JPS6268807A - Production of cellulosic graft copolymer - Google Patents

Abstract

PURPOSE:To industrially obtain the titled copolymer having good processability and thermal stability at a low cost, by suspension polymerizing a cellulosic high polymer with a vinyl based monomer in a specific proportion in an aqueous medium. CONSTITUTION:100pts.wt. cellulosic high polymer, preferably wood meal is polymerized with 30-300pts.wt. vinyl based monomer, preferably vinyl chloride, methyl methacrylate or a mixture of methyl methacrylate with acylate with a 1-12C alcohol or methacrylate with a 2-12C alcohol in the presence of a polymerization initiator, e.g. benzoyl peroxide, and a suspending agent, e.g. methyl cellulose or PVA, to afford the aimed copolymer.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention involves polymerizing a cellulose-based polymer with a vinyl-based mm compound in an aqueous medium in the presence of a suspending agent and a polymerization initiator to obtain a cellulose-based copolymer. It relates to a method for creating a lit.

[Prior art] Conventional methods for producing cellulose copolymers include a method in which a cellulose polymer such as this flour is impregnated with a single substance such as methyl methacrylate, and methyl methacrylate is polymerized in the presence of wood flour. A method of emulsion polymerization of a monomer such as acrylate, a method of polymerizing a cellulose polymer and a monomer using radiation, and the like are known.

[Problems to be solved by the invention] However, the method of impregnating wood flour with a monomer such as methyl methacrylate and polymerizing it requires heat removal and non-uniform polymerization. It is difficult to obtain a powdered graft copolymer.

Furthermore, the emulsion polymerization method is disadvantageous in terms of production, as it requires coagulation, and the radiation copolymerization method is disadvantageous in terms of cost, and the thermal stability of the product is poor.

The present invention was made in order to provide a method for industrially producing cellulose copolymers with good processability and thermal stability using a suspension polymerization method.

[Means for Solving the Problems] The present invention provides 100 parts of cellulose polymer I1 in an aqueous medium.
Part 1) and 30 to 300 parts of a vinyl monomer are polymerized in the presence of a polymerization initiator and a suspending agent to produce a cellulose-based graft copolymer.

[Example] Examples of cellulosic polymers used in the present invention include natural polymers such as wood flour, straw, pulp, and rice husk, purified cellulose, and chemically modified cellulose. Among these, it is particularly advantageous to use wood flour of about 50 to 200 mesh baths in terms of the appearance and strength of the product.

Examples of vinyl monomers used in the present invention include vinyl chloride, vinylidene chloride, styrene, methacrylic acid, methacrylates with alcohols having 1 to 12 carbon atoms, acrylic acid, acrylates with alcohols having 1 to 12 carbon atoms,
Examples include acrylonitrile, vinyl acetate, butadiene, α-methylsdyrene, allyl glycidyl ether, allyl uride, and these may be used alone;
More than one species may be used in combination.

Among the vinyl monomers, it is preferable to use vinyl chloride because the resulting copolymer is aloof, and monomer mixtures containing methyl methacrylate or methyl methacrylate as one component, such as It is preferable to use a ψ-mer mixture of a methacrylate and an acrylate with an alcohol having 1 to 12 carbon atoms or a methacrylate with an alcohol having 2 to 12 carbon atoms because the resulting copolymer has good thermal stability. In particular, a copolymer produced from a monomer mixture containing methyl methacrylate and butyl acrylate or methyl acrylate and a cellulose polymer has good thermal stability, that is, it is difficult to thermally decompose at high temperatures, and has good processability. Therefore, it is preferable.

Furthermore, a copolymer produced from a cellulose polymer and a monomer mixture containing vinyl chloride, methyl methacrylate, or methyl methacrylate as one component is produced by mixing a cellulose polymer and a thermoplastic resin such as polyvinyl chloride. It has the characteristic of improving compatibility between the two when processed.

When using a monomer mixture containing methyl methacrylate as one component, the proportion of methyl methacrylate in the monomer mixture is 30% (weight% or less) from the viewpoint of compatibility with polyvinyl chloride. (similar) or more, and more preferably 50% or more.

Polymerization initiators used in the present invention include, for example, peroxide polymerization initiators such as dialkyl peroxide and diasilver oxide, and azo polymerization initiators such as azobisnitrile, which generally initiate the polymerization of vinyl-based 111 polymers. Any material may be used without particular limitation as long as it can be used as an agent.

Specific examples of the polymerization initiator include benzoyl peroxide, di-3.5□5-trimethyl 4:sanoyl peroxide, [-butylperoxyneodecane h,
Examples include azobisvaleronitrile.

Examples of the suspending agent used in the present invention include those commonly used as suspending agents, such as polymeric suspending agents such as polyvinyl alcohol and methylcellulose, and inorganic suspending agents such as calcium phosphate, and are not particularly limited. It's not a thing.

The ratio of the monomer to 100 parts of the cellulose polymer used in the present invention is 30 to 300 parts, preferably 30 to 200 parts.
Department. If the proportion of the monomer is less than 30 parts, the conversion rate of the monomer will be low and the compatibility with polyvinyl chloride will deteriorate, which is undesirable. If it exceeds 300 parts, the graft copolymerization rate will be low. This is not preferable because the amount of free polymer increases, making it difficult to exhibit the characteristics of cellulose polymers.

The proportion of the polymerization initiator used in the present invention is not particularly limited, but from the viewpoint of economy and productivity, it is preferably used in a range of about 0.01 to 1.0% based on the monomer.

There is no particular limitation on the proportion of the suspending agent used in the present invention, but from the viewpoint of polymerization stability, it is preferably used in an amount of about 0.1 to 5% based on the monomer.

