JPH10272667A - Manufacture of vinyl chloride-based resin molded body having straight grain pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vinyl chloride molded body with fine straight grain pattern by a method wherein a mixture of vinyl chloride-based resin pellets and a powdered colored masterbatch is extrusion-molded. SOLUTION: The compounding ratio of respective components in a powdered colored masterbatch is 5-150 pts.wt. of pigment and 5-70 pts.wt. of lubricant to 100 pts.wt. of vinyl chloride-based resin powder having the average particle diameter of 10-300 μm. The masterbatch is manufactured by mixing respective components in a Henschel mixer kept at 100-200 deg.C for 10-15 min. Next, a mixture of vinyl chloride-based resin pellets and a powdered colored masterbatch is extrusion-molded. As a result, a vinyl chloride resin molded body having fine straight grain pattern excellent in lovely view without complicated operation such as the mounting of a movable plate onto a mold in an extrusion molder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vinyl chloride resin molded article having a fine straight grain pattern.

[0002]

2. Description of the Related Art Synthetic wood made from plastic is
It is widely used in the fields of building materials, furniture, home appliances and automobile parts. Among the synthetic woods, synthetic woods having a straight-grained or plate-grain pattern (hereinafter, these are collectively referred to as a wood-grain pattern) have high commercial value, and methods for producing the same have been conventionally studied. As a typical method for producing a wood grain synthetic wood, there is a method of attaching a film having a wood grain pattern to the surface of plain synthetic wood, or a method of printing a wood grain pattern on the surface of the synthetic wood. However, in these production methods, one more step is required after forming the synthetic wood, and the production efficiency is low.

In recent years, at the same time as plastic molding,
A number of methods have been proposed for imparting a wood grain pattern to the surface of the compact. In these molding methods, a pattern is expressed on the substrate by using two types of resin compositions having different fluidities under heating as the resin for the substrate and the resin for the hue of the molded product, respectively. For example, Japanese Patent Publication No. 49-186
No. 26 discloses that the difference in plasticization temperature is 10 to 30 ° C.
Extrusion molding of a mixture of various kinds of thermoplastic resins, for example, a foamed ABS resin and a colored vinyl chloride resin;
No. 4,146,863 discloses a vinyl chloride-based resin powder and a colored vinyl chloride-based resin flake (having an area of one side of 0.2 to 2 cm).
⁽² ) A method of extruding a mixture having a thickness of about 0.1 to 1.2 mm) to produce a vinyl chloride resin molded article having a wood grain pattern.

[0004] According to the molding method described in the above-mentioned publication, a large grain pattern, such as a sumi-shi, can be obtained almost as expected, but it has been difficult to obtain a fine straight grain pattern. In order to obtain a molded product having a fine grain pattern, a movable plate having comb teeth having a depth of 0.5 to 2 mm is attached to a mold outlet of a molding machine while using the resin composition disclosed in the above publication. And other technical means. In this method, a large number of grooves having a depth of 0.5 to 2 mm are formed on the surface of the molded body, so that the microscopic smoothness of the surface is impaired, but an aesthetically satisfactory straight grain pattern can be obtained. An object of the present invention is to provide a method for producing a vinyl chloride resin molded article having a beautiful straight grain pattern without performing a complicated operation of attaching the movable plate to a die for extrusion molding.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the present invention relates to (A) vinyl chloride resin pellets, and (B) 100 parts by weight of vinyl chloride resin powder having an average particle diameter of 10 to 300 μm, 5 to 150 parts by weight of a pigment and 5 to 70 parts by weight of a lubricant. A method for producing a vinyl chloride resin molded article having a straight grain pattern, comprising extruding a mixture with a part-containing powdery colored master batch.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The (A) vinyl chloride resin pellets of the present invention are mainly composed of a vinyl chloride resin and various additives such as a stabilizer, a lubricant, a filler, a foaming agent and a processing aid. It is a molded article of the vinyl chloride resin composition obtained by addition, and its preferred shape is a cube having a side of about 1 to 3 mm and a cylinder having a circle with an inner diameter of 2 to 3 mm as a bottom and a height of about 2 to 3 mm. And so on. Examples of the vinyl chloride resin include vinyl chloride homopolymers and vinyl esters such as vinyl acetate, and copolymers of vinyl chloride with acrylic acid or α-olefin and the like. A preferable polymerization degree of the vinyl chloride resin is 400. ~ 3000.

[0007] Stabilizers to be incorporated into the vinyl chloride resin pellets include tribasic lead sulfate, dibasic lead sulfite, lead stearate, dibasic lead stearate, octyltin mercapto, butyltin malate and Ba- Examples thereof include metal soaps such as Zn and Ca-Zn, and as a processing aid, polymethyl methacrylate having a molecular weight of 1,000,000 to 3.5,000,000 is preferable. Fillers include inorganic fillers such as heavy calcium carbonate, colloidal calcium carbonate, talc and mica, and organic fillers such as wood flour.

