JPH0680115B2 - Method for producing amide resin molded product - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an amide resin molded article. More specifically, it relates to a method for producing a glass flake reinforced polyamide casting molded product and a reaction injection molded product, wherein at the time of molding, the viscosity of the raw material composition is low and handling and molding operations are easy. The product relates to a method for producing a molded product having good rigidity and gloss, a distortion caused by the particle diameter of glass flakes, and a small anisotropy of mechanical properties.

“Prior Art” In recent years, highly reactive liquid raw materials have been injected or injected into a mold,
Attention has been focused on a method in which polymerization and molding are carried out in a mold to directly obtain a molded article, that is, a so-called reaction injection molding method or a cast molding method.

Polyurethane molded articles have been greatly developed as the conventional molding methods, but recently, new materials such as polyamide, unsaturated polyester and epoxy have begun to be used. Among them, polyamide is low in toughness, strong rigidity, and excellent in heat resistance, and also has good abrasion resistance and wear characteristics, and further has good fluidity of the raw material composition and low heat generation during polymerization. It can be molded with injection pressure, has good transferability on the mold surface, and can be used to obtain thin to thick molded products at will, so it is of particular interest as a material for reaction injection molding and casting. ing.

A method of adding glass fiber as a reinforcing material is used in order to make use of such characteristics of polyamide and to impart higher rigidity and heat resistance.

The glass fibers added to the raw material compositions used for reaction injection molding or casting are often milled or cut glass fibers.

When the raw material composition containing the above glass fiber as a reinforcing material is used, the rigidity and heat resistance of the molded product are certainly improved remarkably. However, on the other hand, the viscosity of the raw material composition is significantly increased to narrow the range of molding conditions, and at the same time, the gloss of the surface of the molded product is impaired, and distortion (warp) of the molded product due to the orientation of the glass fibers and The occurrence of anisotropy in mechanical properties is also remarkable. Recently, a method of adding glass flakes to a raw material composition has been proposed for the purpose of reducing distortion of a molded article and anisotropy of mechanical properties. In order to add glass flakes to the raw material composition so that the rigidity of the molded article becomes equivalent to that when glass fibers are added, it is necessary to add flakes having a large particle size. However, when flakes having a large particle size are added, the rigidity of the molded product is improved, but there is a problem in that the gloss of the surface becomes poor and the distortion (warp) becomes large. Therefore, it is desired to develop a molded product having excellent mechanical properties and less distortion by adding glass flakes as a reinforcing material while maintaining an excellent molded product appearance. .

"Problems to be Solved by the Invention" Problems to be solved by the present invention are as follows.

(1) In the method for producing a molded article by the polyamide reaction injection molding method and the cast molding method, the viscosity of the raw material composition is low at the time of molding even though glass flakes are mixed in the raw material. Provide a method that is easy to handle and mold.

(2) Molded articles obtained by the polyamide-based reaction injection molding method and the casting method are excellent in rigidity, have a good surface gloss, and are free from distortion due to the particle size of glass flakes and mechanical properties. To provide a method of reducing anisotropy.

"Means for Solving Problems" The gist of the present invention is that in the production of an amide-based resin molded product, a melted product of ω-lactam containing a polymerization catalyst and an ω-lactam containing a polymerization promoter are used. At least one of the molten substances is mixed with glass flakes having a particle size of less than 50 μm in an amount of 10% by weight or less and a particle size of more than 150 μm in an amount of 5% by weight or less and injected into a mold. Alternatively, a method for producing an amide-based resin molded article is characterized in that it is injected to obtain a molded article.

Hereinafter, the present invention will be described in detail. In polyamide-based reaction injection molding or casting, some of the raw materials used are prepared by dividing them into compositions of two or more components, and at the time of molding, the raw material compositions divided into these two or more components are Polymerization and molding are carried out simultaneously in the mold by collisional mixing or by coalescence with a static mixer, a dynamic mixer or the like.

