JPH0347285B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a composite resin composition, and more specifically, a molded article obtained using the composition has excellent mechanical properties and good transparency, smoothness, gloss, etc. and furniture, including films and sheets.
This invention relates to a method for producing a composite resin composition that can be effectively used for building materials, automobiles, interior materials for home appliances, housings, etc. [Prior art and problems to be solved by the invention] Cellulose-based materials such as wood and pulp have low thermoplasticity, especially when powdered.
It has been difficult to hot press mold the material itself 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. In view of these circumstances, various studies are being carried out regarding advanced utilization of cellulose-based materials. For example, it has been proposed to knead thermoplastic resin and wood flour and use it as a molding material. However, the thermoplastic resins that can be used are limited due to factors such as the pyrolysis onset temperature of wood and prices, and there are problems with compatibility with wood, adhesion, etc., and the resulting products are mechanically difficult to use. In addition to the properties, the appearance such as surface smoothness and surface gloss was also insufficient. [Means for Solving the Problems] Therefore, as a result of repeated research in order to solve the above problems, the present inventors grafted a modified polyolefin onto a cellulose-based material and then carried out esterification, etherification and It has been discovered that a composite resin composition that provides molded products with excellent mechanical properties as well as good transparency, smoothness, and gloss can be obtained by chemically modifying one of the methods of halogenation, and based on this knowledge, Based on this, the present invention was completed. That is, the present invention involves grafting a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof onto a cellulosic material containing at least cellulose, and then subjecting the resulting product to any one of esterification, etherification, and halogenation. The present invention relates to a method for producing a composite resin composition characterized by carrying out modification. In the present invention, the cellulosic material containing at least cellulose includes 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 (abbreviated as RGP), paper pulp, waste paper,
Examples include wood flour, fruit flour, and various celluloses. Here, the wood flour includes crushed products of pine, fir, poplar, Scots pine, etc., sawdust, and canna shavings, and the fruit flour includes crushed products of fruits such as walnuts, peanuts, and palm. 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 the fibers.
Considering the complexity of the work, economic efficiency, etc., it is usually 20~
A piece of about 400 mesh is used. Also,
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. Note that cellulose may be partially chemically modified, for example, by esterification using acid halides, acid anhydrides, etc., or etherification using various olefin oxides, organometallic compounds, etc. It can be something. When cellulose is partially chemically modified, the affinity and
Adhesion becomes good. Next, as a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof (simply referred to as modified polyolefin), (a) a polyolefin, an unsaturated carboxylic acid or a derivative thereof, and a radical generator are mixed in the presence of a solvent or (b) those obtained by heating and mixing polyolefin, an unsaturated carboxylic acid or its derivative, an elastomer, and a radical generator in the presence or absence of a solvent, etc. can be mentioned. In the present invention, the amount of unsaturated carboxylic acid or its derivative added is preferably 0.1 to 14% by weight, particularly 0.5 to 10% by weight in any of the various modified polyolefins. Any polyolefin may be used as a raw material for the modified polyolefin, such as monoolefin polymers such as low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, polybutene, poly-4-methylpentene-1, etc., or ethylene. -Propylene copolymers or mixtures of these polymers are preferably mentioned. As the modified polyolefin, a mixture of a modified polyolefin and an unmodified polyolefin can also be used. In this case too, 0.1 to 14 unsaturated carboxylic acids or derivatives thereof are present in the mixture.
It is preferable to adjust the amount by weight, particularly from 0.5 to 10 weight%. 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 dicarboxylic acid half esters such as 4-polybutadiene or 1,2-polybutadiene with a number average molecular weight of 500 to 10,000 without functional groups, 1,4
Examples include polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, pyrolyzed rubber, ozonolyzed rubber, and mixtures of the elastomers listed above. 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. The unsaturated carboxylic acid and its derivatives used in this modified polyolefin may be one or more of the aforementioned unsaturated carboxylic acids and derivatives thereof. The radical generator may be one that promotes the reaction between the polyolefin, an elastomer blended as necessary, and an unsaturated carboxylic acid or its derivative, such as benzoyl peroxide, lauryl peroxide, azobisisobutyronitrile. , cumene peroxide, α,α′-bis(t-butylperoxydiisopropyl)benzene, di-
T-butyl peroxide, 2,5-di(t-butylperoxy)hexane, etc. can be suitably used. 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 polyolefin 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, hebutane, or monochlorobenzene. Various types of unmodified polyolefins can be used, such as polypropylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear polyethylene, polybutene,
Preferred examples include monoolefin polymers such as poly-4-methylpentene-1, ethylene-propylene copolymers, ethylene-vinyl chloride copolymers, propylene-vinyl chloride copolymers, and mixtures of these polymers.
In addition, lubricants, antioxidants, colorants,
