JPS60219027A - Mat molding of vinylidene fluoride resin and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide the titled mat molding which enables mat to be manufactured uniformly without any adverse effect on secondary workability by molding a mixture of powder and granular resin of ethylene tetrafluoride based on resin of vinylidene fluoride at special temperature. CONSTITUTION:Resin of vinylidene fluoride such as homopolymer of vinylidene fluoride A and resin of ethylene tetrafluoride such as homopolymer of ethylene tetrafluoride B are mixed by a mixer and the mixture is extruded by an extruder into pellets. Next, it is molded at more than melting point temperature of the component A. As a result, a mat intended for having a sea/island-type construction of a sea substrate as component A and island particles as component B with an average particle diameter of 0.1-10mum is obtained. A mat having particles oriented in a special flowing direction is preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vinylidene fluoride resin mat molded product and a method for producing the same.

[Conventional technology]

Matting a resin molded product scatters the light reflected from the molded product, gives comfort to the human eye, and has the effect of making the molded product a high-class product.

Conventional methods for such matte finishing, i.e., matte finishing, include a method in which the molded product is embossed by passing it through an embossed rubber roll, a method in which sand is blown onto the molded product at room temperature, and the surface of the molded product is embossed ( sandshirast method),
A method of matting a molded article by adding an inorganic substance such as titanium oxide or silicon dioxide to the molded article is known.

However, each of these methods has the following problems. That is, in the embossing method, when the molded product is a film, if the thickness of the film is uneven, some parts will come into contact with the rubber roll and some parts will not, resulting in some parts being matted and some not. Vinylidene fluoride resin is a crystalline resin, and its crystallinity is about 45 degrees, so it is essentially difficult to obtain a uniform thickness, and the embossing method causes unevenness on the matte surface. Cheap.

In addition, in this method, when the matted film is used by covering another resin surface, it is heated and fused to provide adhesive strength. However, this is because the method using adhesive requires a drying process and is difficult to adopt industrially. However, it also has the disadvantage that during such secondary processing, the matte of the matted film may disappear or unevenness may be promoted.

Another matte processing method, the Santonoraste method, involves scratching the surface of the molded product, resulting in a matte molded product that is inferior in appearance to other matte processing methods.

Another matte processing method, which involves adding inorganic substances to molded products, is that when water-absorbing inorganic materials such as titanium oxide are used, the surface of the molded product will be full of bubbles unless the added inorganic material is sufficiently degassed. Become.

In addition, inorganic substances with poor dispersibility have the disadvantage of being difficult to disperse and resulting in non-uniform matte finish.

[Problem that the invention seeks to solve]

In view of the current state of the prior art, the present invention has been developed to matt-process vinylidene fluoride resin without any problems in secondary processability.
An object of the present invention is to provide a mat molded product that enables uniform mat processing and a method for manufacturing the same.

[Structure of the invention]

This invention has a seabird-shaped structure in which a melt-molded vinylidene fluoride resin is used as a sea substrate and a tetrafluoroethylene resin is used as island particles, and the purpose is when the average particle diameter of the islands is 0.1 to 10 μm. This is based on the knowledge that a matte molded product with the following properties can be obtained.

Moreover, such a molded product can be obtained by molding a mixture containing mainly vinylidene fluoride resin and powdered tetrafluoroethylene resin at a temperature higher than the melting point of the vinylidene fluoride resin. It is also based on that.

The present invention will be explained in detail below.

The vinylidene fluoride resin referred to in the present invention is not only a vinylidene fluoride homopolymer, but also a vinylidene fluoride homopolymer containing 70 moles or more of vinylidene fluoride as a constituent unit, and one or two types copolymerizable with this resin.
It refers to a copolymer consisting of the remainder of the structural unit having more than one type of monomer, or a composition containing 70% by weight or more of at least one of these polymers, and also a product having the same effect as these.