[0008] In the present invention, it is preferable to use wood flour and a foaming agent together so that the appearance and texture of the obtained straight grain pattern molded product is close to that of natural wood. Preferred wood flour has a particle size of about 30 mesh pass to 300 mesh pass, and preferred foaming agents include azodicarbonamide, azobisbutyronitrile, dinitropentamethylenetetramine, paratoluenesulfonyl hydrazide or Baking soda and the like are mentioned, and a more preferable blowing agent is azodicarbonamide or baking soda. The preferable mixing ratio of the wood flour and the processing aid in the vinyl chloride resin pellets is 5 to 50 parts by weight of the wood powder and 3 to 30 parts by weight of the processing aid per 100 parts by weight of the vinyl chloride resin. Further, the preferable usage amount of the foaming agent is such that the volume of the obtained molded body is 1.3 to 3 times the volume of the pellet before foaming.
The amount is doubled.

In addition to the above-mentioned additives, known additives generally added to vinyl chloride resin can be added to the vinyl chloride resin pellets. Specifically, antioxidants, plasticizers,
Examples include a modifier made of a polymer compound having rubber elasticity such as NBR, SIS block copolymer or MBS resin, and a flame retardant. In addition, the compounding amount of the above-mentioned wood flour, a foaming agent and an additive other than the processing aid in the vinyl chloride resin pellets may be the compounding amount employed in a general vinyl chloride resin composition for extrusion molding. Specifically, per 100 parts by weight of the vinyl chloride resin, the organotin-based stabilizer 1 to 1
3 parts by weight, 0.5 to 3 parts by weight of a lubricant comprising a higher fatty acid ester of a polyhydric alcohol, and about 2 to 5 parts by weight of calcium carbonate as a filler. The pellets can be obtained by general extrusion molding, or by cutting a sheet obtained by a mixing roll.

The powdery colored masterbatch of the present invention contains, as essential components, a vinyl chloride resin powder having an average particle size of 10 to 300 μm, a pigment and a lubricant. The preferred average particle size of the vinyl chloride resin used for the master batch is
It is 100 to 150 μm. Examples of the vinyl chloride resin include the same resins as those described as the components of the vinyl chloride resin pellet. Average particle size is 10
In the case of a powdery colored masterbatch made of a vinyl chloride resin powder having a size outside the range of about 300 μm, a molded article having a straight-grained pattern excellent in aesthetic appearance cannot be obtained even when the masterbatch is extruded together with the pellets.

In the present invention, preferred pigments are pigments which give a molded article a color similar to that of natural wood. Examples of such pigments include white pigments such as titanium oxide and lead white; and black pigments such as carbon black and iron black. Yellow pigments such as graphite, chrome yellow, cadmium yellow, chromophthal yellow, titanium yellow, condensed azo yellow, and quinophthalone yellow; red pigments such as petals, cadmium red, pyrazolo red, quinacridone red, and condensed azo red; And the like. These pigments are preferably used in the form of fine powder.

As the lubricant to be mixed with the powdery colored masterbatch, a compound used as an external lubricant among compounds for a lubricant usually used in a vinyl chloride resin composition is preferable, and specifically, a compound having a molecular weight of 900 to 4,000.
Polyethylene wax having a density of 0.92 to 0.98, higher fatty acid ester of higher alkyl alcohol, higher fatty acid ester of polyhydric alcohol, stearic acid, behenic acid, stearic amide, behenic amide, N-stearyl stearamide , Methylenebisstearic acid amide and hexamethylenebisoleic acid amide. The external lubricant is a technical term relative to the internal lubricant, and the internal lubricant is mainly used for the purpose of improving the sliding between the molecular chains of the vinyl chloride resin, whereas the external lubricant is mainly used for the resin. It is used for the purpose of improving the slip between the molding machine.

In the present invention, the mixing ratio of each of the above components in the powdery colored masterbatch (hereinafter sometimes simply referred to as the masterbatch) is determined based on 100 parts by weight of the vinyl chloride resin powder having an average particle size of 10 to 300 μm. ~ 1
50 parts by weight and 5 to 70 parts by weight of a lubricant. More preferably, the pigment is 20 to 100 parts by weight and the lubricant is 7 to 40 parts by weight per 100 parts by weight of the vinyl chloride resin powder. If the proportion of the pigment in the masterbatch is less than 5 parts by weight, a fine straight grain pattern cannot be obtained.
The effect obtained does not change even if it exceeds part by weight. If the ratio of the lubricant in the master batch is less than 5 parts by weight, a straight grain pattern does not appear on the molded body, while if it exceeds 70 parts by weight, the vinyl chloride resin powder in the master batch becomes partially unmelted at the time of molding. The surface of the molded body becomes rough. The masterbatch may contain a stabilizer such as dibutyltin malate and a filler additive such as calcium carbonate. The masterbatch is prepared by mixing the ingredients at a temperature of 100 to 120.
Into a Henschel mixer maintained at about
It can be manufactured by mixing for about 15 minutes.

