1 Tensile strength, tensile elongation at break, and tensile modulus test Measured under the conditions of a gauge distance of 40 mm and a tensile speed of 10 mm/min. 2 Transparency Color computer manufactured by Suga Test Instruments Co., Ltd.
Total light transmittance was measured using HGM-20. 3 Smoothness The surface of the specimen was visually observed and evaluated. ○...Extremely smooth △...Partially rough ×...Rough 4 Glossiness The surface of the specimen was visually observed and evaluated. ○...Extremely good △...Slightly cloudy ×...Poor comparative example 7, 8 In Example 1, the blending ratio of component (A) and (B) component was set to the specified amount shown in Table 1, and the kneading time was set to 3 minutes. The same procedure as in Example 1 was carried out except for the changes. The results are shown in Table 1. Next, the weight loss rate of the obtained film was measured, and the film obtained in Comparative Example 7 was
48.7%, and the film obtained in Comparative Example 8 had 28.1%. All of these films were opaque and had poor dispersion of cellulosic material.

【table】

[Table] Reference Example A composition obtained by kneading the same unmodified PP or MAH-modified PP and RGR as used in the Examples and Comparative Examples at the predetermined weight ratio shown in Table 2 under the predetermined conditions was grafted onto RGP. The polypropylene sections without were Soxhlet extracted with xylene for 48 hours. Table 2 shows the weight loss rate due to xylene extraction. In addition, the weight reduction rate was calculated|required by the following formula. M-N/M×100 (However, M indicates the total weight of PP or MAH-modified PP and RGP, and N indicates the weight of the extraction residue obtained by extracting the kneaded product with xylene.)

[Table] As is clear from Table 2, PP is completely removed from the kneaded mixture of RGP and PP by xylene extraction, whereas in RGP and MAH-modified PP, PP is completely removed by xylene extraction.
A portion of PP remains in the residue without being extracted. Next, the extracted residue was subjected to IR analysis. As a result, no absorption peak derived from PP was observed in the IR spectrum of the residue from the mixture of RGP and PP, whereas the spectrum of the residue from the mixture of RGP and MAH-modified PP had 1820 cm ^-1 , Absorption peaks derived from PP were observed at 1890 cm ^-1 etc. Next, mix RGP and PP, RGP and MAH modified
The films obtained by pressure molding each of the PP kneaded products to a thickness of 0.2 mm were stained with safranin and observed using an optical microscope. As a result, the film formed from the mixture of RGP and PP has rough safranin-dyed RGP in the continuous phase of PP, whereas the film formed from the mixture of RGP and MAH-modified PP has RGP. were finely dispersed. From the above results, it was confirmed that grafting occurred partially in the kneaded product of RGP and MAH-modified PP.

Claims (1)

[Claims] 1. A method for producing a novel graft material, which comprises grafting a modified polyolefin modified with an unsaturated carboxylic acid or a derivative thereof onto a cellulose-based material containing at least cellulose. 2. The manufacturing method according to claim 1, wherein the cellulose is partially chemically modified. 3. The manufacturing method according to claim 2, wherein the chemical modification is esterification, etherification, or halogenation. 4. The manufacturing method according to any one of claims 1 to 3, wherein 3% by weight or more of modified polyolefin is grafted.