In the present invention, a cellulose polymer and a vinyl ψ polymer are copolymerized in an aqueous medium, and the weight ratio of the aqueous medium/cellulose polymer is preferably 271 to 10/1, and 5/1. -10/1 is more preferable. When the ratio is less than 271, the aqueous medium tends to be absorbed by the cellulose polymer, making stirring difficult, and when it exceeds 10/1, productivity tends to be insufficient. In the present invention, since water is used as a medium, the heat of reaction can be easily removed and the product can be produced in a stable state.

Next, the method of the present invention will be explained based on an actual IIM embodiment.

For example, around 90℃, 15kO/c++? G Pi!
Into a polymerization vessel which can be heated and pressurized to 100°C and stirred at about 100 to 500 ml/m, water of a predetermined temperature is added, and a cellulose-based polymer impregnated with a monomer and a polymerization initiator is charged. The reaction temperature varies depending on the Ql polymer, but is 50 to 90°C, and the stirring conditions are 100 to 500 rpm.

These conditions are the same as for normal suspension polymerization, and unlike radiation polymerization and impregnation polymerization, which were conventionally used to graft polymerize cellulose polymers, polymerization can be carried out without special equipment or post-treatment. The polymer can be changed.

In the method of the present invention, distearyl diodibrobionate, triethylene glycol bis[3-(
3-t-butyl-5-methyl-4-human D-xyphenyl)
Antioxidants such as propionate 1, epoxidized soybean oil,
It goes without saying that stabilizers such as fatty acid glycerides may also be used.

The thus obtained graft copolymer of the present invention can be suitably used in extrusion processing, roll processing, press processing, and the like.

Next, the method of the present invention will be explained based on Examples, but these are not intended to limit the present invention.

Examples 1 to 2 and Comparative Examples 1 to 4 Wood flour (200 mesh pass), vinyl chloride, polyvinyl alcohol, water, polymerization initiator (G3゜5.5-t-limethylhexanoyl peroxide/l-butyl) Baroxyneodecanate = 171 (weight ratio)) was charged into a 20 p pressure vessel equipped with a stirrer in the proportion shown in Table 1, and the polymerization temperature was 6.
Polymerization was carried out at 5°C for 7 cycles. The conversion rate of vinyl chloride at that time was as shown in Table 1. Note that 100 parts in Table 1 was 2.0k (l).

2 parts of tribasic lead sulfate and 1 part of lead stearate were added to 100 parts of the obtained graft copolymer, and the mixture was rolled at 190°C, and the winding time was measured to evaluate workability. In addition, take out the wrapped sheet material and heat it at 190°C at 58°C.
A 2M thick film was prepared by pressing under fl/cd pressure for 10 minutes, and the presence or absence of a wood texture on the surface was evaluated.

When evaluating, those with a wood grain feel are given a score of 0, those without are given an ×,
The one in the middle was judged as Δ. The results are shown in Table 1.

[Margins below] From the results in Table 1, polymerization hardly progresses when vinyl chloride is contained in 10 parts (less than 30 parts) per 100 parts of wood flour;
It can be seen that when the amount exceeds 500 parts, the wood texture of the surface of the seal cannot be sufficiently obtained.

Examples 3 to 6 and Comparative Examples 5 to 6 Wood flour (100 mesh pass), methyl methacrylate (
HMA), butyl acrylate (BA), methyl acrylate (HA), water, suspending agent (calcium phosphate),
A polymerization initiator (benzoyl peroxide/di-t-butylperoxy-3,5,5-trimethylcyclohexane-2/1 (Iffi ratio)) was charged into the same equipment as in Example 1 in the ratio shown in Table 2. Polymerized. Polymerization is 90
The reaction was carried out at 120°C for 6 hours and then at 120°C for 3 hours. Table 2 shows the yield and condition of the obtained graft copolymer.

For 100 parts of the obtained graft copolymer, 100 parts of polyvinyl chloride (manufactured by Kanebuchi Chemical Industry ■, degree of polymerization 800), barium-zinc stabilizer (MAR manufactured by Adeka Argus ■),
K AC-141) 3 parts, additive (Kanebuchi Chemical Industry)
Using a mixture of 2 parts PA-20") and 5 parts calcium carbonate, 1
Gelation time and thermal decomposition time were measured at 90° C. and 50 rpm.

1 Thermal decomposition time was determined by color change or decomposition. Results 1 □21, [Left below] □ □ □ 'D From the results in Table 2, the graft copolymer obtained in Example 5.6 had a short gelation time, good processability, and It can be seen that the thermal stability is good.

[Effects of the Invention] When a cellulose-based graft copolymer is produced by the method of the present invention, a copolymer in the form of independent particles to powder can be obtained, and can be molded alone or by mixing with a thermoplastic polymer. A suitable copolymer can be obtained. Since conventional suspension polymerization equipment can be used as is, it is advantageous in industrially producing cellulose-based graft copolymers at low cost.

Claims (1)

[Claims] 1. In an aqueous medium, 100 parts by weight of a cellulose polymer and 30 to 300 parts by weight of a vinyl monomer are polymerized in the presence of a polymerization initiator and a suspending agent to produce a cellulose graft copolymer. How to manufacture coalescence. 2. The method according to claim 1, wherein the cellulosic polymer is wood flour. 3 The vinyl monomer is vinyl chloride, methyl methacrylate, or methyl methacrylate and has 1 to 1 carbon atoms.
Acrylate with 12 alcohols or carbon number 2~
A method according to claim 1, wherein the methacrylate is a mixture of 12 alcohols. 4. The method according to claim 3, wherein the acrylate with the alcohol having 1 to 12 carbon atoms is butyl acrylate or methyl acrylate.