In the present invention, a mixture of the vinyl chloride resin pellets and the powdery colored master batch is extruded. The usage ratio of the pellets and the master batch is preferably 0.01 to 30 parts by weight of the master batch per 100 parts by weight of the pellets. More preferably,
Masterbatch 0.5 to 100 parts by weight of pellets
5 parts by weight, particularly preferably 1 to 2 parts by weight of the master batch per 100 parts by weight of the pellets. If the ratio of the master batch is less than 0.01 part by weight, it is difficult to develop a straight grain pattern, while if it exceeds 30 parts by weight, the effect obtained is not changed. When mixing the above-mentioned pellets and the master batch, various methods used for mixing powders can be adopted. For example, mixing with a ribbon mixer or a Henschel mixer at room temperature for a short time (within 1 minute). Can be.

As the extrusion molding, a molding method using a general extrusion molding machine can be adopted. In addition, when performing foam extrusion molding, as usual, the mold used in extrusion molding without foaming is replaced with a foaming mold facility. Examples of the type of the foaming mold equipment include a free form and a Celka process, and any type can be preferably used in the present invention. When a full flight type single screw extruder, which is a typical extruder, is used, the effective screw length, that is, the screw L / D is 40 or less, and the screw compression ratio is 3.
It is preferable to use a screw of 0 or less. By using such a screw, the pellets and the colored powder are not mixed more than necessary, and a beautiful straight grain pattern can be obtained.
Regarding the molding temperature, cylinder temperature 110-160 ° C
It is preferable to set the optimum conditions for beautifully obtaining a straight grain pattern of the obtained molded product from the range of the mold temperature of 160 to 170 ° C.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. In each of the following examples, the vinyl chloride resin powder used for producing the powdery colored master batch is a powder having an average particle size of 100 to 150 μm and composed of a polymer having an average degree of polymerization of 1100.
In each case, a Henschel mixer was used to produce the powdery colored masterbatch. In the production of vinyl chloride resin-based pellets, a vinyl chloride resin having an average degree of polymerization of 700 was used, mixed with other components described below in a Henschel mixer, and then pelletized by a short screw extruder. The shape of the pellet is a cylinder having an inner diameter of 2 to 3 mm as a base and a height of 2 to 3 mm.

[0017]

Example 1 (1) Production of Powdery Colored Masterbatch A brown masterbatch (B-1) was produced by the following formulation. Vinyl chloride resin (degree of polymerization 1100) 100 parts by weight Brown pigment 50 Lubricant (polyethylene wax * 1) 10 {Butyltin malate-based heat stabilizer 2} Heavy calcium carbonate 20 * 1; manufactured by Mitsui Petrochemical Co., Ltd. High Wax 400P (a high-density polyethylene wax having a molecular weight of 4000) (2) Production of vinyl chloride resin pellet (A-1) A pellet was produced from the following composition. Vinyl chloride resin (degree of polymerization 700) 100 parts by weight Pb-based heat stabilizer 2 〃 MMA-based processing aid 7 〃 Azo-based foaming agent 1 〃 Wood flour (100 mesh pass) 30 〃 Heavy calcium carbonate 10 〃 The pellet (A) -1) and master batch (B-1)
Was mixed at a ratio of (B-1) 0.3 part by weight per 100 parts by weight of (A-1), and the resulting composition was extruded.
As a result, a fine straight grain pattern was obtained on the molded body.

[0018]

Comparative Example 1 A brown masterbatch (B-2) was produced according to the following formulation. Vinyl chloride resin (degree of polymerization 1100) 100 parts by weight Brown pigment 50 Lubricant (polyethylene wax) 1 Thermal stabilizer butyltin malate 2 Heavy calcium carbonate 20 Masterbatch (B-2) and pellet (A) -1)
Was mixed at a ratio of (B-2) 0.3 part by weight per 100 parts by weight of (A-1), and the resulting composition was extruded.
As a result, a large grain of ink-washing was obtained on the surface of the molded product, but a fine straight grain pattern was not obtained.

[0019]

Comparative Example 2 A brown masterbatch (B-3) was produced according to the following formulation. Vinyl chloride resin (degree of polymerization 1100) 100 parts by weight Brown pigment 50 Lubricants (polyethylene wax) 80 Thermal butyl tin malate stabilizer 2 Heavy calcium carbonate 20 Master batch (B-3) and pellets (A) -1)
Was mixed at a ratio of (B-3) 0.3 part by weight per 100 parts by weight of (A-1), and the resulting composition was extruded.
As a result, a straight grain pattern was obtained on the surface of the molded body, but the vinyl chloride resin powder in the master batch appeared on the surface in an unmelted state, and a surface with an excellent appearance was not obtained.

[0020]

According to the present invention, there is no need for a complicated operation such as attaching a movable plate to a mold in an extrusion molding machine, and a vinyl chloride resin molded product having a fine straight grain pattern excellent in aesthetic appearance. Is obtained.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 5/00 C08K 5/00 13/04 13/04 C08L 27/06 C08L 27/06 // B29K 27:06 105: 16 B29L 31:10

Claims (1)

[Claims] (A) a vinyl chloride resin pellet,
(B) Extrusion of a mixture with a powdery colored masterbatch containing 5-150 parts by weight of a pigment and 5-70 parts by weight of a lubricant per 100 parts by weight of a vinyl chloride resin powder having an average particle size of 10 to 300 μm. A method for producing a vinyl chloride resin molded article having a straight-grained pattern, characterized in that: