JPH0229422A - Manufacture of plastic-like woody molded product - Google Patents

Abstract

PURPOSE:To produce the title molded product which can be easily molded into any shape by extrusion molding, injection molding, or the like and is excellent in mechanical strengths, by incorporating a thermoplastic resin into a composition comprising a specific oligoesterified woody material and a specific oligomer. CONSTITUTION:A composition is prepared from an oligoesterified woody material (A) (e.g. wood meal) having polymerizable double bonds and hydroxyl groups to which a polybasic acid anhydride (e.g. maleic anhydride) and a monoepoxy compound having a polymerizable double bond (e.g. acryl glycidyl ether) are alternatingly added and an oligomer (B) having a polymerizable double bond which is produced by the reaction of a polybasic acid anhydride with a monoepoxy compound having a polymerizable double bond in a blending ratio of (A) to (B) of (50:50)-(90:10). 5-40pts.wt. thermoplastic resin (C) (e.g. polyethylene oxide) is added to 100pts.wt. above composition to obtain a mixture, and the mixture is subjected to hot press molding. The mixture is good in hot press moldability and can be easily molded into any shape by extrusion molding, injection molding, or the like to give the title molded product having good mechanical strengths.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides an oligoesterified wood material (A) having a polymerizable double bond and an oligomer (B) having a polymerizable double bond.
By mixing a thermoplastic resin (C) into a composition consisting of The present invention relates to a method for producing a plastic-like wood-based molded product that can be easily formed and has good mechanical strength as a molded product.

(Conventional technology) Due to its excellent characteristics, wood has been widely used as a building material and for a variety of other purposes.Also, it is used as small diameter wood, thinned wood, and as industrial waste in the wood industry. Active research is being conducted on the effective use of wood f1 sources, which have not been used much in the past, such as by-product wood flour. Research into adding functions that wood does not originally have through modification is attracting attention.

One of these attempts is to improve the compatibility between wood flour and thermoplastic resin as extenders or fillers by introducing organic groups through a chemical reaction with the hydroxyl groups of wood flour. JP-A-56-135552). This modified wood flour makes it possible to obtain thermoplastic resin molded articles with excellent surface gloss.

The other one is 1. This research aims to mold the wood itself by introducing organic groups through a chemical reaction to the hydroxyl groups in the wood, giving it thermoplasticity that wood does not originally have. The present inventors have previously developed an oligoesterified wood material (A) in which a polybasic acid anhydride and a monoepoxy compound having a polymerizable double bond are alternately added and esterified to the hydroxyl groups of a wood material, and a polybasic acid anhydride. A method for producing wood-based molded products by hot-pressing a composition consisting of an oligomer (B) obtained by an alternating addition-esterification reaction between a monoepoxy compound having a polymerizable double bond and a monoepoxy compound having a polymerizable double bond (Patent Application No. 1983- 14224
) was proposed. In this method, not only the wood components are plasticized (but also the double bonds in the oligoesterified wood (A) and oligomer (B) polymerize and crosslink at the same time as plasticization, resulting in a dense surface). Shiny, dimensionally stable,
A wood-based molded product with excellent mechanical properties can be obtained. But 2
While.

The fluidity during the molding process was not yet sufficient for injection molding and extrusion molding, and it was difficult to obtain molded products with complex shapes. In addition, during hot press molding, cracks occur in the molded product due to heat shrinkage stress, etc., resulting in a 2-year damage.

[Problems to be solved and attempted by the invention] The present invention provides an oligoesterified wood material (A) having a polymerizable double bond and an oligoesterified wood material (A) having a polymerizable ■-single bond (
By adding and mixing the thermoplastic resin (C) to the composition consisting of Y3), the conventional drawback of moldability due to hot pressure can be improved. Furthermore, by crosslinking through polymerization of the polymerizable double bonds of the oligoesterified wood material (A) and oligomer (13) in the &J, l composition, a molded article! To provide a method for producing a dense and glossy plastic-like wood-based molded product having a mechanical strength of -7.