In addition, the tetrafluoroethylene-based resin referred to in the present invention refers to a tetrafluoroethylene homopolymer, a polytetrafluoroethylene homopolymer, and a polytetrafluoroethylene homopolymer containing 5% tetrafluoroethylene as a constituent unit.
A copolymer consisting of a monomer copolymerizable with this, such as ethylene, hexafluorinated propylene, perfluorovinyl ether, etc./-r-0, and the remainder of a structural unit having one or more types of Alternatively, it refers to a polymer in which the hydrogen group of tetrafluoroethylene is replaced with another group, such as trifluoroethylene, perfluoroalkyl ether tetrafluoroethylene, etc., and also a product having the same effect as these.

The resin molded article according to the present invention has a sea-island structure in which the tetrafluoroethylene resin is used as island particles and the melt-molded vinylidene fluoride resin is used as the sea substrate. The sea-island structure is a term well known to those skilled in the art of polymer compositions, and refers to a composition in which a sea resin is dispersed in the form of islands of another resin.

In the present invention, the vinylidene fluoride resin must be melt-molded, but the tetrafluoroethylene resin is island particles formed from 3°tetrafluoroethylene resin, which may or may not be melt-molded. The average particle diameter of C is either too large or too small because C is difficult to matte, so it is 0.1 μm or more.
Those having an average particle size in the range of 10 μm are used.

Preferably 061-5 μm, more preferably 0.1-2
μm is used. Here, the average particle size is the arithmetic mean value of the diameters of 50 particles, excluding 25 from the maximum value and 25 from the minimum value, out of the diameters of 100 particles determined by an electron microscope. be. Each part of the particles is observed substantially equally so that only one part of the mat molded product is not observed, and the diameter of each particle is the arithmetic average of the major axis and the minor axis.

In addition, when the matte molded product of the present invention is in a state where the fluid is oriented in one specific direction, the degree of matting increases and becomes a preferable matte molded product. used. The degree of fluid orientation in a specific direction is determined by the average birefringence when the molded product is transparent, for example, and the average birefringence is 3X1.
0"-5 or more is preferable, 1×10 or more is more preferable, and lXl0-3 or more is particularly preferable. Here, the average birefringence refers to the area of the matte molded product depending on the molding method. The birefringence index is the average birefringence of the molded product because the birefringence index may differ depending on the shape of the molded product.The birefringence index must be measured by an appropriately selected measurement method depending on the shape of the molded product, but for example, in the case of a film, It is measured by applying polarized light perpendicular to the plane of the film.When the molded product is opaque and the degree of flow orientation cannot be determined by the birefringence,
JIS 28741 60° specular gloss is determined by the difference depending on the direction of incidence of light on the molded product, and the difference is preferably 0.2 or more, more preferably 0.3 or more, and even more preferably 0. Those with a value of 4 or more are used.

The vinylidene fluoride resin molded product of the present invention having the above-mentioned structure is matte and can easily have a specular gloss of 75 inches or less according to JIS z8741, and if a suitable structure is selected, it can be 50 inches or less. You can get the following.

The shape of such a molded product may be arbitrary, including films, threads, tubes, etc., but it is especially film-like, and it is made of other thermoplastic resins, typically methacrylate ester resins, especially methyl methacrylate. based resin or a laminate using this as an adhesive surface, such as a laminate of methyl methacrylate resin and vinyl chloride resin, a laminate of methyl methacrylate resin and thermoplastic polyester, etc. to produce wallpaper, panel boards, etc. It is suitably used as building materials such as interior materials and exterior materials.

The above-mentioned mat molded product is made of, for example, a mixture containing mainly vinylidene fluoride resin and secondary ethylene tetrafluoride resin powder.
It is obtained by molding at a temperature higher than the melting point of the vinylidene fluoride resin. Here, "mainly vinylidene fluoride resin" means that vinylidene fluoride resin occupies a larger volume ratio than tetrafluoroethylene resin. Further, the tetrafluoroethylene resin is in the form of powder or particles, and the average particle diameter is at most 10 μm, and each particle forms an island in the mat molded product, either singly or in agglomerated form.

