JPH04353406A - Mold for plastics - Google Patents

Abstract

PURPOSE:To obtain a thin film which has excellent uniformity, wettability, adhesion strength, mold release property, durability, nonadhesiveness on plastics, productivity, etc. CONSTITUTION:A mold for plastics is provided, wherein a fluorine graft polymer layer, or a hardened layer comprising fluorine graft polymer having silyl groups with fluoroalkyl groups and hydrolysis functional groups, or with halogen atoms is formed over the surface of a cavity of a mold.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic mold used for molding polymeric materials for electrical/electronic parts, optical parts, etc.

0002

BACKGROUND OF THE INVENTION In recent years, plastic molding technology has made remarkable progress in reducing weight, increasing precision, and improving productivity, and there are particularly great demands for plastic molding technology in the field of optoelectronics.

[0003] As one of these efforts, the development of mold release agents during molding processing is progressing. Methods of using the mold release agent include adding it internally into the polymer material to be molded, or coating the surface of the mold cavity with the mold release agent. As a mold release agent, silicone oil, mineral oil, derivatives such as paraffin wax fatty acid ester, glycol,
Talc, mica, etc. are used. Also, in recent years,
Mixture of perfluoroalkyl group-containing phosphoric acid ester or its salt and silicone oil (Japanese Patent Publication No. 53-23270
Special Publication No. 53-23271), Special Publication No. 57-480
No. 35, etc., mixtures of perfluoroalkyl group-containing polyether compounds and silicone oils (Japanese Patent Publication No. 59-32
No. 513), silicone oil-based products (Unexamined Japanese Patent Publication No. 63
-153510, JP-A-62-130807)
, fluorine compounds (JP-A-61-35910, JP-A-6
2-21512, JP 62-25914, JP 1-157808, JP 63-104804,
JP-A No. 1-291908, JP-A No. 2-125708, and JP-A No. 2-141210) are the mainstream. Furthermore, the above-mentioned mold release agent is mixed with other polymeric substances, diluted with a solvent system, and formed on the mold surface by dipping, airless spraying, electrostatic spraying, aerosol spraying, etc. A method of forming a coating on the mold surface using a dry method such as a sputtering method (Japanese Patent Application Laid-open No. 1-166914)
has also been proposed.

0004

[Problems to be Solved by the Invention] However, conventional plastic molds have the following problems. (1) The adhesion of the mold release agent to the mold is poor, and although the mold release effect is initially effective, it gradually decreases, so it must be applied each time after several times.

(2) When coating a mold with a mold release agent, cissing, sagging, etc. are likely to occur. However, in the future, optoelectronics and the like will require complex shapes and highly precise molding. In addition, regarding the optical properties and precision molding of plastic lenses, optical memory substrates, etc., we also consider adhesion to molds, repeatability of mold release, durability against molding temperatures, properties of molded polymer materials (optical properties), etc. etc.), etc., there is still no sufficient mold release coating agent available at present.

The present invention was made in view of the above circumstances, and consists of a fluorine-based graft polymer layer, or a fluorine-based graft polymer layer having a fluoroalkyl group and a hydrolyzable functional group, or a silyl group having a halogen atom. By providing a hardened layer on the surface of the mold cavity,
Coated surface uniformity, wettability, adhesion, releasability, durability,
The object of the present invention is to provide a plastic mold that has excellent non-stick properties with synthetic resins, productivity, etc., and can avoid adverse effects on molded products due to transfer.

[0007]

[Means for Solving the Problems] The first invention of the present application is a plastic mold characterized in that a fluorine-based graft polymer layer is provided as a mold release film on the cavity surface of the mold.

In the second invention of the present application, a cured layer made of a fluorine graft polymer having a fluoroalkyl group and a hydrolyzable functional group or a silyl group having a halogen atom is applied to the surface of the mold cavity as a mold release film. This is a plastic mold characterized by being provided as a.