[Means for solving problems]

In view of the above-mentioned circumstances, the inventors of the present invention have conducted repeated research, and as a result, the present invention has developed a method in which a polybasic acid anhydride and a monoepoxy compound having a polymerizable double bond are alternately added to the hydroxyl group in the wood component. Consisting of an oligoesterified wood material (A) having a polymerizable double bond, and an oligomer (B) having a polymerizable double bond obtained from a polybasic acid anhydride and a monoebotic compound having a polymerizable double bond, and (A) and (B) above.
A mixture obtained by adding 5 to 40 parts by weight of a thermoplastic resin (C) to 100 parts by weight of a composition having a weight ratio of 50:50 to 90:10 is hot-press molded to form a wood material. The present invention relates to a method for producing a plastic-like wood-based molded article, which is characterized by carrying out crosslinking by polymerizing the double bonds of an oligoesterified wood material (A) and an oligomer (B) at the same time as plasticizing the components.

That is, to 100 parts by weight of a composition consisting of an oligoesterified wood material (A) having a polymerizable double bond and an oligomer (3) having a polymerizable double bond, 5 to 5 parts of a thermoplastic resin (C) are added.
By mixing 40 parts by weight, the mixture becomes woody during hot press molding (the fluidity of component A is greatly improved, so a molded product can be easily formed at low temperature and low pressure, and the resulting molded product has a Because of its high elongation, molded products are less likely to separate due to heat shrinkage stress during hot press molding.
and oligoesterified wood material (A) and oligomer (B)
It was discovered that crosslinking occurs due to polymerization of the double bonds in ), and a molded product having good a-mechanical strength can be obtained, and the present invention was completed.

According to the method of the present invention, by mixing a thermoplastic resin into the composition, the moldability of the mixture is greatly improved, and the molded products obtained from the mixture do not crack due to heat shrinkage stress during hot-press molding. It is dense, shiny, and has good mechanical strength as a molded product. Oligoesterified wood material with polymerizable double bonds used in the present invention (
A composition consisting of A) and an oligomer (B) having a polymerizable double bond is produced from the following raw materials. As the wood material, crushed wood such as wood powder, wood fiber, and wood chips is mainly used, and there are no particular restrictions on the raw wood or tree species. Also,
The wood materials used in the present invention include plant fibers such as straw and rice husk, and other pulverized lignocellulose materials containing cellulose and lignin as main components. Examples of the polybasic acid anhydride include maleic anhydride, phthalic anhydride, succinic anhydride, tetrahydrophthalic anhydride, hequinahydrophthalic anhydride, itaconic anhydride, het's acid anhydride, and the like. In particular, from an industrial standpoint, maleic anhydride, phthalic anhydride, succinic anhydride, etc., which are low in rank, are preferred. Examples of monoepoxy compounds having a polymerizable double bond include:
Examples include allyl glycidyl ether, glycidyl methacrylate, methallyl glycidyl ether, glycidyl acrylate, vinylcyclohexene monoepoxide, and industrially, allyl glycidyl ether and glycidyl methacrylate are particularly preferred.

The composition consisting of the oligoesterified wood material (A) having a polymerizable double bond and the oligomer (3) having a polymerizable double bond used in the present invention is obtained by adding a polybasic acid anhydride to the above-mentioned wood material and polymerizing the wood material with a polybasic acid anhydride. It is obtained by adding and heating a monoepoxidized compound 1 having a double bond. That is, the oligoesterified wood material (A) having a polymerizable double bond is produced by alternately adding a polybasic acid anhydride and a monoepoxy compound having a polymerizable double bond to the hydroxyl group in the wood component. It is something. At the same time, about 30 to 80% by weight of the polybasic acid anhydride and the monoepoxy compound having a polymerizable double bond that were subjected to this alternating addition esterification reaction was converted into an oligomer (B) having a polymerizable double bond. By-product.