2 in polyamide-based reaction injection molding or casting
One component system (hereinafter referred to as component system (A)) of the raw material composition comprising the component system is a melt of the polymerization catalyst and the ω-lactam,
The other component system (referred to as component system (B)) consists of a polymerization promoter, various additives and a melt of ω-lactam.

The glass flakes used in the present invention can be added to either component system (A) or component system (B),
It is also possible to add them to both component systems (A) and (B) at the same time.

The glass flakes used in the present invention are flaky and preferably have a particle size within a specific range. That is, as the glass flakes, those having a particle size of less than 50 μm are 10% by weight or less, and those having a particle size of more than 150 μm are 5% by weight or less.

If it exceeds these ranges, there are the following inconveniences.

That is, if the particle size of less than 50 μm exceeds 10% by weight, it contributes to the reduction of the viscosity of the composition or the improvement of the appearance of the obtained molded article, but the rigidity of the obtained molded article is improved. Is insufficient.

Further, when the particle size exceeds 150 μm and exceeds 5% by weight, it contributes to the improvement of the rigidity of the obtained molded product, but the viscosity of the composition is significantly increased and the molded product is obtained. When the appearance is extremely deteriorated. The poor appearance of the molded product is caused exclusively by the glass flakes having a size of more than 150 μm.

It is essential that the glass flakes have a particle size satisfying the above requirements, but the thickness is further 1 to 7 μm, preferably 3 to 4 μm, and the aspect ratio (particle size / thickness) is 7 to 15 μm.
It is suitable that the specific gravity after vibration is 0.5 to 1.0 (gr / cc).

There is no particular limitation on the composition of the glass constituting the glass flakes. As the glass flakes, C glass, which has strong acid resistance, is generally used, but it is prepared from E glass, A glass, S glass, M glass, AR glass, Li glass, etc., which are often used for glass fiber production. You can buy it.

In resin-reinforced glass flakes, the flake surface is generally treated with a surface-treating agent in order to provide good interfacial adhesion with the matrix resin. Also in the present invention, for example, a chromium-based surface treatment agent such as methacrylate-chromic chloride, vinyl-tri-ethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, cationic methacrylate. Functional silane, γ-aminopropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, phenyltrimethoxysilane , Silane-based surface treatment agents such as N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and chloropropylmethoxysilane, isopropyltriisostearoyl titanate, isopropyltridecyl pentenesulfonyl titanate, Isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphate) titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl tricumyl phenyl titanate, isopropyl tri (N-aminoethyl-aminoethyl) Glass flakes treated with known surface treatment agents such as titanate, dicumylphenyloxyacetate titanate and other titanate surface treatment agents such as diisostearoylethylene titanate may be used. Moreover, since the effect is recognized in the present invention even with untreated glass flakes, it is not essential to use glass flakes treated with a surface treatment agent.

Although the amount of the glass flake is not particularly limited, it is preferably 0 part by weight per 100 parts by weight of either component system (A) or (B) in the actual composition, that is, From 100 parts by weight to 100 parts by weight of all of the component systems (A), (B) and the glass flakes, up to 120 parts by weight when not blended at all.
Used between 1 and 50 parts by weight. Ingredient system (A)
Alternatively, it is not impossible to use more than 120 parts by weight with respect to 100 parts by weight of the component system (B), but when such a large amount of glass flakes is used, the viscosity of the raw material composition increases significantly. When carrying out reaction injection molding, a high injection pressure is required, and one of the advantages of polyamide-based reaction injection molding, that is, molding at a relatively low injection pressure, cannot be exhibited. In addition, it is not preferable because there is a problem that the throttling portion of the mixing head or the injection machine or the piping is frequently blocked. Further, when the total amount of the glass flakes exceeds 50 parts by weight with respect to 100 parts by weight of the total amount of the component system (A), the component system (B) and the three components of the glass flakes, the surface roughness of the molded article becomes large, and However, a brittle molded product can be obtained, which is not preferable in practical use. Similarly in the casting form, the raw material composition containing more than 50 parts by weight of glass flakes has too high a viscosity, and the following drawbacks appear. That is, the air bubbles entrapped during mixing cannot be completely removed,
Air bubbles remain in the molded product, creating a defective product. Further, in the case of a slightly complicated mold, gas remains in the mold and an unfilled portion is formed, resulting in a defective molded product, resulting in impairing the mold transferability of the polyamide-based casting mold with a sharp corner. Further, in cast rotational molding, if the viscosity of the raw material composition is high, the wall thickness of the molded product becomes non-uniform, giving a defective molded product.

