JPH07711B2 - Starch-based compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION It is known to press-treat starch to produce compression molded articles from starch that has been treated, for example by injection molding. Preferably, such molded bodies are manufactured for filling with medicines, foods, chemicals, etc., in particular as medicine capsules for packaging pharmaceuticals. Such containers are usually
It is composed of a container part and a closure part, both of which are tightly fitted to each other in a sealed state to form a sealed container.

The production of such compression-formed containers from natural starch is known from (European Patent Publication No. 118,240, JP 59-196335).

In industrial production, it is necessary to produce compression moldings, in particular very thin-walled drug capsule parts, with maximum precision and at high speed. Furthermore, during manufacturing, the occurrence of defective parts must be minimized in order to minimize subsequent control and interruptions in the filling machine.

Overcoming these processability problems has proven surprisingly difficult. For example, in the manufacture of very thin walled parts with walls less than 0.5 mm thick, these problems are quite significant.

Starting powder (starting mixture based on free-flowing starch)
Regarding the above, as in the case of the entire injection forming process up to the fluid state, particularly good fluidity is required. The melt should flow as easily as possible to avoid high pressures and, with respect to temperature, should show a distribution as homogeneous as possible in order to mix with the additives and water.

Furthermore, the injection-moulded part must also be easily removable from the mould, as well as having good dimensional stability, in order to avoid sticking to the wall of the molding tool or deformation during removal.

Surprisingly, the problem is that (1) using a starch starting mixture that is particulate at room temperature, free-flowing, and becomes a shaped body with a substantially amorphous wall structure under processing conditions,
(2) The viscosity of the melt at 90 to 240 ° C, particularly 140 to 190 ° C is 2500 to 50 Pa s (Pascal x seconds), preferably 2000.
~ 50 Pa s, particularly preferably between 1500 and 50 Pa s,
(3) The glass transition point of the mixture heated to 140 to 190 ° C in a closed container has a glass transition point of at least 25 ° C, preferably at least 45.
It can be solved if it is 0 ° C, particularly preferably about 65 ° C. These conditions are achieved by the composition defined below.

The composition described below enables the injection molding machine to be operated continuously for 24 hours, with a wide range of elimination of the sources of error or of the drawbacks mentioned above.

In this sense, the present invention relates to a starch-based formulation for pressure processing, which is particulate and free-flowing at room temperature, comprising: (a) 72 to 89.58 parts of chemically unmodified starch, (B) at least one lubricant / release agent 0-5 parts, (c) at least one melt flow promoter 0-5 parts, (d) texturing agent 0.02-1 parts and (e) water. 10 to 22 parts, wherein component (i) components (b) and (c) are always always at least 0.4 parts, at most 5 parts,
And (ii) components (a), (b), (c), (d) and (e)
Relates to a formulation characterized in that the total is always 100 parts.

It has further been discovered that these formulations are suitable for use in pressure processing such as compression molding, injection molding, blow molding, extrusion and the like.

These base formulations can contain additional components as described further below. “Parts” always means “parts by weight”.

It is to be understood that chemically unmodified starch is a naturally occurring vegetable carbohydrate consisting mainly of amylose and amylopectin. This starch is
For example, potatoes, rice, tapioca, corn,
Obtained from rye, oats, wheat and other plants. Similarly, the term refers to gelatinized or pre-boiled (pre-co
oked) starches and starches with modified physical structure, such as easily water-soluble starches, for example starches with a reduced average molecular weight. Such starches or mixtures of such starches can be treated in the defined composition under pressure and at elevated temperature and compressed into shaped bodies.

Preferably, the ratio of physically modified starch to natural starch is 50% or less, more preferably 20% or less.
Natural starch is preferred.

Starch (a) was added to 100 parts of this composition in the base formulation at 72%.
~ 89.58 parts, preferably 75-85 parts, more preferably about 79
Suitably present in an amount of ˜83 parts.

The starch is preferably 0-70% amylose and 100-3.
It has an amylopectin content of 0%. Potato starch is preferred.

