JPS5914949A - Method of treating vessel made of thermoplastic polyester - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a thermoplastic polyester container having a biaxially stretched container body, which has superior gas barrier properties, particularly against oxygen and carbon dioxide, and a high degree of water resistance. The present invention relates to a treatment method for a membrane that introduces permeability, and a treatment method for a membrane that simultaneously introduces excellent surface hardness in addition to the gas barrier properties and moisture impermeability,
A thermoplastic polyester container having excellent gas barrier properties and moisture impermeability, and a thermoplastic polyester having excellent surface hardness in addition to excellent gas barrier properties and moisture impermeability. To provide a method for easily and reliably obtaining a container.

Thermoplastic polyester containers with biaxially oriented container bodies, i.e. biaxially oriented l/-4 container bodies, should be non-toxic and have good sparring properties and moisture impermeability. Because it is superior to molded products made from other synthetic resins and has a glass-like appearance, it is widely used as containers for cosmetics, containers for foodstuffs such as liquid seasonings, containers for pharmaceuticals, etc. In order to store the contents of foodstuffs, medicines, etc. in a stable state for a long period of time, not only the gas barrier properties, especially gas barrier properties against oxygen, are insufficient, but also the surface hardness of the container is low. However, scratches are likely to occur on the outer surface of the container wall due to the containers rubbing against each other during transportation, filling operations, etc., which has disadvantages such as lowering the commercial value.

The present invention provides a container made of thermoplastic polyester having excellent gas barrier properties against oxygen and carbon dioxide gas and moisture impermeability by having the structure set forth in claim 1. Provided is a method for obtaining a thermoplastic polyester container having excellent resistance to oxygen and carbon dioxide gas and moisture impermeability, as well as having a high degree of surface hardness, by adopting the third configuration. It is something to do.

Hereinafter, the structure of the method for treating a thermoplastic polyester container of the present invention will be explained.

The container used in the method for treating a thermoplastic polyester container of the present invention is a container molded from a saturated polyester such as polyethylene terephthalate as a raw material, and is usually molded into a bottomed cylindrical shape called a parison. A container obtained by biaxially stretching the body in a mold for forming a container body or blow molding under heating that can expand the parison, and expanding the parison to about S to O times,
This is a thermoplastic polyester container having a container body that is biaxially oriented by biaxial stretching.

The first aspect of the invention is directed to the outer surface of the body wall of the above-mentioned thermoplastic polyester container, that is, the body wall consisting of the body side wall and the bottom wall, or the inner or outer surface of the body wall. A coating agent containing a vinyl chloride IJ-dene polymer, a vinylidene chloride copolymer, or a mixture of two or more of these polymers as a solid component is applied and dried to a thickness of about 0.57 mm.
．． By forming a coating synthetic resin layer of about 20 .mu.m, a thermoplastic polyester container is obtained which has excellent gas barrier properties, particularly against oxygen and carbon dioxide gas, and moisture impermeability.

Still, the second invention of the present invention provides that, following the step of forming the covering synthetic resin layer according to the first invention, the surface of the resulting covering synthetic resin layer is coated with bendine, A coating agent containing a synthetic resin as a solid component that has both the ability to form a hard surface and the ability to form a transparent film, to which photosensitizers such as benzophenones, quinones, and disulfides are added, is applied to a thickness of ~100 μm. After forming the A-th synthetic resin coating layer of about 10 to 100%, the surface of the U-th synthetic resin coating layer is then subjected to ultraviolet irradiation treatment to introduce a highly cross-linked structure into the first synthetic resin layer. In particular, a thermoplastic polyester container is obtained which has excellent gas barrier properties against oxygen and carbon dioxide gas and moisture impermeability, and also has a high degree of surface hardness.

In the method for treating thermoplastic polyester containers of the present invention, a coating agent containing a solid component of vinylidene chloride polymer, vinylidene chloride copolymer, or a mixture of two or more of these polymers is heated. Before applying to the body wall of a plastic polyester container, degrease the surface to be applied.
1 (7) It is preferable to form a uniform coated synthetic resin layer with the coating agent.