Additives such as antistatic agents and plasticizers can be added as appropriate. The reaction of grafting the modified polyolefin onto the cellulose material described above is carried out using cellulose materials 5 to 90.
It is added at a ratio of 95 to 10 parts by weight, preferably 90 to 20 parts by weight, to the modified polyolefin, preferably 10 to 80 parts by weight, and heated to a temperature of 140 to 200°C, preferably 150°C.
~190℃ temperature for 10-30 minutes, preferably 15-20
Just knead for a minute. In addition, kneading is done by a known method,
For example, a mixer such as a Banbury mixer or a Henschel mixer, a kneader, or various extruders may be used. Also, dimethylformamide,
It may be kneaded in a solvent such as dimethyl sulfoxide. This grafting reaction is due to ester bonds between the hydroxyl groups of the cellulosic material and the carboxyl groups in the modified polyolefin, and if necessary a catalyst to enhance the esterification (e.g. sodium carbonate, N,N-dimethylbenzylamine, triethylamine) is used. , pyridine, etc.) may be added to carry out the reaction. Grafting improves the compatibility between the two and improves their physical properties. The resulting product is then chemically modified. Chemical modification includes esterification using acid halides and acid anhydrides, etherification using various olefin oxides and organometallic compounds, and halogenation using halogens and hydrogen halides. In carrying out chemical modification, a solvent such as dimethylformamide, dimethyl sulfoxide, trifluoroacetic acid, etc. may be used. Esterification includes acetylation, lauroylation, etc., etherification includes ethylation, propylation, allylation, benzylation, carboxylation, hydroxyethylation, etc., and halogenation includes chlorination, bromination, etc. . A molded article can be manufactured by applying various molding means to the composite resin composition obtained in this way. [Effects of the Invention] According to the present invention, a composite resin composition useful as a molding material can be produced using a cellulose material that has not been fully utilized in the past. Molded articles obtained using this composite resin composition have outstanding mechanical properties such as tensile strength, tensile elongation at break, and tensile modulus, and are also excellent in smoothness, gloss, and transparency. Therefore, this composite resin composition is used in various fields as various films and sheets, as well as in furniture, building materials (surface finishing materials, structural materials, etc.), automobiles,
It can be effectively used as a material for interior materials, housings, etc. of home appliances, acoustic materials, etc. [Example] Next, the present invention will be explained in detail with reference to Examples. Examples 1 to 5 A predetermined amount of RGP (radiata pine produced in New Zealand was stirred for 1 minute using deionized water in a home appliance mixer) in a kneader (manufactured by Toyo Seiki, Laboplasto Mill) whose temperature was adjusted to 160°C. After disentangling the fibers, the fibers were collected, washed with methanol, then washed with ether, and dried) and kneaded at 90 rpm for 10 minutes. Next, a predetermined amount of maleic anhydride-modified polypropylene ("H1000P", manufactured by Idemitsu Petrochemical Co., Ltd.) was added to this and kneaded for 30 minutes. The obtained kneaded product of RGP and modified polypropylene was pretreated with an acetic acid-tetralin solution, and then heated at 140°C using acetic anhydride as an acetylating agent, potassium acetate as a catalyst, and tetralin as a solvent.
Acetylation was achieved by reacting for 24 hours. The composite resin composition thus obtained was pressure molded at 170°C to produce a 0.3 mm thick film. The physical properties of this film were evaluated by the following method.
The 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. ○...Very good △...Slightly cloudy ×...Poor comparative examples 1 to 5 Unmodified polypropylene (melt index 30g/10min., density
0.90g/ ^cm3 , "J-3050H" manufactured by Idemitsu Petrochemical Co., Ltd.)
The same procedure as in Examples 1 to 5 was carried out except that the acetylation reaction was omitted. The results are shown in Table 1. Example 6 A film was obtained in the same manner as in Example 3 except that wood flour (200 mesh) was used instead of RGP, and its physical properties were evaluated. The results are shown in Table 1. Comparative Example 6 The same procedure as in Example 6 was carried out except that unmodified polypropylene (same as Comparative Examples 1 to 5) was used instead of modified polypropylene and the acetylation reaction was omitted. The results are shown in Table 1. Examples 7 to 11 To 120 g of a graft body made of RGP and modified polypropylene obtained in the same manner as in Examples 1 to 5,
After pretreatment by adding 180 ml of 40% aqueous sodium hydroxide solution, 324 ml (2.28 mol) of benzyl chloride
was added, and benzyl etherification was carried out in an autoclave at 110°C for 2 and a half hours. Note that the reaction was stopped by adding methanol. In addition, wash thoroughly using deionized water and methanol alternately, and after collection, wash at 60°C.
The mixture was dried in a hot air dryer for about 2 days and then in a vacuum dryer at room temperature for one day and night to obtain an etherified product. Hereinafter, films with a thickness of 0.3 mm were produced in the same manner as in Examples 1 to 5, and their physical properties were evaluated. Results first
Shown in the table. Examples 12 to 16 Acetylated grafts of RGP and modified polypropylene obtained in the same manner as Examples 1 to 5 were further treated with chlorine water with a chlorine concentration of 0.1 to 0.2% at room temperature for 10 minutes. , the chlorinated product was obtained. Even with such mild chlorination, the melt fluidity of the composition is significantly increased and the moldability is improved. Hereinafter, films with a thickness of 0.3 mm were produced in the same manner as in Examples 1 to 5, and their physical properties were evaluated. Results first
Shown in the table.