[0009] In the first invention of the present application, the fluorine-based graft polymer is produced by the macromonomer method, that is, an oligomer having a polymerizable functional group at one end of the molecular chain as at least one raw material component. is suitable. An example of the terminal polymerizable functional group of this oligomer is (meta)
Examples include vinyl polymerization types such as acroyloxy, allyloxy, and styryl groups, and polycondensation addition types such as dicarboxyl and dihydroxy groups, such as (meth)alkyl acrylate, polyethylene glycol methacrylate, and fluoroalkyl acrylate. Examples include rate.

The oligomer is an oligomer having a methacrylic acid ester type terminal group obtained by radical polymerization to obtain a carboxylic acid prepolymer at one end with a molecular weight of 1,000 to 10,000, and reacting this with glycidyl methacrylate. be. Fluoroacrylate (Chemical formula 1 below) is used as a copolymerization component in this oligomer to create a fluorine-based graft polymer (
Monomer (A)) is obtained.

[0011]

[Chemical formula 1]

[0012] The content of the fluoroacrylate is preferably 5 to 90 wt%, more preferably 10 to 60 wt%. The reason for this is that within this range, the most uniform film can be obtained on the surface of metal etc., and the mold releasability is 10wt.
This is because if it is less than %, it is difficult to obtain a good mold release effect.

[0013] Even when the fluorine graft polymer is used alone, it is possible to sufficiently achieve surface adhesion, mold releasability, etc. as intended. In addition, dibutyl laurylate, a silane coupling agent, a reactive group metal chelating agent, and other polymers may be used in combination.

Furthermore, in order to improve the mold release and durability of the fluorine graft polymer itself, a fluorine graft polymer having a silyl group as well as a fluoroalkyl group is formed on the surface of the mold cavity. The performance as a molding agent can be improved.

In the second invention of the present application, the number of carbon atoms in the alkyl group of the fluoroalkyl group is 1 to 25 wt%, preferably 4 to 20 wt%, for the purpose of exhibiting mold releasability and heat resistance.
% range is desirable. Here, if the number of carbon atoms in the alkyl group exceeds 20 wt%, the above-mentioned improvement in performance is likely not to be observed.

In the second invention of the present application, the hydrolyzable functional groups in the polymer are an alkoxy group, an acetoxy group, and (OC2 H4)p OR4. Moreover, CI (chlorine) is the most preferable halogen atom. Examples of such polymers include radically polymerizable monomers having a fluoroalkyl group, such as the following [Chemical formula 2], [Chemical formula 3], and [Chemical formula 3].
Chemical formula 4], [Chemical formula 5], [Chemical formula 6], and fluorine-based macromonomers.

[0017]

[Case 2]

[0018]

[Chemical formula 3]

[0019]

[C4]

[0020]

[C5]

[0021]

[Image Omitted] Note that the number of alkyl groups in the fluoroalkyl group is 1 to 25 wt%, more preferably 4 to 20 wt%, as described above.
It's good.

Furthermore, regarding the above-mentioned fluorine-based macromonomer, for example, the above-mentioned fluoromonomer can be radically polymerized in the coexistence of a thioglycol group to obtain a molecular weight of 1000 to 10.
A fluorine-based macromonomer having a methacrylic acid ester type terminal group is obtained by reacting this with glycidyl methacrylate.

In the second invention of the present application, as the radically polymerizable monomer (monomer (B)) having a silyl group, for example, an acrylate silane or a methacrylate silane shown in [Chemical formula 7] below can be used. Can be mentioned.