In addition, specific coating agents for forming the synthetic resin layer include vinylidene chloride polymer, vinylidene chloride/vinyl chloride copolymer, vinylidene chloride/vinyl acetate copolymer, vinylidene chloride/vinyl acetate/acrylonitrile. A coating agent is used in which a mixture of at least one of these polymers is dissolved in a solvent such as tetrahydrofuran, toluene, MEK, etc. at a concentration of about 3-20% by weight.

Further, as the synthetic resin having both hard surface forming ability and transparent film forming ability used for forming the first coating synthetic resin layer in the invention of claim Ωth, unsaturated polyester resin, acrylic resin, etc. There are resins, alkyd resins, epoxy resins, urethane resins, acetal resins, modified resins of each of the above resins, and copolymer resins of these, and the coating agent that forms the first coating synthetic resin layer is The synthetic resin is diluted with a low viscosity, high boiling point monomer, oligoester acrylate, or a solvent such as thinner, and the viscosity is adjusted to be suitable for coating. The coating agent used to form this first coated synthetic resin layer contains some amount of photosensitizers, such as benzoin, benzyl, benzoin alkyl ether, benzophenone, Michler's ketones, chlorothioxanthone, 2-isozolo It is necessary to contain bilthioxanthone and the like, and if necessary, amine compounds as photopolymerization accelerators, mercaptans as chain transfer agents, etc. may be added.

Further, the irradiation treatment of ultraviolet rays onto the surface of the λ-th coating synthetic resin layer is usually carried out using a high-pressure mercury lamp, a metal halide lamp, or the like having a wavelength of about 200 to 117-30 nm.

The method for treating a thermoplastic polyester container according to the present invention has the above-mentioned configuration. Compared to a container without a resin layer, the amount of oxygen gas permeated per 7 days is about 75-55%, and the amount of carbon dioxide gas permeated based on a test filled with 7 volumes of carbonated water at the initial value is 75-55%. About 0% after filling with water, about 70% after filling with carbonated water,
Furthermore, the water permeation amount based on a test using the same initial value and 7 volumes of carbonated water was approximately 7S to θ% in the first week after filling with carbonated water, and 7% in the first week after filling with carbonated water.
The thermoplastic polyester container can have a content of about 0 to 30%.

Furthermore, in the invention of the Ωth claim, the effects such as sparity against oxygen gas and carbon dioxide gas and moisture impermeability are better than in the case of the invention of the first claim. Moreover, the thermoplastic polyester container has an outer surface of high hardness that does not cause any scratches even when rubbed with stainless wool or with a sharp pencil lead having a hardness of about 3H-4H. I can do it.

In addition, in the method for treating thermoplastic polyester containers of the present invention, the coating agent used in forming the coating synthetic resin layer consisting of vinylidene chloride polymer, vinylidene chloride copolymer, or a mixture of two or more thereof. If the concentration is too high, the resulting thermoplastic polyester container will have a lower svalier effect. In other words, if a coating agent with too high a concentration is used, even though a thick coating synthetic resin layer is formed, the coating agent layer is dried during the layer formation process. - Unless the surface drying speed of the staining agent layer and the drying speed of the inner layer match, tension will occur between the surface layer and the inner layer, causing microscopic damage between the thermoplastic polyester container and the coating synthetic resin layer. This causes gaps to occur everywhere, which reduces the gas barrier effect.For example, if a coating agent with a concentration of 15wt% is used, if a coating agent with a concentration of 20wt% is used. It has been confirmed that containers with better gas barrier properties can be obtained.

In addition, the second claimed invention has better gas barrier properties against oxygen gas and carbon dioxide gas and moisture impermeability than the first claimed invention, and is made of stainless steel. It is possible to obtain a container made of thermoplastic polyester having an outer surface of such high hardness that it does not cause any scratches even when rubbed with wool or with a soft pencil lead having a hardness of about 3 to 1 1H. I can do it.