【table】

[Table] Reference example RGP and modified polypropylene (same as Examples 1 to 5) or unmodified polypropylene (Comparative Examples 1 to 5)
5) were kneaded at a predetermined weight ratio under predetermined conditions, and for each of them, an attempt was made to Soxhlet extract the polypropylene fraction that had not been graft-polymerized to RGP with xylene for a long time (48 hours). The weight loss rate due to xylene extraction was determined by the following method. The results are shown in Table 2. Weight reduction rate (%) = M-N/M×100 M: Total weight of RGP and modified or unmodified polypropylene N: Weight of the residue after extracting the kneaded material with xylene As is clear from the table, RGP and unmodified polypropylene Polypropylene is completely removed from polypropylene kneaded materials by xylene extraction, whereas RGP
In the case of a kneaded product of modified polypropylene and modified polypropylene, a portion of the modified polypropylene remains in the residue. This was confirmed by IR analysis of the extraction residue. In other words, no absorption peak derived from polypropylene is observed in the extraction residue from the mixture of RGP and unmodified polypropylene, but the spectrum of the extraction residue from the mixture of RGP and modified polypropylene shows an absorption peak of 1820 cm.
Absorption peaks derived from polypropylene are observed at ^-1 and 1890 cm ^-1 . Furthermore, when films obtained by molding each of these two types of kneaded products were stained with safranin and observed under an optical microscope, differences were observed between the two. That is, in the film obtained from a mixture of RGP and unmodified polypropylene, coarse safranin-dyed RGP exists in the continuous phase of polypropylene, whereas in the film obtained from a mixture of RGP and modified polypropylene, RGP is finely dispersed. It was observed that the compatibility between RGP and modified polypropylene was improved. From the above results, it was confirmed that grafting occurred partially in the kneaded product of RGP and modified polypropylene.

【table】

Claims (1)

[Claims] 1. A polyolefin modified with an unsaturated carboxylic acid or a derivative thereof is grafted onto a cellulose-based material containing at least cellulose, and the resulting product is then subjected to any one of esterification, etherification, and halogenation. 1. A method for producing a composite resin composition, which comprises chemically modifying the composition. 2. The method according to claim 1, wherein the cellulosic material is either cellulosic fiber or lignocellulosic fiber. 3. The method according to claim 1, wherein the modified polyolefin is maleic anhydride-modified polypropylene.