In the present invention, it is preferable to use a composition having a wood content of 40 to 85% by weight, and the amount of polybasic acid anhydride and monoepoxy compound having a polymerizable double bond to be used is controlled within a range that satisfies this. It is preferable to choose. The monoepoxy compound having a polymerizable double bond is preferably used in an amount of 1 to 2 moles per mole of the polybasic acid anhydride used. Although a conventional addition esterification catalyst may be used to promote the above reaction, the reaction proceeds smoothly even without the use of a catalyst. The progress of the alternating addition esterification reaction varies depending on the polybasic acid anhydride used and the type of monoepoxy compound having a polymerizable double bond, but generally it progresses easily at temperatures above 60°C, and the residual acid value of the system and This continues until the epoxy value decreases to a negligible level.

Generally, the quantitative relationship between the oligoesterified wood material (A) having a polymerizable double bond and the oligomer (B) having a polymerizable double bond in the composition is 50:50-90:
The range is 10. In the present invention, the oligomer (B) having a polymerizable double bond exists inside and outside the cell wall of the wood material, and at the same time the wood material component is plasticized due to the presence of the oligomer (B) during hot press molding. The polymerizable double bonds in the oligoesterified wood material (A) and the oligomer (B) polymerize with crosslinking, and are strongly integrated.

Next, as the thermoplastic resin (C) to be mixed into the composition of the present invention, thermoplastic polymeric substances such as polyolefins such as polyethylene and polypropylene and copolymers thereof, polystyrene, polymethyl methacrylate, Polyvinyl chloride, acrylconitrile-butadiene-
Vinyl polymers and their copolymers such as styrene copolymers, methyl meccrylate-butadiene-styrene copolymers, polycarbonates such as polybisphenol octacarbonate, polyethers such as polyethylene oxide', polyoniF dimethylene, etc. and mixtures thereof, among which polyethylene oquinide, methyl methacrylate-butadiene-styrene copolymer and the like are particularly preferred as they have good affinity with the composition. The mixing ratio of the composition and the thermoplastic resin (C) is in the range of 5 to 40 parts by weight of the thermoplastic resin (C) to 100 parts by weight of the composition, and the blending ratio of the thermoplastic resin (C) is 5 parts by weight. If it is less than 40%, the fluidity of the mixture during hot press molding will be poor;
If the amount exceeds 1 part by weight, the mechanical strength will drop significantly and the molded product will not be able to maintain good strength.

The method of mixing the composition and the thermoplastic resin (C) is not particularly limited, but a mixture can be obtained by using, for example, a kneading machine such as a blender, kneader, mixing roll, or Banbury mixer. At this time, depending on the type of polymerizable double bond, curing can be accelerated by adding a small amount of a radical polymerization initiator (D).

As the polymerization 1511 initiator, dicumyl peroxide,
Hensyl peroxide, azohisisobutyronitrile, cumene hydroperoxide, etc. are used.

In addition, in the present invention, it is also possible to add flame retardants, reinforcing agents such as glass fibers and carbon fibers, coloring agents such as various dyes and pigments, and inorganic fillers.

Next, the mixture obtained as described above is formed into a mold and hot-pressed at 80 to 180'C to obtain a plastic-like wood-based molded product. When the heating temperature is lower than 80°C, oligoesterified wood+, I(A
) does not plasticize, and exceeding 180° (: is not good because the oligoesterified wood material (A) will undergo thermal decomposition. The pressure is generally 10 kg・f/c+A or higher, and the heat pressure time is preferably 0.5 to 30 minutes. Under these hot and pressure conditions, the plasticization of the wood components begins, and at the same time the oligoester Kitamoto ¥ is bonded to the double bond in the moon (A) and the oricoma = ([3) The double bonds inside polymerize and crosslink, forming strong chemical bonds between the oligoesterified wood material (Δ) and the oligomer (B), forming a strong network structure as a whole system.

In the present invention, a good molded product can be obtained even with a mold having a very complicated shape.

On the other hand, when a system in which the thermoplastic resin (C) is not added to the composition is molded using a mold with a complex shape like a donut, cracks occur due to the heat shrinkage stress during hot press molding, resulting in poor quality. Molded products cannot be obtained.

Furthermore, it has been found that the mixture used in the production method of the present invention can also be molded by injection molding because the wood component has excellent fluidity due to heat and pressure.