Specific examples of the ω-lactam used in the present invention include γ
-Butyrolactam, δ-valerolactam, ε-caprolactam, ω-enanthlactam, ω-capryllactam, ω-undecanolactam, ω-laurinlactam and the like. These ω-lactams may be used alone or in combination of two or more.

As the polymerization catalyst contained in the component system (A), known ω
Any compound used in the anionic polymerization of lactams can be used. Specific examples thereof include alkali metals, alkaline earth metals, their hydrides, oxides, hydroxides, carbonates, alkyl compounds, aryl compounds, alkoxides, Grignard compounds, and the above metals or metal compounds and ω- Reaction products with lactams,
Examples thereof include sodium salt, potassium salt, and magnesium halide salt of ω-lactam. The amount of the polymerization catalyst used is in the range of 0.01 to 15, or 20 mol% or more based on the total ω-lactam.

Regarding the polymerization promoter contained in the component system (B), ω-
Any known compound used in the anionic polymerization of lactams can be used. Specific examples thereof include, for example, toluene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl polyisocyanate,
Isocyanates such as diisocyanate modified with carbodiimide, hexamethylene-1,6-biscarbamide, caprolactam, N, N'-diphenyl-P-phenylene biscarbamidocaprolactam, N, N'-diphenyl-P-phenyl Carbamide lactams such as nylene biscarbamidite and pyrrolidone, acid halides such as terephthaloyl chloride, adipic acid chloride and sepacic acid chloride, adipoyl biscaprolactam, adipoyl bispyrrolidone, terephthaloyl biscaprolactam, terephthaloyl Polyacyl lactams such as rubispyrrolidone, or formula [Wherein A is halogen or (Where Y is C ₃ -C ₁₁ alkylene) and a is
1, 2 or 3 is an integer, b is an integer of 2 or more, R ₁ is an alkyl group, an aralkyl group, an alkyloxy group, an aryloxy group, a halogen group, or an aralkyloxy group, and R ₂ is a divalent or higher valent group selected from a hydrocarbon group and a hydrocarbon containing an ether bond, and Z is (1) a polyether having a minimum molecular weight of about 2,000 and (2) a polyether having a minimum molecular weight of about 2,000. Polyester segment containing an ether segment or (3) a hydrocarbon having a minimum molecular weight of 1,000] or an acid halide functional substance or a lactam functional substance selected from the group consisting of the following.

The component system (B) may be blended with a crosslinking agent, a modifier (soft segment), etc. which enter into the polymer chain when reacting with the component system (A) in the mold. Examples of these compounds include compounds having a polyvalent hydroxyl group, a mercapto group, an amino group or an epoxy group.

Examples of the compound having a polyvalent hydroxyl group include alkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, tetramethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, 1.2-propanediol, 1.3. -Propanediol, 1,3-hexanediol, butylene glycol, 1,4-butanediol, dicyclopentadiene glycol, heptaethylene glycol and isopropylidenebis (P-phenyleneoxypropanol-2), polyols other than alkylene glycol, for example Glycerol, pentaerythritol, 1,2,6-hexentriol and 1-trimethylolpropane, polymeric polyols such as polyethylene glycol Polypropylene glycol, polyoxypropylene diols, and triols, polytetramethylene glycols, castor oil, polybutadiene glycols, polyester glycols, poly (ε-caprolactone) diols and numerous compounds containing substituents other than hydroxy groups such as 2.4-dichloro Butylene glycol and the like can be mentioned.