Suitable lubricants / release agents (b) are, for example, animal and vegetable fats, alone or in the mixed state, particularly preferably hydrogenated fats which are solid at room temperature. Preferably, they have a melting point above 50 ° C. These fats are usually C ₁₄ −, C ₁₆ − and C ₁₈ − fatty acids, for example, C ₁₈ (about 65%), C ₁₆ (about 30%), C ₁₄ (about 5%).
Is a triglyceride.

The amount used is preferably 0 based on 100 parts of the base formulation.
To 5 parts, more preferably 0 to 3 parts, most preferably 0.6.
Part to 1.2 parts.

Since these lubricants / release agents simultaneously act as softeners and viscosity reducers, the addition of such special agents is unnecessary.

As the melt flow accelerator (c), solid long-chain fatty acids, more preferably C _14- , C _16- , C ₁₈ -fatty acids, solid mono- and diglycerides, and phospholipids are preferable. Lecithin is particularly preferred. A suitable addition amount of these single compounds or a mixture of these compounds is 0 to 5
Parts, preferably 0.1 to 2 parts, more preferably 0.2 to 1 part.

The sum of components (b) and (c) is always at least 0.4 parts, preferably 0.8 to 2.0 parts, per 100 parts of the base formulation.

The constituent (d) is titanium dioxide or silicon dioxide or a mixture of these compounds. Such compounds ensure the free-flowing properties of the starting material as a powder at room temperature,
Furthermore, it has been found to prevent the formation of bridges in the hopper and in the screw during the process, which impedes the feeding of the starting material to the screw. By adding these ingredients, the feeding occurs continuously, evenly, uniformly, at high speed, one after another.

Therefore, there is no need to micronize the starting material or perform any other pretreatment.

The amount of constituents is preferably 0.02 to 1 part per 100 parts of base formulation. The optimum amount of addition is about 100 parts of the base compound for both values, and for titanium dioxide it is about
0.4 part, and about 0.1 part for silicon dioxide. Of course, more titanium dioxide or silicon dioxide can be added. The excess acts as a fill and has no effect on the product properties.

Water (e) is present in an amount of 10 to 22 parts, preferably 10 to 20 parts, more preferably 15 to 19 parts, based on 100 parts of the base formulation. Preferred ranges apply.

The treatment conditions are mainly starch used and components (b) to (e).
And, depending on the need, depending on the additional additives described below.

The higher the water content, the lower the temperature and pressure that can be selected in the injection molding process, and the lower the water content, the higher the pressure and temperature to be selected. The selection of suitable pressures and temperatures is straightforward and can be easily carried out by all experts. Pressures range from 300 × 10 ⁵ N / m ^{2 to} 3,000 × 10 ⁵ N / m ² for relatively thick walled articles and 600 × 10 ⁵ N / m ^{2 to} 3,000 for relatively thin walled articles.
It is in the range of × 10 ⁵ N / m ² , preferably 900 × 10 ^{5 to} 1,500 × 10 ⁵ N / m ² . Depending on the water content, pressures of several bar, for example less than 10 bar, may be used for the extrusion. The operating temperature is mainly in the range of 80 to 240 ° C, preferably 130 to 210 ° C, especially 150 to 190 ° C.

For example, an apparatus known per se such as an extruder or an extruder can be used.

For the same water content, potato starch can be more easily processed than wheat starch, eg under lower pressure and temperature conditions. The degree of difficulty increases in the order of potato starch, wheat starch, corn starch, and rice starch. Potato starch and wheat starch are preferred, and potato starch is particularly preferred.