(Effect of the invention) As described above (the oligoesterified wood material (A) having a polymerizable double bond and the oligomer (B) having a polymerizable double bond
), and the blending ratio of (A) and (Y3) is 50:50 to 90:10 by weight, and 5 to 40 parts by weight of thermoplastic resin (C) is mixed with 100 parts by weight of the composition. As a result, the resulting mixture exhibits excellent moldability due to the good fluidity of the wood component due to hot pressing, and the molded product obtained by hot pressing the mixture does not suffer from heat shrinkage stress etc. during hot pressing. The molded product does not crack (despite containing a large amount of wood components, it is homogeneous and beautiful like plastic, and has good mechanical strength as a molded product.) The mixture that can be used in the invention can be molded into various shapes, and the molded products obtained are suitable for use in many fields such as electrical insulation + A materials, industrial parts materials, and H materials for construction.Furthermore, The present invention also has the advantage that wood materials as industrial waste in the wood industry and unused wood materials can be effectively utilized, and is extremely useful industrially.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, Comparative Examples, and Production Examples, but the present invention is not limited thereto. "1 part" described below represents "part by weight."

Production Example 1 Describing a production example of the composition used in the present invention 100.0 parts of dry Akamatsuko wood powder that has passed through a 24-mesh sieve as a wood material and 26°5 parts of maleic anhydride are heated in a dryer.
Add to a reaction vessel equipped with a reflux condenser and heat to 120"C.
The mixture was stirred for 1 hour, and then 40.1 parts of allyl glycidyl ether, which was 1.3 times the mole of maleic anhydride, was added dropwise over about 15 minutes. After the dropwise addition, alternate addition esterification reaction was carried out at the same temperature for 7 hours to obtain Composition I. The I&final residual acid value of the system was 0.37 cq/kg. A portion of this composition was taken out and analyzed. As a result, the composition consisted of an oligoesterified wood having a polymerizable double bond and an oligomer having a polymerizable double bond.
The total addition rate of maleic anhydride and allyl glycidyl ether added to wood was 35.1% as ipB.In addition, the oligomer obtained from maleic anhydride and allyl glycidyl ether It existed inside and outside the cell wall, and its content was 33.6% by weight based on the wood.Therefore, the quantitative relationship between the oligoesterified wood and the oligomer in Composition I was 80°1:19.9. Ta.

Examples 1 to 4 and Comparative Examples 1 to 2 Methyl methacrylate-butadiene-styrene copolymer (MBS resin: manufactured by Kanebuchi Chemical Co., Ltd.) and dicumyl peroxide were added to Composition I obtained in Production Example 1 in Table 1. The mixture was added in the proportion shown in , and mixed uniformly with a mixing roll to form a mixture. In order to test the hot-pressure fluidity of the obtained mixture, 5 g of the mixture was inserted between the hot discs of a press, and after hot pressing, the hot-pressure flow area of the mixture was measured to evaluate the moldability. That is, the larger the thermopressure flow area, the better the moldability of the mixture. The heat and pressure conditions are as follows: temperature: 150' C5 pressure: cylinder diameter: 30 cm, gauge pressure: 50 kg -f/c+a,
The heat-pressing time was 2 minutes. Further, the mixture was uniformly formed into a mold, and then this mold was inserted between hot plates of a press machine to perform hot-press molding. The heat and pressure conditions were a temperature of 150' C1 pressure of 270 kg-f/c+K and a time of 30 minutes. After hot press molding, the thickness is approximately 3 and 7 mm respectively.
A plastic-like wood-based molded product for the fence was obtained. Examples 1-4
Samples were cut from the wood-based molded products obtained in Comparative Examples 1 and 2 and subjected to physical property tests. The results of this physical property test are shown in Table 1. The physical property test was conducted in accordance with the ASTM below.