Examples of the compound having a polyvalent mercapto group include hydroxyethyl thioglycolate, ethylene glycol bis (thio-glycolate), pentaerythritol tetrakis- (thioglycolate) and thiodiglycol, and the polyvalent amino group. Examples of compounds having: hexamethylenediamine, tolylenediamine, 2 ·
4-diethyltolylenediamine, polyoxyethylenediamine, polyoxypropylenediamine and triamine, polyoxypropylenediamine, a copolyamide having an amino group as an end group, and the like, and examples of the compound having a polyvalent epoxy group include resorcinol diamine. Glycidyl ether, diglycidyl ether of bisphenol A,
Examples include vinylcyclohexane dioxide, butanediol diglycidyl ether, polyglycidyl ester of polycarboxylic acid, epoxidized polyolefin and glycidyl ether resin, and epoxy novolac resin.

The component system (B) further includes compounds that do not substantially inhibit the polymerization reaction, such as plasticizers, foaming agents, dyes and pigments, antioxidants,
An internal release agent or the like can be added.

Next, a method for producing an amide-based resin molded article according to the present invention will be described. First, a polymerization catalyst is added to ω-lactam, and ω-lactam is added.
Heating to above the melting point of the lactam (for example above 70 ° C. if the ω-lactam is caprolactam) to form a melt of component system (A). The molten material of the component system (A) is kept at 100 ° C. or lower in order to prevent the polymerization reaction by itself. Similarly, for the component system (B), a polymerization promoter, an additive, etc. are added to the ω-lactam and the mixture is heated to a temperature above the melting point of the ω-lactam to form a molten material kept at 140 ° C or lower. Next, in the above-mentioned prepared component system, the total amount of the glass flakes defined in the present invention, which is the required amount relative to the total amount of the two-component polyamide component, is applied to only one of the component systems (A) and (B), or the component system. A part of (A) or (B) and the rest of the mixture are uniformly mixed with the component system (B) or (A), or the component system (A) or (B). The above-mentioned distributive mixing of glass flakes is based on the component system (A)
Alternatively, it is determined each time depending on the viscosity of (B), the type of ω-lactam, and the like.

The following procedure is used to produce a molded product from the polyamide-based molding composition prepared as described above.

First, the component systems (A) and (B) molten slurries are rapidly mixed and injected or injected into a mold. As a method for mixing the two components, for example, in an apparatus called a mixing head, they are subjected to collision mixing, or they are mixed by stirring with a static mixer or a dynamic mixer. The mixing ratio of the component systems (A) and (B) depends on the intended use of the molded product,
It can be changed according to the properties to be provided. In this case, the mixing ratio is preferably in the range of 5/1 to 1/5 by volume.

Mold temperature during molding is 100 ~ 200 ℃, preferably 12
It is preferable to keep the temperature in the range of 0 to 160 ° C. The component system (A) and the component system (B) undergo a chemical reaction in the mold, and within a short time after the mold is injected, depending on the size of the molded product, within 4 minutes, depending on the case. It hardens or solidifies within 2 minutes and completes the chemical reaction. After the completion of the chemical reaction, the target molded product was taken out from the mold.

"Effects of the Invention" As described above, the present invention has the following particularly remarkable effects, and its industrial utility value is extremely large.

(1) According to the method of the present invention, glass flakes are blended in the raw material composition, but since glass flakes having specific physical properties are selected and used, the raw material composition has low viscosity and excellent fluidity. Easy to handle,
Easy to inject into the mold during molding.

(2) The molded product obtained by the method of the present invention has rigidity,
It has excellent heat resistance and excellent surface gloss, and does not impair the characteristics of polyamide-based molded products.

(3) The molded product obtained by the method of the present invention is a molded product having less distortion due to the particle size of glass flakes and less anisotropic mechanical properties.

"Examples" Next, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

The types of glass flakes used in the following examples are as shown in the table below, and the measurement of the particle size distribution of glass flakes, the viscosity measurement of component systems (A) and (B), the appearance of molded articles The evaluation and the flexural rigidity of the molded product were measured as follows.