In the starch-based formulation described above, the starch is
Up to 50%, but preferably up to 20% can be replaced by one or a mixture of other hydrophilic substances. Such other hydrophilic substances are, for example, gelatin,
Sunflower protein, soy protein, cottonseed protein, peanut protein, plant protein such as rapeseed protein, blood protein, egg protein, acrylated protein; alginates, carrageenans, guar gum, agar, gum arabic and related gums (Gatti gum, karaya gum, tragacanth gum), water-soluble polysaccharides such as pectin; water-soluble derivatives of cellulose, such as methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, hydroxybutylmethylcellulose. Alkyl celluloses, hydroxyalkyl celluloses and hydroxyalkyl-alkyl celluloses, cellulose acetylphthalate (CAP), Cellulose esters and hydroxyalkyl cellulose esters such as Le hydroxypropyl methylcellulose (HPMCP); carboxyalkyl celluloses such as carboxymethyl cellulose, carboxyalkyl alkylcelluloses,
Carboxyalkyl cellulose esters and alkali metal salts thereof; polyacrylic acid and polyacrylic acid ester, polymethacrylic acid and polymethacrylic acid ester, polyvinyl acetate, polyvinyl alcohol, polyvinyl acetate phthalates (PVAP),
Water-soluble synthetic polymers such as polyvinylpyrrolidone, polycrotonic acids, water-soluble chemical derivatives of phthalated gelatin, succinic acid gelatin, cross-linked gelatin, shellac, starch, eg, quaternary diethylaminoethyl when required. Also suitable are cationically modified acrylic and methacrylic acid esters having tertiary or quaternary amino groups such as groups, and other similar polymers.

Preferably, the starch is replaced by no more than about 3-10% of these compounds.

In addition to the above-mentioned base formulation, a softening agent, based on 100 parts of the formulation, preferably 0.5 to 10 parts, particularly preferably 0.5 to.
It can be added in an amount of 5 parts. In addition, the starting materials can be mixed with the liquid additives until they are completely absorbed resulting in a solid, free-flowing mixture. Excess or sticking to the particles mixed alone must be removed. Such softening agents include, for example, polyethylene glycols, polypropylene glycols, polyalkylene oxides such as polyethylene propylene glycols, low molecular weight organic softening agents such as glycerin, glycerin mono-, di-, triacetate,
Propylene glycol, sorbitol, sodium diethylsulfosuccinate, triethyl citrate, tributyl citrate.

The sum of the parts by weight of water and softener preferably does not exceed the specified maximum water content. Therefore, preferably,
The total amount of water and softener is 10 to 2 with respect to 100 parts of the base composition.
2, preferably 10 to 20, more preferably 15 to 19 parts.

The mixture can also be dyed. Suitable dyes are
For example, known azo dyes, or organic or inorganic pigments,
Or it is a naturally occurring dye. Based on the weight of all ingredients
Preference is given to inorganic pigments such as iron or titanium oxides which are known per se in concentrations of 0.001 to 10%, preferably 0.5 to 5%.

As mentioned above, the formulations according to the invention can be used in all kinds of molding techniques under pressure, such as compression molding, injection molding, blow molding or extrusion, and all of the many known methods. In variants, containers, bottles, sheets, sacks, films, packaging materials, tubes,
Articles such as rods, drug capsules and the like can be manufactured.

The following example illustrates the invention.

Example 1 Natural potato starch, 81 parts, 65: 31: 4 C in proportions by weight percent _18: C _16: Hydrogenation triglyceride part containing fatty acids C _14, 0.7 parts of lecithin, titanium dioxide 0.3 parts and water 17
The composition of parts was mixed in a powder mixer for 10 minutes. Then, a free-flowing powder was obtained. This powder
Supply into the hopper of injection molding machine, temperature 180 ℃, pressure 150
Injection was carried out at 0 bar and a mold wall temperature of 40 ° C. in an injection mold for the body and cap of the capsule. After cooling and removal from the mould, a dimensionally stable capsule body and cap were obtained which could be machined into containers.

It was found that this mixture allowed the injection molding machine to be easily operated in 24-hour operation without disturbing it and the number of defects on the capsule parts was greatly reduced.

Similar results were obtained by using the following formulations listed in Table 1.