Tensile test: ASTM D638-68 bending test:
As is clear from ASTM D790-66 Table 1,
The mixture of Composition (1) and MBS resin used in the production method of the present invention in Examples 1 to 4 is the mixture of Composition (1) and MBS resin used in the production method of the present invention in Examples 1 to 4.
It has better heat-pressure fluidity than those without S resin, so it is easy to mold. In addition, the plastic-like wood-based molded products produced by the manufacturing method of the present invention in Examples 1 to 4 are MBS
Compared to Comparative Example 1 in which no resin was added, the molded product had a higher tensile elongation rate and moderate elongation, so it was possible to prevent cracking due to heat shrinkage stress during hot press molding, and it had good moldability. be. Generally speaking, the plastic-like wood-based molded products produced by the production method of the present invention obtained in Examples 1 to 4 have better mechanical strength as molded products than Comparative Example 2, in which too much MBS resin is added. It is clear that the effects of the present invention are recognized.

Production Example 2 100.0 parts of dried Akamatsuko wood flour that had passed through a 24-mesh sieve as a woody material and 29.7 parts of phthalic anhydride were added to a reaction pot equipped with a dryer and a reflux condenser, and the mixture was heated to 150"C. Then, 37.0 parts of glycidyl methacrylate (1.3 times the mole of phthalic anhydride) was added dropwise at 90°C over about 15 minutes. After the dropwise addition, the mixture was stirred at the same temperature for 7 hours. An alternating addition esterification reaction was performed to obtain composition (2).

Production Example 3 100.0 parts of dried red pine wood powder passed through a 24-mesh sieve as wood materials and 22.0 parts of maleic anhydride were mixed in a stirrer,
Add to a reaction vessel equipped with a reflux condenser and heat to 120°C.
The mixture was stirred for 1 hour at
The solution was added dropwise at C over about 15 minutes. After dropping, alternating addition esterification reaction was carried out at the same temperature for 7 hours to obtain composition (2).

Production Example 4 Alternate addition esterification in the same manner as Production Example 1 except that 100.0 parts of 100 mesh dried rice hull powder, 26.5 parts of maleic anhydride, and 40.1 parts of allyl glycidiether were used as the wood material. The reaction was carried out to obtain composition (2).

Examples 5 to 8 and Comparative Example 3 Compositions ■, ■, ■, and IV obtained in Production Examples 1 to 4 °M
BS resin or polyethylene oxide resin (PIi
, O resin, molecular weight 500,000, manufactured by Seitetsu Kagaku), and dicumyl peroxide in the formulation shown in Table 2 were added and mixed uniformly with a mixing roll to form a mixture. The mixture was uniformly formed into a mold, and then the mold was inserted between hot discs of a press to perform hot-press molding. Heat and pressure conditions are temperature 150'C1 pressure 270kg-f
/c+a, time was 30 minutes. After hot-press molding, plastic-like wood-based molded products with thicknesses of 3 mm and 7 mm were obtained, respectively. Samples were cut from the wood-based molded products obtained in Examples 5 to B and Comparative Example 3 and subjected to physical property tests. The results of this physical property test are shown in Table 2. The physical property test was carried out in accordance with the AS'rM described above.

As is clear from Table 2, the mixtures of Composition 1-IV and MBS resin or PEO resin used in the production method of the present invention in Examples 5 to 8 had a ratio of ,
MBS resin compositions have superior hot-pressure fluidity compared to those without the addition of PE○ resin, and are therefore easier to mold. In addition, the plastic-like wood-based molded products produced by the manufacturing method of the present invention in Examples 5 to 8 have a higher tensile elongation rate and moderate elongation than Comparative Example 3, so Cracks due to shrinkage stress etc. can be prevented and moldability is good. From the above, it is clear that the effects of the present invention are recognized.

Patent applicant: Okura Industries Co., Ltd.

Claims (1)

[Claims] (1) Oligoesterified wood material (A) having a polymerizable double bond obtained by alternately adding a polybasic acid anhydride and a monoepoxy compound having a polymerizable double bond to the hydroxyl group in the wood component
and an oligomer (B) having a polymerizable double bond obtained from a polybasic acid anhydride and a monoepoxy compound having a polymerizable double bond, and the blending ratio of (A) and (B) is A plastic-like wood-based molded product characterized by hot-press molding a mixture obtained by adding 5 to 40 parts by weight of a thermoplastic resin (C) to 100 parts by weight of a composition having a ratio of 50:50 to 90:10. Manufacturing method.