Types of glass flakes Measurement of particle size distribution of glass flakes: − A standard sieve with a diameter of 200 mm is placed in the order of 48 mesh, 100 mesh, 150 mesh, 325 mesh and saucer from the top,
The sample was placed in the upper part of the screen. The sieve containing the sample was vibrated by a rotor type vibrating sieve machine for 15 minutes to perform sieving, and the weight of the sample remaining on each sieve mesh was weighed and expressed as a percentage.

Measurement of Viscosity of Component System (A) and Component System (B):-Using a Bruckfield viscometer, put the sample in a 500 cc beaker and measure the apparent viscosity at 100 ° C at a shear rate of 13 sec ^-1 .

Appearance evaluation of molded product: -Mainly by visual observation, but in some cases, auxiliary evaluation is performed using a surface roughness meter (Model SE-3A manufactured by Kosaka Laboratory). The display standard of the result is ◎; highest, ○; good, △; acceptable, ×
There were four levels of impossibility.

Measurement of flexural rigidity of molded products: -Dry test pieces were cut from flat plate molded products and ASTM D
It was measured according to −790.

Example 1 The following component system (A) and component system (B) were respectively added to 2,
It was prepared in a 000 cc flask and kept at a temperature of 100 ° C.

Ingredient system (A) ε-caprolactam 986gr Sodium pyrrolidone 14gr Glass flakes B 330gr Ingredient system (B) ε-caprolactam 538gr Terephthaloylbiscaprolactam 77gr Polypropylene glycol (MW = 2,000) 385gr Gawasflake B 333gr Ingredient system (A) and ingredients Samples were taken from the system (B) and the apparent viscosity was measured. The results are shown in Table 1.

Next, 100 gr of the component system (A) and 100 g of the component system (B) were placed in a beaker and mixed with a propeller-type stirrer, and the mixture was immediately temperature-controlled to 140 ° C. with an electric heater, 300 mm in length, 200 mm in width, It was poured into a sheet mold having a depth of 3 mm and held for 4 minutes. The results of measuring the physical properties of the obtained molded product are shown in Table 1.

Comparative Example 1 In the example described in Example 1, as glass flakes,
Component systems (A) and (B) were prepared in the same manner as in the same example except that glass flake A was used in place of glass flake B, and the apparent viscosities of the component systems were measured, and the same method as in Example 1 was used. A molded product was obtained in the following manner and its physical properties were measured. The results are shown in Table 1.

Comparative Example 2 Component systems (A) and (B) were used in the same manner as in Example 1 except that glass flake C was used instead of glass flake B as the glass flake in the example described in Example 1.
Was prepared, the apparent viscosity of each was measured, a molded product was obtained by the same method as in Example 1, and the physical properties thereof were measured. The results are shown in Table 1.

Comparative Example 3 Component systems (A) and (B) were used in the same manner as in Example 1 except that glass flake D was used instead of glass flake B as the glass flake in the example described in Example 1.
Was prepared, the apparent viscosity of each was measured, a molded product was obtained by the same method as in Example 1, and the physical properties thereof were measured. The results are shown in Table 1.

Example 2 The following component system (A) and component system (B) were each added to 20
Prepared in a 00 cc flask and kept each at a temperature of 100 ° C.

Component system (A) ε-caprolactam 802gr Bromomagnesium caprolactam 48gr Glass flake B 150gr Component system (B) ε-caprolactam 470gr Polymerization promoter (A) 380gr Glass flake B 150gr Polymerization promoter added to component system (B) A) is the following formula (In the formula, Z represents a block copolymer of ethylene oxide and propylene oxide having a molecular weight of about 6000.).

Samples were taken from the component systems (A) and (B), and the apparent viscosity was measured. The results are shown in Table 1.

Next, 100 gr of each of the component systems (A) and (B) was placed in a beaker, a molded product was obtained by the same method as in Example 1, and its physical properties were measured. The results are shown in Table 1.