Claims (17)

[Claims] 1. A composition based on starch, which is free-flowing in the form of fine particles at room temperature, comprising: (a) a chemically unmodified starch, or a chemically unmodified starch and a chemically unmodified starch. 72 to 89.58 parts by weight of other hydrophilic substances up to 50% by weight of the starch of (1), (b) 0 to 5 parts by weight of lubricant and mold release agent, (c) 0 to 5 parts by weight of melt flow accelerator, (d) Silicon dioxide, titanium dioxide or a mixture thereof 0.02 to 1 part by weight and (e) water 10 to 22 parts by weight, wherein (i) the total of components (b) and (c) is 0.4 to 5 parts by weight. And (ii) components (a), (b), (c), (d) and (e)
The formulation is characterized in that the total of 100 parts by weight is 100 parts by weight. 2. A chemically unmodified starch is a potato,
A formulation according to claim 1 which is a naturally occurring carbohydrate, gelatinized starch and / or a readily water soluble starch obtained from rice, tapioca, corn, rye, oats, wheat or other plants. 3. A formulation according to claim 1 or 2 which contains starch in an amount of 75 to 85 parts by weight per 100 parts by weight of the formulation. 4. The formulation according to any one of claims 1 to 3, wherein the starch is potato starch or wheat starch. 5. Component (b) is added in an amount of 0.6 parts by weight per 100 parts by weight of the composition.
~ 1.2 parts by weight of the content of claims 1 to 4
A formulation according to any one of paragraphs. 6. Component (b) according to claim 1, wherein the component (b) is selected from animal and / or vegetable fats, hydrogenated fats which are solid at room temperature and have a melting point above 50 ° C. The formulation according to any one of claims. 7. fats is, C ₁₄ -, C ₁₆ - and C ₁₈ - fatty acids, C ₁₈ (approximately 65%), C ₁₆ (approximately 30%), C ₁₄ (about 5%)
A formulation according to claim 6 which is a triglyceride having a proportion of 8. Component (c) is added in an amount of 0.1 parts by weight per 100 parts by weight of the composition.
The formulation according to any one of claims 1 to 7, which is contained in an amount of 2 to 2 parts by weight. 9. Component (c) _{is, C 14 -, C 16 -} , C 18 - fatty acids, solid mono - and / or diglycerides, and are selected from phospholipids, first to claims A formulation according to any one of paragraphs 8. 10. The composition according to claim 1, wherein the total amount of components (b) and (c) is 0.8 to 2.0 parts by weight in 100 parts by weight of the base composition. Formulation. 11. Any of claims 1 to 10 in 100 parts by weight of the formulation in an amount of about 0.25 parts by weight for titanium dioxide and about 0.1 parts by weight for silicon dioxide. The composition according to item 1. 12. A formulation as claimed in any one of claims 1 to 11, in which an amount of up to 20% by weight of the starch is replaced by another hydrophilic substance. 13. The hydrophilic substance is gelatin; vegetable protein; blood protein; water-soluble polysaccharide; water-soluble cellulose derivative; water-soluble synthetic polymer; phthalated gelatin; succinic acid gelatin; cross-linked gelatin; shellac; Or a cationically modified acrylic acid ester and methacrylic acid ester having a quaternary amino group; and the blend according to any one of claims 1 to 12. 14. The composition comprises 0.5-10 parts by weight per 100 parts by weight of the composition.
Claims 1 to 1, containing parts by weight of softener.
The formulation of any one of paragraphs 13. 15. The method according to claim 1, wherein the total amount of parts by weight of water and the softening agent does not exceed the specified maximum content of water.
The formulation according to any one of paragraphs 14. 16. A starch-based formulation, which is particulate and free-flowing at room temperature, comprising: (a) a chemically unmodified starch, or a chemically unmodified starch and a chemically unmodified starch. 72 to 89.58 parts by weight of other hydrophilic substances up to 50% by weight of the starch of (4), (b) 0 to 5 parts by weight of lubricant and mold release agent, (c) 0 to 5 parts by weight of melt flow accelerator, (d) Silicon dioxide, titanium dioxide or a mixture thereof 0.02 to 1 part by weight and (e) water 10 to 22 parts by weight, wherein (i) the total of components (b) and (c) is 0.4 to 5 parts by weight. And (ii) components (a), (b), (c), (d) and (e)
An article produced by press-molding a compound whose total amount is 100 parts by weight. 17. The article of claim 16 wherein the article is a hard capsule.