Furthermore, in the method for treating a thermoplastic polyester container of the present invention, a vinylidene chloride polymer, a vinylidene chloride copolymer, or two or more of these, which is formed on the surface of the biaxially stretched container body wall, Since the coated synthetic resin layer made of the mixture does not form a particularly strong connection strength with the treated thermoplastic polyester container, the treated thermoplastic polyester container is not coated with the synthetic resin layer. At the interface between the resin layer and the thermoplastic polyester container, the covering synthetic resin layer or the covering synthetic resin layer and the first covering synthetic resin layer can be easily peeled off. Therefore,
Since a thermoplastic polyester container, etc. in which the coated synthetic resin layer or the coated synthetic resin layer and the first coated synthetic resin layer are separated can be easily obtained from the scrap of the treated thermoplastic polyester container etc. of the present invention, It also has the effect of facilitating processing operations when reusing processed scrap as a molding material.

Patent Applicant Yoshino Kogyo Co., Ltd. Agent Rikichi Kawa (foreign name) Procedural amendment (spontaneous) February II + Day 1, 1980, Indication of the case 1988 Patent Application No. 12414 + No. 2, Invention Name: Processing method for thermoplastic polyester containers 3, person making the amendment Patent applicant (6179) Kasurishi Rikichi Ichikawa (2 others) Shoulder] Row year - month □ B-2 lines deleted [Attachment ■] Correct to.

(2) In the same book, page 3, line 13, ``Gas/curing properties are not sufficient'' is amended to ``Gas/curing properties are not sufficient.''

(3) In the same book, page 5, line 9, "solid component" is corrected to "contains one film-forming acid component."

(4) ``Film forming ability, especially oxygen'' in page 6, lines 4 to 9 of the same ■'' should be corrected as shown in [Appendix ■].

(5) “Solid components” in page 6, line 17 of the Ministry of Health
"Contained as a film-forming component."

(6) “The coating agent is
'', followed by ``the synthetic resin is as it is, or''
Insert 18 characters.

Insert the 18th character ``application of the coating agent to form []'' next to ``the second coating synthetic resin layer'' on page 8, line 16 of the same book.

(8) "Connection strength" on page 12, line 9 of the same book is corrected to "adhesion strength."

Above (2) [Separate Paper Knee υ "Claims (1) A thermoplastic polyester container having a biaxially stretched container body has at least an outer surface of the body wall containing a vinylidene chloride polymer, a vinylidene chloride polymer, and a vinylidene chloride polymer. A method for treating a container made of thermoplastic polyester, which comprises applying a copolymer or a coating agent of these two types, drying the coating, and saturating the coated synthetic resin layer.

(2) Applying a vinylidene chloride polymer, a vinylidene chloride copolymer, or a coating agent of two of these on at least the outer surface of the body wall of a thermoplastic polyester container having a biaxially stretched container body; Dry to form a coating synthetic resin layer, and then apply a synthetic resin that has the ability to form a hard surface and a transparent film to form a film (3) [Attachment 1-2] A method for treating a container made of thermoplastic polyester, comprising applying a coating agent containing a photosensitizer to the surface of the coating synthetic resin layer, and then subjecting the coated surface to ultraviolet irradiation treatment. ” [Attachment ■] “A coating agent containing a synthetic resin with film-forming ability as a film-forming component is applied, and then the coated surface is subjected to ultraviolet irradiation treatment to introduce a highly cross-linked structure. By forming a second coated synthetic resin layer with a thickness of about 1 to 100 μm, it is possible to eliminate oxygen, etc.” (1) 260-

Claims (2)

[Claims] (1) At least the outer surface of the body wall of a thermoplastic polyester container having a biaxially stretched container body is coated with a solid vinylidene chloride polymer, vinylidene chloride copolymer, or a mixture of these with a grade of Ω or higher. Apply a coating agent as an ingredient. A method for treating a thermoplastic polyester container, which comprises drying to form a covering synthetic resin layer. (2) A solid vinylidene chloride polymer, a vinylidene chloride copolymer, or a mixture of two or more thereof is applied to at least the outer surface of the body wall of a thermoplastic polyester container having a biaxially stretched container body. Apply a coating agent as an ingredient. A synthetic resin that is dried to form a coating synthetic resin layer, and then contains a photosensitizer such as benzoins, benzophenones, quinones, disulfides, etc. and has both hard surface forming ability and transparent film forming ability. A method for treating a container made of thermoplastic polyester, comprising applying a coating agent having a solid component to the surface of the coating synthetic resin layer, and then subjecting the coated surface to ultraviolet irradiation treatment.