Comparative Example 4 Component systems (A) and (B) were used in the same manner as in Example 2 except that glass flake A was used instead of glass flake B as the glass flake in the example described in Example 2.
Were prepared and the apparent viscosities of each were measured.
A molded product was obtained by the same method as described above, and its physical properties were measured. The results are shown in Table 1.

Comparative Example 5 In the example described in Example 2, as glass flakes,
In the same manner as in the same example except that the glass flake C was used, the component systems (A) and (B) were prepared, the apparent viscosities of the components were measured, and the molding was performed in the same manner as in Example 2. A product was obtained and its physical properties were measured. The results are shown in Table 1.

Comparative Example 6 Component systems (A) and (B) were prepared in the same manner as in the example, except that glass flake D was used as the glass flake in the example described in Example 2, and the apparent viscosities of the component systems were calculated. By the same method as in Example 2, the molded product was obtained and its physical properties were measured. The results are shown in Table 1.

Example 3 The following component system (A) and component system (B) were each prepared in a raw material tank of a reaction injection molding machine and kept at 100 ° C.

Component system (A) ε-caprolactam 33.0 kg Bromomagnesium caprolactam 2.0 kg Component system (B) ε-caprolactam 19.4 kg Polymerization promoter (B) 15.6 kg Glass flake B 30.0 kg Polymerization promoter added to component system (B) (B) is the following formula (However, Z represents polybutadiene having a molecular weight of about 6,000).

A sample was taken from the component system (B) and the apparent viscosity was measured.
The results are shown in Table 1.

Next, the component systems (A) and (B) were subjected to collision mixing using a reaction injection molding machine, and the temperature was controlled to 140 ° C. in the vertical and horizontal directions of 500 each.
The sheet was injected into a sheet mold having a cavity with a depth of 3 mm and a depth of 3 mm and held for 2 minutes to measure the physical properties of the obtained molded product. The results are shown in Table 1.

Comparative Examples 7, 8 and 9 In the example described in Example 3, as glass flakes,
Component systems (A) and (B) are the same as in Example 3, except that glass flake A (Comparative Example 7), glass flake C (Comparative Example 8) and glass flake D (Comparative Example 9) are used, respectively. ) Was prepared, the apparent viscosity of each component system was measured, and molded articles were obtained by the same method as described in Example 3, and the physical properties thereof were measured. The results are shown in Table 1.

From the results shown in Table 1, the following is clear.

(1) The amide-based resin cast-molding composition prepared by the method of the present invention has an average viscosity as compared with Comparative Example (a composition containing glass flakes having a physical property outside the range specified in the present invention). Is small. This indicates that the handling is easy and the fluidity of injection into the mold is superior.

(2) The amide resin molded article obtained by the method of the present invention is
Compared with the molded product obtained by the method of the comparative example, the appearance of the molded product is excellent and the features of the amide resin molded product are not impaired. Moreover, the flexural rigidity of the molded product was no better than that of the comparative example, and it can be seen that the glass flakes sufficiently function as a reinforcing material.

Claims (4)

[Claims] 1. When manufacturing an amide resin molded article,
At least one of the melted ω-lactam containing the polymerization catalyst and the melted ω-lactam containing the polymerization cocatalyst has a particle size of less than 50 μm in an amount of 10% by weight or less and a particle size of 150 μm. A method for producing an amide-based resin molded article, characterized in that 5% by weight or less of glass flakes exceeding 5% are blended and injected or injected into a mold to obtain a molded article. 2. The glass flakes have an aspect ratio of 7-15.
The method for producing an amide-based resin molded article according to claim (1), characterized in that it is in the range of 0. 3. The glass flake is compounded in an amount of 1 to 50 parts by weight, based on 100 parts by weight of the total amount of the raw material composition, according to claim (1) or (2). ) The method for producing an amide-based resin molded article according to the item. 4. A cross-linking agent or a reaction product modifier is added to a melted product of ω-lactam containing a polymerization cocatalyst, which is characterized in that: ) Or the method for producing an amide-based resin molded article according to (3).