[0024]

[C7]

[0025] In [Chemical formula 7], R1 is a hydrogen atom or CH3, R2 and R3 are a methyl group or a phenyl group, n = an integer of 1 to 3, m = 0 or 1, I (L) is m = In the case of 0, the value is 0 to 2, and in the case of m=1, the value is 2. Also, x
is an alkoxy group, an acetone group, the general formula (OC2 H4
)p OR2 group (R4: H, CH3, C2 H
5, n=an integer of 1 to 5). Specifically, γ−(
meth)acryloyloxypropyltrimethoxysilane, γ-(meth)acryloyloxypropylmethyldimethoxysilane, γ-(meth)acryloyloxypropyldimethoxysilane, 3-(2-(meth)acryloyloxyethoxy)propyltrimethoxysilane, 3 −
(2-(meth)acryloyloxyethoxy)propylmethyldimethoxysilane, 3-(2-(meth)acryloyloxyethoxy)propyldimethylmethoxysilane, 5-((meth)acryloyloxy)pentyltrimethoxysilane, 5-(( (meth)acryloyloxy)
Pentylmethyldimethoxysilane, 5-((meth)acryloyloxy)pentyldimethyldimethoxysilane,
Examples include p-vinylphenyltrimethoxysilane, p-vinylphenylmethyldimethoxysilane, p-vinylphenyldimethylmethoxysilane, γ-(meth)acryloyloxypropyltri(β-methoxyethoxy)silane, and the like. Among these, γ-methacryloxypropyltrimethoxysilane is most preferred.

Furthermore, the monomer (
Radical polymerizable monomers other than A) and (B) may also be used, such as the following. Examples of olefinic compounds include low-molecular unsaturated hydrocarbons such as ethylene and propylene, vinyl halides such as vinyl chloride and vinyl fluoride, vinyl esters of organic acids such as vinyl acetate, styrene, styrene substitutes, vinylpyridine and vinylnaphthalene. vinyl aromatic compounds such as acrylic acid and/or methacrylic acid (hereinafter abbreviated as (meth)acrylic acid), esters of (meth)acrylic acid, acrolein, acrylonitrile, N-vinylpyrrolidone and N-
Examples include N-vinyl compounds such as vinyl caprolactam, esters of maleic anhydride, maleic acid and fumaric acid, and radically polymerizable macromonomers other than fluorine. These monomers can be used alone or in combination. For radical copolymerization, conventionally known methods can be used. Fluoromonomer
The amount used is 5 to 8 in 100 parts by weight of the monomer mixture.
It is preferably 0 parts by weight, and more preferably 10 to 70 parts by weight.

The amount of silyl monomer added is determined by
It is preferably 0.01 to 50 parts by weight, more preferably 0.5 to 35 parts by weight, based on 100 parts by weight of the mixture. Here, if the silyl monomer is less than 0.01 part by weight, the curability of the polymer of the present invention is poor, and the adhesion to molds etc. is poor.
If it exceeds 0 parts by weight, the mold releasability will deteriorate.

The polymer system of the present invention obtained as described above may be used alone or in combination with other monomers, oligomers, and polymers. In order to obtain coating suitability, fluorocarbon solvents, alcohol solvents such as methanol and IPA, solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, acetone and MIBK, etc. It is preferable to mix one or more of various solvents such as ketone solvents.

In the present invention, methods for forming the mold release layer on the surface of the mold cavity include spraying, brushing, dipping, and spin coating. However, in forming a uniform film on the uneven shape of a lens (planet lens), optical disk, etc., the spin coating method can form the most uniform release layer. This release layer can be cured by crosslinking at room temperature or by heating through the catalytic action of moisture present in the air or on the surface of the base material, but it is also possible to cure the release layer by crosslinking with dibutyltin laurate, dibutyltin maleate, etc. The method is more preferred.

FIG. 1 shows a schematic diagram of a spin coating machine, in which 1 is a rotating shaft that supports a rotary table 2, and 3 is a rotary shaft that is attached to the upper surface of the rotary table 2 with, for example, double-sided tape. 4 is a cover, and 5 is a dropping funnel.

[0031]

[Operation] According to the present invention, the conventional drawbacks are eliminated, and a uniform continuous film is formed on the mold cavity surface with a high mold release film.
A mold release film that is excellent in precision molding of optical elements and the like and has excellent durability can be obtained. In addition, it has various advantages such as excellent wettability, adhesion, mold releasability, non-stick property with synthetic resins, productivity, etc., and avoids adverse effects on molded products due to transfer.