In particular, when the matte molded product is in the form of a film and is to be matted to an extent that does not impair transparency, the amount of ethylene tetrafluoride resin is at most 2 parts by weight per 100 parts by weight of vinylidene fluoride resin.
By setting the amount to 0 parts by weight, preferably 10 parts by weight or less, and more preferably 8 parts by weight or less, a film having a bag value of 80 inches or less can be obtained. On the other hand, if the amount of the tetrafluoroethylene resin powder is too small, it will not become matte (this may be difficult), so it is usually 1 part by weight or more, preferably 3 parts by weight or more, although it varies depending on the thickness of the molded product.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1, 2 and Comparative Example 1 Polyvinylidene fluoride homopolymer (ηinh 1dl/
i: Value measured at 30C for a dimethylformamin r solution with a concentration of 0.411/dl) 100 parts by weight and the following 1st
Fine powder of polytetrafluoroethylene homopolymer in the amount shown in the table (average particle size determined by JISB9921 is 0.3 μm)
) in a Henschel mixer at room temperature for 10 minutes,
A hardlet was obtained by extruding at 210C in a φ extruder. This pellet was extruded at 240C using a 50φ extruder, and a film having a thickness of 30 μm was obtained using a flat die. The matte state of the film is uniformly obtained over the entire film, and the JIS
The gloss was measured using a gloss meter specified in Z8741, and the diameter of the islands was determined as described in the text, and the results shown in Table 1 were obtained.

Table 1 Example 3.4 and Comparative Example 2 The pellets obtained in Comparative Example 1 and Example 1 or 3 were extruded at 245C using a 35φ extruder, and mixed with 70 mol of methyl methacrylate and 30 mol of notyl acrylate. The polymer was extruded at 245C with a 74φ extruder, and both were extruded through a composite flat die for two-layer coextrusion.The surface layer was a composition of polyvinylidene fluoride homopolymer and tetrafluoroethylene homopolymer, and the base layer was a composition of acrylic acid. A two-layer film made of ester resin was obtained. The thickness of the surface layer is 5μ, and the thickness of the base layer is 45μ. The surface of the two-layer film had a uniform matte state, and was measured in the same manner as in Example 1, and the results shown in Table 2 were obtained.

Table 2 Transparency and haze were measured according to JIS K6714.

Example 5.6 and Comparative Example 3 A fine powder of an alternating copolymer of ethylene and tetrafluoroethylene (average particle size determined by JIS B9921: 0.4 am) was used as polyfluorinated ethylene resin 710 as a tetrafluoroethylene resin.
Used in the amounts shown in Table 3 below for 0 parts by weight,
The extrusion temperature during pellet production was 305C, and the extrusion temperature during film production was 310C to obtain a film with a thickness of 20 μm.

The rest was the same as in Example 1. The results are shown in Table 3.

Table 3 Examples 7 and 8 and Comparative Example 4 Fine powder of alternating copolymer of ethylene and tetrafluoroethylene instead of the polytetrafluoroethylene homopolymer of Example 1 (average particle size is the same as Example 5) ) was used in the amounts shown in Table 4 below. The results are shown in Table 4.

〔Effect of the invention〕

As can be seen from the above examples, the mat molded product according to the present invention can be processed into a uniform mat without causing any problems in secondary processability.

(3 others)

Claims (4)

[Claims] (1) Vinylidene fluoride has a sea-island structure with melt-molded vinylidene fluoride resin as the sea substrate and tetrafluoroethylene resin as island particles, and the average particle diameter of the islands is 0.1 to 10 μm. Resin mat molded product. (2) The polyvinylidene fluoride resin mat molded product according to claim 1, characterized in that the molded product is fluidized in one specific direction. (3) Vinylidene fluoride resin mat molding by molding a mixture mainly consisting of vinylidene fluoride resin and tetrafluoroethylene resin powder at a temperature higher than the melting point of the vinylidene fluoride resin. How things are manufactured. (4) The method for producing a bifluoride resin mat molded product according to claim 3, wherein the molding is performed by extrusion molding.