[0032]

[Examples] Examples of the present invention will be described below along with manufacturing methods. (Example 1)

First, a mixture of an oligomer having a polymerizable functional group at one end of the molecular chain obtained by a known macromonomer method and fluoroacrylate (previously described [Chemical formula 1]),
Dissolved in trifluorotoluene solvent at approximately 7:3, AI
0.5 parts by weight of BN was added. Next, approximately 1
A fluorine graft polymer (average molecular weight 15,000) obtained by reacting for about 6 hours under reflux at 00°C and 3 parts by weight of γ-butyltin laurate were added to 100 parts by weight of the polymer, and ethyl acetate/ Toluene/IPA (mixing ratio =
5:3:2). Subsequently, this mixed solution was applied onto a 1.6 μm disk stamper using a spin coating method to obtain a film thickness of about 300 angstroms (300 angstroms).
A thin film of 100 nm) was formed. Furthermore, after baking at about 160° C. for 30 minutes, a mold having a release film was obtained.

The plastic mold obtained as described above is constructed by forming a release film obtained by applying a mixture of a fluorine graft polymer or the like on the surface of the stamper. According to the above invention, it is possible to obtain a uniform thin film that has high mold releasability, good adhesion to the stamper, maintains its shape, has excellent heat resistance, and has other effects such as excellent durability. A mold was obtained.

In fact, the mold of the present invention can increase the number of moldings by 50% or more compared to the mold of the present invention that does not form a mold release layer, and also has improved adhesion to the stamper using the optical precision transfer method. The effect as a mold release agent was confirmed. (Example 2)

[0036]

[Chemical formula 8]

[0037] As a fluoromonomer, the above [Chemical formula 8] is used as 5
0 parts by weight, 25 parts by weight of γ-methacryloxypropyltrimethoxysilane as silane monomer, third monomer
25 parts by weight of stialyl methacrylate, 200 parts by weight of MEK as a catalyst, and AIBN as a radical initiator.
Using 2 parts by weight, the polymer of the present invention was synthesized by reacting in N2 at a temperature of about 100 DEG C. for about 5 hours.

Next, using this polymer as the main component, 3 parts by weight of dibutyl dylate (curing agent) was dropped into a solvent of ethyl acetate/toluene/IPA (mixing ratio = 5:3:2). Subsequently, this mixed solution was uniformly applied to the cavity surface of the planel optical lens mold by a spin coating method (splitting at a rotation speed of 1300 rpm).
A thin film with a thickness of about 40 nm was formed. Furthermore, after baking at about 100° C. for 30 minutes, a mold having a release film was obtained.

As a result, it has excellent adhesion to the mold, and the plate
It was possible to obtain a uniform film with a flannel shape along the mold. Using the mold obtained in this way and using PMMA resin for optical lenses made by Mitsubishi Gas Chemical, it was possible to obtain excellent transferability, and more than three times the durability and number of times.

[0040]

As described in detail above, according to the present invention, a fluorine-based graft polymer layer or a fluorine-based graft polymer layer having a fluoroalkyl group and a hydrolyzable functional group or a silyl group having a halogen atom can be used. By providing a hardened layer on the surface of the mold, the coating surface has excellent uniformity, wettability, adhesion, releasability, durability, non-stick property with synthetic resin, productivity, etc. It is possible to provide a plastic mold that can avoid adverse effects on molded products.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a spin coating machine used when forming a fluorine-containing mold release thin film on a mold body according to the present invention.

[Explanation of symbols]

1... Rotating shaft, 2... Rotating table, 3... Work, 4... Cover.

Claims (2)

[Claims] 1. A plastic molding mold characterized in that a fluorine-based graft polymer layer is provided as a mold release film on the surface of a cavity of the mold. 2. A cured layer made of a fluorine graft polymer having a fluoroalkyl group and a hydrolyzable functional group or a silyl group having a halogen atom is provided as a mold release film on the surface of the mold cavity. A plastic mold that is characterized by: